JPS5860037A - Method and apparatus for opening fiber bundle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method and apparatus for opening fiber bundles.

11! For details, refer to K111, a novel method and apparatus for applying static electricity to a fiber bundle, charging it, and opening the fibers using the repulsive force.

Conventionally, various methods have been proposed for applying static electricity to fibers to open them. For example, in Japanese Patent Publication No. 48-34E, fiber bundles are arranged in a pair of opposing high voltages.

A method has been proposed in which the fibers are fed between pressure-applied belts at a faster speed than the belt, causing electrostatically charged fibers to repel each other, spread, and accumulate on the lower belt. Furthermore, in JP-A-55-8054116, an untwisted filament bundle is charged and sewn, then introduced into a roller whose core is grounded and whose surface is coated with an elastomer. ) A method has been proposed for producing a spread web using K thrusting.

The method of opening fibers using electrostatic force consumes less energy than the mechanical methods (rubbing, loosening, and tension) that utilize airflow, making it an energy-saving method suitable for this era.

However, in Japanese Patent Publication No. 4 B-34544,
The number of belts used is too large, and when performing continuous production,
Special consideration must be given to belt meandering and wear, and maintenance of the machine is complicated.

Another disadvantage is that the fiber bundle tends to get wrapped around the rollers used to feed it between opposing belts. In addition, in JP-A-55-80566, the equipment costs for high-voltage poles are high, the elastomer rubs off quickly, and the fibers are nipped with smooth rollers, which tends to cause wrapping. In the case of a fiber bundle with a high number density of fibers, there is also a drawback that compression bonding occurs between single fibers, resulting in poor opening. Furthermore, the elastomer covering the roller weakens the electric field from the roller toward the collection surface, so it is necessary to apply a very high voltage.

As a result of intensive research into a method that does not have the above drawbacks, the inventors of the present invention have found that the method overcomes the above drawbacks, has extremely good opening properties for high-density fiber bundles, and has a large spread of fibers (thus, increases the strength and bulk of the resulting web). We found a method (with a large degree of gender) and arrived at #4.

That is, the first aspect of the present invention is to apply static electricity to a fiber bundle, spread it in an electrostatic field, and collect it to produce a web structure. )
is α03a~3o, , and when guiding the fiber bundle separated from the roller to the collection surface, the direction from the roller to the collection surface in the area between the roller and the collection surface. An electric field is formed that acts on the fiber bundle in that area, and the fibers that make up the fiber bundle are opened using the repulsive force caused by static electricity, and the opened fiber bundles are collected on a collection surface. A second invention of the present invention is a method for opening a fiber bundle, which is characterized by forming a fiber bundle with static electricity, and (b) a means for applying static electricity to the fiber bundle. Surface roughness Ra) for opening the bundle and guiding it to the following area
is αG'3jl1m~301EII, (c
) an area where an electric field is formed between the roller and a collecting surface of the W4 fiber bundle to move and spread the fiber bundle; and (d) a region where the spread fiber bundle is collected to form a web. This is a fiber bundle opening device consisting of a round collecting surface.

Hereinafter, the present invention will be described in detail with reference to the attached FIG. 11C in order to specifically clarify the present invention. The unopened fiber bundle (1) is rubbed with a rubbing rod (2
) K generates static electricity, and the surface roughness Ra) is α0311EII to 308111 from the feed roller (3) K.
It is supplied to a roller (hereinafter referred to as an uneven roller) that is rotating faster than the feed roller (3) within the range of . The fiber bundle receives a slight tension due to the rotational frictional force of the uneven roller,
Although the wrinkled fiber bundle follows the uneven roller, at the point (a) where the electric field that directs the charged fiber bundle toward the collecting surface becomes strong, the wrinkled fiber bundle leaves the uneven roller and is opened due to the electrostatic repulsion between the individual fibers (5).
) (This area is called the opening zone) The polar plates (8) are deposited in a random loop on the belt (7) arranged on the back side and are conveyed as a web (9).

The fiber bundle used in the present invention preferably has little twist, relatively low interaction between single fibers, and is uniform. For example, a fiber bundle obtained by a manufacturing method such as that disclosed in Japanese Patent Application No. 55-38993, or one in which the fiber bundle is passed through a friction guide to maintain the width of the fiber bundle! The fiber bundle obtained by stretching has almost no twist, and the parallelism between the fibers is extremely good, making it a preferable fiber bundle. In other words, this method involves extruding a melt of a thermoplastic synthetic polymer through a spinneret having a large number of slits to produce a filamentary fiber bundle. A discontinuous protrusion is provided in the gap, and the melt extruded from the slit formed through the concave area existing between the protrusions is extruded from another slit in contact with the molten liquid. The melt is extruded from a spinneret that can pass between the spinneret and the melt, and at this time, a cooling fluid is supplied to the melt discharge surface of the spinneret and its vicinity to cool the melt while cooling the melt!
A method for producing a filamentary fiber bundle (g), characterized in that the melt extruded through a tube is taken over and the melt is converted into a large number of separated fibrous rivulets and solidified, or The filamentary fiber bundle (4) obtained in this manner is continuously passed through a friction guide and drawn by drawing the core bundle at a speed greater than the speed at which it is inserted into the friction guide. This is a method for producing filamentous fiber bundles.

Both the filamentary fiber bundle (A) and the filamentary fiber bundle (B) thus obtained have the following characteristics.

ti) Each filament constituting the bundle (A) or ω) has a cross-sectional area that varies irregularly and periodically in its length direction, and (2) each of the filaments Filament Fi Filament internal cross-sectional area variation coefficient 1t [eV(
F5) is in the range of aO5 to 1.0, and (3) the size of the cross-sectional area of each filament when the bundle is cut in a direction perpendicular to the filament axis at any position of the bundle is substantially It is characterized by being randomly different from each other.

The filament internal cross-sectional area variation coefficient [CV (b)
] refers to the variation in the fineness of the filament in the longitudinal direction (axial direction). The size of the cross-sectional area for each 1101 interval was measured using a microscope, and the average value of the 30 cross-sectional areas (prevention, 3
Find the standard deviation (σA) of the cross-sectional area of °, and use the following formula (
Further, the variation in the cross-sectional area of each filament when the bundle is cut in the direction perpendicular to the filament axis at any position of the present invention can be calculated from the filament cross section in the bundle. Area coefficient of variation (cl
a)] and ranges from αl to L5, especially eV(
It is preferable that A) is in the range of α2 to l.

This eV (A) is calculated by randomly extracting 100 partial focusing bodies from the above focusing body, observing the cross section at any position under a microscope, and measuring the thickness of each cross section. value (i) and its standard deviation of the cross-sectional area of 10011I (σ
B) can be calculated using the following formula.

As a result, for fibers whose cross-sectional area varies relatively greatly along the fiber axis, the amount of charge in the direction of the fiber axis changes, the response to the electric field changes slightly, and the random opening of the fiber bundle is improved. It is preferable as a fiber bundle applied to the present invention in that it can be applied to the present invention.

In addition, a synthetic fiber bundle with a number of crimps of up to 20 per inch while maintaining the parallelism between the fibers is tensioned and relaxed with a notched roller, and a pre-opened fiber bundle, or a fiber bundle with a pair of teeth in Fi. Fiber bundles prepared by rubbing with a roller and pre-shaping can also be preferably applied to the present invention.

The material and shape of the friction body as shown in 2 in FIG. 1 are selected according to the friction coefficient and charging characteristics of the fiber bundle used. Generally, the sign of the static electricity applied to the fiber bundle is determined by the relationship between the charge series order of the friction body and the skeleton fiber bundle. For example, when a polyethylene terephthalate (PIT) fiber bundle is positively charged, iron is used.

Stainless steel, Teflon, HoIJ ethylene.

A material such as polyvinyl chloride whose charge series order is on the negative side compared to PET is used. These are round bars and square bars.

It is formed in the shape of a flat plate, and the surface has a mirror finish.

Battery processing etc. will be carried out. The number of friction bodies may be plural.

When it is desired to increase the electrostatic voltage to be applied, it is desirable to have a large number of them, but it is preferable that the frictional force applied to the fiber bundle be small.

Therefore, the appropriate number of friction bodies is determined automatically, and the arrangement of the friction bodies (plurality) can also be determined by balancing the charging voltage and frictional force.

A method of charging a fiber bundle with a discharge electrode has also been used for a long time. Suitable charging devices are described, for example, in US Pat. No. 163,753. In either method, the preferable electrostatic voltage applied to the fiber bundle has an absolute value of tKV or more, and more preferably Fi20K.
V or more: 1° The material of the uneven roller in the present invention is preferably one with excellent wear resistance. For conductive materials, iron, stainless steel, Nickel, and chrome.

Wear-resistant metals such as tungsten carbide; wear-resistant ceramics such as titanium oxide, aluminum oxide, and zirconia for insulating materials; Abrasion-resistant elastomer: low-pressure polyethylene/super molecular weight polyethylene/LTEFF A7
Tt40-8 + Su40-a6. , t'lJ acetal; etc., or composites thereof are used.

The surface roughness (Ra) of the uneven roller of the present invention is JIS 8
0601rSurface RoughnessEqual to the center line average roughness determined by a method compliant with K.

The centerline average roughness of the uneven roller, that is, the surface roughness (Ra, ) of the present invention is determined as follows. Of the surface of the cough roller, only the surface area in contact with the fiber bundle is taken out and measured. Consider a line segment parallel to the axis and a line segment perpendicular to the axis on the cross section in the surface area, and J11 along the line segment.
3. According to the definition of BO601, the roughness centered on the average height of the surface (1it III y-/den) is determined. However, the X-axis and Y-axis are taken in the direction of the center line from the roughness curve and the longitudinal magnification, respectively. Also, line segments parallel to the axis are taken every 30' around the axis, and six line segments are taken every 30' around the axis, and line segments on the cross section perpendicular to the axis are taken from the end of the surface area to the average diameter of When D is taken, take every distance of 0.524 x D. Connect the obtained roughness curves/(X) to find the following integral over all line segments.

means adding the length of .

Based on the formula for determining the centerline average roughness of JIS BO6Q1 in lie, the centerline average roughness, that is, the surface roughness (Ra) of the present invention, is determined by the following formula.

If the uneven roller has regular surface unevenness, a theoretical KRa may be determined.

Suitable range of Ra found like a scent #I! IFio
, oafi to 30 layers, more preferably α25. ~
5IDI. If the value of Ra is too small,
This is thought to be due to the fact that when the electric force for separating the fiber bundle from the uneven roller decreases, the interaction force between the single yarn of the fiber bundle and the surface of the uneven roller increases. It appears that the fiber bundle frequently gets wrapped around the fiber bundle.

If the value of Ra is too large, this is probably because the force that pulls the fiber bundle by rotational friction force becomes small in the case of the arrangement as shown in Fig. 1, but the fiber bundle will scatter to the key in contact with the uneven roller. . As shown in Fig. 2, when the fiber bundle is gripped by contacting the fiber bundle with the unevenness C'-')f, if Ra is too large, the engagement of the rollers will be insufficient and the fiber gripping force will be reduced. It's inconvenient.

When the radius of curvature p of the convex portion of the uneven roller is defined as described below, the appropriate value range for the door depends in detail on the physical properties (especially electrical properties and mechanical properties) of the material constituting the convex portion. .

Broadly speaking, if it is made of insulating material, ρ
There are no special restrictions.

When the convex portion is made of a conductive material, it is preferably in the range of α011kutoav (3), more preferably Q, l cm <aav...・・・・・・
(4). However, the convex portion may be trapezoidal, that is, pav may be infinite.

However, aav is determined as follows. The minimum radius of curvature among the radii of curvature found along any line segment passing through the point giving the maximum point of the roughness curve found previously is defined as I of the convex portion. Furthermore, the average value of - is taken as aav. In the case of a conductive material, it is necessary to increase aav. When paV is too small, the charged fiber bundle loses its charge the moment it comes into contact with the uneven roller. The reason for this is not clear, but when a convex part is made of a conductive material and a voltage is applied to it, the electric field near the convex part becomes extremely unstable and strong as the paV becomes smaller. It is speculated that the corona discharge that binds the fiber bundle is more easily directed into the air, and the ions in the air that are generated at that time neutralize the charge amount of the fiber bundle. Although it is large, this is probably because the corona discharge from the convex portion is more active. Therefore, pa in (3) and (4)
The exact range of V varies depending on humidity and temperature. (3)
, The range of aav in (4) is temperature 20℃, relative humidity 6
This is in the 5th grade.

At least 41tw from the bottom point of the roughness curve of the uneven roller
There is a conductive layer at the depth, to which a high voltage is applied. When a high voltage is applied to the conductive layer, very complicated lines of electric force are formed at the convex portion of the rotating uneven roller (near the maximum point of the 411 curve), so that the electrically charged fiber bundle is It is estimated that the fibers are subjected to complex oscillating forces#
The fiber bundle leaves the uneven roller in a well-divided state.

The uneven roller may be used alone as shown in FIG.
The twists in FIG. 2 may be used in pairs. When used alone, it is necessary to balance the frictional force between the rotating uneven roller and the fiber bundle and the electrostatic repulsion between the uneven roller and the fiber bundle. Supplementally, an electrode may be placed above the single uneven roller and a high voltage may be applied so that the fiber bundle scatters from the uneven roller in a fixed direction.

When using a pair of uneven rollers, care must be taken to prevent the concave portions and convex portions of the opposing rollers from damaging each other.

Even if you use the uneven rollers alone or in pairs,
It is possible to open fiber bundles without crimping them, and even fiber bundles with high fiber density can be opened uniformly, which is a feature not found in conventional methods.

The optimum value of the applied voltage varies depending on the charging voltage of the fiber bundle.

In particular, if the charged voltage of the fiber bundle is low for some reason, by increasing the absolute value of the applied voltage, even if the charged voltage of the fiber bundle has the same sign, the fibers will not be attracted towards the collecting surface. Rather, it is attracted to and wrapped around the uneven roller.

This phenomenon is remarkable when the convex portion is made of a conductive material.

Although the reason for this is not clear, it is presumed that the tip of the convex portion forms a strong electric field, polarizing the fiber bundle to the opposite charge. It has been found that in the case of a structure in which the convex portion (near the top of the mountain) is electrically insulating and supported by an electrically conductive support material, the above-mentioned problem is alleviated.

By varying the charging voltage of the fiber bundle and the voltage applied to the support material of the convex portion, we investigated the range in which the fiber bundle could be opened and forged in a favorable manner without any trouble of winding the fiber bundle around the uneven roller. It was found that a structure in which a convex portion with an insulating surface is supported by a conductive support material has a wider range than a structure in which a conductive convex portion is used. In particular, in the case of a structure using four-electroconvex convex parts, if some fibers with a small amount of charge were present in the fiber bundle, that part was likely to wrap around the uneven row 2, so the fiber bundle should be charged as uniformly as possible. There was a need. On the other hand, in the case of a structure using insulating convex parts, even if some fibers with a low electrical charge were mixed in the fiber bundle, they did not wrap around the uneven roller and the fibers could not be opened sufficiently. . Therefore, if you want to widen the allowable range of charge amount, use an insulating convex part,
Preferably, an electrically conductive support material is combined.

The preferred value of the voltage to be applied to the conductive support material of the uneven roller depends on the charging voltage of the fiber bundle, temperature and humidity, the shape of the convex parts, etc., but when the charging voltage of the fiber bundle is about 30 KV, 10 ~3
A voltage of about 0 KV is applied.

The fiber bundle that has left the uneven roller is drawn to a grounded collecting surface while spreading out into a conical shape due to the electrostatic self-repulsion of the constituent fibers. At this time, by surrounding the space between the uneven roller and the collection surface with a metal plate or the like and applying an electrostatic voltage to the core metal plate, the size of the conical spread can be regulated.

The surface that collects the opened #fiber bundles is grounded.

As a result of this, an electric charge is formed on the charged fiber bundle from the uneven roller toward the collection surface, and the charged fiber bundle is drawn toward the collection surface as if being attracted.

When the web is produced continuously, the collection surface may be the surface of a rotating conveyor belt as shown in FIG. 1 or the surface of a pair of rotating drums as shown in FIG. In particular, in the latter case, the fibers tend to be arranged in the thickness direction of the web, making it suitable for producing bulky webs. Alternatively, if this Kuep is pressed into a sheet, a very uniform sheet can be obtained.

The diameter of the pair of drums is preferably greater than or equal to tsem. If it is too small, the collection of fibers will be incomplete. , #
The distance between 1 and 2 doms depends on the weight of the web to be obtained, but when trying to obtain a web of about 1001 or more, the distance should be 2 (IJ or less, more preferably 3 cm or less). .

The surface or near surface of the cough pair drum is conductive and electrically grounded. Types of surface insulation materials 11
Although it depends on the condition, it is desirable that a conductive layer exists from the surface to a depth of at least l'101s, preferably 1111ml, and that this layer is electrically grounded in order to collect the iron fibers. It has been found. If it is preferable that the speed at which the charged fibers are neutralized is slow (for example, when producing a web with a large basis weight), it is effective to cover the surface layer of the drum with a porous insulating material, etc. It is.

According to the present invention, fiber bundles can be opened extremely uniformly, so a very uniform and bulky web can be obtained, and a web for thermal insulation batting with excellent cushioning resistance, heat retention, and drapability can be obtained. can get.

Furthermore, when the web is heat-treated to cause the constituent fibers to develop three-dimensional crimp, it is possible to obtain a heat-retaining batting with even greater bulkiness and heat-retaining properties.

The fiber bundle may be a mixture of different A, 33 polymers, and if B has a lower melting point than A, the resulting web may be
By heat-treating the melting point of B to a temperature higher than the melting point of
Crosslinking of the fibers occurs, resulting in a highly cushion-resistant web. If this web is hot pressed at a temperature below the melting point of A and above the melting point of B, a nonwoven fabric with excellent uniformity and improved strength can be obtained.

Of course, it is also possible to produce the above-mentioned crosslinked structure web or sheet by adding a binder such as polyacrylic ester to the resulting web.

By heating the limb collecting surface, the fibers may be three-dimensionally rolled at the same time as the fibers are collected on the collecting surface. By this method, it is possible to shorten the process, reduce equipment costs, and improve bulkiness.

The present invention will be specifically explained below with reference to Examples, but the scope of the present invention is not limited thereto.

Example 1 According to the method disclosed in Japanese Patent Application No. 55-38993, the cap was made into a 30-mesh plain weave wire mesh with a width of 5 o 1. From the molding area of thickness 2 C1, melted polyethylene terephthalate (chip intrinsic viscosity - 172) is discharged using a screenie extruder, and cooling air is blown to form a fibrous rivulet to obtain a fiber bundle, which is then continuous. Then, the bundle was passed through a rattling guide and passed through a hot plate with a surface temperature of 125°C that maintained the width of the bundle, and was stretched approximately 25 times, with an average single yarn fineness of 3 denier and a total of 50,000 denier. Obtained a denier bundle. Further, this bundle was continuously opened by 14 people while maintaining its width in a fiber opening device as shown in FIG. 1, to obtain a spread web having good bulk and uniformity.

The dose line conditions are as follows.

(2) Conditions of bundle and web: Introduction speed of bundle 2011L/min Charge voltage after passing friction rod (2) of bundle +40KV Area weight of obtained opening web t s o t/ze Obtained opening Specific volume of fiber web aoai/f Diameter of friction rod (2) 2 cm φ1141 Material of rod (2) Suden V steel Shape of uneven roller (4) Diameter 30G, φRa L
ljlml Convex material of uneven roller (4) Voltage applied to conductive layer of polyurethane uneven roller (4) 18
Peripheral speed of KV uneven roller 4om/min belt (
7) Peripheral speed L5 weight/min Example 2 In the device as shown in FIG.
(8) was replaced with (2), (3), and (4) in Fig. 3, and the same fiber bundle as in Example 1 was opened and complemented while heating the surface of the collection drum (2) with an infrared heater. At the same time as the bundle was collected, it was heat-treated near the surface of the core collection drum to three-dimensionally crimp the fibers of the fiber bundle and then taken out as a web.

The web showed a high recovery rate of 75 yen according to the Noodle-futon cotton test method (JlB-200).

BRIEF DESCRIPTION OF THE DRAWINGS In FIG. 1, 1 is a fiber bundle, 2 is a friction rod for applying static electricity to the fiber bundle, and 3 is a row 2 and 4 for feeding the fiber bundle, which is an uneven roller according to the present invention. 5 is an opened fiber bundle, 6 is a roller that grips the belt,
7 is a belt, 8 is a ground electrode, 9 is a generated web, and a indicates a point where the fiber bundle is scattered from the uneven roller (4). FIG. 2 shows a case in which #i uneven rollers are used as a pair. For example, roller (3) is used instead of roller (4) in FIG. 1 is a fiber bundle, 2 is a friction rod. 4 represents the opened fiber bundle. FIG. 3 shows the case where a pair of drums is used as the collecting surface. For example, a drum (2) is used instead of the belt 7 in FIG. l is an opened fiber bundle. 3 is a belt, 4 is a static eliminator, and 5 is a generated web. The positive or negative voltage applied to the concavo-convex row 2 is determined depending on the electric charge carried by the fiber bundle. Procedural amendment (method) March 1980, 1r day Dear Commissioner of the Japan Patent Office 1, Indication of the case Patent Application No. 1982-157560 2, Name of the invention Method and device for opening fiber bundles 3 Case of the person making the amendment Relationship with Patent Applicant 1-11 Minamihonmachi, Higashi-ku, Osaka (300) Teijin Limited Representative Tomoo Tokusue (1) From page 24, line 11 to page 25, line 8 of the specification [1 in Figure 1] Fiber bundle...... (omitted)
・・・・・・・・・Negativity is determined according to the electric charge that the fiber bundle carries. [FIG. 1 shows a schematic diagram of the fiber opening method and apparatus of the present invention. In FIG. 1, 1 is an unopened fiber bundle, 2 is a friction rod, and 3 is a feed roller. 4 is an uneven roller, 5 is #Jl fiber in the opening zone, 6 is a belt roller, 7 is a belt, and 8 is an electrode plate. 9 is the web that has not been accumulated after opening, and a is the point where the electric field that directs the charged fiber bundle toward the collection surface becomes strong. FIG. 2 shows a schematic view of another shaft device included in the present invention up to the opening zone. 1 In FIG. , and 4 indicates the edge N of the opening zone. FIG. 3 shows an example of a collection surface included in the present invention. Figure 3 1
2 is the fiber M in the opening zone, and 2 is the first collection surface (a pair of drums) that is in contact with the ground. 3 is a second collection surface (belt) which is grounded, 4 is a static eliminator, and 5 is a web accumulated after opening. ” he corrected. Paste 1

Claims (1)

[Scope of Claims] L In producing a web structure by applying static electricity to a fiber bundle, opening and collecting it in an electrostatic field, the surface roughness of the static electricity-applied fiber bundle (Ra) is 0.031EI. When the fiber bundle separated from the roller is guided to a rotating roller in the order of ~30 and the fiber bundle is guided to a collecting surface, the fiber bundle is directed from the roller toward the collecting surface in the area between the roller and the collecting surface. An electric field is formed that acts on the bundle, and the fibers that make up the fiber bundle are opened in that area using the repulsive force caused by static electricity, and the opened fiber bundles are collected on a collection surface to form a web. 2. A method for opening a fiber bundle, characterized in that the collecting surface for collecting the opened fiber bundles and forming a web is the surface of a rotating drum, and heating the core surface to form a web. 2. The method for opening fibers according to claim 1, wherein the fiber bundles are collected and crimped at the same time. λ (IL) A means capable of imparting static electricity to the fiber bundle, a roller (surface roughness Ra for opening the fiber bundle imparted with zero static electricity and guiding it to the following area) of o, oa+o+ to 30fi, (C ) an area where an electric field is formed between the roller and a collection surface of the spread fiber bundles, where the fiber bundles move and provide a force to spread the fibers; and (cl) a region where the spread fiber bundles are collected to form a web. A device for opening fiber bundles consisting of a collecting surface. 4. The fiber opening device according to claim 3, wherein the carcasses collecting surface is the surface of a rotating drum.