JPS62125815A - Filter cloth for solid-liquid separation and its production - Google Patents

Abstract

PURPOSE:To increase filter performance and durability and to obtain stable solid-liquid separation efficiency by bonding a filter cloth which has the standing crops having direction property on a fabric base having high water permeability and wear resistance by means of a low-m.p. powdery high polymer and integrating both into one body. CONSTITUTION:A filter layer part 1a is formed by arranging properly the standing crops of extremely fine fiber having >=3X10<3>cm<2>/g specific surface area which are obtained by raising a base material consisting of a fabric, a knitted web and a nonwoven fabric of synthetic fiber in the nearly unidirection and allowing these to lie on the base material. A fabric base 1b consists of the fabric and the knitted web wherein spun yarn and filament yarn, etc., of natural fiber and synthetic fiber are used. Powdery high polymer substance consisting of low-m.p. polymer is interposed in a dotty shape between the filter layer part 1a and the fabric base 1b and a filter cloth for solid-liquid separation is obtained by pressurizing and heating these with a calender roller heated at m.p. of this polymer or above to melt the high polymer substance and thereby bonding into an integrated body.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filter cloth for solid-liquid separation, and more specifically, it is used when dewatering or filtration is performed while rotating an endless cloth carrying a solid-liquid. This article relates to effectively used ffi and its rational manufacturing method.

[Prior Art] Conventionally, an endless filter (h) is run through which a solid liquid is placed on a pressing section consisting of a transfer drum and a press roll, and the liquid components are squeezed out in the pressing section, and the so-called A belt press type dehydrator transfers solid components to a transfer drum and collects them by scraping them with a scraper, and filters liquid components using gravity without squeezing the solid liquid on the filter 5. So-called solid-liquid separators, such as filters that collect remaining solid components using water nozzles or scrapers, are used in various fields. In these solid-liquid separators, especially in filters, a pressure reducing part is provided near the solid-liquid supply part and opposite the back surface of the filter layer (2) to suck out liquid components and improve separation efficiency. There are also things.

The filter layer of the present invention is used in such a solid-liquid separation device.

Conventionally, the filter cloth used in the solid-liquid separator as described above is one in which thick short fibers with a thickness of 30 to 100 μm are flocked on the surface of a textile base material with an adhesive to form raised naps that are inclined in one direction. , (2) A fabric is known in which thick raised fibers with a thickness of several tens of microns are formed by raising the plugging material on the surface of a textile base material.

These conventional 'fa cloths obtain the necessary strength as a filter cloth through the woven base material, and at the same time, the naps on the surface prevent solid components from entering the cloth. In other words, it forms a piloerection or cline. However, such conventional
Both have the drawbacks of low solid-liquid separation performance and poor transferability.

In other words, in conventional method d and imitation ii above, raised fibers are formed when flocking with adhesive, and the density of the raised fibers cannot be made so high in order to prevent the holes in the base material from being buried by the adhesive. , and the thickness of the raised hairs is very thick, 30 to 100 μm, so the gaps formed between the raised hairs, that is, the eyes, are quite large, and fine solid components can easily pass through the gaps.

Therefore, when using this conventional filter cloth, it is essential to coarsen the solid component by using a flocculant, which not only increases running costs but also poses problems such as toxicity depending on the type of flocculant. . The use of flocculants also increases the amount of solid components.

Furthermore, the conventional filter cloth (2) has very thick naps of 30 to 100 μm in thickness, so it is rigid and difficult to lie on the surface of the substrate. Therefore, the gaps formed between the raised fluffs are very deep, and if solid components get into those gaps, it will be difficult for them to come out and the filter cloth will become clogged. This tendency is very remarkable, partly because the piloere is rigid and tends to pierce solid components.

In other words, the fact that the piloerection is difficult to lie down also means that the cline formed by the piloerection is bulky. Therefore, airtightness is poor when vacuum suction is performed. Further, since the gaps between the naps are deep, the surface has large irregularities, and the thickness of the solid component on the filter cloth becomes uneven, so that pressure at the pressing part is not uniformly applied.

For the reasons mentioned above, conventional filter cloth (3) has very low solid-liquid separation performance. If the solid-liquid separation performance is low, not only will a large amount of solid components be included in the liquid component, but also the amount of water in the recovered solid component will increase, requiring a large amount of energy for post-processing such as incineration. Become.

In addition, as mentioned above, in the case of conventional filters (■), the solid components that have gotten into the nape are difficult to remove.

Therefore, when the filter cloth is separated from the transfer drum, the solid components are drawn back to the filter layer E side by the raised fluff, resulting in poor transferability.

On the other hand, the above-mentioned conventional filter cloth (2) has considerably larger and deeper gaps in the nape than the conventional filter cloth (2). Therefore, this conventional filter cloth (2) also has low solid-liquid separation performance and poor transferability.

On the other hand, the inventors of this invention previously filed a patent application filed in 1983-22.
In the No. 6384 application, a new type of recognition engine was proposed. This filter layer is the cline layer on the surface of the wood, with a thickness of 0.1~
It is made of ultra-fine fibers with a diameter of 10μ.

The above filter cloth is made of napped microfibers with a thickness of 0.1 to 10 μm.
Because of the formation of f and l, the gaps formed between the raised floes are very small, and even fine solid components can be blocked. In addition, the napped fibers of microfibers are very flexible and lie easily, so the gaps between the napped fibers are shallow, and the solid components are deformed and inserted into the gaps when handled (they do not become difficult to bulge out) and are less prone to clogging. The fact that the piloerection is easy to lie down also means that the cline formed by it does not become bulky and the filling rate of the piloerection is high, so airtightness can be maintained when vacuum suction is performed.These reasons. The above filter cloth has a very high solid-liquid separation efficiency.

Furthermore, the transferability is also high because the gaps between the piloerection gates are small and it is difficult for solid components to enter the gaps, and the piloerection is flexible and prevents it from digging into the solid components.

In this way, the eV 15 proposed in the above application is an excellent product that does not have the drawbacks of the conventional filter cloths ① and ② mentioned above, but because the nap is necessarily thin and pliable, it is difficult to use it. Another problem is that the solid-liquid separation performance is unstable because the fibers are pushed into the grooves of the base material, making it difficult to stand up again, and the raised fibers become entangled.

Therefore, in order to improve this problem, the inventors of the present invention proposed that the raised fluff forming the a-layer of the filter cloth have directionality,
In addition, we have proposed a filter cloth whose directional index is 1°2 to 10.

In the filter cloth proposed in this application, the naps forming the cline have directionality, and the directional index is 1.2 to 10, so the naps are pushed into the eyes of the base material during use. It is possible to prevent the raised floes from becoming difficult to stand up again or from getting entangled, and stable solid-liquid separation efficiency can be obtained.
A filter cloth with raised microfibers alone lacks durability;
There is a problem that it cannot be used for a long time.

In order to solve this problem, the inventors of the present invention and others proposed a combination of the KW layer and the base in Japanese Patent Application No. 60-12473.
We proposed a filter fabric in which the filter layer and the base fabric were layered together, and this improved the durability, but the problem was that the filtration performance deteriorated, and the peel strength was still insufficient and the filter layer and base fabric could come apart after long use. This had the disadvantage of causing peeling.

(Problems to be Solved by the Invention) This invention was made in order to improve the above-mentioned problems, and its purpose is to provide excellent filtration performance and sufficient durability for long-term use. The purpose of the present invention is to provide a filter cloth for solid-liquid separation with improved water resistance and durability, and a rational method for producing the same.

(Means for Solving the Problems) The filter cloth for solid-liquid separation of the present invention that achieves the above object is a filter cloth for solid-liquid separation in which the stratified portion and the base portion are overlapped and integrated. The layered portion has raised fluffs made of synthetic fibers, the raised fluffs have directionality in the longitudinal direction of the filter cloth with a directionality index of 1.2 to 10, and the specific surface area of the raised fluffs is 3 x 103 ot.
f/Cl or more, while the base fabric has higher water permeability and abrasion resistance than the filter layer part, and the layered part and the base part substantially contain a polymeric substance having a lower melting point than both. It is characterized in that it is essentially point-bonded by being present in a shape. Further, the method for manufacturing a filter cloth for solid-liquid separation of the present invention includes:
A powdery polymeric material made of a polymer with a melting point lower than that of the two is interposed between the layered part and the base fabric, and heated under pressure with a calender roller heated to a temperature higher than the melting point of the low melting point polymer to form the powdery material. The feature is that the laminated portion and the base fabric are bonded and integrated by melting a polymeric substance.

(Operations and Examples) The present invention will be described in more detail below based on the drawings and the like.

To explain the single-piece IM aspect of the filter cloth of the present invention, in FIG. 1, the filter @1 is sewn together along the dotted lines and processed into an endless shape. Perforated belts 2.3 are sewn to both ends of the filter cloth 1 to stretch the filter layer 51 and run it without meandering. It is preferable that the belt 2.3 has some elasticity in order to stretch the filter cloth 1 without causing wrinkles.
It is preferable that No. 3 is made of a synthetic fiber fabric as a core material and a bonded body of the core material and rubber.

The filter layer h is composed of a filter layer portion and a base fabric overlaid and integrated with the filter layer portion.

First, to explain the '6fi layer part, the filter layer part is:
The specific surface area obtained by raising the surface of a base material made of synthetic fibers such as woven fabrics, knitted fabrics, non-woven fabrics, woven fabrics, etc.
The naps of ultrafine fibers of yt/Q or more are laid out aligned in one direction, and the naps form a stratification, and the directional index is 1.2 to 10.

The synthetic fibers constituting the above-mentioned base material preferably have abrasion resistance and grain resistance, and polyamide fibers, polyester fibers, polyvinyl alcohol fibers, polyfluoroethylene fibers, polypropylene fibers, polyacrylonitrile fibers, etc. may be used. I can do it. The fibers are preferably non-crimped, and those with circular or deformed cross sections can be used as staples or filaments.

In addition, as the fiber, a so-called multifilamentary composite fiber having different polymeric substances as seabird components, or a splittable composite fiber obtained by laminating and spinning different polymeric substances and being splittable at the laminated part are used. It is also possible. Moreover, depending on the type of solid-liquid, these fibers subjected to rice water processing or hydrophobic processing can also be used.

As the base material, woven fabrics, knitted fabrics, nonwoven fabrics, etc. can be used. As a textile base material, the warp is a processed synthetic fiber filament yarn, and the weft is a yarn made of non-crimped fiber.
It is preferable to raise the weft yarn, and it is also possible to use a spun yarn or a bulky textured yarn having loops or protrusions as the weft yarn. The weave structure is preferably satin weave so that the warp and weft have a desired density and a desired floating structure.

Further, as the knitted material, circular knitting such as rib knitting, double-sided knitting, etc., warp knitting, such as half knitting, Queen's cord knitting, etc., can be used. Among these, it is preferable to use half-knitted tricot fabric because it is relatively easy to form naps.

Furthermore, in the case of using a non-woven fabric base material, the staples or filaments of the synthetic fibers are mixed with fibers or fine particles having a lower melting point than that, and the paper is made into paper, and the low melting point fibers or fine particles are partially melted. After integrating the synthetic fibers, the surface is puffed to raise the synthetic fibers,
Alternatively, the staples or filaments may be accumulated using an air stream or a water stream, punched to form felt, and the surface of the felt may be raised to form a cline. It may be something.

Methods for forming naps on the substrate include clothing, sandpaper, sand cloth, sand net, grindstone, steel brush, polishing brush, sand roll, garnet, sand honing, and the like.

Among these, it is most preferable to use clothing.

Now, in this fii layer part, it is necessary that the above-mentioned naps have directionality and the directionality index is 1.2 to 10. A preferred directionality index is 1.3-5. Here, the directional index is measured as follows.

■ Four cut pieces each 25 cm long and 3 cm wide, with the longitudinal direction of the filter cloth to be measured, that is, the warp direction if the base material is a woven fabric, or the wale direction if it is a knitted fabric. make. At the end of each shredded piece, a mark is attached to the end that will become the leading edge when it is run as a filter layer h.

(2) Next, in order to remove distortion in the wire layer, each of the shredded pieces was placed on a 50-mesh wire mesh with the wire layer facing up, and submerged in water. After 24 hours, the filter cloth was pulled up along with the wire gauze and left in a wind-blown atmosphere with a temperature of 25±2° C. and a relative humidity of 65±5% for 24 hours to maintain constant moisture absorption.

(2) Next, a glass plate having a length of 65 cm and a width of 3 Q cm is placed in a semi-pitch, and one longitudinal end of the glass plate is lifted up by 2.5 cm and tilted. Furthermore, place one of the shredded pieces provided in item 11 in (2) above on the glass plate so that its longitudinal direction is the longitudinal direction of the glass plate, and the mark end is positioned above the slope of the glass plate. 7c from the top of the young neck
The length is 7 cm, the width is 3 cm, and the thickness is 75 μm.
Cover it with a polyester film and roughly line it with a length of 3
5cm, width 2.4. 2 cm cellophane tape so that both ends protrude 5 cm from the top and bottom ends of the filter cloth and come into contact with the surface of the glass plate, and the adhesive side is on the coating side.

■ Next, place a SUS steel roll with an outer diameter of 5 cm, a length of 15 cm, and a smooth surface of am2.3 on top.

Roll the cellophane tape from the top edge using gravity to adhere the filter cloth and cellophane tape. To reduce measurement errors, this rolling operation is performed twice. After adhesion, 5 cm of both ends of the cellophane tape are cut off to obtain a bonded product of the filter cloth and the cellophane tape.

(2) Next, the adhesive obtained in (1) above is subjected to a peel test between a filter cloth and cellophane tape. This test was carried out using a tensile testing machine, with the upper chuck holding the polyester film and the lower chuck holding the filter cloth, at a tensile speed of 30.
It is carried out continuously at cm/min. Then, the peeling force is measured as the average value within 9 cm from the starting edge, with a portion 3 cm from the starting edge of the peeling being the starting edge. Hereinafter, the peeling force obtained by this measurement will be referred to as A.

■ Next, another cut piece is subjected to exactly the same test, but this time with the other end corresponding to the above mark end being on the upper side of the slope of the glass plate. This measurement yields the peel force.

(2) Next, the third cut piece is subjected to the same tests as (1) to (3) above, but this time, a polyester film is placed on the lower end of the filter cloth.

This measurement determines the peeling force B as f? Ru.

(2) Next, perform the same test as (2) above on the last test piece. However, in this case as well, the polyester film is placed close to the lower end of the cline F, as in the above case. By this measurement, the peeling force C is obtained.

■ Next, from the above peeling forces A, B, C, and D, (B+D>
/ (A+C) is performed. The result of this calculation is the directional index referred to in the present invention.

As is clear from the above definition, the directional index is the ratio of the peeling force in the direction in which the cellophane tape is easy to peel and in the direction in which it is difficult to peel, and this indicates the stability of the direction of napping. A directional index of 1.2 to 10 can be obtained by appropriately selecting the number of times and direction of napping, the type of napping machine, and the like. In the above test, the cellophane tape used has adhesive strength specified in JIS Z15221982 and has a width of 24 mm.

In addition, in this filter 15 part, it is necessary that the specific surface area of the fluffed synthetic fibers be 3×10 3 o+f/g or more. Here, the specific surface area is the product of the average circumference of the fiber cross section and the total fiber length per 1 g, and the average circumference is the average value of several samples.

Next, the base fabric that is integrated with the layered part will be explained. The base fabric is made of woven or knitted fabric, and its constituent yarns include spun yarns such as natural fibers and synthetic fibers, filament yarns, etc. However, spun yarn is preferable from the viewpoint of adhesion to the layered part, abrasion resistance, etc. In addition, the structure of the fabric F is plain woven gauze using spun yarn for both warp and warp, plain woven fabric using spun yarn for warp and weft,
Tricot or the like in which spun yarn is inserted can be used.

Note that the above-mentioned layered portion and base 5 can be integrated by the following method.

That is, a powdery polymeric substance made of a low melting point polymer is interposed between the filter layer portion and the base fabric in a dotted manner, and by heating to a temperature higher than the melting point of the low melting point polymer to melt and bond, good adhesion is achieved. At the same time, the adhesion points between the filter layer part and the base fabric can be scattered, and the filtration performance with excellent water permeability can be maintained without impairing the filtration performance of the layered part.

FIG. 2 is a schematic perspective view showing an example of the cline 5 of the present invention, and FIG. 3 is a model diagram showing a weft section thereof.

In the filter cloth of the present invention, as shown in FIGS. 2 and 3, the laminated portion 1a and the base cloth 1b are integrated by overlapping and contacting.

Therefore, in the filter cloth of this invention, the filter layer portion only has filtration performance.
On the other hand, since it is only necessary to maintain durability and the filter layer and base can be optimized separately, it is possible to create a base with excellent filter performance and durability. It is something.

In the filter cloth of the present invention, various combinations of the filter layer portion and the base can be selected. Next, a preferred example thereof will be shown.

That is, the filter layer part is a fabric in which weft yarns made of synthetic fibers having a specific surface area of 3 x 103 ci/q or more intersect with warp yarns of crimped synthetic fiber yarns, and the directionality index is 1.0 in the longitudinal direction of the fabric. A combination may be used in which raised naps having a directionality of 2 to 10 are formed, and the base fabric is a single fabric made by mixing and weaving spun yarns.

In this combination, the yarns described in connection with the textile base material above can be used as the wefts in the layered portion. Note that this weft yarn must be made of synthetic fibers with a specific surface area of 3×10 3 cJ/g or more, thereby increasing the blocking rate and transfer rate. Specifically, the specific surface area is 3X103
-If the amount is less than 7 g, sufficient filtration cannot be obtained without coarsening the solid components by using a flocculant. In addition, synthetic fiber crimped yarns for the warp include false twisted yarns, push-type yarns,
A crimped thread such as a conjugate type can be used.
Requires elasticity. Considering napping properties, false twisted yarn is most preferred. In other words, if you use crimped warp threads, they will shrink in the width direction at the same time as they are raised, making it easier to create a dense structure. In addition, as for the weave reduction, it is preferable to use a satin weave with a lot of weft float.

On the other hand, since a fabric obtained by mixing and weaving spun yarns is used as the base fabric, the fuzz of the yarns increases the welding strength of the haE portion and improves reinforcing properties and abrasion resistance.

Therefore, by using such a combination, it is possible to obtain a filter cloth in which a dense thin layer portion and a base fabric with excellent abrasion resistance are integrated.
A filter cloth with favorable filtration performance and durability can be obtained.

It is also possible to use a combination in which the base fabric that is overlapped and integrated with the laminated portion has an apparent specific gravity smaller than that of the filter layer portion. Here, the appearance and specific gravity are JIS L
It is defined as a thickness measured according to the thickness measurement method described in 1079.

In this way, by making the base fabric have a rough structure that has an apparent specific gravity smaller than that of the filter layer, for example, a bulky yarn such as air turbulence textured yarn, it is possible to create a dense stratified layer. Drainability J: A filter that is integrated with the base fabric is obtained. Therefore, fine solid components can be removed, sufficient filtration can be obtained without coarsening of solid components due to the use of coagulants, the transfer rate is improved, the recovery rate of solid components is improved, and the recovered solid components are Since the water content is small, fuel consumption for post-treatment such as incineration can be reduced, and as mentioned above, a filter cloth with excellent filtration performance and improved durability can be obtained.

When the filter cloth of the present invention is used in a belt press type dehydrator, as shown in FIG. The loaded endless cline layer 51 is run, and the liquid component in the solid liquid 6 is squeezed out by the squeezing section, and the solid component remaining on the filter cloth 1 is transferred to the transfer drum 4 and scraped off by the scraper 7. to recover. In this case, the cline layer 51 is mounted so that the side having the raised bristles, that is, the surface thereof, faces the surface of the transfer drum, and the direction of the inclination of the raised bristles faces in the opposite direction to the running direction of the filter. In FIG. 4, reference numeral 8 is a water spray nozzle for washing the filter cloth from the front and back surfaces after transfer, and 9 is a vacuum suction tank for liquid components.

The reader does not have a transfer drum as described above, and
The solid components remaining on the toy F are collected using a scraper or a water spray nozzle.

The filter cloth of the present invention can stably separate extremely fine solid components, and therefore can be used for various purposes. For example, sludge, scum, etc. generated during wastewater treatment, such as so-called suspended sludge and so-called fixed sludge discharged from biofilm treatment equipment,
It can be used to concentrate and dehydrate flocs, wash water, concentrated sludge, etc. Specifically, for example, sludge generated from water and sewage treatment, excess sludge generated from septic tanks, sludge generated from human waste treatment, scum generated from pressurized flotation operations, coagulated flocs and coagulated sediment flocs generated from industrial wastewater treatment, and sand. These include backwash water from various filtration devices, sludge concentrated in screen devices, etc. Furthermore, it can be used to recover solid components in various manufacturing industries, such as paper pulp manufacturing, food manufacturing, sake brewing, and miso brewing. It can also be used to purify water in ponds and rivers.

Next, an example of a method for manufacturing the filter cloth of the present invention will be described. A powdery polymeric substance made of a polymer having a melting point lower than that of both base fabrics of the filter layer is coated with a gravure roll or the like. , dotted on Wi'r and heat-treated in a heat box heated above the melting point of the low melting point polymer to melt the powdery polymer material and fuse and fix it to the base fabric. The base fabric and the laminated part are overlapped, and while being preheated again in the first box part heated to above the melting point of the low melting point polymer, the material is heated under pressure with a calender roller heated to above the melting point of the low melting point polymer. The filter layer and the base fabric are bonded and integrated by melting a powdery polymeric substance.

5 and 6 show the state in which the cline F is manufactured by implementing the manufacturing method of the present invention, and FIG. 5 shows the base fabric 1
Powdered polymer substance 1 made of a low melting point polymer on b.
2 shows a state in which the base fabric is provided in the heat box 13 while interspersing the base fabric with the gravure roller 11.

The heat box 13 heats the low melting point polymer to a temperature higher than the melting point, so that the powdery polymer 'f110 is melted and fused and fixed onto the surface of the base 15.

FIG. 6 shows that the surface of the base fabric 1b obtained above, on which the powdery polymeric substance 10 is fused and fixed, is aligned so that it overlaps the anti-napped surface of the lfM layer portion 1a, and the filter layer is A state in which the paper is supplied so that the raised part side of the portion 1a is located on the surface of the calender roller 12 is shown.

The calendar roller 12 is a gravure roller 11 (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 heating roller 12 made of steel, and the layered part of the supplied filter layer part and base fabric is heated to the heat box 1.
While being preheated in step 4, the base material is directly heated under pressure with a calender roller 11 heated above the melting point of the low melting point polymer.
By melting the powdery polymeric substance 10, the filter layer portion 1a and the base fabric 1b are bonded and integrated, thereby obtaining the filter fabric of the present invention.

In addition, the filter cloth of the present invention is obtained by fusing and fixing a powdery polymer substance 10 of a low melting point polymer to the anti-pillared side of the filter layer portion 1a, and then overlapping the filter layer portion 1a and the base cloth 1b. It can also be manufactured by supplying it to the calender roller 11, applying pressure and heat, and adhering it.

In addition, in the filter cloth of the present invention, a powdery polymeric material 10 of a low melting point polymer is interspersed between the filter layer portion 1a and the base cloth 1b, and the material is supplied to a calender roller 11 and bonded by pressure and heating. It is also possible to manufacture by continuously performing the integration in one step.

Example 1 A 20/2S spun yarn made by spinning 70 core multifilament composite fibers (fineness 5D) with polyester as an island component and polystyrene as a sea component was used as a weft, and a polyester fiber with a thickness of 20μ was used as a weft. The warp is the final bundle, and the weft is 30.
A 5-ply satin fabric with 40 warps/cm and 40 warps/cm was obtained.

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 fineness of 0.06D.

Next, the above-mentioned fabric is raised in the napping area, and the napping operation is carried out 20 times in the warp direction, and the napping operation is further carried out 10 times in the opposite direction to mainly nap the weft yarns, so that the number of naps is about 1000/
This marginal layer was obtained with a diameter of 1.5 mm and a directionality index of approximately 2°2.

Further, as a base fabric, a plain woven fabric with a warp density of 24 yarns/bun x weft yarn density of 22 yarns/in was prepared using polyester high tenacity spun yarn with a fine count of 30 for the warp and weft yarns.

Next, according to the manufacturing process shown in FIG. 5, a powdery polymeric substance 10 with a melting point of 13
An amount of 0'C polyethylene adhesive corresponding to a basis weight of 30 g/T112 is applied at a density of 900 pieces/1 nch2 via a gravure roller 11, and heat treatment is performed while being supplied to a heat box 13 under the following conditions. The polyethylene adhesive was melted and fixed to the base plate.

Heat box temperature: 140°C Processing speed: m/min Next, according to the manufacturing process shown in FIG.
The iron is supplied so that it is located on the raised part side of the IW part or on the calender roller surface side, and calendered under the following conditions to melt the polyethylene adhesive on the base fabric part and bond the base fabric part and the laminated part. A filter cloth for solid-liquid separation of the present invention was obtained.

Heating roller temperature: 230'C Processing speed: 4 m/min Pressure weight: 10 tons Processing Width: 120 Cm Next, the above filter cloth was prepared with a width of 39 cm with the warp direction as the longitudinal direction.
The filter cloth was cut to a length of 2.5 m and the cut ends were sewn to obtain an endless filter cloth as shown in FIG.

Next, the endless filter cloth was placed in a belt press type dehydrator shown in Fig. 4.The running speed of the filter cloth was 4 m/min, the degree of vacuum in the vacuum suction tank was set to about 900 mm water column, and the pressing force to the transfer drum was applied. A dehydration test was conducted with the amount of water being approximately 60 kq. As the solid liquid, tap water and clay with an average particle size of approximately 20μ were used, and the clay concentration was adjusted to approximately 300 mM liters, which was supplied at a rate of approximately 80 liters/min without adding a flocculant. did. The particle size distribution of the clay in the solid-liquid as measured by a Coulter counter was approximately 1 to 50 microns, and was divided into a fairly wide range.

As a result of the test, the rejection rate by cline layer 1 was 90%, and the components recovered by scraping with a scraper were about 50% solid. Furthermore, the transfer rate to the transfer drum was approximately 85%, which was extremely high. Roughly speaking, the particle size of clay in the solid component measured with a coulter counter is approximately 1 to 5μ, and 5μ
Most of the items exceeding this amount have been removed. Also, about 20
Even after 00 hours of operation, the above-mentioned performance did not change at all, and no abnormality was observed in the filter cloth, indicating that it had remarkable durability.

Example 2 In the process of obtaining a layered part, polyester is used as the island component and polystyrene is used as the sea component as the spun yarn of the weft.
A 3-core multicore composite fiber (with a fineness of 2°5D) is used, and the weft is made of a bundle of ultrafine fibers with a fineness of 0.02D. The warp and weft density are both 20 wood/in.
A filter cloth was produced and tested under the same conditions as in Example 1, using a plain woven fabric.

As a result of the test, the filtration performance was stable and almost the same as in Example 1, and the durability (time of use without problems) was particularly improved to 2500 hours.

〔Effect of the invention〕

As described above, the filter cloth for solid-liquid separation of the present invention is a filter cloth in which a layered portion and a base fabric are laminated and integrated, and the filter layer portion has naps made of synthetic fibers, and the naps are made of synthetic fibers. The filter cloth has a directionality with a directionality index of 1.2 to 10 in the length direction, and the specific surface area of the nap is 3X103cJ/Q or more, while the base fabric has higher water permeability than the filter layer. The filter cloth of the present invention is characterized by having abrasion resistance, and the layered portion only needs to maintain filtration performance, and the base fabric only needs to maintain durability, and the layered portion and base fabric can be optimized separately. As a result, a filter cloth with excellent filtration performance and durability can be obtained.

In addition, in the filter cloth of the present invention, the naps in the filter layer portion have a directionality with a directionality index of 1.2 to 10 in the length direction of the filter cloth, so that the naps may appear on the base material during use. It is possible to prevent the fibers from being pushed in and making it difficult to stand up again, and from getting entangled with the raised fibers, resulting in stable solid-liquid separation efficiency.

Moreover, since the base fabric of the cline b of the present invention has high water permeability and abrasion resistance, it is possible to improve the durability of the filter fabric, and the water permeability is improved, resulting in good drainage. Therefore, it is possible to increase the traveling speed of the filter cloth, and it is possible to improve the throughput of the filter and increase the throughput. Furthermore, since the amount of water permeation can be increased, the recovery rate of solid components is improved, and since the amount of water in the recovered solid components is small, it is possible to reduce fuel consumption for post-processing such as incineration.

In addition, in the cline F of the present invention, the specific surface area of the raised hairs in the stratified portion is 3×103c+rf10 or more, so the gaps formed between the raised hairs are extremely small, and even fine solid components can be blocked. Therefore, addition of a flocculant is not necessarily required.

In addition, the method for manufacturing a filter cloth for solid-liquid separation of the present invention includes dots of a powdery polymeric substance made of a polymer having a melting point lower than that of the filter layer and the base material, The layered portion and the base fabric are bonded by applying pressure and heating with a calender roller heated to a temperature higher than the melting point of the low melting point polymer to melt the powdery polymer substance, and the filter layer portion and Integration with the base fabric can be easily and efficiently achieved by interspersing a binder made of a low melting point polymer and thermally adhering it. Since the bonding points exist in a dotted manner, the base fabric is not clogged with the bonding agent, and good filtration performance can be maintained.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the filter cloth of the present invention, in which it is configured as an endless filter cloth, and FIG. 2 is a schematic perspective view showing an example of the filter cloth shown in FIG. 1, Third
The figure is a model diagram showing the weft cross-section, and Figure 4 is a schematic front view showing the state in which the belt press type dehydrator is operated using the filter cloth shown in Figure 1 above. FIG. 6 is a schematic front view showing a state in which a filter cloth is manufactured by implementing the present invention. 1... i [Jih, 1 a ・
... aai layer part, 1 b ... base color, 2.3 ... belt with holes, 4 ... transfer drum, 5 ... press roll, 6 ... solid liquid, 7 ...
・Scraper, 8...Water spray nozzle, 9・
... Decompression suction tank, 10 ... Powdered polymeric substance of low melting point polymer, 11
... Gravure roller, 12... Calendar roller, 13.14... Heat box Patent applicant Toshi Co., Ltd. Figure 1 Figure 4 Figure 3

Claims (3)

[Claims] (1) A filter cloth for solid-liquid separation in which a filter layer portion and a base portion are overlapped and integrated, wherein the filter layer portion has a nap made of synthetic fiber, and the nap is in the longitudinal direction of the filter cloth. The direction index is 1.
It has a directionality of 2 to 10, and the specific surface area of the raised hair is 3×
10^3cm^2/g or more, on the other hand, the base fabric has higher water permeability and abrasion resistance than the filter layer, and the filter layer and the base are made of a polymeric material having a lower melting point than both. 1. A filter cloth for solid-liquid separation, characterized in that it is substantially dot-bonded by making it exist in a dot-like manner. (2) A powdery polymeric material made of a polymer having a melting point lower than that of the two is interposed between the filter layer portion and the base fabric, and the material is heated under pressure with a calender roller heated to a temperature higher than the melting point of the low melting point polymer. A method for manufacturing a filter cloth for solid-liquid separation, characterized in that the filter layer portion and the base cloth are bonded and integrated by melting the powdery polymeric substance. (3) A powdery polymer substance of a low melting point polymer is combined with the base fabric, and then the filter layer portion and the base fabric combined with the powdery polymer substance are heated under pressure to be bonded and integrated. A method for manufacturing a filter cloth for solid-liquid separation according to claim (2).