JP7082797B2 - A filter cloth made of monofilament yarn as an aggregate - Google Patents

Description

The present invention relates to a filter cloth using a monofilament yarn as an aggregate.

Filtration is used to separate a gas from a solid or a liquid from a solid. In filtration, a fine woven cloth may be used as a filter cloth. However, a filter cloth made of woven cloth is not stiff and easily bends. For this reason, the shape of the filter cloth is maintained by combining the filter cloth with an aggregate.

For example, Patent Document 1 describes a filter medium for a centrifuge, which is composed of an aggregate and a cloth arranged so as to cover the aggregate.

Japanese Unexamined Patent Publication No. 2009-279518

In the filter medium of Patent Document 1, the upper end of the filter cloth is sewn and fixed to the back surface side of the aggregate, and the lower end of the filter cloth is a locking means such as a wire fastener to the back surface side of the aggregate (hereinafter, It is simply called a wire fastener.).

In the filter medium for a centrifuge of Patent Document 1, the upper end of the aggregate and the filter cloth is sewn on the back side of the aggregate, and the lower end is fixed to the back side of the aggregate with a wire fastener . Therefore, no seam appears on the front side of the filter cloth, that is, the surface where the filter cloth comes into contact with the filter medium. If the filter cloth has seams, minute filters may leak from the holes in the seams. In the filter medium for a centrifuge of Patent Document 1, since no seam appears on the front side, the filter medium is less likely to leak.

However, in the filter medium for a centrifuge of Patent Document 1, it is necessary to sew the wire fastener and the aggregate, and it is necessary to sew the wire fastener and the lower end of the filter cloth. Further, depending on the configuration of the filtration device, the wire fastener may interfere with the components of the filtration device.

An object of the present invention is to provide a filter cloth in which a filter cloth and an aggregate are integrated without using a means such as a wire fastener or a suture.

A filter cloth containing a multi-layered structure having a first structure arranged on a surface in contact with the filter medium and a second structure arranged on the opposite side of the surface in contact with the filter medium, and the second structure is a warp and weft. At least one of the wefts contains a monofilament yarn as an aggregate, and the first tissue and the second tissue are directly or indirectly connected by a filter cloth having a monofilament yarn as an aggregate. Solve the problem.

In the above filter cloth, at least one of the warp and the weft contains a multifilament yarn or a spun yarn in the first structure, and at least one of the warp and the weft contains a monofilament yarn in the second structure. The first structure and the second structure are directly or indirectly connected to each other, and more multifilament yarns or spun yarns are exposed on the surface of the first structure that comes into contact with the filter media than the monofilament yarns. It is preferable to keep the state.

In the above filter cloth, an intermediate structure may be arranged between the first structure and the second structure. By arranging the intermediate structure, for example, the filter cloth can be made thicker, and the first structure and the second structure can be indirectly connected to each other.

In the above-mentioned filter cloth, it is preferable that the warp and weft threads constituting the second structure are monofilament threads, which are arranged in a direction in which the filter cloth is easily bent. This makes it possible to effectively prevent the filter cloth from bending.

According to the present invention, it is possible to provide a filter cloth in which a filter cloth and an aggregate are integrated without using a means such as a wire fastener or a suture.

It is a figure which shows the state which looked at the filter cloth which concerns on 1st Embodiment from the back side. It is the organization chart of the filter cloth which concerns on 1st Embodiment, and is the organization chart which showed the complete organization chart and the organization | organization which it divided into the 1st structure and the 2nd structure. It is an end view in the AA part of FIG. It is an end view in the BB part of FIG. It is a figure which shows an example of a centrifugal filtration apparatus. It is a figure which shows an example of the filter cloth for a centrifugal filtration apparatus. It is an end view in the CC part of FIG. It is a figure which shows an example of the filter plate type filtration apparatus. It is a figure which shows an example of the filter cloth for the filter plate type filtration apparatus. It is the organization chart of the filter cloth which concerns on 2nd Embodiment, and is the organization chart which showed the complete organization chart, and it divided into the 1st structure and the 2nd structure. It is the organization chart of the filter cloth which concerns on 3rd Embodiment, and is the organization chart which showed the complete organization chart, and it divided into the 1st organization and the 2nd organization. It is the organization chart of the filter cloth which concerns on 4th Embodiment, and it is the organization chart which showed the complete organization chart and it divided into the 1st organization and the 2nd organization. It is the organization chart of the filter cloth which concerns on 5th Embodiment, and it is the organization chart which showed the complete organization chart and it divided into the 1st organization and the 2nd organization. It is the organization chart of the filter cloth which concerns on 6th Embodiment, and is the organization chart which showed the complete organization chart and the organization chart divided into the 1st structure, the intermediate structure and the 2nd structure. It is the organization chart of the filter cloth which concerns on 7th Embodiment, and is the organization chart which showed the complete organization chart and the organization chart divided into the 1st structure, the intermediate structure and the 2nd structure.

An embodiment of the filter cloth of the present invention will be described with reference to the drawings. The embodiments listed below are merely examples, and the present invention is not limited thereto.

[First Embodiment]
As shown in FIGS. 1 and 2, the filter cloth of the present embodiment has a first structure 11a arranged on the surface in contact with the filter medium and a second structure arranged on the opposite side of the surface in contact with the filter medium. It is a filter cloth 1a containing a multiple structure having a structure 12a. In the example of FIG. 1, the second structure 12a appearing on the opposite side of the surface in contact with the filter is visible in the foreground, and the surface in contact with the filter is hidden. In the example of FIG. 2, the surface in contact with the filter medium is shown in the front side state.

The first structure can be composed of a woven fabric woven with various threads such as monofilament yarn, multifilament yarn, or spun yarn according to the nature of the filter medium to be filtered, but the first structure is the first structure. It is preferable that at least one of the warp and weft constituting the above contains a multifilament yarn or a spun yarn. Multifilament yarns or spun yarns are more supple than monofilament yarns. Since the multifilament yarn or the spun yarn bends flexibly when woven, it is possible to obtain a dense woven fabric having a small gap between the warp and weft. Therefore, by constructing the first structure arranged on the surface in contact with the filter medium so as to include the multifilament yarn or the spun yarn, it is possible to obtain a dense filter cloth in which the filter matter does not easily leak. In the filter cloth 1a shown in FIGS. 1 and 2, the warp and weft 112a constituting the first structure 11a are both multifilament yarns. In FIG. 1, the weft 112a of the first structure 11a is shown in black, and the warp 111a of the first structure 11a is shown in white.

In the first structure, it is preferable that both the warp and weft are multifilament yarns or spun yarns in order to make the filter cloth dense. When one of the warp and weft is composed of a multifilament yarn or a spun yarn and the other is composed of a monofilament yarn, the ratio of the monofilament yarn exposed on the surface in contact with the filter medium in the first structure is small. It is preferable to adopt a structure such as a twill weft or a satin weft.

As described above, the first structure can have various configurations according to the properties of the filter medium, and for example, a flexible woven fabric can be used. For example, in the rigidity test in which the width of the test cloth of JIS L 1096 is changed to 5 cm, a flexible woven fabric having a rigidity of 150 mm or less in the vertical or horizontal direction or 130 mm or less can be mentioned. Since such a flexible woven fabric is easily bent, it can be suitably combined with a monofilament yarn as an aggregate. The lower limit of the rigidity is not particularly limited, but is preferably larger than 0 mm.

The second structure may be such that at least one of the warp and weft contains a monofilament yarn. The monofilament yarn is less likely to bend than the multifilament yarn or the spun yarn. By weaving so that the second structure contains the monofilament yarn, it is possible to give the filter cloth a firmness. In the filter cloth 1a shown in FIGS. 1 and 2, the warp threads 121a and the weft threads 122a constituting the second structure 12a are both monofilament threads. In FIG. 1, the warp and weft 122a of the second structure is shown in white with diagonal lines, and the warp and weft 122a of the second structure is shown in white.

In FIG. 2, the warp number 5, the warp number 10, the warp number 15, the warp number 20, and the weft number 3, the weft number 6, the weft number 9, and the weft number 12 are marked with circles. Each of the yarns marked with these circles is a warp yarn 121a or a weft yarn 122a constituting the second structure, and both are composed of a monofilament yarn. The other warp or weft not marked with a circle are all warp 111a or weft 112a constituting the first structure, and both are composed of multifilament yarn. Also in FIGS. 10 to 13 below, the warp and weft numbers marked with a circle indicate the warp and weft constituting the second structure, and the warp and weft numbers not marked with a circle indicate the first structure. Indicates that the warp or weft constitutes the above. In FIG. 2, a complete organization chart showing the first structure 11a and the second structure 12a together, a first structure diagram showing the warp threads 111a and the weft threads 112a constituting the first structure 11a extracted, and a second structure are shown. The warp threads 121a and the weft threads 122a constituting the 12a are extracted and described separately from the second organizational chart (the same applies to the following organizational chart).

Further, in the organizational charts of FIGS. 2 and 10 to 15, the black squares are the warp and weft as shown in FIGS. 3 and 4 as the end faces of the AA portion and the BB portion of FIG. On the other hand, it shall indicate the state of being up, that is, the state of being floating. In addition, in FIG. 3 and FIG. 4, the weft is indicated by a circle, and the weft number is entered in the circle.

Further, in the organizational charts of FIGS. 2 and 10 to 13, the squares with black circles indicate the joints of the first tissue and the second tissue. As shown in FIG. 4, the knotting is performed by entwining one of the warp and weft of one tissue such as the second tissue with the warp and weft of another tissue such as the first tissue. In the example of FIG. 4, the warp 121a of the warp number 5 constituting the second structure 12a is woven so as to be entwined with the weft 112a of the weft number 4 constituting the first structure 11a, and the binding portion 13 is formed. ..

In the filter cloth 1a of the present embodiment, as shown in FIGS. 1 and 2, the first structure 11a is a plain weave structure having a high density of warp 111a and weft 112a, and the second structure 12a is a warp 121a and weft 121b. It is a 2/2 twill weave structure with a low density. The first structure 11a is a plain weave structure as described above, and the warp 111a and the weft 112a of the first structure 11a are both composed of multifilament yarns. The second structure 12a is a 2/2 twill structure as described above, and the warp and weft 122a of the second structure 12a are both composed of monofilament threads. When the filter cloth 1a of the present embodiment is viewed from the opposite side of the filtration surface, as shown in FIG. 1, a state in which a coarse second structure 12a is bonded to the back side of the dense first structure 11a. There is.

In the filter cloth 1a of the present embodiment, both the warp and weft 122a of the second structure 12a are made of monofilament yarn. Therefore, the filter cloth is less likely to bend in the vertical direction, the horizontal direction, and the diagonal direction. It is not always necessary to use both warp and weft as monofilament yarn. For example, at least one of the warp and wefts constituting the second structure, in which the filter cloth is arranged in a direction in which the filter cloth is easily flexed, may be a monofilament yarn. This makes it possible to make the filter cloth flexible in one direction and prevent the filter cloth from bending in the other direction.

As shown in FIG. 2, the monofilament yarns are arranged at intervals of four warps in the weft direction and two wefts in the warp direction. .. Therefore, the second structure 12a has a lower density than the first structure 11a.

The monofilament yarn may be arranged to such an extent that the filter cloth can be prevented from bending. For example, the density of the warp or weft of the monofilament yarn is preferably 10 to 100 yarns / inch, more preferably 10 to 50 yarns / inch, and further preferably 10 to 25 yarns / inch. In the filter cloth 1a of the present embodiment, the density of the monofilament yarn is 12.3 yarns / inch for warp yarns and 11.5 yarns / inch for weft yarns.

The density of the warp or weft in the first structure may be determined according to the filtration performance required for the filter cloth. For example, the density of warps in the first structure is preferably 40 to 500 threads / inch, more preferably 40 to 100 threads / inch, and even more preferably 40 to 70 threads / inch. The density of the wefts in the first structure is preferably 10 to 200 threads / inch, more preferably 10 to 80 threads / inch, and even more preferably 10 to 40 threads / inch. In the filter cloth 1a of the present embodiment, the density of the multifilament yarn is 48.2 warp yarns / inch and 22.5 weft yarns / inch. It is preferable to make the density of the weft smaller than the density of the warp because the number of times the weft is driven is reduced.

In the filter cloth 1a of the present embodiment, the density of the second structure 12a is smaller than the density of the first structure 11a. Therefore, when performing filtration, a fluid such as a liquid or a gas easily escapes from the filter cloth 1a, and the efficiency of filtration increases.

As shown by the black circles in FIG. 2 and FIG. 4, in the filter cloth 1a of the present embodiment, the monofilament yarns constituting the warp and weft 121a of the second tissue 12a are formed by a total of four connecting portions 13 per constituent unit of the tissue. Is directly connected while floating on the weft 112a constituting the first structure 11a. In the filter cloth 1a of the present embodiment, as shown in FIG. 2, 20 squares in the horizontal direction × 12 squares in the vertical direction = 240 squares are set as one constituent unit, and the constituent units are continuous in the vertical direction and the horizontal direction. The exposure rate of the monofilament yarn calculated by the ratio of the mass of the connecting portion to all the masses of the constituent unit is 4/240 × 100 = 1.667%. As described above, in the filter cloth 1a of the present embodiment, the multifilament yarn is exposed in a larger amount than the monofilament yarn on the surface of the first structure 11a that comes into contact with the filter medium. Therefore, the fineness of the first structure 1a is hardly impaired by the monofilament yarn. Further, since the monofilament thread of the first tissue 11a exhibiting the filtering ability and the monofilament thread of the second tissue 12a functioning as an aggregate are joined by knotting, a needle hole is not formed by suturing. Therefore, leakage of the filter medium due to the use of the needle hole or the monofilament thread can be prevented. The exposure rate of the monofilament yarn is preferably 30% or less, more preferably 20% or less, and further preferably 5% or less. The lower limit of the exposure rate of the monofilament yarn is preferably 0% or more. Similarly, the exposure rate of the multifilament yarn or the spun yarn is preferably 70% or more, preferably 80% or more, and further preferably 95% or more. The upper limit of the exposure rate of the multifilament yarn or the spun yarn is preferably 100% or less.

For example, in a filter cloth consisting of only a first structure and a second structure, in order to expose more multifilament yarns or spun yarns than monofilament yarns on the surface in contact with the filter medium of the first structure, a second method is used. Even if one of the warps or wefts of the structure is composed of a multifilament yarn or a spun yarn and the other is composed of a monofilament yarn, the multifilament yarn or the spun yarn may be joined to the warp or the weft of the first structure. good. By adopting such a configuration, the exposure rate of the monofilament yarn on the surface of the first structure in contact with the filter medium can be set to 0%. That is, the state in which the multifilament yarn or the spun yarn is exposed more than the monofilament yarn includes the state in which the monofilament yarn is not exposed in the first structure.

For example, the fineness of the monofilament yarn is preferably 100 to 50,000 dtex, more preferably 500 to 2000 dex. The fineness of the multifilament yarn or the spun yarn is preferably 100 to 3000 dtex, more preferably 1000 to 1800 dtex. In the filter cloth 1a of the present embodiment, the multifilament yarn has a warp and weft of 1520 dtex, and the monofilament yarn has a warp and weft of 875 dtex.

Regarding the monofilament yarn that exhibits rigidity and functions as an aggregate, the monofilament yarn may be made less likely to bend than the multifilament yarn or the spun yarn when the same load is applied. For example, it is preferable that the ratio of the fineness of the monofilament yarn to the fineness of the multifilament yarn or the spun yarn is 50% or more (ratio of the fineness of the monofilament yarn (%) = the fineness of the monofilament yarn ÷ the fineness of the multifilament yarn or Fineness of spun yarn x 100). The upper limit of the fineness ratio of the monofilament yarn is not particularly limited, but is preferably 200% or less, and more preferably 130% or less, for example.

If it is sufficient for the filter cloth to exhibit rigidity mainly in one direction, the warp and weft yarns constituting the second structure, which are arranged in the direction in which rigidity is not required, are multifilament yarns or spun yarns. You may use a supple thread such as.

The composition and material of the multifilament yarn or the spun yarn can be appropriately changed depending on the properties of the filter medium. In the filter cloth of the present embodiment, a multifilament in which 240 filament long fibers are aligned and twisted 2.5 times per inch is used for both the warp and weft. The material is polypropylene for both warp and weft. In the case of spun yarn, for example, a fiber having a fiber length of 38 to 100 mm can be used. Similarly, the composition and material of the monofilament yarn can be appropriately changed depending on the properties of the filter medium. In the filter cloth of the present embodiment, polypropylene monofilament yarn is used for both the warp and weft.

The multifilament yarn, spun yarn, or monofilament yarn is preferably composed of a thermoplastic resin so that it can be joined by heat welding. By making it possible to join by heat welding, it is possible to prevent the formation of needle holes due to suturing in the filter cloth. For example, by joining one end and the other end of the filter cloth main body 31 by heat welding, the filter cloth main body 31 can be formed into an annular shape as shown in FIG. 6 described later. Further, as shown in FIG. 7, which will be described later, it becomes possible to join the filter cloth main body 31 and other members such as the packing 32.

The filter cloth 1a of the present embodiment can be preferably used as a filter cloth 3 for a centrifugal filtration device, for example, as shown in FIGS. 5 to 7. The centrifugal filtration device 4 shown in FIG. 5 has a basket 43 having a plurality of through holes 42 in the side wall 41, and a rotating shaft 44 of the basket 43. As shown in FIG. 6, as the centrifugal filtration device 4, a filter cloth 3 formed in an annular shape so that the flat surface and the bottom surface are open is used.

As shown in FIG. 5, the filter cloth 3 of FIG. 6 is used by being fitted so that the filter cloth 3 comes into contact with the inner surface of the side wall 41 of the basket 43. The filter cloth 3 is fitted so that the filter surface is located on the surface in contact with the filter material 5 (cake), that is, the inner peripheral surface of the annular filter cloth. Then, the aggregate is fitted so as to be located on the side opposite to the side in contact with the filter, that is, on the outer peripheral surface of the annular filter cloth. At this time, if the filter cloth 3 is not stiff, the filter cloth 3 bends diagonally downward as shown by an arrow in FIG. When the filter cloth 3 bends, a gap is formed between the filter cloth 3 and the upper end portion of the side wall 41 of the basket 43, and the filter medium 5 leaks from the gap.

In the filter cloth 1a of the present embodiment, the first structure 11a that exerts a filtering function and the second structure 12a that is composed of monofilament yarn and functions as an aggregate are integrated by joining. Therefore, the filter cloth 3 is prevented from bending. Further, since the first tissue 11a and the second tissue 12a are not joined by suturing, the filter cloth can be efficiently manufactured, and the filter matter is prevented from leaking from the needle hole at the time of suturing. To. Further, in the filter cloth 1a of the present embodiment, more multifilament yarns or spun yarns are exposed on the surface of the first structure 11a that comes into contact with the filter, and the surface that comes into contact with the filter is exposed. It has become precise. For this reason, the filter cloth leaks due to the use of the monofilament yarn, gets caught in the monofilament yarn when scraping off the filter media, and is contaminated by the filter matter remaining between the monofilament yarn and the first structure. Performance degradation is reduced.

As shown in FIGS. 6 and 7, packing 32 is joined to the upper end portion and the lower end portion of the filter cloth main body 31 of the filter cloth 3 fitted to the inner wall of the basket 43. As shown in FIG. 6, the packing 32 is provided to close the gap between the basket 43 of the centrifugal filtration device 4 and the filter cloth 3 to prevent the filter medium 5 from leaking from the gap. There is. The packing 32 is heat-welded so as to cover the filtration surface at the upper end and the lower end of the filter cloth 3 and the surface opposite to the filtration surface.

The packing 32 is preferably made of a thermoplastic resin so that it can be bonded to the filter cloth main body 31 by heat welding. In order to impart filtration performance to the packing 32, it is preferable that the packing 32 is made of a material having filtration performance such as a woven fabric or a non-woven fabric. The packing 32 is preferably made of a material similar to the thermoplastic resin constituting the filter cloth main body 31 in order to enable heat welding to the filter cloth main body 31.

As shown in FIGS. 8 and 9, the filter cloth 1a of the present embodiment is also suitably used for the filtration device 6 having a filter plate. The filtration device 6 of FIG. 8 supplies a liquid containing a filter medium before filtration to a filtration tank 62 in which a plurality of flat filter plates 61 are arranged. As shown in FIG. 9, the filter plate 61 has a mesh shape on the front side and the back side of the filter plate 61, and the outside and the inside of the filter plate communicate with each other through the mesh, as shown by arrows in FIG. In addition, the liquid can flow into the filter plate 61 from the outside of the filter plate 61 through the mesh. The liquid that has flowed into the filter plate 61 is discharged from the waste liquid port 63 arranged in the filter plate 61. The filter plate 61 is covered with a bag-shaped filter cloth 7. Therefore, the liquid containing the filter medium is filtered by the filter cloth 7 before flowing into the filter plate 61. The filtered liquid is discharged from the waste liquid port 63. In FIG. 9, the configuration of the filter plate 61 hidden in the filter cloth 7 is shown by a broken line.

In the filter cloth 7 used in the above-mentioned filtration device 6, if the filter cloth 7 is not stiff, the filter cloth 7 bends and comes into close contact with the filter plate 61. When the filter cloth 7 comes into close contact with the filter plate 61, it may be difficult for the liquid to flow into the filter plate 61. If the second structure 12a of the filter cloth 1a of the present embodiment is on the side of the filter plate 61 and the first structure 11a is on the outside and the filter cloth 61 is covered with the filter cloth 61, the filter cloth 7 has elasticity. It is possible to prevent the filter cloth 7 from bending. Since the filter cloth 1a of the present embodiment does not have a needle hole due to suturing, the possibility of the filter matter leaking from the needle hole is reduced, and the deterioration of the filtration efficiency due to the bending of the filter cloth 7 can be prevented. It is possible. Further, in the filter cloth 1a, the monofilament thread functions as an aggregate, but the filter plate is not damaged even if it interferes with the filter plate 61 like a wire fastener. Further, in the filter cloth 1a, since the monofilament thread hardly appears on the front side of the filter cloth, the filter medium may remain between the monofilament thread and the filter cloth, or the filter medium scraper may be caught on the monofilament thread. Is prevented.

[Second Embodiment]
As shown in FIG. 10, in the filter cloth 1b of the present embodiment, the first structure 11b is a plain weave structure and the second structure 12b is also a plain weave structure. As shown by marking the thread numbers with circles in FIG. 10, the warp number 5, the warp number 10, the warp number 15, and the warp number 20, and the weft number 3, the weft number 6, the weft number 9, and the weft number 12 Consists of the warp and weft of the second structure 12b. The warp and weft of the first structure 11b are both multifilament threads, and the warp and weft of the second structure 12b are both monofilament threads. The multifilament yarn and the monofilament yarn have the same configuration as that of the first embodiment. The density of the warps of the first structure is 49.0 threads / inch, and the density of the wefts is 22.5 threads / inch. The density of the warps of the second structure is 12.5 threads / inch, and the density of the wefts is 11.2 threads / inch. The exposure rate of the monofilament yarn is 1.667%, and the remaining 98.333% is the multifilament yarn.

[Third Embodiment]
In the filter cloth 1c of the present embodiment, as shown in FIG. 11, the first structure 11c is a 2/2 twill structure and the second structure 12c is a plain weave structure. As shown by marking the thread numbers with circles in FIG. 11, the warp number 5, the warp number 10, the warp number 15, and the warp number 20, and the weft number 5, the weft number 10, the weft number 15, and the weft number 20 Consists of the warp and weft of the second structure 12c. The warp and weft of the first structure 11c are both multifilament threads, and the warp and weft of the second structure 12c are both monofilament threads. The multifilament yarn and the monofilament yarn have the same configuration as that of the first embodiment. The density of the warp threads of the first structure 11c is 49.5 threads / inch, and the density of the weft threads is 31.7 threads / inch. The density of the warp threads of the second structure 12c is 12.7 threads / inch, and the density of the weft threads is 8.0 threads / inch. The exposure rate of the monofilament yarn is 1.0%.

[Fourth Embodiment]
As shown in FIG. 12, in the filter cloth 1d of the present embodiment, the first structure 11d has a 2/2 twill structure and the second structure 12d also has a 2/2 twill structure. As shown by marking the thread numbers with circles in FIG. 12, the warp number 5, the warp number 10, the warp number 15, and the warp number 20, and the weft number 5, the weft number 10, the weft number 15, and the weft number 20 Consists of the warp and weft of the second structure 12d. The warp and weft of the first structure 11d are both multifilament threads, and the warp and weft of the second structure are both monofilament threads. The multifilament yarn and the monofilament yarn have the same configuration as that of the first embodiment. The density of the warp threads of the first structure is 49.0 threads / inch, and the density of the weft threads is 31.0 threads / inch. The density of the warp threads of the second structure is 12.5 threads / inch, and the density of the weft threads is 7.5 threads / inch. The exposure rate of the monofilament yarn is 1.0%, and the remaining 99.0% is the multifilament yarn.

[Fifth Embodiment]
In the filter cloth 1e of the present embodiment, as shown in FIG. 13, the first structure 11e is a 3/1 twill structure and the second structure 12e is a plain weave structure. As shown by marking the thread numbers with circles in FIG. 13, the warp number 5, the warp number 10, the warp number 15, and the warp number 20, and the weft number 3, the weft number 6, the weft number 9, and the weft number 12 Consists of the warp and weft of the second structure 12e. The warp and weft of the first structure 11e are both multifilament threads, and the warp and weft of the second structure 12e are both monofilament threads. The multifilament yarn has the same configuration as that of the first embodiment. As the monofilament yarn of the weft of the second structure, a polypropylene monofilament yarn of 1786 dtex was used. There are two connections. The exposure rate of the monofilament yarn is 0.83%, and the remaining 9.170% is the multifilament yarn. The density of the warps of the first structure is 48.5 threads / inch, and the density of the wefts is 28.5 threads / inch. The density of the warps of the second structure is 12.3 threads / inch, and the density of the wefts is 14.3 threads / inch.

[Sixth Embodiment]
As shown in FIG. 14, the filter cloth 1f of the sixth embodiment is composed of a triple woven fabric composed of a first structure 11f, an intermediate structure 14f, and a second structure 12f. The intermediate structure 14f is arranged between the first structure 11f and the second structure 12f. The first structure 11f is a surface in contact with the filter medium, the second structure 12f is the back surface of the filter cloth, and the intermediate structure 14f is the intermediate surface.

In FIG. 14, the warp and weft numbers marked with circles are the warp or wefts constituting the second structure 12f. In FIG. 14, the warp and weft numbers with square marks are the warp or wefts constituting the intermediate structure 14f. Further, in FIG. 14, those without a circle mark or a square mark show the warp or weft constituting the first structure 11f. Further, in FIG. 14, the connection point between the first structure 11f and the intermediate structure 14f is indicated by a white circle, and the connection point between the intermediate structure 14f and the second structure 12f is indicated by a black circle. In FIG. 15, which will be described later, the thread usage and the connection point are expressed by the same method.

In the filter cloth 1f of the present embodiment, the warp and weft of the first structure 11f and the warp and weft of the intermediate structure 14f are composed of multifilament threads. Then, the warp and weft of the second structure 12f were composed of monofilament yarn. The multifilament yarn and the monofilament yarn are the same as those in the first embodiment. Specifically, the warp number 5, the warp number 10, the warp number 16, and the warp number 21, and the weft number 3, the weft number 7, the weft number 10, and the weft number 14 constitute an intermediate structure 14f. Then, the warp number 11, the warp number 22, the weft number 4, and the weft number 11 constitute the second structure 12f. Then, the remaining warp and weft other than that constitute the first structure 11f.

As shown by the white circles in FIG. 14, the first structure 11f and the intermediate structure 14f have a total of two places, one where the warp number 5 and the weft number 2 intersect and the other where the warp number 16 and the weft number 9 intersect. It is connected with. In the former case, the warp of the intermediate structure 14f represented by the warp number 5 floats on the weft of the first structure 11f represented by the weft number 2. In the latter case, the warp of the intermediate structure 14f represented by the warp number 16 floats on the weft of the first structure 11f represented by the weft number 9.

As shown by the black circles in FIG. 14, the intermediate structure 11f and the second structure 12f have a total of two points, one at the intersection of the warp number 10 and the weft number 11 and the other at the intersection of the warp number 21 and the weft number 4. Be tied up. In the former case, the weft of the second structure 12f represented by the weft number 11 floats above the warp of the intermediate structure 14f represented by the warp number 10 and below the first structure 11f. In the latter case, the weft of the second structure 12f represented by the weft number 4 floats above the warp of the intermediate structure 14f represented by the warp number 21 and below the first structure.

As described above, in the filter cloth of the sixth embodiment, the first tissue 11f and the second tissue 12f are indirectly connected via the intermediate tissue 14f. Therefore, the monofilament yarn constituting the second structure 12f does not appear at all on the side of the first structure that comes into contact with the filter medium. That is, the exposure rate of the monofilament yarn is 0%, and the exposure rate of the multifilament yarn is 100%. In this way, it is possible to prevent the monofilament yarn from appearing on the surface of the first structure that comes into contact with the filter by forming a multi-structure having a triple structure or more.

[7th Embodiment]
In 1 g of the filter cloth of the present embodiment, as shown in FIG. 15, the first structure 11 is a plain weave structure, the intermediate structure 14 g is also a plain weave structure, and the second structure 12 g is also a plain weave structure. As shown by marking the thread numbers with circles in FIG. 15, the warp number 3, the warp number 6, the warp number 9, and the warp number 12, and the weft number 3, the weft number 6, the weft number 9, and the weft number 12 Consists of a warp and weft of 12 g of the second structure, which corresponds to the bottom layer. Then, as shown by adding a square mark to the thread number in FIG. 15, the warp number 2, the warp number 5, the warp number 8, and the warp number 11, and the weft number 2, the weft number 5, the weft number 8, and The weft number 11 constitutes an intermediate structure 14 g sandwiched between the first structure and the second structure. Then, the other warp and weft constitutes the first structure 11 g.

The warp and weft of the first structure 11 g are multifilament threads for both the warp and weft, the warp and weft of the intermediate structure 14 g are also multifilament threads for both the warp and weft, and the warp and weft of the second structure 12 g are monofilament threads for both the warp and weft. It is composed. The multifilament yarn and the monofilament yarn have the same configuration as that of the first embodiment. As for the connection, the connection between the first tissue and the intermediate tissue is at two points, and the connection between the intermediate tissue and the second tissue is at two points. The exposure rate of the monofilament yarn in the first structure is 0% because the first structure and the second structure are indirectly connected via the intermediate layer, and the exposure rate of the multifilament yarn is 100%. be.

In the above embodiment, an example in which the filter cloth is double-woven or triple-woven is shown. A structure having a quadruple weave or more may be adopted as long as it has a second structure containing a monofilament yarn.

Hereinafter, examples are given, and the rigidity and air permeability of the filter cloth according to each example were evaluated.

The filter cloths having the configurations of the first to fifth embodiments described above were used as the filter cloths of Examples 1 to 5, respectively, and the rigidity and air permeability were determined. For comparison, the filter cloths of Comparative Example 1 and Comparative Example 2 having the following configurations were prepared, and only the rigidity and softness were determined for this. The rigidity was determined by the method of JIS L 1096 with the width of the test cloth changed to 5 cm.

In Comparative Example 1, the material and composition of the warp and weft are the same as those of the warp and weft of the first structure of Example 1, and the plain weave has a single structure. Comparative Example 2 is the same as that of Comparative Example 1 except that the warp is changed to a 890 dtex multifilament yarn and the structure is a single structure of 2/2 twill weave.

Table 1 shows the rigidity and air permeability obtained for the test pieces of each Example and each Comparative Example. The rigidity and softness were determined in both the vertical direction and the horizontal direction of the test piece.

As shown in Table 1, it can be seen that the filter cloths according to Examples 1 to 5 have stronger elasticity than the filter cloths of Comparative Examples. It can be seen that the filter cloth of each example has sufficient breathability, and the breathability, that is, the denseness of the first structure is not impaired by the monofilament yarn.

The filter cloths according to Examples 1 to 5 and Comparative Examples 1 to 2 were set in the centrifugal filtration device shown in FIG. 5 and filtered. In the filter cloth according to Examples 1 to 5, the filter cloth was effectively prevented from bending downward in the basket. With the filter cloths of Examples 1 to 5, it was easy to remove the filter matter accumulated on the filter surface. On the other hand, in the filter cloth according to Comparative Example 1 to Comparative Example 2, the filter cloth was bent downward in the basket, and a gap was formed between the basket and the filter cloth. Therefore, the liquid after filtration was mixed with a filter medium.

1a Filter cloth 11a First structure 12a Second structure 111a Warp of first structure 112a Weft of first structure 121a Warp of second structure 122a Weft of second structure 14f Intermediate structure

Claims (4)

A filter cloth containing a multi-structure having a first structure arranged on the surface in contact with the filter medium and a second structure arranged on the opposite side of the surface in contact with the filter medium.
The first structure and the second structure are woven fabrics.
The second structure contains monofilament yarn as an aggregate in both warp and weft.
The first tissue and the second tissue are made of monofilament yarn directly or indirectly connected as an aggregate.
The density of the monofilament yarn constituting the second structure is 10 to 25 yarns / inch for both the warp and the weft.
A filter cloth using the monofilament yarn as an aggregate to prevent bending.
Its use is a filter cloth for a centrifugal filtration device or a filtration device having a filter plate . The first structure contains at least one of warp and weft including multifilament yarn or spun yarn.
The second structure contains monofilament yarn as an aggregate in both warp and weft.
The first organization and the second organization are directly or indirectly connected to each other.
The filter cloth using the monofilament yarn as an aggregate according to claim 1, wherein the multifilament yarn or the spun yarn is exposed more than the monofilament yarn on the surface of the first structure that comes into contact with the filter medium. The filter cloth having a monofilament yarn as an aggregate according to claim 1 or 2 having an intermediate structure between the first tissue and the second tissue. The filter using the monofilament yarn according to any one of claims 1 to 3 as a monofilament yarn in which the warp and weft constituting the second structure are arranged in a direction in which the filter cloth is easily flexed as an aggregate. cloth.

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