CN109890480A

CN109890480A - Filter Media Containing Flame Retardant Fibers

Info

Publication number: CN109890480A
Application number: CN201780060186.1A
Authority: CN
Inventors: 张晓丹; 道格拉斯·M·吉蒙; 嘉利·刘; 纳根德拉·阿南塔拉迈亚; 苏达卡尔·贾加纳坦; 杰拉尔德·加德布瓦; 马克西姆·西林; 马克·A·加利莫尔
Original assignee: Hollingsworth and Vose Co
Current assignee: Hollingsworth and Vose Co
Priority date: 2016-09-30
Filing date: 2017-09-29
Publication date: 2019-06-14
Also published as: EP3519076A4; WO2018064500A1; EP3519076A1

Abstract

Filter media including a filter layer comprising fibers (e.g., synthetic fibers) containing a flame retardant, and related components, systems, and methods associated therewith, are provided. In some embodiments, the filtration layer may comprise a nonwoven web (e.g., a wet-laid nonwoven web) comprising fibers that comprise certain flame retardants having a relatively low concentration or that are substantially free of certain undesirable and/or toxic components (e.g., halogens). In certain embodiments, the nonwoven web may also comprise a blend of fibers. For example, in some embodiments, the nonwoven web may also comprise a blend of large diameter synthetic fibers and small diameter synthetic fibers that impart beneficial performance characteristics to the filtration layer. In some embodiments, the filter layer may be designed to have desirable flame retardancy (e.g., F1 rating, K1 rating) and performance characteristics without compromising certain mechanical properties (e.g., pleatability of the media) and/or environmental attributes (e.g., relatively low toxicity). The filter media described herein may be particularly useful in applications involving filtering air, although the media may be used in other applications as well.

Description

Filter medium comprising fire resistance fibre

Technical field

Embodiment of the present invention be generally related to include fire-retardant filter layer filter medium, and in particular it relates to tool There is the filter medium of the filtering feature of enhancing.

Background technique

Plurality of filter media can be used to remove pollutant in numerous applications.Filter medium can be according to its desired use It is designed to have different performance characteristics on the way.For example, the filter medium of relatively low efficiency can be used for heat, ventilation, Refrigeration, air conditioning application.The application of the performance characteristics (for example, very high efficiency) different for needs, such as clean Efficiency particulate air (HEPA) filter or ultralow penetrance air (ULPA) filtering can be used in clean room or biomedical applications Device.

Filter medium can be used to remove pollutant in numerous applications.In general, filter medium includes one or more Web.Web provides the porous structure for allowing fluid (for example, air) to flow through the net.Include pollutant in a fluid Grain can be trapped on web.Web characteristics are (for example, aperture, fiber size, fiber composition, fixed weight (basis Weight the strainability of medium) etc.) is influenced.Although different types of filter medium is available, there is still a need for improvement.

Summary of the invention

It provides the filter medium including fire-retardant filter layer (for example, back sheet) and relative related component, be System and method.In some cases, the theme of the application is related to Related product, the substitution solution of particular problem and/or knot A variety of different purposes of structure and composition.

In one group of embodiment, filter medium is provided.In one embodiment, filter medium includes fire-retardant wet process Networking nonwoven web, the fire-retardant Wet laid nonwoven net include the fiber containing the fire retardant based on phosphorus.

In another embodiment, filter medium includes the Wet laid nonwoven net comprising fire resistance fibre, wherein institute Stating Wet laid nonwoven net includes total halogen less than or equal to about 1500ppm.

In one embodiment, filter medium includes fireblocking nonwoven net, and the fireblocking nonwoven net includes that length is small In or equal to about 30mm the fiber containing the fire retardant based on phosphorus, wherein the fiber package contain the fire retardant based on phosphorus, and Wherein the thickness of the nonwoven web is less than or equal to about 1mm, and the air penetrability of the nonwoven web greater than or equal to about 20CFM and less than or equal to about 800CFM.

In another embodiment, filter medium includes nonwoven web, and the nonwoven web includes that length is less than or waits In the fire resistance fibre of about 30mm, wherein the nonwoven web includes total halogen less than or equal to about 1500ppm, it is described non-woven The thickness of net is less than or equal to about 1mm, and the air penetrability of the nonwoven web greater than or equal to about 20CFM and is less than or equal to About 800CFM.

In one embodiment, filter medium includes fireblocking nonwoven net, and the fireblocking nonwoven net includes average fibre Dimension first synthetic fibers of the diameter greater than or equal to about 15 microns and avarage fiber diameter greater than or equal to about 0.5 micron and are less than About 15 microns of the second synthetic fibers, wherein the weight percent of the first synthetic fibers of whole fibers is big in fireblocking nonwoven net In or equal to about 40 weight %.The weight percent of the second synthetic fibers of whole fibers is less than or equal in fireblocking nonwoven net About 50 weight %, the first synthetic fibers and/or the second synthetic fibers include the fire retardant based on phosphorus, and the surface of nonwoven web Avarage fiber diameter is measured greater than or equal to about 13 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fireblocking nonwoven net of unit, and ρ is with g/cm³For unit layer it is close Degree.Filter medium can also include efficiency layer, and wherein the dust containing capacity of filter medium is greater than or equal to about 20g/m²。

In another embodiment, filter medium includes fireblocking nonwoven net, and the fireblocking nonwoven net includes average Fibre diameter is greater than or equal to about 0.5 micron and small greater than or equal to about 15 microns of the first synthetic fibers and avarage fiber diameter In about 15 microns of the second synthetic fibers, wherein in fireblocking nonwoven net the first synthetic fibers of whole fibers weight percent Greater than or equal to about 40 weight %.The weight percent of the second synthetic fibers of whole fibers is less than or waits in fireblocking nonwoven net In about 50 weight %, the first synthetic fibers and/or the second synthetic fibers include the fire retardant based on phosphorus, the table of fireblocking nonwoven net Face avarage fiber diameter is measured greater than or equal to about 13 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fireblocking nonwoven net of unit, and ρ is with g/cm³For unit layer it is close Degree, and fireblocking nonwoven net determines weight less than or equal to about 110g/m².Filter medium can also include efficiency layer.

In one embodiment, fire-retardant Wet laid nonwoven net includes that avarage fiber diameter is micro- greater than or equal to about 15 Second synthesis of the first synthetic fibers and avarage fiber diameter of rice greater than or equal to about 0.5 micron and less than about 15 microns is fine Dimension, wherein the weight percent of the first synthetic fibers of whole fibers is greater than or equal to about 40 in fire-retardant Wet laid nonwoven net Weight %.The weight percent of the second synthetic fibers of whole fibers is less than or equal to about 50 in fire-retardant Wet laid nonwoven net Weight %, the first synthetic fibers and/or the second synthetic fibers include the fire retardant based on phosphorus, fire-retardant Wet laid nonwoven net Surface avarage fiber diameter is measured greater than or equal to about 13 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fire-retardant Wet laid nonwoven net of unit, and ρ is with g/cm³For unit Layer density.

In another set of embodiments, method is provided.In one embodiment, the method for manufacturing nonwoven web includes Fiber comprising the fire retardant based on phosphorus is provided and forms nonwoven web using wet laying process.

When considered in conjunction with the accompanying drawings, other advantages of the invention and new feature will be by of the invention below multiple non-limiting The detailed description of embodiment and become obvious.It include to conflict and/or different in this specification and the document that is incorporated by reference into It, should be subject to the present specification in the case where the disclosure of cause.If two or more document packets being incorporated by reference into Containing conflict and/or inconsistent disclosure relative to each other, then effective date posterior document should be subject to.

Detailed description of the invention

Non-limiting embodiments of the invention will be described by way of example with reference to attached drawing, attached drawing is schematical And it is not intended to drawn to scale.In the accompanying drawings, each of shown identical or almost the same component usually uses single attached drawing Label indicates.For purposes of clarity, the unnecessary feelings for keeping those of ordinary skill in the art's understanding of the invention are being illustrated Under condition, each component is not marked in each figure, does not also show that each component of each embodiment of the invention.? In attached drawing:

Figure 1A shows the section of filter medium according to certain embodiment；

Figure 1B shows the section of filter medium according to certain embodiment；

Fig. 1 C shows the section of filter medium according to certain embodiment；

Fig. 1 D shows the section of filter medium according to certain embodiment；

Fig. 1 E shows the section of filter medium according to certain embodiment；

Fig. 1 F shows the section of filter medium according to certain embodiment；

Fig. 1 G shows the section of filter medium according to certain embodiment；And

Fig. 2 shows the figures of the dust containing capacity of various filter mediums and surface avarage fiber diameter.

Specific embodiment

Provide filter medium including fire-retardant filter layer (for example, pleated back sheet) and relative related Components, systems and methods.In some embodiments, filter layer may include comprising certain fibers (for example, fire resistance fibre) Nonwoven web (for example, Wet laid nonwoven net).Fiber (for example, synthetic fibers) may include fire retardant, such as certain bases In the fire retardant of phosphorus, the fire retardant has relatively low intensity of or substantially free of certain undesirable and/or toxic group Divide (for example, halogen).In certain embodiments, nonwoven web may include fiber (for example, fire resistance fibre, non-flame resistant fiber) Blend.For example, in some embodiments, nonwoven web can also be comprising assigning the thick of the beneficial performance characteristics of filter layer The blend of diameter synthetic fibers and thin diameter synthetic fibers.In some embodiments, filter layer can be designed to have Desired anti-flammability (for example, F1 grade, K1 grade) and performance characteristics without damage certain mechanical properties (for example, medium can Pleating property) and/or environment attribute (for example, relatively low toxicity).Filter medium as described herein can be especially suitable for being related to The application of air filtering is crossed, although the medium can be used for other application.

In some typical filter medias, produced using being found to be toxic in direct exposure, generating toxic degradation Object, and/or certain conventional flame retardants of corrosivity and/or toxic fire emission are generated to realize anti-flammability.It is some existing Filter medium have attempted to by solving the problems, such as this using unconventional fire retardant in resin.However, these fire-retardant trees Even if rouge may also assign limited anti-flammability with relatively high weight percent.In addition, comprising assigning needed for some anti-flammabilitys Fire retardant resin (for example, flame-retarded resin) amount may negatively affect one or more times filtering and/or mechanical property. Here, describe not by existing filter medium and/or typical filter media one or more limitations include filter layer Filter medium.

As the following more detailed description, comprising the fiber (for example, synthetic fibers) containing fire retardant and without fire-retardant The filter layer of the suitable blend (for example, to generate high flame retardant) of the fiber of agent can have beneficial anti-flammability (for example, F1 grade, K1 grade), performance characteristics (for example, dust containing capacity), environment attribute (for example, low total halogen) and mechanical property (example Such as, stiffness (stiffness), durability).For example, opposite in the fiber characteristics (for example, composition, diameter) and layer of filter layer Weight percent can be selected as assigning beneficial characteristic, such as anti-flammability and High dust holding amount.In some embodiments, mistake Filtering layer may include the synthetic fibers (for example, fire resistance fibre) of relative high weight percentage and/or substantially free of glass fibre To assign durability, assign the applicability, and/or enhancing anti-flammability for certain applications.In some cases, filter layer can be with Comprising assigning stiffness and/or enhancing the binder (for example, resin, fiber) of anti-flammability.In some embodiments, described herein Filter medium may include filter layer and efficiency layer (for example, electrostatic spinning layer, meltblown layer).

The non-limiting example of filter medium comprising fire-retardant filter layer (for example, pleated back sheet) is shown in Figure 1A extremely In 1G.In some embodiments, as shown in Figure 1A, filter medium 10 may include the filter layer 15 comprising nonwoven web, institute Stating nonwoven web includes the fiber (for example, synthetic fibers) containing fire retardant.These fibers (for example, fire resistance fibre) can be chosen It is selected as assigning high flame retardant without negatively affecting one or more key properties for given application.For example, filtering Layer 15 and the fiber comprising fire retardant may include relatively low amount or substantially free of it is undesirable for given application certain A little components, such as halogen, antimony trioxide and/or metal hydrate.For example, fiber and/or nonwoven web comprising fire retardant can Comprising total halogen less than or equal to about 1500ppm, the chlorine less than 900ppm, and/or less than the bromine of 900ppm.In some realities It applies in scheme, the fiber comprising fire retardant can be synthetic fibers.In certain embodiments, fiber (for example, fire resistance fibre) It may include the fire retardant based on phosphorus.Filter layer 15 as described herein can have to be surveyed according to DIN 53438 (in June, 1984) The F1 grade and/or K1 grade of amount.

In some embodiments, the structure of the filter layer 15 including nonwoven web (for example, pleated back sheet) is special Sign can be selected as generating such layer: it assigns filter medium beneficial performance characteristics, while to the another of filter medium Kind characteristic (for example, stiffness) has relatively minimal adverse effect or has no adverse effect.For example, filter layer 15 can have it is beneficial Performance and mechanical property, such as relatively low thickness (for example, greater than or equal to about 0.25mm and less than or equal to about 2.0mm, Or less than or equal to about 1.0mm), high air penetrability (for example, greater than or equal to about 20CFM and less than or equal to about 800CFM), High dust containing capacity and/or pleated property.In certain embodiments, filter layer can have thick fiber diameters and thin fiber diameters Blend, the blend generates with the relatively low fixed average fibre in surface for assigning enough dust containing capacities and/or air penetrability again Tie up diameter.Term " surface avarage fiber diameter " is described more particularly below.The blend of thick fiber diameters and thin fiber diameters It may include the thick fiber diameters containing fire retardant, the thin fiber diameters containing fire retardant, the thick fiber diameters without fire retardant (for example, thick diameter non-flame resistant fiber) and thin fiber diameters without fire retardant.In some embodiments, filter layer 15 can be with As the depth-type filtration back sheet in filter medium 10 (for example, pleated filter medium).

In some embodiments, filter medium 10 may include (this of filter layer 15 comprising the fiber containing fire retardant " fire-retardant filter layer " is also referred to as in text) and the second layer 20, as shown in Figure 1B to 1G.In some embodiments, the second layer 20 can Think efficiency layer (for example, melt-blown efficiency layer, electrostatic spinning efficiency layer).In some embodiments, filter layer 15 and the second layer 20 can be with direct neighbor.In other embodiments, layer 15 and layer 20 can be adjacent to each other, and one or more centres Layer (for example, pre-filter layer) can be with separate layer.In some embodiments, filter medium 10 may include being located at layer 15 and layer 20 One or more optional layers (for example, scrim layer, back sheet, pre-filter layer, efficiency layer) of upstream and/or downstream, such as Shown in Fig. 1 C to 1G.In certain embodiments, filter medium 10 may include at one of 20 upstream of layer 15 and/or layer or more Multiple layers.For example, as shown in Figure 1 C, in some embodiments, filter medium may include in fire-retardant filter layer (for example, can The back sheet of pleating) and second layer upstream third layer 25 (for example, scrim layer, the second efficiency layer, capacity layer).For example, mistake Filter medium (for example, HEPA filter medium) may include the capacity layer in layer 20 (for example, electrostatic spinning layer) upstream, such as pre- mistake Filtering layer (for example, meltblown layer), the layer 20 is in the upstream of layer 15.In some such embodiments, capacity layer can be with layer 20 direct neighbors, and layer 20 can be with 15 direct neighbor of layer.

In certain embodiments, filter medium may include in fire-retardant filter layer (for example, pleated back sheet) and The third layer 25 (for example, scrim layer, the second efficiency layer, pre-filter layer) in second layer downstream.For example, filter medium 10 (for example, HVAC filter medium) it may include filter layer 15, the second layer 20 (for example, electrostatic spinning layer) and scrim layer.In some cases Under, third layer can be with the second layer (for example, efficiency layer) direct neighbor.In other embodiments, layer 20 and layer 25 can be with Indirect neighbor each other, and one or more middle layers can be with separate layer.As another example, filter medium may include In the third layer 25 (for example, electrostatic spinning layer) of 20 upstream of layer 15 and layer and the 4th layer 30 (for example, second filter layer), such as Fig. 1 D It is shown.In some embodiments, layer 25 can be with 25 direct neighbor of layer with 20 direct neighbor of layer and/or layer 30.At certain In a little embodiments, filter medium may include the third layer 25 in 20 upstream of layer 15 and layer (for example, scrim layer, the second mistake Filtering layer), the 4th layer 30 (for example, electrostatic spinning layer) and layer 5 35 (for example, scrim layer, pre-filter layer), as referring to figure 1E. In some embodiments, layer 25 can can be with 25 direct neighbor of layer and/or layer 35 with 20 direct neighbor of layer, layer 30 With 30 direct neighbor of layer.

No matter whether filter medium includes layer 25, and filter medium 10 may include at one of 20 downstream of layer 15 and/or layer Or more layer.For example, as shown in fig. 1F, filter medium 10 may include the layer 40 in second layer downstream.In some cases, Layer 40 can be with 15 direct neighbor of filter layer.In other embodiments, one or more middle layers can be with separate layer 15 With layer 40.In some embodiments, filter medium 10 may include filter layer 15, the second layer 20 (for example, efficiency layer), third Layer 25 (for example, meltblown layer) and the 4th layer 40 (for example, electrostatic spinning layer), as illustrated in Fig. 1 F.In some implementations In scheme, layer 15 can with 40 direct neighbor of layer 20 and/or layer, layer 25 can with 30 direct neighbor of layer 20 and/or layer, and/or Layer 20 can be with 25 direct neighbor of layer 15 and/or layer.In certain embodiments, filter medium can also be included in 40 downstream of layer Layer 5 45 (for example, scrim layer), as shown in Figure 1 G.In some embodiments, layer 45 can be with 40 direct neighbor of layer. In other embodiments, filter medium 10 may include filter layer 15, the second layer 20 and third layer 25 or the 4th layer 30.

In general, one or more optional layers can be any suitable layer (for example, scrim layer, basal layer, efficiency Layer, capacity layer, wall, supporting layer).

As it is used herein, when layer be referred to as with another layer " adjacent " when, can with the layer direct neighbor, or There may also be middle layers by person.Mean that there is no middle layers with the layer of another layer " direct neighbor ".

In some embodiments, one or more layers in filter medium can be designed independently from another Layer.That is, the fiber from a layer does not substantially mix (for example, not mixing completely) with the fiber from another layer.For example, For Figure 1A to 1G, in one group of embodiment, the fiber from fire-retardant filter layer is substantially not with the second layer (for example, efficiency Layer) fiber mixing.Independent layer can pass through any suitable technique (including for example laminated, hot spot bonding, calendering, ultrasound Wave processing) or by adhesive bond, as described in more detail below.However, it should be understood that certain embodiments can wrap Include not independent one or more layers relative to each other.

It should be understood that layer shown in figure configuration only as an example, and in other embodiments, including its of layer The filter medium that he configures is also possible.Although for example, showing first layer, optional into 1G in Figure 1B with particular order The second layer, optional third layer, optional the 4th layer and optional layer 5, but other configurations are also possible.For example, mistake Filter medium may include filter layer 15 and can not include the second layer 20 (for example, efficiency layer).In some such embodiment party In case, product (for example, filter medium) can be substantially made of filter layer 15 (for example, pleated back sheet).Certain In embodiment, product may include filter layer 15.It should be understood that as used herein term " second ", " third ", " the 4th " " the 5th " layer refers to layer different in medium, is not meant to that the position to the layer limits.In addition, in some implementations In scheme, other than layer shown in figure, there may also be extra play (for example, " the 6th " or " the 7th " layers).It should also be understood that In some embodiments, all layers not shown in figure require to exist.

As described herein, filter layer 15 can be fire-retardant.As it is used herein, term " fire-retardant filter layer " (for example, Fireblocking nonwoven net) with its ordinary meaning in the art, and can refer to have according to DIN 53438 (1984 6 Month) measurement F1 grade and K1 grade filter layer.In some embodiments, filter layer includes fire resistance fibre.Such as this paper institute Use, term " fire resistance fibre " has its ordinary meaning in the art, and can refer to have be distributed in fiber neutralize/ Or the fiber of the fire retardant throughout fiber.In general, fiber may include with any suitable fire-retardant of enough flame-retarding characteristics Agent.In some cases, fiber also may include relatively low amount or substantially free of (for example, not including) certain not phases The component (for example, halogen, bromine, chlorine, antimony trioxide, metal hydrate) of prestige.For example, fire resistance fibre may include the resistance based on phosphorus Fire agent and/or the fire retardant based on nitrogen.

In some embodiments, fire retardant can covalently be attached to one of fiber or more component.For example, Polymer in fiber may include fire retardant.In some such embodiments, fire retardant can be in the main chain of polymer In and/or be the side group in polymer.In some embodiments, the polymer comprising fire retardant can be by making on polymer One or more of functional groups reacted with fire retardant to be formed.In certain embodiments, polymer can be for comprising fire-retardant Copolymer of the agent as repetitive unit.In some such situations, polymer can be by making monomer and as comonomer Fire retardant react to be formed.For example, PET/ inflaming retarding copolymer can by during esterification have terephthalic acid (TPA) With the reaction in the reaction mixture of ethylene glycol or during ester exchange reaction with ethylene glycol and dimethyl terephthalate (DMT) The fire retardant based on phosphorus is added in mixture to be formed.After fire retardant to be covalently attached to the component of fiber, the component It can be used for manufacturing the fiber comprising fire retardant.

Can with fire retardant be copolymerized suitable monomer non-limiting example include ester, alkene, styrene, vinyl chloride, It is vinyl monomer, amine monomers, the monomer comprising one or more of carboxylic acids, bis-phenol, phosgene, epoxides, isocyanates, polynary Alcohol, and combinations thereof.It can include polyester, polyolefin, polystyrene, benzene with the non-limiting example of the modified polymer of fire retardant Ethylene copolymer, vinyl chloride-base polymer, polyvinyl, polyamide, polycarbonate, polyurethane, polyepoxide, lyocell And artificial silk.

In some embodiments, fire retardant may not be able to covalently be attached to the component of fiber.In some embodiments, Fire retardant can be added in the material for being used to form fiber before fiber formation.

In some embodiments, the fiber comprising fire retardant (for example, fire resistance fibre) may include relatively low amount Or substantially free of certain undesirable components (for example, halogen, bromine, chlorine, antimony trioxide, metal hydrate).For example, some In embodiment, as determined according to EPA SW-8465050/9056, fiber and/or filter layer may include and be less than or equal to About 1500ppm, less than or equal to about 1200ppm, less than or equal to about 1000ppm, less than or equal to about 900ppm, be less than or wait In about 750ppm, less than or equal to about 500ppm, less than or equal to about 350ppm, less than or equal to about 200ppm or be less than Or total halogen equal to about 100ppm.In some embodiments, the fiber comprising fire retardant and/or filter layer can be substantially Without total halogen (for example, total halogen of 0ppm).

In some embodiments, it is such as determined according to EPA SW-846 5050/9056 or DIN EN 14582 (method A) , fiber (also referred herein as " fire resistance fibre ") and/or filter layer comprising fire retardant may include less than or equal to about 900ppm, less than or equal to about 800ppm, less than or equal to about 700ppm, less than or equal to about 600ppm, less than or equal to about 500ppm, less than or equal to about 400ppm, less than or equal to about 300ppm, less than or equal to about 200ppm or be less than or wait In the chlorine and/or bromine of about 100ppm.In some embodiments, the fiber comprising fire retardant and/or filter layer can be substantially Without chlorine and/or bromine (for example, bromine of the chlorine of 0ppm, 0ppm).

In some embodiments, the fiber comprising fire retardant (for example, fire resistance fibre) and/or filter layer may include phase To low amount or substantially free of antimony trioxide.For example, in some embodiments, when lighting filter layer, such as according to MAK Occupational Health and Safety collection (The MAK Collection for Occupational Health and Safety) (2012) " method (Method for the Determination of Antimony Trioxide) for determining antimony trioxide is [empty Gas monitoring method (Air Monitoring Methods), volume 7 (2003)] " measurement, can discharge less than or equal to about 0.5mg/m³, less than or equal to about 0.4mg/m³, less than or equal to about 0.3mg/m³, less than or equal to about 0.2mg/m³, be less than or Equal to about 0.1mg/m³, less than or equal to about 0.05mg/m³, less than or equal to about 0.025mg/m³Or less than or equal to about 0.01mg/m³.In some embodiments, fire resistance fibre and/or filter layer can substantially free of antimony trioxide (for example, 0mg/m is discharged when lighting³)。

In some embodiments, the fiber comprising fire retardant can assign filter layer relatively high anti-flammability.For example, In some embodiments, filter layer can have the F1 grade and/or K1 grade measured according to DIN 53438 (in June, 1984).

In some embodiments, fire-retardant filter layer may include the fire resistance fibre of relative high weight percentage (for example, big In or equal to about 60 weight % and less than or equal to about 80 weight %).In certain embodiments, fire-retardant in fire-retardant filter layer The total weight percent of the fire resistance fibre of whole fibers can be greater than or equal in the total weight percent and/or filter layer of fiber About 10 weight %, greater than or equal to about 20 weight %, greater than or equal to about 30 weight %, greater than or equal to about 40 weight %, big In or be equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight %, greater than or equal to about 80 weights Measure %, greater than or equal to about 85 weight % or greater than or equal to about 90 weight %.In some cases, in fire-retardant filter layer The total weight percent of fire resistance fibre and/or the total weight percent of fire resistance fibre of whole fibers in filter layer can be less than Or be equal to about 97 weight %, less than or equal to about 90 weight %, less than or equal to about 80 weight %, less than or equal to about 70 weights Amount %, less than or equal to about 60 weight %, less than or equal to about 50 weight %, less than or equal to about 40 weight %, be less than or wait In about 30 weight % or less than or equal to about 25 weight %.All suitable combinations of above range are also possible (example Such as, greater than or equal to about 10 weight % and less than or equal to about 97 weight %, greater than or equal to about 20 weight % and it is less than or waits In about 90 weight %, greater than or equal to about 60 weight % and less than or equal to about 80 weight %).

In some embodiments, the weight percent of the fiber comprising fire retardant can be based on filter layer and/or filtering Other fibers in medium and change.For example, in some embodiments, it is fire-retardant in filter layer when there are glass fibre In the total weight percent and/or filter layer of fiber the total weight percent of the fire resistance fibre of whole fibers may include be greater than or Equal to about 80 weight % and less than or equal to about 95 weight %.In some embodiments, when there are cellulose fibre, filtering The total weight percent of the fire resistance fibre of whole fibers can be in the total weight percent and/or filter layer of fire resistance fibre in layer Comprising greater than or equal to about 40 weight % and less than or equal to about 60 weight %.In some embodiments, fine when there is synthesis When dimension, the total weight of the fire resistance fibre of whole fibers in the total weight percent and/or filter layer of the fire resistance fibre in filter layer Percentage may include greater than or equal to about 20 weight % and less than or equal to about 60 weight %.

In some embodiments, filter layer may include the fiber not crimped.For example, the fiber comprising fire retardant can be with For the fiber not crimped.In certain embodiments, filter layer can be substantially made of the fiber not crimped.

In some embodiments, the avarage fiber diameter for the fiber comprising fire retardant of filter layer can be greater than or Equal to about 0.5 micron, greater than or equal to about 1 micron, greater than or equal to about 2 microns, greater than or equal to about 5 microns, be greater than or wait In about 10 microns, greater than or equal to about 15 microns, greater than or equal to about 20 microns, greater than or equal to about 25 microns, be greater than or wait In about 30 microns, greater than or equal to about 35 microns, greater than or equal to about 40 microns, greater than or equal to about 45 microns, be greater than or wait In about 50 microns, greater than or equal to about 75 microns or greater than or equal to about 100 microns.In some cases, average fiber is straight Diameter can less than or equal to about 100 microns, less than or equal to about 75 microns, less than or equal to about 60 microns, less than or equal to about 55 microns, less than or equal to about 50 microns, less than or equal to about 45 microns, less than or equal to about 40 microns, less than or equal to about 35 microns, less than or equal to about 30 microns, less than or equal to about 25 microns, less than or equal to about 20 microns, less than or equal to about 15 microns, less than or equal to about 10 microns or less than or equal to about 5 microns.Above range it is all it is suitable combination be also It is possible (for example, greater than or equal to about 0.3 micron and less than or equal to about 100 microns, greater than or equal to about 2 microns and being less than Or it is equal to about 50 microns).

In some embodiments, the fiber in filter layer 15 can be relatively short.For example, in some embodiments In, the average length of fiber can less than or equal to about 30mm, less than or equal to about 27mm, less than or equal to about 25mm, be less than Or be equal to about 22mm, less than or equal to about 20mm, less than or equal to about 18mm, less than or equal to about 15mm, less than or equal to about 12mm, less than or equal to about 9mm or less than or equal to about 6mm.In some cases, average length can be greater than or equal to About 3mm, greater than or equal to about 6mm, greater than or equal to about 9mm, greater than or equal to about 12mm, greater than or equal to about 15mm, be greater than Or be equal to about 18mm, greater than or equal to about 20mm, greater than or equal to about 22mm or greater than or equal to about 25mm.Above range All suitable combinations be also possible (for example, greater than or equal to about 3mm and less than or equal to about 30mm, being greater than or equal to About 3mm and less than or equal to about 20mm, greater than or equal to about 6mm and less than or equal to about 12mm).

As described herein, the fiber characteristics of filter layer 15 can also be selected as assigning filter medium desired performance spy Property.In some embodiments, such filter layer can be comprising thick fiber diameters and thin fiber diameters (for example, synthesis is fine Dimension) nonwoven web.It is certain that the fibre diameter and relative weight percents of fiber may be selected so that nonwoven web has Surface avarage fiber diameter, as described in more detail below.For example, filter layer may include greater than or equal to about 40 weights Measure the thick fiber diameters (for example, greater than or equal to about 15 microns) of one or more of % and less than or equal to about 50 weight %'s One or more of thin fiber diameters (for example, being less than about 15 microns) to generate the surface avarage fiber diameter in expected range, For example, greater than or equal to about 13 microns and less than or equal to about 17 microns.In such embodiments, the appearance dirt of filter medium Amount can be greater than or equal to about 20g/m²And/or Gurley stiffness horizontally can be greater than or be equal to about 50mg and small In or equal to about 1500mg.As described in more detail below, and with similar face avarage fiber diameter but different fibers spy The filter layer of sign (for example, relative weight percents, diameter) is compared, and fire-retardant filter layer as described herein can have higher appearance Dust quantity and/or air penetrability.

For example, in some embodiments, filter layer 15 may be used as the depth filtration layer for capturing particle in layer.One In a little embodiments, the weight percent of surface avarage fiber diameter, the weight percent of thick fiber diameters and thin diameter is needed Suitable range filtered with allowable depth.For example, filter layer is caught if surface avarage fiber diameter is higher than suitable range The ability for obtaining particle may substantially reduce.If surface avarage fiber diameter is lower than suitable range, the filtration mechanism of layer can It can become the capture in the upstream face of layer and be permitted granose surface filtration, as a result, layer may pressure drop with higher.Some In embodiment, high pressure drop can reduce the service life of filter medium.It is without being bound by theory, it is believed that surface avarage fiber diameter It may be used as the efficiency of prediction interval and the parameter of filtration mechanism (for example, depth-type filtration, surface filtration).

Even if surface avarage fiber diameter is in suitable range, higher than the weight hundred of the thin fiber diameters of suitable range Dividing reduces than may also lead to air penetrability and dust containing capacity, at least partially due to making in the presence of certain binders and/or in net The networking of thin fiber diameters and/or bunchy during making process.The networking of thin fiber diameters and/or bunchy can cause very big in layer The hole plug of percentage.In surface avarage fiber diameter in the embodiment in suitable range, higher than suitable range The weight percent of thick fiber diameters can lead to the layer of the ability with the capture particle reduced.In certain embodiments, The blend of thick fiber diameters and thin fiber diameters may be needed to realize suitable surface avarage fiber diameter.

In general, filter layer may include the multiple fiber with different avarage fiber diameter and/or distribution of fiber diameters. In this case, the average diameter of the fiber in layer can be used weighted average such as surface avarage fiber diameter and carry out table Sign.Surface avarage fiber diameter is defined as

D=∑ (m_i/ρ_i)/∑(m_i/d_iρ_i)；

Wherein d is the surface avarage fiber diameter as unit of micron, m_iIt is to have as unit of micron in filter layer Diameter d_iWith with g/cm³For the density p of unit_iFiber number fraction.Party's formula assumes that fiber is cylindrical, fiber With circular cross-section, and fibre length is noticeably greater than fibre diameter.It should be understood that when nonwoven web includes substantial cylindrical and is had When having the fiber of approximate circular cross-section, party's formula additionally provides significant surface avarage fiber diameter value.

Surface avarage fiber diameter can be used above equation and calculate or measure as described further below.? It, can be with gauging surface avarage fiber diameter in the embodiment for knowing the diameter of the fiber in filter layer, density and mass percent.

In other embodiments, the surface avarage fiber diameter of filter layer can pass through the BET table of measurement filter layer The density p of face average value (i.e. SSA) and layer determines, as described in more detail below.In this case, surface is average The following formula being corrected can be used to determine in fibre diameter SAFD:

Wherein SSA is with m²/ g is the surface BET of the filter layer of unit, and ρ is with g/cm³For the density of the layer of unit.

As it is used herein, BET surface area is measured by using standard BET surface area measuring technique.BET surface area According to battery association international standard (the Battery Council International Standard) BCIS-03A " electricity of recommendation The valve-regulated recombination battery of pond material specification (Recommended Battery Materials Specifications Valve Regulated Recombinant Batteries) " Section 10 measurement, Section 10 is the " surface area of recombination battery separator pad Standard method of test (Standard Test Method for Surface Area of Recombinant Battery Separator Mat)".According to the technology, using BET surface analyzer (for example, Micromeritics Gemini III 2375 Surface Area Analyzers) with nitrogen BET surface area is measured via adsorption analysis；Sample size is 0.5 in such as 3/4 " pipe Gram to 0.6 gram；And sample is made to deaerate at 75 DEG C minimum 3 hours.

As it is used herein, can be by the quality and volume of precise measurement layer (for example, excluding voidage) then The density of computation layer determines the density of layer.The quality of layer can be determined by weighing layer.The volume of layer can be used accurately Any of method of volume is measured to determine.For example, pycnometry can be used to determine in volume.As another reality Archimedes method can be used to determine in example, the volume of layer, and precondition is to generate accurate volume measurement.For example, volume Can by layer is completely immersed in wetting fluid and is measured due to caused by being totally submerged layer fountain solution it is volume displaced come It determines.

In some embodiments, the surface avarage fiber diameter of fire-retardant filter layer can greater than or equal to about 1 micron, it is big In or equal to about 2 microns, greater than or equal to about 4 microns, greater than or equal to about 6 microns, greater than or equal to about 8 microns, be greater than or Equal to about 10 microns, greater than or equal to about 11 microns, greater than or equal to about 12 microns, greater than or equal to about 13 microns, be greater than or Equal to about 14 microns, greater than or equal to about 15 microns, greater than or equal to about 16 microns, greater than or equal to about 17 microns, be greater than or Equal to about 18 microns, greater than or equal to about 19 microns, greater than or equal to about 20 microns, greater than or equal to about 25 microns, be greater than or Equal to about 30 microns or greater than or equal to about 35 microns.In some cases, surface avarage fiber diameter can be less than or wait In about 40 microns, less than or equal to about 35 microns, less than or equal to about 30 microns, less than or equal to about 25 microns, be less than or wait In about 20 microns, less than or equal to about 19 microns, less than or equal to about 18 microns, less than or equal to about 18 microns, be less than or wait In about 17 microns, less than or equal to about 16 microns, less than or equal to about 15 microns, less than or equal to about 14 microns, be less than or wait In about 13 microns, less than or equal to about 12 microns, less than or equal to about 10 microns or less than or equal to about 5 microns.Above-mentioned model Enclose it is all it is suitable combination be also it is possible (for example, greater than or equal to about 13 microns and less than or equal to about 17 microns, be greater than Or equal to about 14 microns and less than or equal to about 16 microns, greater than or equal to about 2 microns and less than or equal to about 40 microns, be greater than Or be equal to about 1 micron and less than or equal to about 25 microns, greater than or equal to about 6 microns and less than or equal to about 17 microns).One In a little embodiments, the surface avarage fiber diameter greater than or equal to about 13 microns and less than or equal to about 17 microns can be excellent Choosing.

As described above, filter layer 15 may include thick fiber diameters for generating suitable surface avarage fiber diameter and thin straight The blend of diameter fiber.For example, in some embodiments, the thick diameter that filter layer may include relative high weight percentage is fine It ties up (for example, greater than or equal to about 40 weight %).In certain embodiments, the total weight hundred of the thick fiber diameters in filter layer Point ratio and/or filter layer in whole fibers thick fiber diameters total weight percent can greater than or equal to about 10 weight %, Greater than or equal to about 20 weight %, greater than or equal to about 30 weight %, greater than or equal to about 40 weight %, greater than or equal to about 50 Weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight %, greater than or equal to about 80 weight % or big In or equal to about 85 weight %.In some cases, the total weight percent and/or filter layer of the thick fiber diameters in filter layer It is middle whole fiber thick fiber diameters total weight percent can less than or equal to about 90 weight %, less than or equal to about 80 weights Amount %, less than or equal to about 70 weight %, less than or equal to about 60 weight %, less than or equal to about 50 weight %, be less than or wait In about 40 weight %, less than or equal to about 30 weight %, less than or equal to about 20 weight % or less than or equal to about 15 weights Measure %.All suitable combinations of above range are also possible (for example, greater than or equal to about 10 weight % and being less than or equal to About 90 weight %, greater than or equal to about 40 weight % and less than or equal to about 80 weight %).In some embodiments, it is greater than Or the total weight percent of the thick fiber diameters equal to about 40 weight % can be preferably.

In some embodiments, in the total weight percent of the thick fiber diameters in fire-retardant filter layer and/or filter layer The total weight percent of the thick fiber diameters of whole fibers may include two or more with different avarage fiber diameters Thick fiber diameters group.For example, the total weight percent of thick fiber diameters greater than or equal to about 40 weight % and less than or equal to about The fire-retardant filter layer of 80 weight % may include weight percent greater than or equal to about 5 weight % and less than or equal to about 95 weights The avarage fiber diameter of amount % (for example, greater than or equal to about 10 weight % and less than or equal to about 60 weight %) is greater than or equal to About 15 microns and the first thick fiber diameters group less than or equal to about 25 microns and weight percent are greater than or equal to about 5 weight % And being averaged less than or equal to about 95 weight % (for example, greater than or equal to about 10 weight % and less than or equal to about 60 weight %) Second thick fiber diameters group of the fibre diameter greater than or equal to about 25 microns and less than or equal to about 50 microns.In certain embodiment party In case, the blend of thick fiber diameters can be used for helping to realize desired surface avarage fiber diameter.Appoint in general, can be used What appropriate number of thick fiber diameters group with different avarage fiber diameters.In other embodiments, thick fiber diameters Total weight percent be made of a thick fiber diameters group.That is, layer does not include two or more with different average fibers The thick fiber diameters group of diameter.

In some embodiments, the avarage fiber diameter for the thick fiber diameters of fire-retardant filter layer can be greater than or wait In about 15 microns, greater than or equal to about 17 microns, greater than or equal to about 20 microns, greater than or equal to about 25 microns, be greater than or wait In about 30 microns, greater than or equal to about 35 microns, greater than or equal to about 40 microns, greater than or equal to about 45 microns, be greater than or wait In about 50 microns or greater than or equal to about 55 microns.In some cases, avarage fiber diameter can be less than or equal to about 60 Micron, less than or equal to about 55 microns, less than or equal to about 50 microns, less than or equal to about 45 microns, less than or equal to about 40 Micron, less than or equal to about 35 microns, less than or equal to about 30 microns, less than or equal to about 25 microns, less than or equal to about 20 Micron or less than or equal to about 17 microns.All suitable combinations of above range are also possible (for example, being greater than or waiting In about 10 microns and less than or equal to about 60 microns, greater than or equal to about 17 microns and less than or equal to about 35 microns).

In some embodiments, the average length of the thick fiber diameters in filter layer can be greater than or equal to about 3mm, big In or be equal to about 6mm, greater than or equal to about 9mm, greater than or equal to about 12mm, greater than or equal to about 15mm, greater than or equal to about 18mm, greater than or equal to about 20mm, greater than or equal to about 22mm or greater than or equal to about 25mm.In some cases, thick straight The average length of diameter fiber can less than or equal to about 30mm, less than or equal to about 27mm, less than or equal to about 25mm, be less than or Equal to about 22mm, less than or equal to about 20mm, less than or equal to about 18mm, less than or equal to about 15mm, less than or equal to about 12mm, less than or equal to about 9mm or less than or equal to about 6mm.All suitable combinations of above range are also possible (for example, greater than or equal to about 3mm and less than or equal to about 30mm, greater than or equal to about 6mm and less than or equal to about 12mm).

As described above, filter layer 15 may include the blend of thick fiber diameters and thin fiber diameters to generate suitable table Face avarage fiber diameter.In certain embodiments, the total weight percent and/or filter layer of the thin fiber diameters in filter layer It is middle whole fiber thin fiber diameters total weight percent can less than or equal to about 50 weight %, less than or equal to about 45 weights Amount %, less than or equal to about 40 weight %, less than or equal to about 35 weight %, less than or equal to about 30 weight %, be less than or wait In about 25 weight %, less than or equal to about 20 weight % or less than or equal to about 15 weight %.In some cases, it filters The total weight percent of the thin fiber diameters of whole fibers in the total weight percent and/or filter layer of thin fiber diameters in layer Can greater than or equal to about 0.5 weight %, greater than or equal to about 5 weight %, greater than or equal to about 10 weight %, be greater than or equal to About 15 weight %, greater than or equal to about 20 weight %, greater than or equal to about 25 weight %, greater than or equal to about 30 weight %, big In or equal to about 35 weight %, greater than or equal to about 40 weight % or greater than or equal to about 45 weight %.The institute of above range Having suitable combination is also possible (for example, greater than or equal to about 0.5 weight % and less than or equal to about 50 weight %, being greater than Or equal to about 10 weight % and less than or equal to about 30 weight %).

In some embodiments, in the total weight percent of the thin fiber diameters in fire-retardant filter layer and/or filter layer The total weight percent of the thin fiber diameters of whole fibers may include two or more with different avarage fiber diameters Thin fiber diameters group.For example, the total weight percent of thin fiber diameters greater than or equal to about 10 weight % and less than or equal to about The filter layer comprising fire resistance fibre of 30 weight % may include weight percent greater than or equal to about 5 weight % and be less than or wait It is big in the avarage fiber diameter of about 95 weight % (for example, greater than or equal to about 10 weight % and less than or equal to about 60 weight %) It is greater than or equal in or equal to about 0.1 micron and the first thin fiber diameters group less than or equal to about 10 microns and weight percent About 5 weight % and less than or equal to about 95 weight % (for example, greater than or equal to about 10 weight % and less than or equal to about 60 weights Measure %) avarage fiber diameter greater than or equal to about 10 microns and be less than about 15 microns of the second thin fiber diameters group.Certain In embodiment, the blend of thin fiber diameters can be used for helping to realize desired surface avarage fiber diameter.In general, can be with Use any appropriate number of fine fibre group with different avarage fiber diameters.In other embodiments, thin diameter is fine The total weight percent of dimension is made of one thin fiber diameters group.That is, layer, which does not include two or more, has different average fibres Tie up the thin fiber diameters group of diameter.

It in some embodiments, can be micro- less than about 15 for the avarage fiber diameter of the thin fiber diameters of filter layer Rice, less than or equal to about 12 microns, less than or equal to about 10 microns, less than or equal to about 8 microns, less than or equal to about 6 microns, Less than or equal to about 5 microns, less than or equal to about 4 microns, less than or equal to about 3 microns, less than or equal to about 2 microns or Less than or equal to about 1 micron.In some cases, avarage fiber diameter can greater than or equal to about 0.5 micron, be greater than or equal to About 1 micron, greater than or equal to about 2 microns, greater than or equal to about 3 microns, greater than or equal to about 4 microns, it is micro- greater than or equal to about 5 Rice, greater than or equal to about 6 microns, greater than or equal to about 8 microns, greater than or equal to about 10 microns or greater than or equal to about 12 Micron.All suitable combinations of above range are also possible (for example, greater than or equal to about 0.5 micron and micro- less than about 15 Rice, greater than or equal to about 2 microns and less than or equal to about 10 microns).

In some embodiments, the average length of the thin fiber diameters in filter layer can greater than or equal to about 0.1mm, Greater than or equal to about 0.3mm, greater than or equal to about 0.5mm, greater than or equal to about 0.8mm, greater than or equal to about 1mm, be greater than or Equal to about 3mm, greater than or equal to about 6mm, greater than or equal to about 9mm, greater than or equal to about 12mm, greater than or equal to about 15mm, Greater than or equal to about 18mm, greater than or equal to about 20mm, greater than or equal to about 22mm or greater than or equal to about 25mm.One In a little situations, the average lengths of thin fiber diameters can less than or equal to about 30mm, less than or equal to about 27mm, be less than or equal to About 25mm, less than or equal to about 22mm, less than or equal to about 20mm, less than or equal to about 18mm, less than or equal to about 15mm, small In or equal to about 12mm, less than or equal to about 9mm, less than or equal to about 6mm, less than or equal to about 3mm or be less than or equal to About 1mm.Above range it is all it is suitable combination be also it is possible (for example, greater than or equal to about 0.1mm and less than or equal to about 30mm, greater than or equal to about 0.3mm and less than or equal to about 12mm).

In some embodiments, thick fiber diameters and/or thin fiber diameters are not glass fibres.In certain embodiments In, the total thick fiber diameters and/or thin fiber diameters of the relative high weight percentage in fire-retardant filter layer can be synthetic fibers. For example, in some embodiments, the weight percent of the synthetic fibers of whole fibers can be greater than or equal to about in filter layer 80 weight %, greater than or equal to about 85 weight %, greater than or equal to about 88 weight %, greater than or equal to about 90 weight %, be greater than Or be equal to about 92 weight %, greater than or equal to about 95 weight %, greater than or equal to about 97 weight % or greater than or equal to about 99 Weight %.In some embodiments, fire-retardant filter layer may include the synthetic fibers of 100 weight %.In some embodiments In, filter layer can be substantially free of glass fibre.

In certain embodiments, all the weight percent of the synthetic macro-fiber of thick fiber diameters can be big in filter layer In or be equal to about 80 weight %, greater than or equal to about 85 weight %, greater than or equal to about 88 weight %, greater than or equal to about 90 weights Amount %, greater than or equal to about 92 weight %, greater than or equal to about 95 weight %, greater than or equal to about 97 weight % or be greater than Or it is equal to about 99 weight %.In certain embodiments, whole weight hundred of the synthetic macro-fibers of thick fiber diameters in filter layer Dividing ratio can be 100 weight %.In some embodiments, whole weight hundred of the synthetic fibers of thin fiber diameters in filter layer Point than can greater than or equal to about 80 weight %, greater than or equal to about 85 weight %, greater than or equal to about 88 weight %, be greater than or Equal to about 90 weight %, greater than or equal to about 92 weight %, greater than or equal to about 95 weight %, greater than or equal to about 97 weights Measure % or greater than or equal to about 99 weight %.In some embodiments, all the synthesis of thin fiber diameters is fine in filter layer The weight percent of dimension can be 100 weight %.

In general, synthetic fibers may include the synthetic polymer of any suitable type.The example packet of suitable synthetic fibers Include polyester (for example, polyethylene terephthalate, polybutylene terephthalate (PBT)), polycarbonate, polyamide (for example, Various nylon polymers), Nomex, polyimides, polyethylene, polypropylene, polyether-ether-ketone, polyolefin, acrylic compounds, poly- second Enol, regenerated cellulose (for example, synthetic cellulose such as lyocell, artificial silk), polyacrylonitrile, polyvinylidene fluoride (PVDF), The copolymer of polyethylene and PVDF, polyether sulfone, and combinations thereof.In some embodiments, synthetic fibers are that organic polymer is fine Dimension.Synthetic fibers can also include multicomponent fibre (that is, fiber such as bicomponent fibre with Multiple components).In some cases Under, synthetic fibers may include meltblown fibers, melt spun fibre, electrostatic spinning (for example, melting electrostatic spinning, solvent electrostatic spinning) Fiber or centrifugal spinning fiber can be formed by polymer as described herein (for example, polyester, polypropylene).In some implementations In scheme, synthetic fibers can be staple fiber.In some embodiments, synthetic fibers can be the fiber comprising fire retardant. Each layer in filter medium and filter medium also may include the combination of the synthetic fibers of more than one type.It should be understood that Other kinds of synthetic fibers can also be used.In some embodiments, the fiber comprising fire retardant can be synthetic fibers. In general, the total weight percent of thick fiber diameters and/or thin fiber diameters may include the fiber comprising fire retardant (for example, resistance Fire fiber).

In some embodiments, one or more layers (for example, second layer) in filter medium may include one kind Or more cellulose fibre, such as cork fibrous, hardwood fiber, hardwood fiber and cork fibrous mixture, regenerated fiber Cellulose fiber (for example, artificial silk, fibrillated synthetic cellulose fiber such as Lyocell fibers), microfibrillated cellulose and machinery Paper pulp fiber (for example, ground wood pulp, chemically treated mechanical pulp and thermomechanical pulp).Exemplary cork fibrous includes from following The fiber of acquisition: mercerising Southern Pine (for example, mercerising Southern Pine fiber or " HPZ fiber "), northern bleached softwood kraft paper (example Such as, from robur flash of light (Robur Flash) obtain fiber (" robur flashing fiber ")), southern bleached softwood brown paper (example Such as, the fiber (" Brunswick's pine fiber ") obtained from Brunswick (Brunswick) pine) or chemically treated mechanical paper It starches (" CTMP fiber ").For example, HPZ fiber can be obtained from the Buckeye Technologies of Tennessee State Memphis, Inc. ?；Robur flashing fiber can be obtained from the Rottneros AB of Stockholm, SWE；And Brunswick's pine fiber can be with It is obtained from the Georgia-Pacific of Atlanta, Georgia.Exemplary hardwood fiber includes the fiber obtained from eucalyptus (" eucalyptus fibers ").Suzano Group (" Suzano fiber ") of the eucalyptus fibers available commercially from such as (1) Brazil Suzano； (2) the Group Portucel Soporcel (" Cacia fiber ") of Portugal Cacia；(3) Quebec, CAN The Tembec of Temiscaming, Inc. (" Tarascon fiber ")；(4) Kartonimex of Dusseldorf ,Germany Intercell (" Acacia fiber ")；(5) Mead-Westvaco (" Westvaco fiber ") of Stamford, Connecticut； (6) Georgia-Pacific (" Leaf River fiber ") of Atlanta, Georgia.

The average diameter of cellulose fibre in one or more layers can be greater than or equal to about 1 micron, be greater than Or equal to about 2 microns, greater than or equal to about 3 microns, greater than or equal to about 4 microns, greater than or equal to about 5 microns, be greater than or wait In about 8 microns, greater than or equal to about 10 microns, greater than or equal to about 15 microns, greater than or equal to about 20 microns, be greater than or equal to About 30 microns or greater than or equal to about 40 microns.In some cases, the average diameter of cellulose fibre can be less than or wait In about 50 microns, less than or equal to about 40 microns, less than or equal to about 30 microns, less than or equal to about 20 microns, be less than or wait In about 15 microns, less than or equal to about 10 microns, less than or equal to about 7 microns, less than or equal to about 5 microns, be less than or equal to About 4 microns or less than or equal to about 2 microns.The combination of above range is also possible (for example, greater than or equal to about 1 micron And less than or equal to about 5 microns).The other values of avarage fiber diameter are also possible.

In some embodiments, cellulose fibre can have average length.For example, in some embodiments, it is fine The average length of cellulose fiber can greater than or equal to about 0.5mm, greater than or equal to about 1mm, greater than or equal to about 2mm, be greater than Or be equal to about 3mm, greater than or equal to about 4mm, greater than or equal to about 5mm, greater than or equal to about 6mm or greater than or equal to about 8mm.In some cases, the average length of cellulose fibre can less than or equal to about 10mm, less than or equal to about 8mm, small In or be equal to about 6mm, less than or equal to about 4mm, less than or equal to about 2mm or less than or equal to about 1mm.Above range Combination is also possible (for example, greater than or equal to about 1mm and less than or equal to about 3mm).The other values of average fiber length It is possible.

In some embodiments, the weight percent of the cellulose fibre in one or more layers (for example, second layer) Than can greater than or equal to about 0 weight %, greater than or equal to about 5 weight %, greater than or equal to about 10 weight %, be greater than or equal to About 15 weight %, greater than or equal to about 45 weight %, greater than or equal to about 65 weight % or greater than or equal to about 90 weights Measure %.In some cases, the weight percent of the cellulose fibre in one or more layers can be less than or equal to about 100 Weight %, less than or equal to about 85 weight %, less than or equal to about 55 weight %, less than or equal to about 20 weight %, be less than or Equal to about 10 weight % or less than or equal to about 2 weight %.The combination of above range is also possible (for example, being greater than or waiting In about 0 weight % and less than or equal to about 100 weight %).In some embodiments, the gross weight relative to the fiber in layer Amount, layer include the cellulose fibre of above range.

In some embodiments, one or more layers (for example, fire-retardant filter layer, the second layer) and/or entire filtering Medium is substantially free of glass fibre (for example, the glass of glass fibre, about 0 weight % less than 1 weight % to about 1 weight % Fiber).For example, fire-retardant filter layer may include the glass fibre of 0 weight %.However, in other embodiments, filtering is situated between One or more layers in matter may include glass fibre (for example, micro- glass fibre, short glass fiber, or combinations thereof). The average diameter of glass fibre can e.g., less than or equal to about 30 microns, less than or equal to about 25 microns, less than or equal to about 15 microns, less than or equal to about 12 microns, less than or equal to about 10 microns, less than or equal to about 9 microns, less than or equal to about 7 Micron, less than or equal to about 5 microns, less than or equal to about 3 microns or less than or equal to about 1 micron.In some cases, The avarage fiber diameter of glass fibre can greater than or equal to about 0.1 micron, greater than or equal to about 0.3 micron, be greater than or equal to About 1 micron, greater than or equal to about 3 microns or be more than or equal to about 7 microns, greater than or equal to about 9 microns, greater than or equal to about 11 microns or greater than or equal to about 20 microns.The combination of above range is also possible (for example, micro- greater than or equal to about 0.1 Rice and less than or equal to about 9 microns).The other values of avarage fiber diameter are also possible.

In some embodiments, the weight percent of glass fibre can greater than or equal to about 0 weight %, be greater than or wait In about 5 weight %, greater than or equal to about 10 weight %, greater than or equal to about 15 weight %, greater than or equal to about 45 weight %, big In or equal to about 65 weight % or greater than or equal to about 90 weight %.In some cases, the glass in one or more layers The weight percent of glass fiber can less than or equal to about 100 weight %, less than or equal to about 85 weight %, less than or equal to about 55 weight %, less than or equal to about 20 weight %, less than or equal to about 10 weight % or less than or equal to about 2 weight %.On The combination for stating range is also possible (for example, greater than or equal to about 0 weight % and less than or equal to about 100 weight %).One In a little embodiments, relative to the total weight of the fiber in layer, layer includes the glass fibre of above range.

In some embodiments, filter layer 15 may include one or more of binders (for example, binder resin, Viscose fibre), it is used to assign filtering layer structure integrality and important mechanical property is provided to medium, such as Gurley is endured Degree, Mullen burst (Mullen burst) and/or tensile strength.In some embodiments, binder may include fire retardant. For example, filter layer may include the flame-retarded resin of opposite low weight percentage.In certain embodiments, at least some bondings are fine Dimension can be the fiber comprising fire retardant.

In some embodiments, binder can be one or more of viscose fibres.In general, viscose fibre can be used Fiber in bonding layer.In some embodiments, viscose fibre includes to have main than one of layer or more group The polymer of the fusing point for dividing (such as certain fibers) low.Viscose fibre can be one pack system (for example, polyethylene fibre, copolyesters Fiber) or multicomponent (for example, bicomponent fibre).For example, viscose fibre can be bicomponent fibre.Bicomponent fibre can wrap Include thermoplastic polymer.The each component of bicomponent fibre can have different melting temperatures.For example, fiber may include core and Sheath, the activation temperature of mesotheca are lower than the melting temperature of core.This melts sheath before core, so that sheath is bonded to other in layer Fiber, and core keeps its structural intergrity.Core/sheath viscose fibre can be coaxial or non-coaxial.Other exemplary bi-components Fiber may include fibrilled film fibre fiber, bilateral fibre and/or " fabric of island-in-sea type " fiber.In general, thick fiber diameters and/or thin straight The total weight percent of diameter fiber may include viscose fibre.

In some embodiments, binder can be one or more of binder resins.In general, binder resin can For the fiber in bonding layer.In general, binder resin can have any suitable composition.For example, binder resin can To include thermoplastic resin (for example, acrylic compounds, polyvinyl acetate, polyester, polyamide), thermosetting resin (for example, epoxy Resin, phenol resin), or combinations thereof.In some cases, binder resin includes vinyl acetate resin, epoxy resin, polyester Resin, conjugated polyester resin, polyvinyl alcohol resin, acrylic resin such as one of styrene acrylic resin and phenol resin Or more.Other resins are also possible.In some such embodiments, resin may include comprising being covalently attached The fluoropolymer resin of fire retardant.

As described further below, resin can be added in any suitable manner (including for example with wet condition) In fiber.In some embodiments, resin coats fiber and for being adhering to each other fiber to promote gluing between fiber It is attached.Any suitable method and apparatus can be used to coat fiber, for example, using curtain coating, rotogravure application, fusion coating, leaching Painting, rotor coating or spin coating etc..In some embodiments, binder precipitating when being added into fiber blends.Appropriate When, any suitable precipitating reagent (for example, epichlorohydrin, fluorocarbon) can be provided to fiber, for example, by being injected into blending In object.In some embodiments, when being added in fiber, resin is so that one or more layers or entire filtering are situated between The mode that matter is impregnated with resin (for example, resin penetration is whole) is added.In Multilayer Network, it can be incited somebody to action before combining layer Resin is respectively added in each layer, or resin can be added in layer after combining layer.In some embodiments, Resin is added in fiber when with drying regime, for example, passing through sprinkling or saturation dipping or any of above method.Another In some embodiments, resin is added in wet layer.

In certain embodiments, binder may include both viscose fibre and binder resin.

No matter binder is viscose fibre, binder resin or the two, the total weight percentage of the binder in filter layer Than can greater than or equal to about 0.5 weight %, greater than or equal to about 1 weight %, greater than or equal to about 5 weight %, be greater than or wait In about 10 weight %, greater than or equal to about 20 weight %, greater than or equal to about 30 weight %, greater than or equal to about 40 weight %, Greater than or equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight % or be greater than or equal to About 80 weight %.In some cases, total weight percent can less than or equal to about 90 weight %, less than or equal to about 80 weights Amount %, less than or equal to about 70 weight %, less than or equal to about 60 weight %, less than or equal to about 50 weight %, be less than or wait In about 40 weight %, less than or equal to about 30 weight %, less than or equal to about 20 weight %, less than or equal to about 15 weight %, Less than or equal to about 10 weight % or less than or equal to about 5 weight %.All suitable combinations of above range are also may (for example, greater than or equal to about 0.5 weight % and less than or equal to about 90 weight %, greater than or equal to about 10 weight % and small In or equal to about 30 weight %).

Viscose fibre in the embodiment that binder includes viscose fibre and optional binder resin, in filter layer The total weight percent of (for example, bicomponent fibre) can greater than or equal to about 0.5 weight %, greater than or equal to about 1 weight %, Greater than or equal to about 3 weight %, greater than or equal to about 5 weight %, greater than or equal to about 8 weight %, greater than or equal to about 10 weights Amount %, greater than or equal to about 20 weight %, greater than or equal to about 25 weight %, greater than or equal to about 30 weight %, be greater than or wait In about 40 weight %, greater than or equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight %, Or greater than or equal to about 80 weight %.In some cases, the total weight percent of viscose fibre (for example, bicomponent fibre) Can less than or equal to about 90 weight %, less than or equal to about 80 weight %, less than or equal to about 70 weight %, be less than or equal to About 60 weight %, less than or equal to about 50 weight %, less than or equal to about 40 weight %, less than or equal to about 30 weight %, small In or be equal to about 25 weight %, less than or equal to about 20 weight %, less than or equal to about 18 weight %, less than or equal to about 15 weights Amount %, less than or equal to about 12 weight %, less than or equal to about 10 weight %, less than or equal to about 8 weight %, be less than or equal to About 5 weight %, less than or equal to about 3 weight % or less than or equal to about 1 weight %.All suitable groups of above range Close be also it is possible (for example, greater than or equal to about 0.5 weight % and less than or equal to about 90 weight %, greater than or equal to about 5 weights Measure % and less than or equal to about 15 weight %, greater than or equal to about 0.5 weight % and less than or equal to about 10 weight %).One In a little embodiments, one or more layers (for example, filter layer, the second layer) and/or entire filter medium be may include relatively Low percentage (for example, less than or equal to about 10 weight %, less than or equal to about 5 weight %, less than or equal to about 1 weight %, 0 Weight %) viscose fibre (for example, bicomponent fibre).

Bonding in the embodiment that binder includes binder resin and optional viscose fibre, in fire-retardant filter layer The total weight percent of agent resin can greater than or equal to about 0 weight %, greater than or equal to about 1 weight %, greater than or equal to about 3 Weight %, greater than or equal to about 5 weight %, greater than or equal to about 8 weight %, greater than or equal to about 10 weight %, be greater than or wait In about 20 weight %, greater than or equal to about 25 weight %, greater than or equal to about 30 weight %, greater than or equal to about 40 weight %, Greater than or equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight % or be greater than or equal to About 80 weight %.In some cases, the total weight percent of binder resin can less than or equal to about 90 weight %, be less than Or be equal to about 80 weight %, less than or equal to about 70 weight %, less than or equal to about 60 weight %, less than or equal to about 50 weights Amount %, less than or equal to about 40 weight %, less than or equal to about 30 weight %, less than or equal to about 25 weight %, be less than or wait In about 20 weight %, less than or equal to about 18 weight %, less than or equal to about 15 weight %, less than or equal to about 12 weight %, Less than or equal to about 10 weight %, less than or equal to about 8 weight %, less than or equal to about 5 weight %, less than or equal to about 3 weights Measure % or less than or equal to about 1 weight %.All suitable combinations of above range are also possible (for example, being greater than or waiting In about 0 weight % and less than or equal to about 90 weight %, greater than or equal to about 10 weight % and less than or equal to about 30 weights Measure %).In some embodiments, the weight percent of binder resin can be less than or equal to 30 weight %.In some realities It applies in scheme, filter layer may include the binder resin of 0 weight %.

In some embodiments, the fibre diameter for the viscose fibre (for example, fire resistance fibre) of fire-retardant filter layer can With greater than or equal to about 1 micron, greater than or equal to about 2 microns, greater than or equal to about 5 microns, greater than or equal to about 8 microns, it is big In or be equal to about 10 microns, greater than or equal to about 12 microns, greater than or equal to about 15 microns, greater than or equal to about 18 microns, it is big In or be equal to about 20 microns, greater than or equal to about 22 microns or greater than or equal to about 25 microns.In some cases, fiber Diameter can less than or equal to about 30 microns, less than or equal to about 28 microns, less than or equal to about 25 microns, less than or equal to about 22 microns, less than or equal to about 20 microns, less than or equal to about 18 microns, less than or equal to about 15 microns, less than or equal to about 12 microns, less than or equal to about 10 microns, less than or equal to about 5 microns or less than or equal to about 2 microns.Above range All suitable combinations be also it is possible (for example, greater than or equal to about 1 micron and less than or equal to about 30 microns, be greater than or wait In about 2 microns and less than or equal to about 20 microns).

In some embodiments, the average length of the viscose fibre in fire-retardant filter layer can greater than or equal to about 3mm, Greater than or equal to about 6mm, greater than or equal to about 9mm, greater than or equal to about 12mm, greater than or equal to about 15mm, be greater than or equal to About 18mm, greater than or equal to about 20mm, greater than or equal to about 22mm or greater than or equal to about 25mm.In some cases, it glues Tie fiber average length can less than or equal to about 30mm, less than or equal to about 27mm, less than or equal to about 25mm, be less than or Equal to about 22mm, less than or equal to about 20mm, less than or equal to about 18mm, less than or equal to about 15mm, less than or equal to about 12mm, less than or equal to about 9mm or less than or equal to about 6mm.All suitable combinations of above range are also possible (for example, greater than or equal to about 3mm and less than or equal to about 30mm, greater than or equal to about 6mm and less than or equal to about 12mm).

As described herein, filter medium 10 may include fire-retardant filter layer.In some embodiments, fire-retardant filter layer can With the mechanical property with certain enhancings, such as Gurley stiffness, tensile strength, and/or Mullen burst strength.In general, fire-retardant Filter layer can provide enough Gurley stiffness, and filter medium is pleated into including sharp sharp outline Peak, the peak can keep stable construction during use.

Fire-retardant filter layer can have relatively high Gurley stiffness.For example, in some embodiments, filter layer is in cross Upward Gurley stiffness can greater than or equal to about 10mg, greater than or equal to about 50mg, greater than or equal to about 100mg, be greater than Or equal to about 200mg, greater than or equal to about 300mg, greater than or equal to about 500mg, greater than or equal to about 800mg, be greater than or wait In about 1000mg, greater than or equal to about 1200mg or greater than or equal to about 1400mg.In some embodiments, filter layer Gurley stiffness horizontally can less than or equal to about 1500mg, less than or equal to about 1400mg, less than or equal to about 1200mg, less than or equal to about 1000mg, less than or equal to about 800mg, less than or equal to about 500mg, less than or equal to about 300mg, less than or equal to about 200mg or less than or equal to about 100mg.All suitable combinations of above range are also can Can (for example, greater than or equal to about 10mg and less than or equal to about 3500mg, greater than or equal to about 50mg and less than or equal to about 1500mg, greater than or equal to about 200mg and less than or equal to about 1000mg).Stiffness can be used according to TAPPI T543om-94 It is determined with the Gurley stiffness (flexing resistance) that mm (being equivalent to gu) is unit record.

In some embodiments, the Gurley stiffness of fire-retardant filter layer in a machine direction can be greater than or equal to about 200mg, greater than or equal to about 350mg, greater than or equal to about 500mg, greater than or equal to about 750mg, greater than or equal to about 1000mg, greater than or equal to about 1500mg, greater than or equal to about 2000mg, greater than or equal to about 2500mg or be greater than or wait In about 3000mg.In some embodiments, the Gurley stiffness of fire-retardant filter layer in a machine direction can be less than or equal to About 3500mg, less than or equal to about 3000mg, less than or equal to about 2500mg, less than or equal to about 2000mg, be less than or equal to About 1500mg, less than or equal to about 1000mg, less than or equal to about 750mg or less than or equal to about 500mg.Above range All suitable combinations be also it is possible (for example, greater than or equal to about 200mg and less than or equal to about 3500mg, be greater than or Equal to about 350mg and less than or equal to about 2000mg).

In some embodiments, dry tensile strength of the fire-retardant filter layer on machine direction (MD) can be greater than or equal to About 2 pounds per inch, greater than or equal to about 4 pounds per inch, greater than or equal to about 5 pounds per inch, greater than or equal to about 10 pounds per inch, big In or be equal to about 15 pounds per inch, greater than or equal to about 20 pounds per inch, greater than or equal to about 30 pounds per inch, greater than or equal to about 40 pounds per inch, greater than or equal to about 50 pounds per inch or greater than or equal to about 55 pounds per inch.In some cases, in machine Dry tensile strength on direction can less than or equal to about 60 pounds per inch, less than or equal to about 50 pounds per inch, be less than or equal to About 40 pounds per inch, less than or equal to about 30 pounds per inch, less than or equal to about 20 pounds per inch, less than or equal to about 10 pounds/English It is very little or less than or equal to about 5 pounds per inch.All suitable combinations of above range are also possible (for example, being greater than or waiting In about 2 pounds per inch and less than or equal to about 60 pounds per inch, greater than or equal to about 10 pounds per inch and less than or equal to about 40 pounds/ Inch).The other values of dry tensile strength in a machine direction are also possible.Dry tensile strength in a machine direction can be with It is determined according to normalized thyroxine 94om-96 using 4 inches of test span and the jaw separation speed of 1 inch/minute.

In some embodiments, dry tensile strength of the fire-retardant filter layer on transverse direction (CD) can be greater than or equal to about 1 Pounds per inch, greater than or equal to about 2 pounds per inch, greater than or equal to about 5 pounds per inch, greater than or equal to about 6 pounds per inch, be greater than or Equal to about 8 pounds per inch, greater than or equal to about 10 pounds per inch, greater than or equal to about 12 pounds per inch, greater than or equal to about 15 pounds/ Inch or greater than or equal to about 18 pounds per inch.In some cases, dry tensile strength horizontally can be less than or wait In about 20 pounds per inch, less than or equal to about 18 pounds per inch, less than or equal to about 15 pounds per inch, less than or equal to about 12 pounds/English It is very little, less than or equal to about 10 pounds per inch, less than or equal to about 8 pounds per inch, less than or equal to about 6 pounds per inch or be less than or Equal to about 5 pounds per inch.All suitable combinations of above range be also it is possible (for example, greater than or equal to about 1 pounds per inch and Less than or equal to about 20 pounds per inch, greater than or equal to about 6 pounds per inch and less than or equal to about 15 pounds per inch).Horizontally The other values of dry tensile strength are also possible.Dry tensile strength horizontally can use 4 English according to normalized thyroxine 94om-96 The jaw separation speed of very little test span and 1 inch/minute determines.

In some embodiments, the dry Mullen burst strength of fire-retardant filter layer can greater than or equal to about 5psi, be greater than Or equal to about 20psi, greater than or equal to about 25psi, greater than or equal to about 30psi, greater than or equal to about 50psi, be greater than or wait In about 75psi, greater than or equal to about 100psi, greater than or equal to about 125psi, greater than or equal to about 150psi, be greater than or equal to About 175psi, greater than or equal to about 200psi, greater than or equal to about 225psi or greater than or equal to about 240psi.Some In the case of, dry Mullen burst strength can less than or equal to about 250psi, less than or equal to about 240psi, less than or equal to about 225psi, less than or equal to about 200psi, less than or equal to about 175psi, less than or equal to about 150psi, less than or equal to about 125psi, less than or equal to about 100psi, less than or equal to about 75psi, less than or equal to about 50psi or be less than or equal to About 25psi.All suitable combinations of above range are also possible (for example, greater than or equal to about 20psi and being less than or equal to About 250psi, greater than or equal to about 30psi and less than or equal to about 150psi).The other values of dry Mullen burst strength are also can Can.Dry Mullen burst strength can be determined according to normalized thyroxine 03om-91.

In some embodiments, filter layer 15 can have relatively high air penetrability.For example, in some embodiments In, the air penetrability of fire-retardant filter layer can be greater than or equal to about 20 feet³/ minute/foot²(CFM), greater than or equal to about 50 English Ruler³/ minute/foot²(CFM), greater than or equal to about 75CFM, greater than or equal to about 100CFM, greater than or equal to about 150CFM, big In or equal to about 200CFM, greater than or equal to about 250CFM, greater than or equal to about 300CFM, more than or equal to 350CFM, be greater than Or equal to about 400CFM, greater than or equal to about 450CFM, greater than or equal to about 500CFM, greater than or equal to about 550CFM, be greater than Or be equal to about 600CFM, greater than or equal to about 650CFM, greater than or equal to about 700CFM or greater than or equal to about 750CFM. In some cases, the air penetrability of fire-retardant filter layer can less than or equal to about 800CFM, less than or equal to about 750CFM, be less than Or equal to about 700CFM, less than or equal to about 650CFM, less than or equal to about 600CFM, less than or equal to about 550CFM, be less than Or equal to about 500CFM, less than or equal to about 450CFM, less than or equal to about 400CFM, less than or equal to about 350CFM, be less than Or be equal to about 300CFM, less than or equal to about 250CFM, less than or equal to about 200CFM, less than or equal to about 150CFM or Less than or equal to about 100CFM.It should be understood that above range it is all it is suitable combination be it is possible (for example, greater than or equal to about 20CFM and less than or equal to about 800CFM, greater than or equal to about 50CFM and less than or equal to about 800CFM, greater than or equal to about 150CFM and less than or equal to about 500CFM).

As it is used herein, air penetrability is measured according to standard ASTM D737-75.In air permeability test device, so that The power (do not make sample deformations and have the smallest ovfl) of few 50+/- 5N is providing specimen holder to 38.3cm²Round survey On the measuring head (referred to as nozzle) for trying area.Then the stable air stream perpendicular to sample testing area is supplied, is being crossed over 12.5mm H is provided on the material tested₂The pressure difference of O.The pressure difference is remembered by the pressure gauge or pressure gauge for being connected to measuring head Record.Using flowmeter or volumetric enumeration device with foot³/ minute/foot²To measure the air penetrability across test zone.Frazier Air penetrability tester is the exemplary device for such measurement.

In some embodiments, fire-retardant filter layer, which can have, relatively small determines weight.For example, in some embodiments In, the weight of determining of filter layer can be less than or equal to about 200g/m², less than or equal to about 175g/m², less than or equal to about 150g/ m², less than or equal to about 120g/m², less than or equal to about 110g/m², less than or equal to about 100g/m², less than or equal to about 97g/m², less than or equal to about 95g/m², less than or equal to about 92g/m², less than or equal to about 90g/m², less than or equal to about 87g/m², less than or equal to about 85g/m², less than or equal to about 82g/m², less than or equal to about 80g/m², less than or equal to about 70g/m², less than or equal to about 60g/m², less than or equal to about 50g/m², less than or equal to about 40g/m²Or it is less than or equal to About 30g/m².In some cases, the weight of determining of fire-retardant filter layer can be greater than or equal to about 20g/m², greater than or equal to about 30g/ m², greater than or equal to about 40g/m², greater than or equal to about 50g/m², greater than or equal to about 60g/m², greater than or equal to about 70g/m²、 Greater than or equal to about 80g/m², greater than or equal to about 90g/m², greater than or equal to about 100g/m², greater than or equal to about 120g/m²、 Greater than or equal to about 140g/m², greater than or equal to about 160g/m²Or greater than or equal to about 180g/m².Above range owns Suitable combination is also possible (for example, greater than or equal to about 20g/m²And less than or equal to about 110g/m², greater than or equal to about 20g/m²And less than or equal to about 90g/m²).Surely heavy other values are also possible.Fixed weight can be according to standard ASTM D- 13776 determine.

In some embodiments, fire-retardant filter layer can be relatively thin.For example, in some embodiments, it is fire-retardant The thickness of filter layer can less than or equal to about 2.0mm, less than or equal to about 1.8mm, less than or equal to about 1.5mm, be less than or Equal to about 1.2mm, less than or equal to about 1.0mm, less than or equal to about 0.8mm, less than or equal to about 0.7mm, be less than or equal to About 0.6mm or less than or equal to about 0.5mm or less than or equal to about 0.4mm.In some cases, fire-retardant filter layer Thickness can greater than or equal to about 0.25mm, greater than or equal to about 0.3mm, greater than or equal to about 0.4mm, greater than or equal to about 0.5mm, greater than or equal to about 0.6mm, greater than or equal to about 0.8mm, greater than or equal to about 1.0mm, greater than or equal to about 1.2mm, greater than or equal to about 1.5mm or greater than or equal to about 1.8mm.All suitable combinations of above range are also can Can (for example, greater than or equal to about 0.25mm and less than or equal to about 2.0mm, greater than or equal to about 0.4mm and being less than or equal to About 1.0mm, greater than or equal to about 0.25mm and less than or equal to about 0.7mm, greater than or equal to about 0.4mm and less than or equal to about 0.8mm).Thickness is determined at 0.3psi according to standard ASTM D1777.

Mean flow pore size can according to need selection.For example, in some embodiments, the mean flow of fire-retardant filter layer Metering-orifice diameter can greater than or equal to about 20 microns, greater than or equal to about 40 microns, greater than or equal to about 50 microns, be greater than or equal to About 75 microns, greater than or equal to about 100 microns, greater than or equal to about 125 microns, greater than or equal to about 150 microns, be greater than or wait In about 175 microns, greater than or equal to about 200 microns, greater than or equal to about 225 microns, greater than or equal to about 250 microns or Greater than or equal to about 275 microns.In some cases, the mean flow pore size of fire-retardant filter layer can be less than or equal to about 300 Micron, less than or equal to about 275 microns, less than or equal to about 250 microns, less than or equal to about 225 microns, less than or equal to about 200 microns, less than or equal to about 175 microns, less than or equal to about 150 microns, less than or equal to about 125 microns, be less than or wait In about 100 microns, less than or equal to about 75 microns or less than or equal to about 50 microns.The combination of above range is also possible (for example, greater than or equal to about 20 microns and less than or equal to about 300 microns, greater than or equal to about 50 microns and being less than or waiting In about 150 microns).The other values of mean flow pore size are also possible.Mean flow pore size can be according to standard ASTM F316 (2003) it determines.

As described above, filter medium may include the second layer.In some embodiments, the second layer, which rises, improves filter medium Particle capture efficiency effect, and efficiency layer can be referred to as.In general, when the architectural characteristic and performance that refer to efficiency layer are special When the number of plies in property and/or efficiency layer, efficiency layer does not include wall (for example, spunbond layer).

In general, the average efficiency of the second layer and/or entire filter medium can be changed based on application.In some embodiment party In case, the DEHS average efficiency of the second layer and/or entire filter medium under 0.4 micron can greater than or equal to about 10%, it is big In or equal to about 20%, greater than or equal to about 35%, greater than or equal to about 50%, greater than or equal to about 60%, be greater than or equal to About 70%, greater than or equal to about 80%, greater than or equal to about 90%, greater than or equal to about 95%, greater than or equal to about 97%, it is big In or equal to about 99%, greater than or equal to about 99.5%, greater than or equal to about 99.9%, greater than or equal to about 99.95%, be greater than Or be equal to about 99.99%, greater than or equal to about 99.995%, be greater than or equal to 99.999%, be greater than or equal to 99.9999%, Or it is greater than or equal to 99.99999%.In some cases, the second layer and/or entire filter medium are under 0.4 micron DEHS average efficiency can be less than or equal to 99.99999%, be less than or equal to 99.9999%, less than or equal to about 99.999%, less than or equal to about 99.99%, less than or equal to about 99.997%, less than or equal to about 99.995%, be less than or Equal to about 99.9%, less than or equal to about 99.5%, less than or equal to about 99%, less than or equal to about 98%, be less than or equal to About 97%, less than or equal to about 95%, less than or equal to about 90%, less than or equal to about 85%, less than or equal to about 75%, it is small In or equal to about 60%, less than or equal to about 50%, less than or equal to about 40%, less than or equal to about 30%, be less than or equal to About 20% or less than or equal to about 10%.It should be understood that all suitable combinations of above range are possible (for example, being greater than Or equal to about 20% and less than or equal to about 99.99999%).DEHS average efficiency can be measured according to EN1822, for efficiency < 90%, it can be measured according to EN779:2012.In some embodiments, layer (for example, second layer) and/or filter medium Average efficiency can be tested according to EN779-2012 standard.Test uses 0.944m³/ second (3400m³/ hour) air mass flow With the maximum final test pressure drop (for example, for thick or G filter medium) of 250Pa or the maximum final test pressure drop (example of 450Pa Such as, for medium or M or thin or F filter medium).

As described in more detail below, the second layer (for example, efficiency layer) may include the fiber types such as synthetic fibers.? Under some cases, the second layer, third layer, the 4th layer and/or layer 5 may include the synthetic fibers of relative high weight percentage (for example, 100 weight %).In some embodiments, the second layer, third layer, the 4th layer and/or layer 5 may include by melting The synthetic fibers that pressure spray process, melt-spinning technology, centrifugal spinning process or electrostatic spinning process are formed.In some cases, such as Described further below, synthetic fibers can be continuous.In some embodiments, the second layer may include the short fibre of synthesis Dimension.In some embodiments, the second layer, third layer, the 4th layer and/or layer 5 may include it is relatively smaller (for example, be less than or Equal to about 10 weight %, less than or equal to about 5 weight %, less than or equal to about 3 weight %, less than or equal to about 1 weight %) Glass fibre is free of glass fibre.In other embodiments, the second layer, third layer, the 4th layer and/or layer 5 can To include glass fibre.For example, in some embodiments, the second layer may include the glass fibers of relative high weight percentage Dimension.For example, the second layer may include total fiber in filter medium greater than or equal to about 5 weight % and less than or equal to about 100 The glass fibre of weight % (for example, greater than or equal to about 10 weight % and less than or equal to about 97 weight %).In some implementations In scheme, one or more layers (for example, the second layer, third layer, the 4th layer, layer 5) may include the fiber not crimped. In some such embodiments, one or more layers can be substantially made of the fiber not crimped.

In some embodiments, the average fibre of the second layer (for example, efficiency layer), third layer, the 4th layer and/or layer 5 Tie up diameter can less than or equal to about 5 microns, less than or equal to about 4 microns, less than or equal to about 3 microns, less than or equal to about 2 Micron, less than or equal to about 1 micron, less than or equal to about 0.9 micron, less than or equal to about 0.8 micron, less than or equal to about 0.7 micron, less than or equal to about 0.6 micron, less than or equal to about 0.5 micron, less than or equal to about 0.4 micron, be less than or wait In about 0.3 micron, less than or equal to about 0.2 micron, less than or equal to about 0.1 micron, less than or equal to about 0.08 micron or Less than or equal to about 0.06 micron.In some cases, avarage fiber diameter can greater than or equal to about 0.05 micron, be greater than or Equal to about 0.06 micron, greater than or equal to about 0.07 micron, greater than or equal to about 0.08 micron, it is micro- greater than or equal to about 0.09 Rice, greater than or equal to about 0.1 micron, greater than or equal to about 0.2 micron, greater than or equal to about 0.3 micron, greater than or equal to about 0.4 micron, greater than or equal to about 0.5 micron, greater than or equal to about 0.8 micron, greater than or equal to about 1 micron, be greater than or equal to About 2 microns, greater than or equal to about 3 microns or greater than or equal to about 4 microns.Above range it is all it is suitable combination be also Possible (for example, greater than or equal to about 0.05 micron and less than or equal to about 5 microns).

In some embodiments, can have can be with for the fiber in the second layer, third layer, the 4th layer and/or layer 5 The average length of forming method depending on fiber.In some cases, synthetic fibers can be to be continuous (for example, melt-blown is fine Dimension, spun-bonded fibre, electrospun fibers, centrifugal spinning fiber etc.).For example, the average length of continuous synthetic fibers can be for extremely Few about 5cm, at least about 10cm, at least about 15cm, at least about 20cm, at least about 50cm, at least about 100cm, at least about 200cm, At least about 500cm, at least about 700cm, at least about 1000cm, at least about 1500cm, at least about 2000cm, at least about 2500cm, At least about 5000cm, at least about 10000cm；And/or less than or equal to about 10000cm, less than or equal to about 5000cm, be less than or Equal to about 2500cm, less than or equal to about 2000cm, less than or equal to about 1000cm, less than or equal to about 500cm or be less than Or it is equal to about 200cm.All suitable combinations of above range are also possible (for example, greater than or equal to about 100cm and being less than Or it is equal to about 2500cm).The other values of average fiber length are also possible.

In other embodiments, synthetic fibers are not continuous (for example, staple fibers).In general, discontinuous synthesis is fine The feature of dimension can be shorter than continuous synthetic fibers.For example, in some embodiments, the second layer, third layer, the 4th layer And/or the average length of the fiber in layer 5 can greater than or equal to about 0.1mm, greater than or equal to about 0.3mm, be greater than or wait In about 0.5mm, greater than or equal to about 0.8mm, greater than or equal to about 1mm, greater than or equal to about 3mm, greater than or equal to about 6mm, Greater than or equal to about 9mm, greater than or equal to about 12mm, greater than or equal to about 15mm, greater than or equal to about 18mm, be greater than or equal to About 20mm, greater than or equal to about 22mm, greater than or equal to about 25mm, greater than or equal to about 28mm, greater than or equal to about 30mm, big In or equal to about 32mm, greater than or equal to about 35mm, greater than or equal to about 38mm, greater than or equal to about 40mm, be greater than or equal to About 42mm or greater than or equal to about 45mm.In some cases, in the second layer, third layer, the 4th layer and/or layer 5 The average length of fiber can less than or equal to about 50mm, less than or equal to about 48mm, less than or equal to about 45mm, be less than or wait In about 42mm, less than or equal to about 40mm, less than or equal to about 38mm, less than or equal to about 35mm, less than or equal to about 32mm, Less than or equal to about 30mm, less than or equal to about 27mm, less than or equal to about 25mm, less than or equal to about 22mm, be less than or wait In about 20mm, less than or equal to about 18mm, less than or equal to about 15mm, less than or equal to about 12mm, less than or equal to about 9mm, Less than or equal to about 6mm, less than or equal to about 3mm or less than or equal to about 1mm.All suitable combinations of above range Be also it is possible (for example, greater than or equal to about 0.1mm and less than or equal to about 30mm, greater than or equal to about 0.3mm and be less than or Equal to about 12mm).

It include the second layer, third layer, in some embodiments in the 4th layer and/or layer 5 in synthetic fibers, Whole fibers in two layers, third layer, the 4th layer and/or the weight percent and/or the second layer of the synthetic fibers in layer 5 The weight percent of synthetic fibers can greater than or equal to about 1%, greater than or equal to about 20%, greater than or equal to about 40%, it is big In or be equal to about 60%, greater than or equal to about 80%, greater than or equal to about 90% or greater than or equal to about 95%.Some In the case of, in the second layer, the weight hundred of the synthetic fibers of the weight percent of synthetic fibers and/or whole fibers in the second layer Point than can less than or equal to about 100%, less than or equal to about 98%, less than or equal to about 85%, less than or equal to about 75%, Less than or equal to about 50%, less than or equal to about 25% or less than or equal to about 10%.All suitable groups of above range Close is also possible (for example, greater than or equal to about 80% and less than or equal to about 100%).The weight of synthetic fibers in the second layer It is also possible for measuring the other values of percentage.In some embodiments, the second layer includes 100% synthetic fibers.

In some embodiments, the second layer (for example, efficiency layer), third layer, the 4th layer and/or layer 5 weight of determining can Less than or equal to about 120g/m², less than or equal to about 100g/m², less than or equal to about 75g/m², less than or equal to about 50g/ m², less than or equal to about 35g/m², less than or equal to about 25g/m², less than or equal to about 20g/m², less than or equal to about 15g/m²、 Less than or equal to about 10g/m², less than or equal to about 5g/m², less than or equal to about 1g/m², less than or equal to about 0.8g/m², it is small In or equal to about 0.5g/m², less than or equal to about 0.1g/m², less than or equal to about 0.08g/m²Or less than or equal to about 0.06g/m².In some cases, the second layer, third layer, the 4th layer and/or layer 5 weight of determining can be greater than or equal to about 0.05g/m², greater than or equal to about 0.06g/m², greater than or equal to about 0.08g/m², greater than or equal to about 0.1g/m², be greater than or Equal to about 0.2g/m², greater than or equal to about 0.5g/m², greater than or equal to about 0.8g/m², greater than or equal to about 1g/m², be greater than or Equal to about 5g/m², greater than or equal to about 10g/m², greater than or equal to about 15g/m², greater than or equal to about 20g/m², be greater than or wait In about 30g/m², greater than or equal to about 40g/m², greater than or equal to about 50g/m², greater than or equal to about 60g/m², be greater than or equal to About 70g/m², greater than or equal to about 80g/m², greater than or equal to about 90g/m²Or greater than or equal to about 100g/m².Above-mentioned model All suitable combinations enclosed are also possible (for example, greater than or equal to about 0.05g/m²And less than or equal to about 75g/m², it is big In or equal to about 0.05g/m²And less than or equal to about 120g/m²).Surely heavy other values are also possible.Repeated root is determined according to standard ASTM D-13776 is determined.

In some embodiments, the second layer, third layer, the 4th layer and/or layer 5 thickness can be less than or equal to About 5mm, less than or equal to about 4.5mm, less than or equal to about 4mm, less than or equal to about 3.5mm, less than or equal to about 3mm, small In or equal to about 2.5mm, less than or equal to about 2mm, less than or equal to about 1.5mm, less than or equal to about 1mm, be less than or equal to About 0.5mm, less than or equal to about 0.1mm, less than or equal to about 0.05mm or less than or equal to about 0.01mm.In some feelings Under condition, the second layer, third layer, the 4th layer and/or layer 5 thickness can greater than or equal to about 0.001mm, be greater than or equal to About 0.005mm, greater than or equal to about 0.01mm, greater than or equal to about 0.05mm, greater than or equal to about 0.08mm, be greater than or equal to About 0.1mm, greater than or equal to about 0.5mm, greater than or equal to about 1mm, greater than or equal to about 1.5mm, greater than or equal to about 2mm, Greater than or equal to about 2.5mm, greater than or equal to about 3mm, greater than or equal to about 3.5mm or greater than or equal to about 4mm.It is above-mentioned All suitable combinations of range are also possible (for example, greater than or equal to about 0.005mm and less than or equal to about 5mm, being greater than Or equal to about 0.01mm and less than or equal to about 1mm).The other values of average thickness are also possible.Thickness can be according to standard ASTM D1777 is determined at 0.3psi.

In certain embodiments, the second layer (for example, efficiency layer), third layer, the 4th layer and/or layer 5 may include Single layer.However, in other embodiments, the second layer may include more than one layer (that is, sublayer) to form multilayer knot Structure.When layer includes more than one sublayer, a plurality of sublayers can be based on certain features (such as air penetrability, fixed weight, fiber type And/or particulate efficiency) and it is different.In some cases, a plurality of sublayers can be independent and by any suitable method (such as laminated, point bonding or arrangement) combination.In some embodiments, sublayer is substantially engaged with each other (for example, passing through layer Conjunction, hot spot bonding, ultrasonic bonding, calendering, uses adhesive (such as glue net) and/or pleating altogether at point bonding).In some feelings Under condition, sublayer can be formed as composite layer (for example, passing through wet laying process).

In some embodiments, efficiency layer can be static electrification.It can be used known to those of ordinary skill in the art Method assign electrostatic charge to the second efficiency layer or filter medium, the method includes but be not limited to corona charging, charging wand, water Thorn charges, is charged by friction, waterpower charges or uses additive.In other embodiments, efficiency layer can not be electrification.

Filter medium as described herein with fire-retardant filter layer can show advantageous and enhancing strainability characteristic, Such as dust containing capacity (DHC) and efficiency.

Filter medium as described herein can have relatively high dust containing capacity.Dust containing capacity is to be exposed to a certain amount of fine powder Before dirt the weight of filter medium with after being exposed to fine dust when reaching across the specific pressure drop of filter medium filter be situated between The difference of the weight of matter divided by web area.Dust containing capacity can be according to medium every square centimeter (for example, passing through 100cm² Test area) weight (mg) of dust of capture determines.Such as defined herein, use with 15fpm velocity test ASHRAE52.2 flat brake tester is using the gasoloid dust containing capacity for being atomized salt (for example, KCl) particle, wherein when dirt is held in measurement The H that final pressure drop when amount is 1.5 inches₂O column.Dust containing capacity can be used 52.2 standard of ASHRAE and determine.

In some embodiments, the dust containing capacity of filter medium can be greater than or equal to about 10g/m², greater than or equal to about 20g/m², greater than or equal to about 25g/m², greater than or equal to about 50g/m², greater than or equal to about 75g/m², greater than or equal to about 100g/m², greater than or equal to about 125g/m², greater than or equal to about 150g/m², greater than or equal to about 175g/m², be greater than or equal to About 200g/m², greater than or equal to about 225g/m², greater than or equal to about 250g/m²Or greater than or equal to about 275g/m².One In a little situations, dust containing capacity can be less than or equal to about 300g/m², less than or equal to about 275g/m², less than or equal to about 250g/ m², less than or equal to about 225g/m², less than or equal to about 200g/m², less than or equal to about 175g/m², less than or equal to about 150g/m², less than or equal to about 125g/m², less than or equal to about 100g/m², less than or equal to about 80g/m², be less than or equal to About 60g/m²Or less than or equal to about 50g/m².All suitable combinations of above range are possible (for example, being greater than or waiting In about 10g/m²And less than or equal to about 300g/m², greater than or equal to about 20g/m²And less than or equal to about 80g/m²)。

In some embodiments, function of the average efficiency of layer (for example, second layer) and/or filter medium as partial size And increase.In some embodiments, for 0.3 micron to 1.0 micron-scales particle, for 1.0 microns to 3.0 micron meters Very little particle or 3.0 microns of particles to 10.0 micron-scales, average efficiency can greater than or equal to about 20% and be less than or Equal to about 100% (for example, greater than or equal to about 40% and less than or equal to about 100%).For example, in certain embodiments, Extremely for 0.3 micron to 1.0 micron-scales of particle, for 1.0 microns to the particle of 3.0 micron-scales or 3.0 microns The average efficiency of the particle of 10.0 micron-scales, filter layer (for example, second layer) and/or filter medium can be greater than or equal to about 10%, greater than or equal to about 20%, greater than or equal to about 35%, greater than or equal to about 50%, greater than or equal to about 60%, be greater than Or be equal to about 70%, greater than or equal to about 80%, greater than or equal to about 90%, greater than or equal to about 95%, greater than or equal to about 97%, greater than or equal to about 99%, greater than or equal to about 99.5%, greater than or equal to about 99.9%, greater than or equal to about 99.95%, greater than or equal to about 99.99% or greater than or equal to about 99.995%.In some embodiments, for 0.3 Micron to the particle of 1.0 micron-scales, for 1.0 microns to the particle of 3.0 micron-scales or 3.0 microns to 10.0 microns The particle of size, average efficiency can less than or equal to about 100%, less than or equal to about 99.999%, less than or equal to about 99.99%, less than or equal to about 99.997%, less than or equal to about 99.995%, less than or equal to about 99.9%, be less than or wait In about 99.5%, less than or equal to about 99%, less than or equal to about 98%, less than or equal to about 97%, less than or equal to about 95%, less than or equal to about 90%, less than or equal to about 85%, less than or equal to about 75%, less than or equal to about 60%, be less than Or equal to about 50%, less than or equal to about 40%, less than or equal to about 30%, less than or equal to about 20% or be less than or wait In about 10%.It should be understood that all suitable combinations of above range are possible (for example, greater than or equal to about 20% and being less than Or it is equal to about 100%).The average efficiency of function as partial size can be determined according to EN1822.In some embodiments, machine EN 1822 can be used to test in the average efficiency of tool efficiency layer and/or filter medium.

In some embodiments, the average efficiency of the second layer or filter medium can be come according to 52.2 standard of ASHRAE Test.For example, 52.2 standard of ASHRAE can be used to test in the average efficiency of charging efficiency layer and/or filter medium.Test Use the test airflow of 25FPM.Test the gas in 69 °F of air themperature, 25% relative humidity and 29.30 inches of Hg Pressure carries out.Test is also 0.3 micron to 1.0 microns, 1.0 microns to 3.0 microns or 3.0 microns to 10.0 using particle size range The attack aerosol of atomization salt (for example, KCl) particle of micron.

In certain embodiments, the second layer (for example, efficiency layer) as described herein and/or filter medium can be based on The result of 52.2 efficiency of ASHRAE is according to MERV (Minimum Efficiency Reporting Value, minimum efficiency report Value) grade classifies.HVAC (Heating, Ventilating, and Air Conditioning, heating, ventilation and air Adjust) industry usually using MERV grade come describe filter from air remove degranulation ability.Higher MERV grade meaning Refer to preferable filtering and higher performance.In some embodiments, the MERV etc. of the second layer or filter medium as described herein Grade is about 5 to 12 in the range of (for example, between about 8 to 12, between about 6 to 9), however, grade can be based on being expected with Change on the way.In some embodiments, the MERV grade of filter layer or filter medium as described herein greater than or equal to about 5, Greater than or equal to about 6, greater than or equal to about 7, greater than or equal to about 8, greater than or equal to about 9, greater than or equal to about 10, be greater than or Equal to about 11 or greater than or equal to about 12.MERV grade can with e.g., less than or equal to 15, less than or equal to 14, be less than or Equal to 13, it is less than or equal to 12, is less than or equal to 11 or is less than or equal to 10.It should be understood that above range is all suitable Combination is possible (for example, greater than or equal to about 5 and less than or equal to about 15).

In some embodiments, the air penetrability of filter medium can greater than or equal to about 1CFM, greater than or equal to about 5CFM, greater than or equal to about 10CFM, greater than or equal to about 25CFM, greater than or equal to about 50CFM, greater than or equal to about 75CFM, Greater than or equal to about 100CFM, be greater than or equal to 125CFM, greater than or equal to about 150CFM, greater than or equal to about 175CFM, big In or equal to about 200CFM, it is greater than or equal to 225CFM, greater than or equal to about 250CFM or greater than or equal to about 275CFM. In some cases, the air penetrability of filter medium can less than or equal to about 300CFM, less than or equal to about 275CFM, be less than or Equal to about 250CFM, less than or equal to about 225CFM, less than or equal to about 200CFM, less than or equal to about 175CFM, be less than or Equal to about 150CFM, less than or equal to about 125CFM, less than or equal to about 100CFM, less than or equal to about 75CFM, be less than or wait In about 50CFM or less than or equal to about 25CFM.It should be understood that above range it is all it is suitable combination be it is possible (for example, Greater than or equal to about 1CFM and less than or equal to about 300CFM, greater than or equal to about 10CFM and less than or equal to about 250CFM).

In some embodiments, filter medium can have relatively low pressure drop.For example, in some embodiments, The pressure drop of filter medium can less than or equal to about 1300Pa, less than or equal to about 1200Pa, less than or equal to about 1000Pa, small In or equal to about 750Pa, less than or equal to about 500Pa, less than or equal to about 250Pa, less than or equal to about 150Pa, be less than or Equal to about 130Pa, less than or equal to about 100Pa, less than or equal to about 80Pa, less than or equal to about 60Pa, less than or equal to about 40Pa, less than or equal to about 20Pa or less than or equal to about 10Pa.In some cases, the pressure drop of filter medium can be big In or be equal to about 4Pa, greater than or equal to about 6Pa, greater than or equal to about 10Pa, greater than or equal to about 20Pa, greater than or equal to about 40Pa, greater than or equal to about 60Pa, greater than or equal to about 80Pa, greater than or equal to about 100Pa, greater than or equal to about 150Pa, big In or be equal to about 250Pa, greater than or equal to about 500Pa, greater than or equal to about 750Pa, greater than or equal to about 1000Pa or big In or equal to about 1250Pa.All suitable combinations of above range are also possible (for example, greater than or equal to about 4Pa and small In or equal to about 1300Pa, greater than or equal to about 6Pa and less than or equal to about 130Pa).Pressure drop as described herein can basis ISO 3968 is determined under 10.5FPM face velocity using the filtering tester of TSI 8130.

In some embodiments, the weight of determining of filter medium can be greater than or equal to about 20g/m², greater than or equal to about 25g/m², greater than or equal to about 50g/m², greater than or equal to about 75g/m², greater than or equal to about 100g/m², greater than or equal to about 125g/m², greater than or equal to about 150g/m²Or greater than or equal to about 175g/m².In some cases, filter medium is determined Weight can be less than or equal to about 200g/m², less than or equal to about 175g/m², less than or equal to about 150g/m², less than or equal to about 125g/m², less than or equal to about 100g/m², less than or equal to about 75g/m², less than or equal to about 50g/m², less than or equal to about 40g/m²Or less than or equal to about 30g/m².All suitable combinations of above range are also possible (for example, being greater than or waiting In about 20g/m²And less than or equal to about 200g/m², greater than or equal to about 25g/m²And less than or equal to about 125g/m²).Fixed weight Other values be also possible.Fixed weight can be determined according to standard ASTM D-13776.

In some embodiments, the thickness of filter medium can greater than or equal to about 0.25mm, greater than or equal to about 0.3mm, greater than or equal to about 0.4mm, greater than or equal to about 0.5mm, greater than or equal to about 0.6mm, greater than or equal to about 0.8mm, greater than or equal to about 1.0mm, greater than or equal to about 1.2mm, greater than or equal to about 1.5mm, greater than or equal to about 1.8mm, greater than or equal to about 2.0mm or greater than or equal to about 2.2mm.In some cases, the thickness of filter medium can be with Less than or equal to about 2.5mm, less than or equal to about 2.2mm, less than or equal to about 2.0mm, less than or equal to about 1.8mm, be less than Or equal to about 1.5mm, less than or equal to about 1.2mm, less than or equal to about 1.0mm, less than or equal to about 0.8mm, be less than or wait In about 0.6mm, less than or equal to about 0.5mm or less than or equal to about 0.4mm.All suitable combinations of above range Be it is possible (for example, greater than or equal to about 0.25mm and less than or equal to about 2.5mm, greater than or equal to about 0.4mm and be less than or Equal to about 1.2mm).Thickness is determined at 0.3psi according to standard ASTMD1777.

In some embodiments, fire-retardant filter layer can account for the relatively high weight percent of filter medium (for example, big In or equal to about 65 weight %).In certain embodiments, the weight percent of the fire-retardant filter layer in filter medium can be big In or be equal to about 65 weight %, greater than or equal to about 70 weight %, greater than or equal to about 75 weight %, greater than or equal to about 80 weights Amount %, greater than or equal to about 85 weight %, greater than or equal to about 90 weight %, greater than or equal to about 92 weight %, be greater than or wait In about 95 weight %, greater than or equal to about 97 weight % or greater than or equal to about 99 weight %.In some cases, it filters The weight percent of fire-retardant filter layer in medium can less than or equal to about 99.5 weight %, less than or equal to about 99 weights Amount %, less than or equal to about 98 weight %, less than or equal to about 97 weight %, less than or equal to about 95 weight %, be less than or wait In about 92 weight %, less than or equal to about 90 weight %, less than or equal to about 85 weight %, less than or equal to about 80 weight %, Less than or equal to about 75 weight % or less than or equal to about 70 weight %.All suitable combinations of above range are also can Can (for example, greater than or equal to about 20 weight % and less than or equal to about 99 weight %, greater than or equal to about 65 weight % and small In or equal to about 99.5 weight %, greater than or equal to about 80 weight % and less than or equal to about 95 weight %).

In some embodiments, filter medium may include the fire resistance fibre of relative high weight percentage.In certain realities It applies in scheme, the fire resistance fibre of whole fibers in the total weight percent and/or filter medium of the fire resistance fibre in filter medium Total weight percent can greater than or equal to about 20 weight %, greater than or equal to about 30 weight %, greater than or equal to about 40 weights Amount %, greater than or equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight % or be greater than Or it is equal to about 80 weight %.In some cases, the total weight percent and/or filter medium of the fire resistance fibre in filter medium It is middle whole fiber fire resistance fibre total weight percent can less than or equal to about 90 weight %, less than or equal to about 85 weights Amount %, less than or equal to about 80 weight %, less than or equal to about 70 weight %, less than or equal to about 60 weight %, be less than or wait In about 50 weight %, less than or equal to about 40 weight %, less than or equal to about 30 weight %, less than or equal to about 20 weight %, Or less than or equal to about 15 weight %.Above range it is all it is suitable combination be also it is possible (for example, greater than or equal to about 20 weight % and less than or equal to about 90 weight %, greater than or equal to about 20 weight % and less than or equal to about 60 weight %).

In some embodiments, filter medium may include the thick fiber diameters of relative high weight percentage.Certain In embodiment, whole fibers is thick straight in the total weight percent and/or filter medium of the thick fiber diameters in filter medium The total weight percent of diameter fiber can greater than or equal to about 20 weight %, greater than or equal to about 30 weight %, be greater than or equal to About 40 weight %, greater than or equal to about 50 weight %, greater than or equal to about 60 weight %, greater than or equal to about 70 weight % or Person is greater than or equal to about 80 weight %.In some cases, the total weight percent of the thick fiber diameters in filter medium and/or In filter medium the total weight percent of the thick fiber diameters of whole fibers can less than or equal to about 85 weight %, be less than or wait In about 80 weight %, less than or equal to about 70 weight %, less than or equal to about 60 weight %, less than or equal to about 50 weight %, Less than or equal to about 40 weight %, less than or equal to about 30 weight %, less than or equal to about 20 weight % or be less than or equal to About 15 weight %.All suitable combinations of above range are also possible (for example, greater than or equal to about 20 weight % and being less than Or it is equal to about 85 weight %, greater than or equal to about 40 weight % and less than or equal to about 70 weight %).

In certain embodiments, in the total weight percent of the thin fiber diameters in filter medium and/or filter medium The total weight percent of the thin fiber diameters of whole fibers can less than or equal to about 40 weight %, less than or equal to about 35 weights Amount %, less than or equal to about 30 weight %, less than or equal to about 25 weight %, less than or equal to about 20 weight %, be less than or wait In about 15 weight % or less than or equal to about 10 weight %.In some cases, thin fiber diameters in fire-retardant filter layer The total weight percent of the thin fiber diameters of whole fibers can be greater than or equal to about in total weight percent and/or filter medium 5 weight %, greater than or equal to about 10 weight %, greater than or equal to about 15 weight %, greater than or equal to about 20 weight %, be greater than or Equal to about 25 weight %, greater than or equal to about 30 weight % or greater than or equal to about 35 weight %.All conjunctions of above range Suitable combination is also possible (for example, greater than or equal to about 5 weight % and less than or equal to about 40 weight %, being greater than or equal to About 10 weight % and less than or equal to about 20 weight %).

In some embodiments, filter medium may include the synthetic fibers of relative high weight percentage.For example, one In a little embodiments, the synthesis of whole fibers is fine in the weight percent and/or filter medium of the synthetic fibers in filter medium The weight percent of dimension can greater than or equal to about 1%, greater than or equal to about 20%, greater than or equal to about 40%, be greater than or wait In about 60%, greater than or equal to about 80%, greater than or equal to about 90% or greater than or equal to about 95%.In some cases, The weight percent of the synthetic fibers of whole fibers in the weight percent and/or filter medium of synthetic fibers in filter medium Can less than or equal to about 100%, less than or equal to about 98%, less than or equal to about 85%, less than or equal to about 75%, be less than Or equal to about 50% or less than or equal to about 10%.All suitable combinations of above range are also possible (for example, big In or be equal to about 80% and less than or equal to about 100%).In some embodiments, filter medium includes 100% synthesis fibre Dimension.

In some embodiments, one or more layers (for example, filter layer, the second layer comprising fire resistance fibre) and/ Or entire filter medium substantially free of glass fibre (for example, glass fibre, about 0 weight % less than 1 weight % are to about 1 weight Measure the glass fibre of %).For example, fire-retardant filter layer, the second layer and/or entire filter medium may include the glass of 0 weight % Fiber.

Suitable technique can be used to produce in filter medium as described herein, such as wet-laying or non-wet-laying work Skill.In some embodiments, it is raw that wet laying process can be used in fire-retardant filter layer and/or filter medium as described herein It produces.In general, wet laying process includes mixing the fiber of one or more of seed types；For example, can will be a kind of straight The synthetic macro-fiber of diameter is mixed with the synthetic macro-fiber of another diameter and/or thin fiber diameters, to provide fiber pulp Material.Slurry can be such as water-based slurry.In certain embodiments, fiber is admixed together (for example, in the mixture Realize largely uniformity) Optional individually store or combine and be stored in different holding vessels.

For example, the first fiber can be made to mix simultaneously slurrying in a vessel, and the second fiber can be made to exist Mixing and slurrying in individual container.The first fiber and the second fiber can be then merged together and be mixed as Single Fiber Object.Before or after admixed together, fiber appropriate can be handled by pulper.In some embodiments In, before admixed together, the combination of fiber is handled by pulper and/or holding vessel.It is appreciated that can also be to Other components are introduced in mixture.Furthermore, it is to be understood that other combinations of fiber type, example can be used in fibre blend Fiber type as described herein.

In certain embodiments, formed by wet laying process includes two or more layers (for example, comprising fire-retardant The filter layer and the second layer of fiber) medium.For example, can will packet fibrous the in solvent (for example, aqueous solvent such as water) One dispersion (for example, paper pulp) is applied to the net conveyor in paper machine (for example, fourdrinier machine or Rotoformer) On to form the first layer that is supported by the net conveyor.While first layer deposits on the net or later by solvent (for example, water Property solvent such as water) in fibrous second dispersion (for example, another paper pulp) of packet be applied on first layer.During the above process Apply vacuum constantly to the first dispersion of fiber and the second dispersion to remove solvent from fiber, so that generating includes the The product of one layer and the second layer.Then the product being consequently formed is dry, and if it is necessary, by using known method (for example, calendering) is further processed to form multiple layer filter media.

Other wet laying processes are also likely to be suitable.Any suitable side for generating fibre stuff can be used Method.In some embodiments, other additive is added in slurry and is handled with promotion.Temperature can also be adjusted to conjunction Suitable range, for example, 33 °F to 100 °F (for example, 50 °F to 85 °F).In some cases, the temperature of slurry is kept.Some In the case of, temperature is not adjusted actively.

In some embodiments, wet laying process uses the equipment similar with conventional paper technology, for example, waterpower Pulper, forming machine or head box, drying machine and optional converter.After mixing slurry suitably in pulper, Can be by slurry pumping into head box, slurry may or may not merge with other slurries in head box.It can add Or other additives can not be added.Slurry can also be diluted with other water, so that the ultimate density of fiber is in suitable model In enclosing, for example, about 0.1 weight % to 0.5 weight %.

In some cases, it can be adjusted according to the needs the pH of fibre stuff.For example, the fiber of slurry can be in usually Disperse under conditions of property.

It send by slurry to before head box, can optionally make slurry by centrifugal purifier and/or pressurized screen to remove Remove unfiberized material.Slurry can by or can not be by other equipment such as refiner or fluffer with further The dispersion of reinforcing fiber.For example, fluffer can be used for smoothly or removing may be at any point during fibre stuff formation The block or protrusion of appearance.Then any suitable equipment can be used (for example, fourdrinier machine, Rotoformer, cylinder Shape paper machine or inclined wire fourdrinier machine) fiber is collected by sieve or online with rate appropriate.

In some embodiments, resin is added in layer (for example, the preformed layer formed by wet laying process). For example, the use of suitable technology will be able to be being included in for independent emulsion form when keeping layer out-of-date along sieve appropriate or Netcom Different component (for example, polymeric binder and/or other components) in resin is added in fibrous layer.In some cases, With other components and/or it is laminated and before, each component of resin is mixed into lotion.Such as gravity and/or true can be used Sky will include that component in resin is pulled through layer.In some embodiments, it is included in one of resin or more component It can be diluted and be pumped into layer with softened water.In some embodiments, it can be incited somebody to action before introducing slurry into head box Resin is applied to fibre stuff.For example, resin can be introduced into (for example, injection) fibre stuff and with fiber impregnation and/or It is deposited in it on fiber.In some embodiments, resin can be added in layer by solvent saturation process.

In some embodiments, the second layer as described herein can be used non-wet laying process (such as blowing or spin Silk technique) production.In some embodiments, the second layer can be formed by electrostatic spinning process.In certain embodiments, The second layer can be formed by melt-blown systems, such as entitled " the Meltblown Filter that on November 7th, 2008 submits Entitled " the Fine Fiber Filter that the U.S. Publication of Medium " the 2009/0120048th and on December 17th, 2010 submit Melt-blown systems described in U.S. Publication the 2012-0152824th of Media and Processes ", respectively for all Purpose is incorporated herein by reference in their entirety.In certain embodiments, the second layer can pass through melt-spun or centrifugal spinning process shape At.In some embodiments, non-wet laying process such as air-laid process or carding process can be used to form second Layer.For example, synthetic fibers can be mixed, while air being blown on conveyer belt in air-laid process.In carding process In, in some embodiments, fiber is operated by roller and the extension connecting with roller (for example, hook, needle).In some cases Under, it is more likely to be appropriate for producing highly porous medium by non-wet laying process forming layer.As set forth above, it is possible to any Suitable resin dipping (for example, passing through saturation, sprinkling etc.) layer.In some embodiments, non-wet-laying work can be used Skill (for example, melt-blown, electrostatic spinning) forms the second layer, and wet laying process can be used to form fire-retardant filter layer.Second Any suitable method can be used (for example, adhesive, laminated, total pleating or whole in layer (for example, efficiency layer) and fire-retardant filter layer Reason) Lai Zuhe.

During or after filter medium formation, filter medium can be further processed according to a variety of known technologies.For example, Cladding process can be used so that resin is included in filter medium.It is optionally possible to use such as adhesive, laminated, total pleating Or arrange method come formed extra play and/or to filter medium add extra play.For example, in some cases, as described above, Two layers (for example, filter layer and the second layer comprising fire resistance fibre) are made to be formed as composite article by wet laying process, so Afterwards combined the composite article with third layer by any suitable method (for example, adhesive, laminated, total pleating or arrangement). It is appreciated that the filter medium that is formed by method described herein or composite article not only can based on the component of each layer, and And can suitably be customized according to multiple layers of the effect appropriate that different characteristics are applied in combination, have herein to be formed The filter medium of the characteristic.

As described herein, in some embodiments, two or more layers of filter medium are (for example, include fire-retardant fibre The filter layer and the second layer of dimension) can independently form, and by any suitable method (such as it is laminated, arrange or by using Adhesive) it is combined.Different technique can be used in two or more layers or identical technique is formed.For example, each layer Can by non-wet laying process (for example, melt-blown process, melt-spinning technology, centrifugal spinning process, electrostatic spinning process, Dry-laying process, air-laid process), wet laying process or any other suitable technique is separately formed.

Different layers can be adhered to each other by any suitable method.For example, layer can be adhered to by adhesive And/or it is melt bonded each other in either side.Laminated and calen-dering process can also be used.In some embodiments, extra play can To be formed by the blend of any kind of fiber or fiber by the head box or coating machine of addition, and it is suitably adhered to On another layer.

In some embodiments, further processing may include being pleated to filter medium.For example, two layers can To be engaged by total pleating methods.In some cases, filter medium or its multiple layer can by be spaced each other it is appropriate Scribing line is formed at spacing and is suitably pleated, so that filter medium be made to be folded.In some cases, a layer can wind On pleated layer.It should be understood that any suitable pleating technology can be used.

In some embodiments, (such as being subjected to corrugation processing) can be post-processed to filter medium to increase in net Surface area.In other embodiments, filter medium can be embossed.

Filter medium may include any appropriate number of layer, for example, a layer, at least two, at least three, at least four, At least five, at least six, at least seven layer.In some embodiments, filter medium may include up to 20 layers.

Filter medium as described herein can be used for entirely filtering in arrangement or filter element.In some embodiments, Filter medium includes one or more extra plays or component.The non-limiting example of extra play (for example, third layer, the 4th layer) (forcespun) layer or electrostatic are spun including meltblown layer, wet laid layer, spunbond layer, carded layer, airlaid layer, hydroentangled layer, power Spinning layer.

It should be understood that filter medium can also include other parts in addition to one or more layers as described herein.One In a little embodiments, it is further processed including being incorporated to one or more structure features and/or reinforcing element.For example, can make Filter medium is combined with additional structure feature such as polymeric web and/or metal mesh.In one embodiment, sieve backing can To be arranged on filter medium, bigger Gurley stiffness is provided.In some cases, sieve backing can contribute to keep warp The construction of pleating.For example, sieve backing can be drawn metal line or extrusion plastic net.

In some embodiments, layer as described herein can be nonwoven web.Nonwoven web may include non-directional fibre It ties up (for example, the fiber randomly arranged in net).The example of nonwoven web includes passing through wet-laying as described herein or non- Net made of wet laying process.

Filter medium can be incorporated to be used in a variety of suitable filter elements include gas filtration and liquid filtering it is more Kind application.Filter medium suitable for gas filtration can be used for HVAC, HEPA, mask and ULPA filtration application.For example, filtering Medium can be used in heating and air conditioning pipe.In another example, filter medium can be used for respirator and mask is answered With (for example, surgery mask, industrial mask and industrial respirator).Filter medium can be incorporated in various filter element and be used for liquid Press filtration application.The example of use of hydraulic filter (for example, high pressure, middle pressure and low pressure private filter) includes mobile and work Industry filter.

Filter element can have any suitable construction as known in the art, including bag filter and plate-type filtering Device.Filter assemblies for filtration application may include any one of plurality of filter media and/or filter element.Filter element It may include above-mentioned filter medium.The example of filter element includes gas turbine filter element, dust collection elements, Heavy duty air filtering Element, automotive air filter element, the air filtration member for huge discharge petrol engine (for example, SUV, picking-up vehicle, truck) Part, HVAC air filter element, HEPA filter element, ULPA filter element, vacuum bag filter element, fuel filter element and Oily filter element (for example, lubrication oil filtration element or HD lubricating oil filter element).

Filter element can be incorporated to corresponding filtration system (gas turbine filtration system, Heavy duty air filtration system, automobile Air filtering system, HVAC air filtering system, HEPA filtration system, ULPA filtration system, vacuum bag filter systems, fuel Filtration system and oil filtration system) in.Filter medium can be optionally pleated into a variety of constructions (for example, plate, cylindricality) It is any.

Filter element can also be any suitable form, such as radial filter element, panel-style filter element or slot stream member Part (channel flow element).Radial filter element may include being limited in the opening mesh screen of two cylindrical shapes The filter medium through being pleated.During use, fluid can flow in radial members from outside by the medium through being pleated Portion.

In some cases, filter element includes the shell that can be set around filter medium.Shell can have more Kind construction, wherein construction is changed based on intended application.In some embodiments, shell can be by being arranged in filter medium Frame around periphery is formed.For example, frame can be heated seal around periphery.In some cases, frame has around substantially rectangular The substantially rectangular construction of all four sides of filter medium.Frame can be formed of a variety of materials, including such as cardboard, gold Belong to, any combination of polymer or suitable material.Filter element can also include various other features known in the art, such as Stabilisation feature or any other suitable feature for keeping filter medium stable relative to frame, spacer.

As described above, in some embodiments, filter medium can be incorporated in pocket type (or pocket-type) filter element. Bag type filter elements can be formed by any suitable method, such as (or right by putting together two filter mediums Semi-folded single filter medium), and so that three sides (or if it is folding, two sides) is matched each other so that only side is protected Opening is held, to form pocket in filter.In some embodiments, multiple filtering pockets can be attached to frame with shape At filter element.It should be understood that filter medium and filter element can have a variety of different structures, and specific structure depends on In the application for wherein using filter medium and element.In some cases, substrate can be added into filter medium.

Filter element can have with above with respect to the identical characteristic value of characteristic value described in filter medium.For example, above-mentioned Pressure drop, thickness and/or fixed weight can also see filter element.

During use, when fluid (for example, air) flows through filter medium, filter medium is mechanically by contaminant particle Capture is on filter medium.Filter medium does not need to charge to improve the capture of pollutant.Therefore, in some embodiments, Filter medium is uncharged.However, in some embodiments, filter medium can be electrification.In some embodiments In, fire-retardant filter layer (for example, pleated back sheet) and/or filter medium can be used for non-filtered application.For example, fire-retardant mistake Filtering layer (for example, pleated back sheet) and/or filter medium can be used for window-blind application.

Embodiment

Embodiment 1

This embodiment describes include five kinds for being meltblown efficiency layer for being adhesively bound to the filter layer comprising synthetic fibers The dust containing capacity of filter medium.In this embodiment, the filter layer comprising synthetic fibers is pleated back sheet.Pleated back The surface avarage fiber diameter of lining changes in each filter medium.When surface avarage fiber diameter (SAFD) is at 13 microns to 17 When in the range of micron, best dust containing capacity is observed.

Form the filter medium including being meltblown efficiency layer and pleated back sheet.Pleated back sheet upstream simultaneously And with melt-blown efficiency layer direct neighbor.Efficiency layer is the meltblown polypropylene fibres net that avarage fiber diameter is 0.6 micron.Efficiency layer It is the mechanical efficiency layer with the F9 level of efficiency according to EN779 standard.Pleated back sheet includes blend below: flat The first thick polyester fiber group that equal diameter is 25 microns, the second thick polyester fiber group that average diameter is 15 microns, average fiber The second thin polyester fiber group and third that the first thin polyester fiber group and avarage fiber diameter that diameter is 9 microns are 13 microns Olefin(e) acid binder.Pleated back sheet is formed by wet laying process, and has about 80g/m²To 85g/m²Determine weight. It is straight that table 1 shows the weight percent of whole fibers of every kind of fiber type and surface average fiber in pleated back sheet Diameter and air penetrability.Gauging surface avarage fiber diameter as described herein.Unless otherwise noted, otherwise measurement layer as described herein and The architectural characteristic and performance characteristics of entire filter.

The pleated back sheet characteristic of table 1.

It combines five kinds of different pleated back sheets with efficiency layer.Pleated back sheet is in the thin fiber diameters used It is different in terms of the weight percent of thick fiber diameters and surface avarage fiber diameter.It is 13 for surface avarage fiber diameter The filter medium of micron to 17 microns, dust containing capacity highest.Fig. 2 shows the dust containing capacity of the filter medium in embodiment 1 and surfaces Avarage fiber diameter.

Embodiment 2

This embodiment describes two kinds of filter mediums for including the filter layer comprising the fiber containing fire retardant and without packet The anti-flammability of the filter medium of fiber containing fire retardant.Filter medium comprising the fiber containing fire retardant is realized than without this The higher flame retardant rating of the filter medium of the fiber of sample.

Two kinds of filter mediums comprising the fiber containing fire retardant are formd (that is, filter medium 1 using wet laying process With filter medium 2).Filter medium includes the polyester fiber containing the fire retardant based on phosphorus and the non-flame resistant fibre not comprising fire retardant The blend of dimension.Table 1 provides the composition of two kinds of filter mediums.Also a kind of contain is formd using wet laying process The filter medium (that is, filter medium 3) of the fiber of fire retardant.Table 2 additionally provides the composition of filter medium 3.In filter medium The average length of whole fibers is less than or equal to about 6mm.The weight of determining of all filter mediums is about 47g/m²To 53g/m².Filtering is situated between Matter 1 and 3 is substantially the same, the difference is that the average diameter that filter medium 1 includes 69 weight % is 13 microns and contains base In the polyester fiber of the fire retardant of phosphorus, and the average diameter that filter medium 3 includes 69 weight % is 13 microns without fire retardant Polyester fiber.Filter medium 1 and 2 is different on the composition of non-flame resistant fiber.

2. filter medium of table composition

As described herein, determine that filtering is situated between according to DIN53438 surface ignition (F test) and edge igniting test (K test) The anti-flammability of matter.Filter medium 1 and 2 be it is fire-retardant, have F1 and K1 grade.Filter medium 3 is not fire-retardant and obtains F2 With K3 grade.Anti-flammability test data and grade are as shown in table 3 to 8.

The DIN53438 F grade of 3. filter medium 1 of table

The DIN53438 K grade of 4. filter medium 1 of table

The DIN53438 F grade of 5. filter medium 2 of table

The DIN53438 K grade of 6. filter medium 2 of table

The DIN53438 F grade of 7. filter medium 3 of table

The DIN53438 K grade of 8. filter medium 3 of table

Embodiment 3

This embodiment describes include fire-retardant filter layer (fiber comprising containing the fire retardant based on phosphorus) and glass efficiency Layer filter medium and including filter layer (without the fiber comprising the fire retardant based on phosphorus) and glass efficiency layer filtering Jie The anti-flammability of matter.Filter medium including fire-retardant filter layer realizes the filtering than being free of the fiber comprising the fire retardant based on phosphorus The higher flame retardant rating of medium.

The filter medium (that is, filter medium 4) including fire-retardant filter layer is formd using wet laying process.Such as embodiment The fire-retardant filter layer of the formation described in filter medium 1 and 2 in 2.Glass efficiency layer is formed on fire-retardant filter layer.Glass efficiency The bicomponent fibre of layer 106 glass fibre of Johns Manville containing 92 weight % and 8 weight %.Glass efficiency layer Determining weight is 30g/m²。

Also another filter medium for being free of the fiber comprising the fire retardant based on phosphorus is formd using wet laying process (that is, filter medium 5).Filter medium 5 includes filter layer and the glass effect of the formation as described in embodiment 1 about filter medium 3 Rate layer.Glass efficiency layer contains 106 glass fibre of Johns Manville of 92 weight % and the bicomponent fibre of 8 weight %. The weight of determining of glass efficiency layer is 30g/m².Filter medium 4 and 5 is substantially the same, the difference is that filter medium 4 includes 69 weights The average diameter of % is measured as 13 microns of polyester fiber (it contains the fire retardant based on phosphorus in filter layer), and filter medium 5 The polyester fiber that average diameter comprising 69 weight % is 13 microns (it is free of fire retardant in filter layer).

As described herein, determine that filtering is situated between according to DIN53438 surface ignition (F test) and edge igniting test (K test) The anti-flammability of matter.Filter medium 4 be it is fire-retardant, have F1 and K1 grade, as shown in Tables 9 and 10.Filter medium 5 is not fire-retardant And F3 and K3 grade is obtained, as shown in table 11 and 12.

The DIN53438 F grade of 9. filter medium 4 of table

The DIN53438 K grade of 10. filter medium 4 of table

The DIN53438 F grade of 11. filter medium 5 of table

The DIN53438 K grade of 12. filter medium 5 of table

It is described several aspects of at least one embodiment of the invention, it should be appreciated that those skilled in the art Member will readily occur to a variety of changes, modifications and improvement.Such changes, modifications and improvement are intended for one of present disclosure Point, and be intended to fall in the spirit and scope of the present invention.Therefore, foregoing description and attached drawing are only used as example.

Claims

1. a kind of filter medium, comprising:

Fire-retardant Wet laid nonwoven net, the fire-retardant Wet laid nonwoven net include the fibre containing the fire retardant based on phosphorus Dimension.

2. a kind of filter medium, comprising:

Wet laid nonwoven net comprising fire resistance fibre, wherein the Wet laid nonwoven net include less than or equal to about Total halogen of 1500ppm.

3. filter medium according to any preceding claims, wherein the fiber is synthetic fibers.

4. filter medium according to any preceding claims, wherein the Wet laid nonwoven net includes to be less than or wait In the chlorine of about 900ppm.

5. filter medium according to any preceding claims, wherein the Wet laid nonwoven net includes to be less than or wait In the bromine of about 900ppm.

6. filter medium according to any preceding claims, wherein the Wet laid nonwoven net is substantially free of halogen Element.

7. filter medium according to any preceding claims, wherein the Wet laid nonwoven net is substantially free of gold Belong to hydrate.

8. filter medium according to any preceding claims, wherein the Wet laid nonwoven net is substantially free of three Antimony oxide.

9. filter medium according to any preceding claims, wherein the fire retardant include phosphate, phosphonate/ester, Phosphine oxide, red phosphorus, inorganic phosphate, melamine, dicyandiamide, guanidine, or derivatives thereof.

10. filter medium according to any preceding claims, wherein the fire retardant based on phosphorus includes phosphate, phosphine Hydrochlorate/ester, phosphine oxide, red phosphorus, inorganic phosphate, or derivatives thereof.

11. filter medium according to any preceding claims, wherein the fire retardant is the fire retardant based on nitrogen.

12. filter medium according to any preceding claims, wherein the fiber package includes synthetic polymer.

13. filter medium according to any preceding claims, wherein the main chain of the synthetic polymer includes fire retardant.

14. filter medium according to any preceding claims, wherein one or more side group packets of the polymer Containing fire retardant.

15. filter medium according to any preceding claims, wherein the fire retardant is distributed across the fiber.

16. filter medium according to any preceding claims, wherein including base in the Wet laid nonwoven net In the fire retardant of phosphorus fiber weight percent greater than or equal to about 20 weight % and less than or equal to about 99 weight %.

17. filter medium according to any preceding claims, wherein including base in the Wet laid nonwoven net In the fire retardant of phosphorus fiber weight percent greater than or equal to about 60 weight % and less than or equal to about 80 weight %.

18. filter medium according to any preceding claims, wherein the Wet laid nonwoven net also include containing The resin of fire retardant.

19. filter medium according to any preceding claims, wherein the Wet laid nonwoven net also includes to be free of The non-flame resistant fiber of fire retardant.

20. filter medium according to any preceding claims, wherein the non-flame resistant fiber is synthetic fibers.

21. filter medium according to any preceding claims, wherein the Wet laid nonwoven net includes less than 1 weight Measure the glass fibre of %.

22. filter medium according to any preceding claims, wherein the with good grounds DIN of Wet laid nonwoven netting gear The F1 grade of 53438 measurements.

23. filter medium according to any preceding claims, wherein the with good grounds DIN of Wet laid nonwoven netting gear The K1 grade of 53438 measurements.

24. filter medium according to any preceding claims, wherein the Wet laid nonwoven net includes average fibre Dimension first synthetic fibers of the diameter greater than or equal to about 15 microns and avarage fiber diameter greater than or equal to about 0.5 micron and are less than About 15 microns of the second synthetic fibers, wherein first synthetic fibers and/or second synthetic fibers include described fire-retardant Fiber.

25. filter medium according to any preceding claims, wherein whole fibers in the Wet laid nonwoven net The first synthetic fibers weight percent greater than or equal to about 40 weight %.

26. filter medium according to any preceding claims, wherein whole fibers in the Wet laid nonwoven net The second synthetic fibers weight percent less than or equal to about 50 weight %.

27. filter medium according to any preceding claims, wherein the surface of the Wet laid nonwoven net is average Fibre diameter is measured greater than or equal to about 6 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the filter layer of unit and ρ is with g/cm³It is averaged for the layer of unit Density.

28. filter medium according to any preceding claims, wherein the thickness of the Wet laid nonwoven net is greater than Or equal to about 0.25mm and less than or equal to about 2.0mm.

29. filter medium according to any preceding claims, wherein the Wet laid nonwoven net it is fixed it is great in Or it is equal to about 20g/m²And less than or equal to about 200g/m²。

30. filter medium according to any preceding claims, wherein the machine direction of the Wet laid nonwoven net On dry Gurley stiffness greater than or equal to about 200mg and less than or equal to about 3500mg.

31. filter medium according to any preceding claims further includes efficiency layer.

32. filter medium according to any preceding claims, wherein the efficiency layer is meltblown layer.

33. filter medium according to any preceding claims, wherein the efficiency layer is electrostatic spinning layer.

34. filter medium according to any preceding claims, wherein the efficiency layer includes glass fibre.

35. filter medium according to any preceding claims further includes electrostatic spinning layer and meltblown layer.

36. a kind of filter medium, comprising:

Fireblocking nonwoven net, the fireblocking nonwoven net contain the fire retardant based on phosphorus less than or equal to about 30mm comprising length Fiber, wherein the fiber package contains the fire retardant based on phosphorus, wherein the thickness of the nonwoven web is less than or equal to about 1mm, The air penetrability of the nonwoven web is greater than or equal to about 20CFM and less than or equal to about 800CFM.

37. a kind of filter medium, comprising:

Nonwoven web, the nonwoven web includes fire resistance fibre of the length less than or equal to about 30mm, wherein the nonwoven web Comprising total halogen less than or equal to about 1500ppm, the thickness of the nonwoven web is described non-woven less than or equal to about 1mm The air penetrability of net is greater than or equal to about 20CFM and less than or equal to about 800CFM.

38. filter medium according to any preceding claims, wherein the fiber is synthetic fibers.

39. filter medium according to any preceding claims, wherein the nonwoven web include less than or equal to about The chlorine of 900ppm.

40. filter medium according to any preceding claims, wherein the nonwoven web include less than or equal to about The bromine of 900ppm.

41. filter medium according to any preceding claims, wherein the fire retardant include phosphate, phosphonate/ester, Phosphine oxide, red phosphorus, inorganic phosphate, melamine, dicyandiamide, guanidine, or derivatives thereof.

42. filter medium according to any preceding claims, wherein the fire retardant based on phosphorus includes phosphate, phosphine Hydrochlorate/ester, phosphine oxide, red phosphorus, inorganic phosphate, or derivatives thereof.

43. filter medium according to any preceding claims, wherein the fire retardant is the fire retardant based on nitrogen.

44. filter medium according to any preceding claims, wherein the fiber package includes synthetic polymer, the polymerization The main chain of object includes fire retardant.

45. filter medium according to any preceding claims, wherein one or more side group packets of the polymer Containing fire retardant.

46. filter medium according to any preceding claims, wherein the fire retardant is distributed across the fiber.

47. filter medium according to any preceding claims, wherein including the resistance based on phosphorus in the nonwoven web The weight percent of the fiber of agent is fired greater than or equal to about 20 weight % and less than or equal to about 90 weight %.

48. filter medium according to any preceding claims, wherein the nonwoven web also includes containing fire retardant Resin.

49. filter medium according to any preceding claims, wherein the nonwoven web also includes without fire retardant Non-flame resistant fiber.

50. filter medium according to any preceding claims, wherein the nonwoven web includes the glass less than 1 weight % Glass fiber.

51. filter medium according to any preceding claims is surveyed wherein the nonwoven web has according to DIN 53438 The F1 grade of amount.

52. filter medium according to any preceding claims is surveyed wherein the nonwoven web has according to DIN 53438 The K1 grade of amount.

53. filter medium according to any preceding claims, wherein the nonwoven web includes that avarage fiber diameter is big In or equal to about 15 microns the first synthetic fibers and avarage fiber diameter greater than or equal to about 0.5 micron and be less than about 15 microns The second synthetic fibers, wherein first synthetic fibers and/or second synthetic fibers include the fire resistance fibre.

54. filter medium according to any preceding claims, wherein the surface of the Wet laid nonwoven net is average Fibre diameter is measured greater than or equal to about 6 microns and less than or equal to about 17 microns and using following formula:

55. filter medium according to any preceding claims further includes efficiency layer.

56. filter medium according to any preceding claims, wherein the efficiency layer is meltblown layer.

57. filter medium according to any preceding claims, wherein the efficiency layer is electrostatic spinning layer.

58. filter medium according to any preceding claims, wherein the efficiency layer includes glass fibre.

59. filter medium according to any preceding claims further includes electrostatic spinning layer and meltblown layer.

60. a kind of filter medium, comprising:

Fireblocking nonwoven net, the fireblocking nonwoven net includes:

First synthetic fibers of the avarage fiber diameter greater than or equal to about 15 microns, wherein all fine in the fireblocking nonwoven net The weight percent of first synthetic fibers of dimension is greater than or equal to about 40 weight %；With

Second synthetic fibers of the avarage fiber diameter greater than or equal to about 0.5 micron and less than about 15 microns, wherein described fire-retardant The weight percent of the second synthetic fibers of whole fibers is less than or equal to about 50 weight % in nonwoven web, wherein described first Synthetic fibers and/or second synthetic fibers include the fire retardant based on phosphorus, wherein the average fibre in the surface of the nonwoven web Dimension diameter is measured greater than or equal to about 13 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fireblocking nonwoven net of unit and ρ is with g/cm³For the layer of unit Density；And

Efficiency layer, wherein the dust containing capacity of the filter medium is greater than or equal to about 20g/m²。

61. a kind of filter medium, comprising:

Fireblocking nonwoven net, the fireblocking nonwoven net includes:

Second synthetic fibers of the avarage fiber diameter greater than or equal to about 0.5 micron and less than about 15 microns, wherein described fire-retardant The weight percent of the second synthetic fibers of whole fibers is less than or equal to about 50 weight % in nonwoven web, wherein described first Synthetic fibers and/or second synthetic fibers include the fire retardant based on phosphorus, wherein the surface of the fireblocking nonwoven net is flat Equal fibre diameter is measured greater than or equal to about 13 microns and less than or equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fireblocking nonwoven net of unit and ρ is with g/cm³For the layer of unit Density, wherein the fireblocking nonwoven net determines weight less than or equal to about 110g/m²；And

Efficiency layer.

62. a kind of fire-retardant Wet laid nonwoven net, includes:

First synthetic fibers of the avarage fiber diameter greater than or equal to about 15 microns, wherein the fire-retardant Wet laid nonwoven net The weight percent of first synthetic fibers of middle whole fiber is greater than or equal to about 40 weight %；With

Second synthetic fibers of the avarage fiber diameter greater than or equal to about 0.5 micron and less than about 15 microns, wherein described fire-retardant The weight percent of the second synthetic fibers of whole fibers is less than or equal to about 50 weight % in Wet laid nonwoven net, wherein First synthetic fibers and/or second synthetic fibers include the fire retardant based on phosphorus, and

Wherein the surface avarage fiber diameter of the fire-retardant Wet laid nonwoven net greater than or equal to about 13 microns and be less than or It is measured equal to about 17 microns and using following formula:

Wherein SSA is with m²/ g is the surface BET of the fire-retardant Wet laid nonwoven net of unit and ρ is with g/cm³For The density of the layer of unit.

63. a kind of method for manufacturing nonwoven web, comprising:

Fiber comprising the fire retardant based on phosphorus is provided；And

Nonwoven web is formed using wet laying process.

64. filter medium according to any preceding claims, wherein the Wet laid nonwoven net includes less than 10 The glass fibre of weight %.

65. filter medium according to any preceding claims, wherein the surface of the Wet laid nonwoven net is average Fibre diameter is measured greater than or equal to about 1 micron and less than or equal to about 25 microns and using following formula:

66. filter medium according to any preceding claims, wherein the machine direction of the Wet laid nonwoven net On dry Gurley stiffness greater than or equal to about 10mg and less than or equal to about 3500mg.

67. filter medium according to any preceding claims, wherein the fiber does not crimp.