JPH07136432A - Dust collecting filter cloth - Google Patents

Abstract

PURPOSE:To reduce the passing amt. of fine particles after the shaking-off of dust and carry out the good shaking-off of dust by entangling a fabric specified in wt. basis and warp and weft yarn density and a fiber web composed of fibers with specific fineness by water streams to integrate them. CONSTITUTION:A dust collecting filter cloth is constituted by using a fabric with a basis wt. of 200-400g/m<2> and warp and weft yarn density of 30-130/inch and develops excellent filtering capacity by the plane filtering of the fabric. A fiber web composed of fibers (fine fibers) with finness of 3 denier or less and a wt. basis of 100g/m<2> or less is entangled and integrated with the fabric by water streams. By this constitution, fine fibers are present in an entangled state in place of coarse particles remaining in the gaps of the fabric heretofore and, when the filter cloth is used for the first time or after the shaking-off of dust is performed, the passing amt. of fine particles is reduced. Even after the shaking-off of dust is performed, stable filtering capacity can be developed over a long period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collecting filter cloth.

[0002]

2. Description of the Related Art The filtering performance of a dust collector, for example, a bag filter, is mainly caused by coarse particles remaining on the surface of the filter cloth and the voids of the filter cloth. Therefore, when the filter cloth is used for the first time, or after dust is removed, before the coarse particles remain in the pores of the filter cloth, particles finer than the pores of the filter cloth are collected by the filter cloth. Instead, it was something that would pass.

On the other hand, in Japanese Unexamined Patent Publication No. 62-140615, polytetrafluoroethylene fiber (hereinafter referred to as PTFE fiber) and glass fiber are integrated with a scrim as a felt for a filter by the action of water flow. Things are disclosed. This is because the use of only PTFE fibers does not give a felt that is uniform and has excellent mechanical stability. Therefore, not only the glass fibers are mixed, but a scrim that does not block the air flow is used to stabilize the felt. It gives the sex and strength. As described above, since the scrim has a coarse mesh, when this felt is used for a filter application, it becomes a filter by internal filtration having filtration performance with PTFE fiber or glass fiber. When this filter is used as a dust collector, for example, as a filter cloth for a bag filter, since it is internal filtration, dust cannot be removed sufficiently even if it is removed, resulting in low air permeability and processing capacity. Will decrease rapidly and the service life will be short.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and passes fine particles when the filter cloth is used for the first time or after dust is removed. An object of the present invention is to provide a surface filtration type dust collecting filter cloth which has a small amount and is capable of sufficiently removing dust.

[0005]

The dust collecting filter cloth of the present invention (hereinafter sometimes referred to as "filter cloth") has a basis weight of 200 to 40.
A woven fabric of 0 g / m ² , warp and weft densities of 30 to 130 threads / inch, and a fiber web made of fibers having a fineness of 3 denier or less and having a basis weight of 100 g / m ² or less are entangled and integrated by a water current. is there.

When the warp yarn and weft yarn of the woven fabric of the present invention have a density of 40 to 100 yarns / inch and the fiber web has a basis weight of 70 g / m ² or less, the surface filtration performance is more excellent.

The fineness of the fibers constituting the fiber web of the present invention is 2 denier or less, or the fibers constituting the fiber web contain easily splittable fibers which can be divided into ultrafine fibers having a fineness of 0.5 denier or less. It is a filter cloth for dust collection that can collect finer particles.

[0008]

The filter cloth of the present invention has a basis weight of 200 to 400, which is as dense as the woven cloth conventionally used as a dust collecting filter cloth.
g / m ² , warp and weft densities of 30 to 130 yarns / inch are used in the fabric, and basically, the filtration performance is exhibited by the flat filtration of this fabric, so that dust can be sufficiently removed. it can. In the present invention, a small amount of fiber web having a fineness of 3 denier or less (hereinafter sometimes referred to as fine fiber) and having a basis weight of 100 g / m ² or less is entangled and integrated with the woven fabric by the water flow, Conventionally, instead of the coarse particles remaining in the voids of the woven fabric, fine fibers are entangled, and therefore, when the filter cloth is used for the first time or after the dust is removed, It is a filter medium that not only has a small passage amount but also does not open the eyes of the woven fabric when dust is blown off, and thus exhibits stable filtration performance for a long period of time.

The woven fabric of the present invention may be as dense as the woven fabric conventionally used as a dust collecting filter cloth, and by using such a woven cloth, flat filtration performance is provided. More specifically, the basis weight is 200 to 400 g /
Woven fabrics with a density of 30-130 yarns / inch of m ² , warp and weft are used. When the basis weight of this woven fabric is less than 200 g / m ² , the woven fabric is coarse and it is difficult to efficiently filter the surface, despite having a density of 30 to 130 fibers / inch. If the fabric weight exceeds 400 g / m ² ,
This is because the breathability becomes poor. More preferably, the basis weight 2
It is 50 to 350 g / m ² . In addition, when the density is less than 30 fibers / inch, the woven fabric has coarse meshes and it is difficult to filter the surface efficiently even though the basis weight is 200 to 400 g / m ^2. This is because if it exceeds 130 lines / inch, the air permeability will deteriorate. More preferably, the warp yarn and weft yarn have a density of 40 to 100 yarns / inch.

The breathability of such a fabric is 5-30 cm ³ / (c
m ² · s) is preferred. If it is less than 5 cm ³ / (cm ² · s), the air permeability will deteriorate, and if it exceeds 30 cm ³ / (cm ² · s),
This is because the dust collection efficiency decreases. More preferably 10
It is about 20 cm ³ / (cm ² · s).

The fibers constituting the woven fabric may be monofilaments or multifilaments and are not particularly limited. Further, the type of fibers constituting the woven fabric can be appropriately selected depending on the temperature of the processing gas, the degree of acidity and alkalinity, the required dimensional stability, the required life, and the like. For example, natural fibers such as silk, wool, cotton and hemp, regenerated fibers such as rayon fibers, semi-synthetic fibers such as acetate fibers, animal fibers such as wool, glass fibers, inorganic fibers such as carbon fibers, polyamide fibers, polyvinyl alcohol. Synthetic fibers such as fibers, acrylic fibers, polyester fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyurethane fibers, polyethylene fibers, polypropylene fibers, fluorine fibers, or electroconductive fibers or electroconductive particles mixed with electroconductive particles. The fibers can be used alone or in a mixture.

It should be noted that not only fibers made of one component such as these fibers, but also heat-sealable core-sheath type and side-by-side type fibers made of two or more resin components, or mechanically and / or chemically treated It is also possible to use a composite fiber that can be divided into ultrafine fibers, and after forming a woven fabric using these fibers, fusion and / or division may be performed.

The weaving method of the woven fabric of the present invention is not particularly limited, and may be plain weave, twill weave or satin weave.

The filter cloth of the present invention is made of fine fibers having a fineness of 3 denier or less with respect to such a woven fabric.
A small amount of g / m ² or less fiber web is entangled and integrated by water flow, and since fine fibers act as conventional coarse particles, the amount of fine particles passing is small and the fibers of the woven fabric are fixed together. Therefore, the eyes of the fabric do not open when the dust is removed, and the fabric can be used for a long time. Further, since the amount of the fiber web is small, the basic action of flat filtration by the woven fabric is not hindered.

As described above, the fineness of the fibers constituting the fiber web of the present invention is 3 denier or less. This is because if the fineness exceeds 3 denier, it becomes difficult to collect fine particles. More preferably, it is 2 denier or less. vice versa,
When the fineness is less than 0.01 denier, the fiber has no strength and the life is shortened. Therefore, the fineness is preferably 0.01 denier or more. Also, the type of fiber can be appropriately selected depending on the temperature of the processing gas, the degree of acidity and alkalinity, the required dimensional stability, the required life, etc., as in the case of the fibers constituting the woven fabric. Fibers similar to those used can be used.

Among these, as the fibers constituting the fiber web, easily splittable fibers that can be divided into ultrafine fibers having a fineness of 0.5 denier or less are included, and the fibers are divided into ultrafine fibers by the action of water flow. With this, finer particles can be collected, the fibers of the woven fabric can be more firmly fixed to each other, and the amount of fiber web can be further reduced (40 g / m ² or less in basis weight), so that it can be more preferably used.

Examples of the easily splittable fiber include a multi-bimetal type fiber having a cross section in which different components are alternately laminated in layers, or a cross section obtained by splitting one component by another component extending from the center of the fiber to the fiber surface. There are chrysanthemum-shaped fibers.

As a combination of resin components constituting the easily splittable fiber, polyamide resin and polyester resin, polyamide resin and polyolefin resin, polyester resin and polyolefin resin, polyester resin and polyacrylonitrile resin, Examples include polyamide-based resin and polyacrylonitrile-based resin, and polyolefin-based resin and polyacrylonitrile-based resin, but are not limited thereto.

It is preferable that the easily splittable fiber is contained in an amount of 20% by weight or more. The larger the amount, the finer particles can be collected, the fibers of the woven fabric can be more firmly fixed to each other, and the amount of the fiber web is reduced. Therefore, it is more preferably 50% by weight or more, and most preferably 100% by weight.

In the present invention, from the above fibers, for example, a card method, an air lay method, a wet method, a spun bond method,
The fiber web can be formed by a melt blow method or the like, but is not limited to these methods.

The basis weight of the fibrous web thus formed is 100 g / m ² or less. When the basis weight exceeds 100 g / m ² ,
This is because the amount of fibers becomes too large, and internal filtration is performed using fibers rather than surface filtration of the woven fabric, dust is insufficiently removed, and the life is shortened. More preferably, 70
g / m ² or less. In addition, in order to collect fine particles and fix the fibers of the woven fabric by the fine fibers, it is preferably 5 g / m ² or more. It is more preferably 10 g / m ² or more.

Since the woven fabric and the fibrous web are entangled with each other by the flow of water and can be integrated without damaging the woven fabric or the fine fibers, there is no problem that the collection efficiency is lowered. It is cloth. As the entanglement integration by the water flow, for example, after laminating the woven fabric and the fiber web, a water flow having a water pressure of 50 kg / cm ² or more is applied from the nozzle plate. Further, the conveyer for conveying the laminate of the woven fabric and the fiber web is not particularly limited, and may be, for example, a net or a perforated plate made of metal or plastic, 60 to 15
A 0 mesh plain weave net or the like can be used. Furthermore, the water flow may be acted not only once but twice or more, or may be acted from only one side or both sides.

Examples of the present invention will be described below, but the invention is not limited to the following examples.

[0024]

【Example】

(Example 1) Five sheets satin weave having a basis weight of 300 g / m ² , a fresh density of 50 filaments / inch, a horizontal density of 40 filaments / inch, and a polyester multifilament and having a breathability of 16 cm ³ / (cm ² · s). Prepared the fabric. On the other hand, a polyester fiber having a fineness of 1.5 denier and a fiber length of 38 mm was opened by a card machine to obtain a fiber web having a basis weight of 60 g / m ² . After laminating this fibrous web on a woven fabric, it is placed on an 80 mesh plain weave net, and a water flow of 100 kg / cm ² of water pressure is applied twice from the nozzle plate from the same direction to entangle and integrate the woven fabric and the fibrous web. To obtain a filter cloth having a thickness of 1.1 mm.

(Example 2) As a fiber constituting a fiber web, a polyester component was divided into eight polyamide components radially extending from the center of the fiber to the surface of the fiber, and was divided into eight polyamide components. 20 g / weight, which was opened by a card machine and was splittable with a fineness of 2 denier and a fiber length of 38 mm, which was easy to split (polyester component fineness 0.175 denier, polyamide component fineness 0.075 denier) A filter cloth having a thickness of 1.1 mm was obtained in the same manner as in Example 1 except that a m ² fiber web was used.

Comparative Example 1 A filter cloth having a thickness of 1.1 mm was prepared in the same manner as in Example 1 except that polyester fiber having a fineness of 6 denier and a fiber length of 51 mm was used as the fiber constituting the fiber web. Obtained.

Comparative Example 2 A filter cloth having a thickness of 1.2 mm was obtained in the same manner as in Example 1 except that a fiber web having a basis weight of 110 g / m ² was used.

(Comparative Example 3) The same as in Example 1, after laminating the woven fabric and the fibrous web, the needle was made to act to entangle and integrate with a needle density of 50 needles / cm ² , and the temperature was 180 ° C. Thermal calendering was performed at a pressure of 3 kg / cm to obtain a filter cloth having a thickness of 1.1 mm.

Comparative Example 4 Only the woven fabric used in Example 1 was used as a filter cloth (thickness 1.0 mm).

(Dust Collection Efficiency Test) With the filter cloths of Examples 1 and 2 and Comparative Examples 1 to 4, polystyrene latex having a single particle size of 0.3 μm was filtered at a filter cloth passage speed of 2 m / min. On this occasion,
The particle concentration before and after filtration was measured with a particle counter, and the dust collection efficiency was calculated by the following formula. The results show that the filter cloth of the present invention has a high collection efficiency as shown in Table 1. In this way, although the collection efficiency was measured with a filter cloth having the same thickness as that of the conventional woven fabric, the filter cloth of the present invention has a high collection efficiency, and therefore it is collected by surface filtration. It can be seen that, therefore, it is possible to sufficiently remove the dust.

[0031]

[Table 1]

(Breathability test) Examples 1 and 2 and Comparative Example 1
The air permeability of the filter cloths of 4 to 4 of JIS L 1096 6.27.
It was measured by the method defined in Method A of 1 above. The results are also shown in Table 1.

[0033]

EFFECT OF THE INVENTION The dust collecting filter cloth of the present invention uses a dense woven fabric, and since the amount of fibers entangled and integrated with the woven fabric is small, the surface filtration performance of the woven fabric is not impaired. Therefore, the dust can be sufficiently removed, and the fibers having a denier of 3 denier or less are entangled in the voids of the woven fabric,
Capable of collecting fine particles, having a small amount of fine particles passing through, and having stable filtration performance for a long period of time without opening the eyes of the woven fabric when dust is removed Is.

In the filter cloth for dust collection of the present invention, the warp and weft of the woven fabric have a density of 40 to 100 yarns / inch,
When the basis weight of the fibrous web is 70 g / m ² or less, the surface filtration performance is more excellent and the dust can be sufficiently removed.

The dust-collecting filter cloth of the present invention can be easily divided into ultrafine fibers having a fineness of 2 denier or less in the fibers constituting the fiber web, or 0.5 denier or less in the fibers constituting the fiber web. When the splittable fiber is contained, finer particles can be collected and the amount of the fiber web can be reduced, so that the filter cloth has more excellent surface filtration performance.

Claims (5)

[Claims] 1. A woven fabric having a basis weight of 200 to 400 g / m ² , warp and weft densities of 30 to 130 yarns / inch, and a fiber web having a basis weight of 100 g / m ² or less, which comprises fibers having a fineness of 3 denier or less, The filter cloth for collecting dust is characterized by being entangled and integrated with each other. 2. The density of the warp and weft of the woven fabric is 40
The filter cloth for dust collection according to claim 1, wherein the filter cloth is from about 100 fibers / inch. 3. The filter cloth for dust collection according to claim 1 or 2, wherein the fibers constituting the fiber web have a fineness of 2 denier or less. 4. The fiber constituting the fiber web contains easily splittable fibers that can be split into ultrafine fibers having a fineness of 0.5 denier or less. Filter cloth for dust collection. 5. The filter cloth for dust collection according to claim 1, wherein the fiber web has a basis weight of 70 g / m ² or less.