JPS63162012A - Production of filter cloth for solid-liquid separation - Google Patents

Abstract

PURPOSE:To increase the blocking rate of fine particles without deteriorating the water permeability of the title filter cloth and to prolong the service life of the filter cloth, by bonding and integrating a specified reinfocing cloth with the satin fabric which has been gigged, impregnated with urethane bound, and then further gigged. CONSTITUTION:The crimped yarn of 50-500 denier is used as a warp, and the multifilament consisting of the extra fine fibers of <=10mum or spun yarn is used as a woof to form a satin fabric base material consisting of synthetic fiber. First gigging is applied to the base material. When the gigged layer of the extra fine fibers is formed to some extent, the material is impregnated with urethane and bound, and gigging is additionally carried out. The reinforcing cloth having higher water permeability and wear resistance than the satin fabric is laminated on the additionally gigged satin fabric, a powdery high polymer substance consisting of a low-m.p. polymer is sporadically interposed between both materials, the materials are heated to a temp. above the m.p. of the low-m. p. polymer to melt the polymer and both materials are bound and integrated.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a method for manufacturing a filter cloth for solid-liquid separation, and more specifically, it relates to a method for manufacturing a filter cloth for solid-liquid separation. ! Concerning a method of manufacturing cloth.

[Prior art 1] Conventionally, an endless filter cloth carrying a solid liquid is run on a pressing section consisting of a transfer drum and a pressing roll, and the liquid component in the solid liquid is squeezed out by the pressing section, while remaining on the line Iti. The cake is transferred to a transfer drum and collected by scraping it with a scraper.The filter cloth traveling type dehydrator (belt press type dehydrator) or the liquid component is removed by gravity or vacuum suction without squeezing. Filter and remove the remaining half-cake-like ingredient.
Devices such as solid-liquid valve II1, such as filter cloth traveling type filters that collect water from above, are used in various fields. The first reading related to this invention is J: Eel solid-liquid separation device! f
This is what I use for fi.

As the filter cloth used in the solid-liquid separator as mentioned above,
Conventionally, for example, JP-A-59-115720, JP-A-60-31'8''11, JP-A-60-4401
Publication No. 3, Japanese Patent Publication No. 60-44014@publication, Japanese Patent Publication No. 6
Publication No. 1-164613, Japanese Unexamined Patent Publication No. 1-171516
No. 61-174912, JP-A-61-174912
174915, Japanese Patent Laid-Open No. 61-174916M, etc. are known. This conventional embroidery 1 has a raised line layer of ultrafine fibers having a thickness of 0.1 to 10 .mu.TH formed by raising mainly weft threads of the base material on the surface of a textile base material. This filter cloth is
A linear layer is formed by the naps of ultrafine fibers with a diameter of 0.1 to 10 μm, so the gaps between the naps are very small, and even fine solid components can be blocked.In other words, the conventional 'd7 tf
The fabric serving as the base material of i has a weft of 0.1 to 10 μrn.
A multifilament or spun yarn made by bundling ultrafine fibers is used, and a crimped yarn with high elasticity is used as the warp yarn in the longitudinal direction to sufficiently raise the JlflI yarn. This is because when crimped yarn is used, the arranged warp yarns shrink in the width direction of the base material at the same time as the weft yarns are raised, making it easier to form a dense structure. Further, as the base fabric, a satin fabric is used because a structure in which the wefts are floating is easier to raise.

[Problems to be solved by the invention] However, in the conventional cotton i
The following issues remain.

In other words, in order to increase the rejection rate of fine particles in the solid-liquid to be filtered, it is necessary to increase the thickness of the linear layer consisting of the napped microfibers. However, if the number of naps is increased to increase the number of naps, the width of the filter cloth will shrink as described above.
There was a problem that the warp density increased and the woven structure became too dense, resulting in a large decrease in water permeability.

In addition to this problem of reduced water permeability, the conventional filter cloths mentioned above still do not have sufficient prevention of deformation (especially elongation) when used in solid-liquid separation equipment, and they cannot be used as endless filter cloths. There remains the problem that the durability of the surface that contacts and covers the guide rolls and the like during circulation in the device is insufficient, and a sufficient lifespan cannot be obtained. Regarding this problem, although the application has not yet been published, the applicant has previously proposed a method in which a filter layer I and a reinforcement 15 having high water permeability that does not impair the water permeability of the filter fabric are laminated. , K for solid-liquid separation, in which both are bonded together using a powdery polymeric substance made of a low-melting point polymer.
G4fi is proposed.

The purpose of this invention is to improve the contradictory characteristics of rejection rate and water permeation rate in conventional filter cloths as mentioned above, by increasing the napping effect by raising the fibers without significantly shrinking the fibers in the width direction, and by increasing the water permeation rate. The object of this invention is to improve the rejection rate of fine particles without reducing the filter cloth, and also to improve the durability of the filter cloth and extend its life.

[Means for solving the problem] The method for producing a filter cloth for solid-liquid separation of the present invention that meets this objective is as follows:
The floating side of the weft of a synthetic fiber satin fabric base material with crimped yarn as the warp and a bundle of ultra-fine fibers as the weft was raised, and then the raised satin fabric was impregnated and fixed with urethane. Afterwards, additional raising is performed on the raised surface, and a reinforcing fabric having higher water permeability and LF abrasion resistance than the satin fabric is laminated on the additionally raised satin fabric, and the sateen fabric and the reinforcing fabric are laminated. The additionally raised satin fabric is obtained by interposing a powdery polymeric material made of a polymer with a melting point lower than that of both of them, and melting the powdery polymeric material by heating above the melting point of the low melting point polymer. It consists of a method of bonding and integrating reinforcing cloth.

The satin weave used as the base material has 50 to 500 denier crimped yarn as the warp, and multifilament or spun yarn made of ultrafine fibers with a thickness of 10 μTn or less as the weft. It is preferable that 3 to 8 weft yarns are suspended. This is because if the satin weave has a loose texture, it can be sufficiently raised.

The ultrafine fiber has a thickness of 0.1 to 10 μIn,
If it is more than that, it will not be possible to form a rigid and flexible kFH, and the gaps between the raised fluffs will be large, and the rejection rate of fine solids will be poor. 0
．． If the thickness is less than 1 μm, the raised fluffs will be severely worn and a stable solid-liquid valve head 1 cannot be formed.

Further, as the synthetic fiber crimped yarn for the warp, false twisted yarn, push-type crimped yarn, conjugate type crimped yarn, etc. can be used, and elasticity is required. Considering napping properties, false twisted yarn is most preferable. In other words, if you use crimped warp threads, they will shrink in the width direction at the same time as they are raised.
If you want to get a detailed structure, you need to cover it.

The raising is performed by directly raising the surface of the base material made of synthetic fiber satin fabric using a raising machine.

In contrast to this raised yarn, the weft yarn has a single yarn thickness of 0.1 to 10 μm.
It is preferably made of spun yarn (double yarn or triple filament) or multifilament of ultrafine fibers, with a number of single yarns of 200 to 50,000, and a twist of 9,100 to 400 times/m. However, there are 20 to 100 weft threads/
The fabric is arranged in the width direction of the cotton fabric with a density of cm, while the warp yarns are arranged in the longitudinal direction (running direction of the filter), and the weft yarns are mainly raised in the longitudinal direction of the fabric to form a raised line layer.

As a result of the naps being raised in the longitudinal direction, the naps either lie generally facing in that direction or, in use, are expanded so that the naps face in the opposite direction to the running direction of the filter cloth. Note that the reason why the weft yarns are mainly raised is that the warp yarns are subjected to a large expansion tension during use, and if they are raised, the strength of the filter cloth will be reduced.

Methods for forming naps on the substrate include needle A5, sand paper, sand cloth, sand net, grindstone, steel brush, polishing brush, Nandolol, carnet, sand honing, and the like. Among these, one using a napping machine using cloth is preferable, especially one using a French-style napping machine.
It is preferable to pass about 0 to 30 times. The additional raising is preferably carried out by a raising machine using a cloth, and it is particularly preferable to pass through a French raising machine about 5 to 15 times. The reason why this range is preferable is that even if the number of naps is increased more than this, the number of naps will not increase so much, but the wear of the weft yarns will increase, which will have a serious effect on reducing the strength of the filter cloth.

In this invention, first, the first
When a raised layer of ultrafine fibers has been formed to some extent, urethane is impregnated and fixed, and then additional raising is performed. It is preferable that the first raising is carried out to such an extent that the ground structure of the satin weave is no longer visible due to the raised layer of ultra-fine fibers, and this first raising increases the warp density in the width direction of the base material to about 10 to 20.
% increased. If the number of naps is not increased further, there will be a problem that the warp density becomes too high and the water permeability of the filter cloth decreases significantly, which is the problem of the decrease in the strength of the filter cloth described in (a) above.

Therefore, in the present invention, after the first raising is performed an appropriate number of times, urethane is impregnated and fixed to fix the warp density, and then additional raising is performed.

For urethane impregnation, a dimethylformamide solution of polyurethane obtained from polyether, polyester, methylene diphenyl diisocyanate, and methylene hisaniline can be applied from the bottom of the filter cloth using a gravure coater or as a polyurethane aqueous emulsion. .

Alternatively, the base material may be simply immersed in an aqueous polyurethane emulsion, and after immersion, excess urethane may be removed using a squeezing roll or the like. Furthermore, a method of simply applying and impregnating urethane by spraying may be used.

The impregnated urethane is dried and fixed.

Drying is performed, for example, by passing the urethane-impregnated base material through a tenter, and if necessary, excess urethane may be blown off in a circular motion after drying.

In the urethane-impregnated and fixed base material obtained in this way, the amount of urethane relative to the textile base material is ultimately 2 to 2.
It is preferable to have a culm degree of about 10%.

Additional raising is performed on the satin fabric base material which has already been subjected to the first raising of urethane impregnation and fastening.

After being impregnated with urethane and fixed, the cotton fabric is fixed and stable by the tissue or urethane, so when it is raised (raised) and additionally raised, there is no shrinkage in the width direction, the warp density increases, the woven structure becomes denser, and water permeability increases. The pilonidal layer is increased without causing a phenomenon such as a decrease in volume.

This additional raising after impregnating with urethane can improve the rejection rate of fine solid particles by about 10 to 20% without reducing water permeability, and when the rejection rate is constant, water permeation can be increased by 3%.
It can be improved by about 0 to 50%.

Next, the reinforcing fibers are laminated on the additionally raised satin fabric with high water permeability and high 1L rate, which is obtained as described above, and are bonded and integrated.

Reinforcement A has higher water permeability and abrasion resistance than the additionally raised satin fabric.

Due to its high water permeability, by laminating reinforcing fabric,
The water permeability of the satin fabric is hardly impaired. In addition, due to its high abrasion resistance, the high abrasion resistance of the reinforcing cloth is directly demonstrated, especially when the filter cloth is installed so that the reinforcing cloth is located on the side of the guide roller of the device, and the durability of the filter cloth is increased. is improved.

The reinforcement 15 having such characteristics is made of a woven or knitted fabric, and its constituent yarns include natural fibers and synthetic fibers.
Spun yarns such as i-fibers, filament yarns, etc. can be used, but spun yarns are preferred from the viewpoint of adhesion to satin fabrics, abrasion resistance, etc. In addition, the structure of the reinforcing fabric is plain woven gauze using spun yarn for warp and warp yarns, filament yarn for warp yarn,
Plain woven fabric using spun yarn, tricot using spun yarn, etc. can be used.

Adhesive integration is performed as follows.

In other words, a powdery polymeric substance made of a low melting point polymer is interposed between the added satin fabric and the reinforcing cloth in the form of dots, and the material is melted and bonded by heating to a temperature higher than the melting point of the low melting point polymer. In addition to providing excellent adhesion, the adhesion points between the satin fabric and the reinforcing layer can be scattered, resulting in excellent water permeability and filtration without impairing the filtration performance of the satin fabric, which has a napped layer. Performance can be maintained.

FIG. 1 is a schematic perspective view showing an example of the filter cloth of the present invention. It is unified by this.

Therefore, in the filter cloth of the present invention, the satin fabric side only needs to maintain filtration performance, while the sleeve strength 45 only needs to maintain durability, and since the satin fabric side and the reinforcing fabric can be optimized separately, the filtration performance, It is possible to obtain a filter cloth with excellent durability.

Specifically, the above-mentioned satin fabric and reinforcing fabric are bonded and integrated, for example, as shown in FIGS. 2 and 3.

FIG. 2 shows a state in which the reinforcing cloth b is placed in a heat box 4 while a powdery polymer substance 2 made of a low melting point polymer is scattered on the reinforcing cloth b via a gravure roller 3. . The heat box 4 is heated to a temperature higher than the melting point of the low melting point polymer, and the powdery polymeric substance 2 is melted and fused and fixed to the reinforcing surface 11i.

FIG. 3 shows the reinforcing cloth 1q prepared above, with the side of the reinforcing cloth 1b on which the powdered polymeric substance 2 is fused and fixed so that the opposite raised side of the satin cloth 1a is smaller, and the satin cloth 1a is A state in which the paper is supplied so that it is located on the napping part side of 1a or next to the calender roller 5 is shown.

The calender roller 5 is composed of a gravure roller 3 (such as a roller having a concave portion in a resin portion that is in close contact with the surface of an iron roller) and a steel heating roller 5. The fabric is heat box 6
While being preheated, the reinforcing fabric is directly pressurized and heated by a calender roller 3 heated above the melting point of the low melting point polymer, and the powdery polymeric substance 2 is melted to form the satin fabric 1.
A and the reinforcing cloth 1b are integrated with each other by adhesion, and the brocade F of this invention
is obtained.

In addition, the filter cloth of the present invention is produced by fusing and fixing a powdery high molecular substance 2 of a low melting point polymer to the opposite side of the satin fabric 1a, and then twisting the satin fabric 1a and the reinforcing fabric 1b together and applying a calender roller. It can also be manufactured by supplying the adhesive to the substrate No. 3, heating it under pressure, and adhering it.

In addition, the filter cloth of the present invention is produced by interspersing a powdery polymer substance 2 of a low melting point polymer between the satin fabric 1a and the reinforcing cloth 1b, and supplying it to a calender roller 3, heating it under pressure, and bonding it together. It can also be produced by continuously converting and converting in one step.

Next, more specific embodiments of the present invention will be described.

(Example 1) Wefts are 20/23 spun yarns made by spinning 18-core multicore composite fibers containing polyester as an island component and boris dylene as an additional component, and 38 yarns with a single yarn fineness of 5 denier are used. 1 q of 5-ply satin fabric with bundled false-twisted threads as warp threads was prepared.

Next, the sea component of the weft was removed using trichlorethylene as a solvent to obtain a fabric whose weft was a bundle of ultrafine fibers with a thickness of 3 μm.

Next, the above-mentioned fabric is passed through a French-style napping machine with 11 fabrics 16 times, and the wefts are mainly napped in the warp direction, resulting in approximately 100 naps.
A raised fabric having 0 cline layers/# was obtained.

This was immersed in a solution containing urethane emulsion, and the excess liquid was squeezed out using a mangle device. After drying at 120'C and then heating at 180'C to react the urethane, it was heated at 20°C using a circular device. A filter cloth impregnated with urethane having a urethane adhesion amount of 5% was obtained by soaking it in hot water (C) and drying it.

The resulting filter cloth has a water permeability of 4rn! /cfflsec, the inhibition rate of fine diatomaceous earth was 40%. This filter cloth was roughly passed through the above-mentioned napping machine 10 times to obtain a filter cloth of the present invention. The performance of the obtained filter cloth is that the water permeability is 4ml/cr.
With iSec, the rejection rate of fine diatomaceous earth is 60%, and the water permeability,
Both the rejection rate was superior to that of conventional filter cloths that were simply raised.

In addition, the warp and weft are made of high tenacity spun polyester yarn with a cotton count of 30 as a reinforcing material, with a warp density of 24 yarns/in.
A plain woven fabric with a weft density of 22/10 was prepared.

Next, black ink equivalent to a basis weight of 30 ci/rd of polyethylene adhesive (powder) with a melting point of 130°C was applied onto the reinforcing fabric part using a gravure roller at a density of 900 pieces/in2, and the mixture was placed in a heat box. It was heated to 140'C and fused and fixed to the reinforcement A[j].

Next, the raised fabric and the processed reinforcement 45 are placed together, and fed to a heating calendar machine so that the raised part is located on the side of the calendar C1, and the polyethylene adhesive of 45 parts of the reinforcement is melted. By adhering and bonding with the brushed satin fabric, the filter fabric of this invention weighs 1q.

Next, in order to confirm the performance of the filter cloth of the present invention in use in a solid-liquid separator, the filter cloth was cut into a width of 30 cm and a length of 2.5 m with the warp direction as the longitudinal direction. were sewn together to obtain an endless filter cloth 1 as shown in FIG. Rubber belts 7 with holes 8 are sewn to both ends of the endless filter cloth 1 in the width direction to enable running drive or right and left phase matching during running.

Next, the endless filter cloth was applied to the belt press type dehydrator 11 shown in FIG.
A dehydration test was conducted in water with a vacuum degree of about 900 M in the vacuum suction tank 21 and with a pressing force of about 60 kg to each transfer drum. In the ↓ device 11 shown in the figure, the filter cloth 1 is connected to the drive roll 1.
2 and h-id rolls 13, 14, 15, and a certain amount of pressure regulated by these rolls 12, 13, 14, 15, a pressing roller 16, 17, 18, and a transfer drum 19. Run and circle on F/lJ in the direction of the arrow. 20 is a solid liquid to be processed, the liquid component is sucked by the reduced pressure suction tank 21 through the moving part t51, and the solid component is removed if, l! It is left on cloth 1 and filtered. The solid components are squeezed onto the transfer drum 19 by squeeze rolls 16, 17, 18 and scraped off by the scraper 22.

As the solid liquid, water was used and clay with an average particle size of about 20 μm was used, and the concentration of the clay was adjusted to about 100 hly/ρ. 80ρ
/min. The particle size molecule ti of the clay in the above solid liquid measured using a Coulter counter is approximately 1 to 50 μm.
So, it was distributed over a fairly wide range of areas.

As a result of the test, the rejection rate by the filter cloth 1 was 95%, and the components recovered by scraping with the scraper 22 were about 50% solids. Further, the transfer rate to the transfer drum 19 was approximately 95%, which was extremely high. Roughly speaking, the particle size distribution of clay in the solid component measured using a coal tanker was approximately 1 to 5 .mu.m, and most of the particles larger than 5 .mu.m were removed.

Further, even after approximately 2,000 hours of operation, the above-mentioned performance did not change at all, and no abnormalities were observed in the filter cloth, indicating that it had remarkable durability.

In addition, the "reading cloth" obtained by the method according to the present invention has an ultrafine fiber napped cotton layer with a large amount of naps without reducing the amount of water permeation due to additional naps, so it has high solid-liquid separation efficiency. In addition, the reinforcement material provides sufficient durability and deformation prevention performance, resulting in high running stability and excellent operability.Furthermore, the permanent deformation and wear of the embroidery wire is small, so the processing capacity is stable. It also has a long life.As a result, it can be used for various solid-liquid separations.For example, it can be used for so-called suspended sludge discharged from activated sludge treatment equipment,
It can be used to concentrate and dehydrate sludge, scum, flocs, wash water, concentrated sludge, etc. generated by wastewater treatment, such as so-called fixed sludge discharged from a biofilm treatment device. Specifically, sludge generated from water and sewage treatment, excess sludge generated from septic tanks, overlying sludge generated from human waste treatment, scum generated from HO pressure flotation operations, coagulated flocs and flocculated sediment flocs generated from industrial wastewater treatment, These include backwash water from various filtration devices such as sand filters, and sludge condensed in screen devices.

In addition, for example, paper pulp manufacturing industry, food manufacturing industry, alcoholic beverage industry,
It can be used to recover solid components in various manufacturing industries, such as the brewing industry of miso and other products.

Furthermore, it can be used to purify ponds and rivers, remove algae at water purification plants, and prevent rivers and lakes from becoming contaminated during dredging.

[Effects of the Invention] In the method according to the present invention, after the first raising, urethane is impregnated and fixed, and then the satin fabric base material is increased by additional raising to increase the raised layer of ultrafine fibers. The reinforcing fabric, which does not impair water permeability and has excellent abrasion resistance, is bonded and integrated in dots, so it is possible to increase the nap line layer while preventing an increase in warp yarn density during additional raising, making it possible to increase water permeability. It is possible to improve the rejection rate of fine particles without reducing the amount of particles, and at the same time, the durability can be greatly improved by reinforcing the material, providing high-precision filtration performance and an extremely long service life. High performance cotton fabric can be obtained.

Additionally, the reinforcing fabric can deform and stretch the white of the cotton fabric.

Since this can be prevented, stable running of the filter cloth in the solid-liquid separator can be achieved over a long period of time, making it easier to operate the device and stabilizing the processing performance.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a cotton fabric produced by the method of the present invention, FIGS. 2 and 3 are schematic side views showing the state in which a cloth is manufactured by implementing the present invention, and FIG. FIG. 5 is a schematic perspective view showing one embodiment of the filter cloth obtained by the method, and FIG. 5 is a schematic side view of a belt press type dehydrator using the filter cloth according to the present invention. 1. ...Filter cloth 1a...Additionally brushed satin fabric 1b.
・・・・・・・・・Reinforcement cloth

Claims (1)

[Claims] The floating side of the weft of a synthetic fiber satin fabric base material with crimped yarn as the warp and a bundle of ultra-fine fibers as the weft was raised, and then the raised satin fabric was impregnated and fixed with urethane. Afterwards, additional raising is performed on the raised surface, and a reinforcing fabric having higher water permeability and abrasion resistance than the satin fabric is laminated on the additionally raised satin fabric, and a reinforcing fabric is layered between the satin fabric and the reinforcing fabric. The additionally raised satin fabric is obtained by interposing a powdery polymeric material made of a polymer having a melting point lower than that of both of them, and melting the powdery polymeric material by heating above the melting point of the low melting point polymer. A method for manufacturing a filter cloth for solid-liquid separation, characterized by integrally bonding and reinforcing cloth.