JP2006116534A - Filter and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily remove dust by suppressing electrostatic charge even in a dried state. <P>SOLUTION: This filter comprises woven knitted matter with conductive synthetic fibers arranged among non-conductive fibers, a surface electric resistance of the woven knitted matter is 1.0×10<SP>11</SP>Ω/sq. or less, and an aperture ratio is 30-80%. Fiber diameters of conductive synthetic fibers are preferably 10-50 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter, a prefilter, and a manufacturing method thereof suitable for collecting air for air conditioning and vacuum cleaners.

  In order to prevent indoor dust and dirt from entering the interior of an air conditioner or cyclone type vacuum cleaner, nonwoven fabrics and woven fabrics made of polyolefin monofilaments such as polyethylene and polypropylene are used as prefilters.

  This pre-filter extends the clogging life of a high-performance filter such as a HEPA filter after the pre-filter by removing rough dust / dust beforehand. Further, the air conditioner is provided in order to prevent dust / dust from entering the heat exchanger and prevent a decrease in energy efficiency.

  These pre-filters are clogged over time, and the performance as a dust collecting filter is remarkably deteriorated. The pre-filters have a removable structure so that they can be easily replaced.

As an example of such a prefilter, Patent Document 1 discloses a non-woven fabric. Patent Document 2 discloses a prefilter made of a net formed by knitting fibers having a two-layer structure of an outer layer and an inner layer, and welding and fixing the outer layer.
JP 2001-96118 A JP 2004-89847 A

  However, in the case of using the nonwoven fabric of Patent Document 1 as a prefilter, when clogging occurs, it is difficult to remove and clean the prefilter to remove dust, and after cleaning the prefilter, It is difficult to return and reuse.

  Moreover, since the thing of patent document 2 is what knitted the fiber, after cleaning and removing dust, it can return to a prefilter again, but in dry conditions, such as winter, Since dust, dust, and the material constituting the prefilter are charged, there is a problem that they cannot be removed even after cleaning.

In order to solve the above problems, the present invention comprises a woven or knitted fabric in which conductive synthetic fibers are arranged between non-conductive synthetic fibers, and the surface electrical resistance of the woven or knitted fabric is 1.0 × 10 ¹¹ Ω / □. Hereinafter, the gist is a filter having an aperture ratio of 30 to 80%. The fiber diameter of the conductive synthetic fiber is preferably 10 to 50 μm, the electrical resistance value of the conductive synthetic fiber is 1.0 × 10 ¹⁰ Ω / cm or less, and the electrical resistance value of the non-conductive synthetic fiber is 1.0. × 10 ¹³ Ω / cm or more, and the interval between adjacent conductive synthetic fibers arranged in the same direction is 1 mm or more and 20 mm or less, and the amount of the conductive synthetic fibers used is 0.5% with respect to the entire woven or knitted fabric. More preferably, the content is from 10% by weight to 10% by weight. Among these, it is more preferable that the non-conductive synthetic fibers include those obtained by fusing core-sheath composite fibers made of a resin having a melting point lower than that of the core. And the fiber diameter of the said nonelectroconductive synthetic fiber is preferable in it being 20-100 micrometers, More preferably, it is a filter whose maximum space | gap length of the said woven / knitted fabric is 40-800 micrometers.
The present invention is also a filter having a numerical aperture of 30 to 80% or less, comprising a woven or knitted fabric made of conductive synthetic fibers and non-conductive synthetic fibers kneaded with conductive components in the fibers. The conductive synthetic fiber is preferably one in which a part of the conductive component is exposed.
Moreover, it is also a pre-filter of a dust collection filter formed by sandwiching the filter between frame bodies. And it is also a dust collection filter provided with the pre-filter which removes dust by putting the woven or knitted fabric between the frames, and the main filter which passes through the pre-filter and further removes fine dust. This dust collection filter is preferably used for air conditioning or vacuum cleaner.
Further, the woven or knitted fabric is preferably composed mainly of polyester, and the frame is formed by fusing and molding a thermoplastic resin having a melting point of polyester or lower.
In the present invention, the opening ratio is 30 to 80%, and the conductive synthetic fiber is a woven fabric in which the sheath component is arranged between the non-conductive synthetic fibers including the core-sheath type composite fiber having a melting point lower than that of the core component. It is also a method for producing a dust collecting prefilter in which a frame made of a synthetic resin having a melting point lower than that of the core component is fused and molded on a knitted fabric.

  According to the filter of the present invention, electrification can be suppressed even when dry, and dust and dust can be easily removed. Moreover, according to the manufacturing method of this invention, since a prefilter can be manufactured easily, the prefilter for dust collection using the filter of this invention can be manufactured cheaply.

  The filter of the present invention can be suitably used as a dust pre-filter for removing dust or dust in advance, which is detachably provided in front of a high-precision filter for air conditioning or a vacuum cleaner.

  The filter of the present invention comprises a woven or knitted fabric containing conductive synthetic fibers and non-conductive synthetic fibers. Here, as the woven or knitted fabric, for example, weaving such as plain weaving, satin weaving, twill weaving, honeycomb weaving, warp knitting such as single tricot or double tricot, circular knitting, etc. can be used, but there is smoothness with good dust separation. From the viewpoint of the structure, a mesh fabric (in particular, a plain weave) having an appropriate void is particularly preferable.

  The woven or knitted fabric has a mesh shape with an opening ratio of 30 to 80%, and an opening ratio of 30 to 60% is particularly preferable. The opening ratio is a ratio of the gap to the entire area of the woven or knitted fabric. Specifically, referring to FIG. 1, [(area of the woven or knitted fabric 10−area occupied by the yarn (that is, diagonal lines) The void portion shown)) / area of the woven / knitted fabric 10] × 100 (%). Here, it is usually preferable that each aperture ratio is substantially uniform. If the aperture ratio of each gap is substantially uniform, it is easy to obtain a product that is excellent in aesthetics and filter performance. When the aperture ratio is less than 30%, a large pressure loss occurs when used as an air filter or the like, and clogging is likely to occur. If the opening ratio exceeds 80%, pressure loss is less likely to occur, but the strength of the knitted or knitted fabric tends to be insufficient, and it tends to tear when cleaned, resulting in poor durability.

The surface electrical resistance of the woven or knitted fabric is preferably 1.0 × 10 ¹¹ Ω / □ (ohms per square) or less. This surface electrical resistance has a correlation with the withstand voltage of friction, and if it is 1.0 × 10 ¹¹ Ω / □ or less, good antistatic performance can be exhibited. This is preferable because it can be easily removed. Among these, 1.0 × 10 ⁶ Ω / □ to 1.0 × 10 ¹⁰ Ω / □ is preferable.

In addition, as a method of setting the surface electrical resistance of the woven or knitted fabric to 1.0 × 10 ¹¹ Ω / □ or less, a method of introducing a hydrophilic group to the fiber surface by graft polymerization or the like, or a method of attaching a surfactant by post-processing And so on. However, in these methods, the antistatic performance is hardly exhibited under conditions of low temperature and low humidity, and the surface surfactant is washed away by washing with water and the like, and the performance may be remarkably deteriorated. Therefore, in the present invention, conductive synthetic fibers are arranged on the woven or knitted fabric.

In order to maintain the necessary strength of the woven or knitted fabric as a filter while maintaining the antistatic performance, the woven or knitted fabric has an electrical resistance value of 1.0 × 10 ¹⁰ Ω / cm or less, non-conductive. The electrical resistance value of the synthetic fiber is 1.0 × 10 ¹³ Ω / cm or more, the interval between adjacent conductive synthetic fibers arranged in the same direction is 1 to 20 mm, and the amount of the conductive synthetic fiber used is woven or knitted It is preferable that it is 0.5 weight% or more and 10 weight% or less with respect to the whole, especially 1 to 5 weight% or less. In addition, as for the space | interval of the said conductive synthetic fiber, 2-10 mm is more preferable, and 3-5 mm is especially preferable.

  Hereinafter, more specific conductive synthetic fibers will be described.

  Examples of the conductive synthetic fiber include a synthetic fiber coated with a conductive component and a synthetic fiber itself containing a conductive component. Among these, from the viewpoint that it is difficult to peel off due to friction or the like, it is preferable that the conductive synthetic fiber itself contains a conductive component.

  Examples of conductive components of such conductive synthetic fibers include furnace-based carbon black, carbon nanotubes, ketjen black, graphite, silver, copper, tin, nickel, aluminum and other conductive metal powders, tin oxide, Examples thereof include a fine powder of zinc oxide, ITO, ATO conductive metal oxide or a fine ceramic powder such as titanium oxide coated with a conductive metal oxide such as metal, ITO, or ATO. It is preferable that these conductive components are mixed and contained in a synthetic fiber at a high concentration.

  The thermoplastic resin containing a conductive component to form a synthetic fiber includes polyamides such as 6 nylon, 12 nylon and 66 nylon and copolymers thereof, polypropylene and polyethylene, and copolymers thereof, polyolefins And fiber-forming polymers such as polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyesters and copolymers thereof. Of these, conductive synthetic fibers in which furnace-type carbon black is mixed with polyester are preferred from the viewpoint of antistatic performance, ease of production and low cost production.

  The fiber diameter of the conductive synthetic fiber is preferably 10 to 50 μm. That is, 10 μm or more is preferable from the viewpoint of the durability of the filter, and 50 μm or less is preferable from the viewpoint of ease of production of conductive synthetic fibers.

  The conductive synthetic fiber is preferably composed of two or more twisted yarns in the range of 10 to 50 μm. A preferable number of twists is 10 times / m to 100 times / m. More preferably, 3 to 6 twisted ones having a thickness of 15 to 30 μm are twisted, which is preferable in terms of the ease of manufacturing the conductive synthetic fiber and the durability of the filter.

  Basically, the smaller the diameter of a single fiber composing the conductive synthetic fiber, the lower the energy and induces corona discharge by electrostatic induction, and neutralizes the charge by ionizing surrounding gas molecules. However, if the single yarn fiber diameter is too small, the single yarn may stretch and break with a small tension, and if it is too large, the antistatic performance of the woven or knitted fabric tends to deteriorate. Therefore, the single yarn fiber diameter of the conductive synthetic fiber is preferably 10 to 50 μm, and more preferably 15 to 30 μm.

The conductive synthetic fiber may be a monofilament or a multifilament, but a multifilament is preferred from the viewpoint of dust separation and durability of the filter and ease of production of the conductive synthetic fiber.

  Examples of the cross-sectional shape of the single yarn of the conductive synthetic fiber include those shown in FIG. In the figure, A represents the conductive component, and B represents a fiber-forming polymer. The cross-sectional shape is not limited to that shown in FIG. 2 and may be circular or non-circular. However, in order to obtain sufficient conductive performance efficiently, FIGS. ) And (c) are preferably exposed on at least a part of the fiber surface. Among them, from the viewpoint of antistatic, the conductive component is exposed on the surface and the conductive component is sandwiched between non-conductive components, as shown in FIG. 2C, and the conductive component is present on the fiber surface. It is preferable that the A and B components in FIG. 2 (d) which are completely exposed are reversed.

  Next, the non-conductive synthetic fiber will be described.

  First, the non-conductive synthetic fiber is not particularly limited as long as it is made of a thermoplastic resin capable of forming fibers and does not impair the performance as a filter.

  Examples of the thermoplastic resin constituting the non-conductive synthetic fiber include polyamides such as 6 nylon, 12 nylon and 66 nylon and copolymers thereof, polyolefins such as polypropylene and polyethylene, and copolymers thereof, polyethylene terephthalate , Polybutylene terephthalate, polytetramethylene terephthalate, polyesters and copolymers thereof. The non-conductive synthetic fiber may be a fiber composed of the same component using only one of these components, or may be a fiber composed of different components. In the fiber which consists of a different component, the core-sheath-type composite fiber comprised from two types of components which arranged resin whose melting | fusing point is lower than a core component in a sheath part is used suitably. In addition, these fibers may be composed of a single fiber or may be a yarn in which a plurality of fibers are aligned.

  In particular, if the core-sheath type composite fiber is composed of two types of components in which a resin having a lower melting point than that of the core component is arranged in the sheath, the sheath component is fused, so that it can be dried even during normal use. Even when washed with water and used, it is preferable because it is easy to maintain the initial filter performance without misalignment. In addition, if the core-sheath type composite fiber and conductive synthetic fiber containing a conductive component in the fiber are arranged and the intersection of the woven or knitted fabric is fused, there will be no misalignment when drying or washing with water. Also, the conductive performance is easy to maintain the initial state, the initial filter performance is easy to maintain, and the durability is excellent and preferable. As the core-sheath type composite fiber, a combination of polyester as a core component and a copolymer component with a sheath component having a melting point higher than that of the core component by 20 ° C. or more is preferable because of excellent versatility and recyclability. . Such a core-sheath type composite fiber may be composed only of the core-sheath type composite fiber, or may be composed of a thread in which the core-sheath type composite fiber and a fiber made of a monopolymer are aligned. This is preferable from the viewpoint of obtaining excellent filter performance.

  The fiber diameter of the non-conductive synthetic fiber is preferably 10 to 100 μm. More preferably, it is 20-80 micrometers. If it is this range, even if the charged dust and dust will enter into the uneven part of the woven or knitted fabric, it can be easily removed while maintaining the ease of manufacturing the woven or knitted fabric and the strength to use as a filter.

  As a preferred embodiment of the non-conductive synthetic fiber of the present invention, there is a polyester fiber. When a monofilament is used, a polyester monofilament having a low fineness of 20 to 50 dtex, or 30 to 30 from the viewpoint of durability and separation of charged dust. 100 dtex polyester multifilament is preferred.

  Normally, such a filter often uses a monofilament, but it is preferable to use a multifilament. That is, when the multifilament has the same thickness as a normal monofilament, the area of contact between the warp and the weft becomes large when the woven fabric is used, and the woven fabric is smooth and easily separated from dust. Moreover, in the case of the core-sheath type composite multifilament, the strength and stiffness of the woven or knitted fabric can be easily given by heat fusion, so that the durability as a filter can be easily maintained. In addition, there is an advantage that when the filter is integrated with the frame, it can be easily molded and can be efficiently produced.

  In the case of a polyester multifilament, the number of filaments can be selected as appropriate, but the single yarn fineness is preferably 1 to 25 dtex from the viewpoint of easy production of the woven or knitted fabric. In the case of multifilaments, after weaving and weaving, it is covered with resin and fixed, or the filaments are fused to form a monofilament by heat, etc., preventing dust and dust from entering between the single filaments of the multifilament. It is preferable to do. If it is such, it can be easily removed even when dust is collected by using it as a pre-filter for air conditioning or a vacuum cleaner, and it is easy to maintain the initial filter performance.

  The non-conductive synthetic fiber is preferably composed of two or more twisted yarns having a fiber diameter of 10 to 100 μm. The number of twists is preferably 500 to 1500 times / m, and more preferably 800 to 1200 times / m. Among them, if the fiber diameter is 20 to 80 μm, a plurality of (for example, 8 to 50) twisted ones are twisted 800 to 1200 times / m, the filter has a certain hardness or more. It is excellent in that it is easy to handle as a product and easily prevents misalignment. Also, weaving is good.

  Further, as described above, the conductive synthetic fiber is used at least as a part of the woven or knitted fabric. It may be used only in the warp direction, may be used only in the weft direction, or may be used in both directions. Preferably, only the non-conductive synthetic fiber is arranged in either direction, and the conductive synthetic fiber is arranged at regular intervals between the plurality of non-conductive synthetic fibers. It is preferable to do. The distance between the conductive synthetic fibers is preferably 1 to 20 mm, more preferably 2 to 10 mm, and still more preferably 3 to 5 mm, from the viewpoint of efficiently expressing electrostatic performance.

  When the conductive synthetic fiber is used for warp or weft, a yarn composed only of the conductive conductive synthetic fiber may be used for the warp or weft, or the conductive synthetic fiber and the non-conductive synthetic fiber. May be used for warp or weft. In addition, in the case of a mixed fiber, it is preferably a twisted yarn in which the conductive synthetic fiber and the nonconductive synthetic fiber are aligned and twisted together.

  The maximum gap length of the warp and weft of the woven or knitted fabric (in the case of warp, the maximum length of the gap between adjacent warps, the same applies to the weft) may be appropriately selected depending on the dust to be removed. If it is the pre filter of an air filter, it is preferable that it is 40-800 micrometers. In addition, if it is a pre filter in a cyclone type vacuum cleaner, the range of 40-200 micrometers is preferable. Moreover, if it is a pre filter for air conditioning, 200-800 micrometers is preferable.

  The strength of the woven or knitted fabric is 300 kPa because it is easy to hold the shape when taking out dust collected in the prefilter and cleaning it when used for air conditioning devices such as air filters and prefilters for vacuum cleaners. In particular, 400 kPa or more is preferable.

The bending resistance of the woven or knitted fabric is preferably 60 mm or more, and more preferably 80 to 120 mm. In particular, when used for air conditioning devices such as air filters and pre-filters for vacuum cleaners, it is usually formed by sandwiching a woven or knitted fabric between frames, and a reinforcing bridge is used to maintain the shape of the woven or knitted fabric. However, since the amount of bridges can be reduced if the fabric has high bending resistance, the opening ratio of the woven or knitted fabric can be made close to the opening ratio of the prefilter. Therefore, dust can be collected more effectively. Even when the aperture ratio is high, the yield can be improved when the pre-filter is manufactured by fixing the woven or knitted fabric to the frame, so that it can be provided at a low cost.

  The dust collecting filter of the present invention is obtained by fixing a filter made of the woven or knitted fabric to a frame body as a pre-filter and detachably attaching to the main filter.

  Here, the frame is preferably molded from a thermoplastic resin such as polyester. More specific thermoplastic resins include, for example, polyamides such as 6 nylon, 12 nylon and 66 nylon and copolymers thereof, polyolefins such as polypropylene and polyethylene and copolymers thereof, ABS (acrylonitrile butadiene), and the like. Enstyrene), polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyesters and copolymers thereof, and thermoplastic resins such as vinyl chloride, polycarbonate polyphenylene ether, polystyrene, and polyacetal. In addition, in this thermoplastic resin, glass fibers, fillers such as talc, conductive agents such as carbon black and metals, thermal stabilizers, antioxidants, colorants such as pigments, etc., as long as the performance as a filter is not impaired. You may add additives, such as a flame retardant, an antistatic agent, a ultraviolet stabilizer, and a ultraviolet absorber. Among these, polypropylene and ABS are preferable because they are easy to mold and can be provided at low cost.

  Moreover, it is preferable that the said frame is a thing whose melting | fusing point is lower than the synthetic fiber which comprises the woven / knitted fabric of a pre filter. Such a frame body is easy to manufacture because it can be easily fused by heating and pressurizing after obtaining a woven or knitted fabric. In addition, if the sheath component is a woven or knitted fabric composed of a non-conductive synthetic fiber and a conductive synthetic fiber made of a core-sheath type composite fiber having a melting point lower than that of the core component, the frame body and the sheath component can be fused at once. The molding process can be simplified.

  In addition, when manufacturing a prefilter, as a method of fixing the frame and the woven or knitted fabric, other methods such as injection molding, ultrasonic bonding, and bonding with an adhesive can be appropriately selected. From the viewpoint of ease of operation and low cost, coupling by injection molding is preferable. This pre-filter is provided in front of a main filter such as a HEPA filter, and can be suitably used as a dust collection filter for air conditioning or a vacuum cleaner.

In addition, a suitable aspect is shown below about the woven / knitted fabric used for the pre filter of air conditioner apparatuses, such as an air conditioner. Usually, since there is not so much dust, the larger the gap of the filter as much as possible, the less clogging and the collected dust can be easily removed as long as other physical properties such as strength are not impaired. From such a point, it is preferable that the aperture ratio is 60 to 80%, and the fiber diameters of the conductive synthetic fiber and the non-conductive synthetic fiber are 30 to 120 μm, particularly 50 to 100 μm.
An air conditioning device such as an air conditioner uses a prefilter in a relatively wide area (for example, 300 cm ² ). However, the prefilter is not misaligned, has a uniform opening, and has a high opening ratio. From the point of obtaining a product with excellent recyclability and durability, composite fiber multifilaments containing conductive components and low-melting-point components such as low-melting polyester in the sheath, and sheathing components such as regular polyester in the core, as conductive synthetic fibers The core-sheath type composite fiber is used as a non-conductive synthetic fiber by using a twisted yarn obtained by twisting a core-sheath type composite fiber multifilament combined with a high melting point component having a higher melting point and giving a twist of 800 to 1200 times / m. A woven or knitted fabric obtained by weaving and knitting using fiber multifilaments, etc. is fused at a temperature higher than the sheath component and lower than the core component. The touch area and large dirt dust separation well, preferable that there is a certain level hardness. When the opening ratio is high, if there is no certain hardness, when forming a woven or knitted fabric into a filter, the yield tends to be poor and the incidence of defective products tends to be high. When it is used and the bending resistance is 60 mm or more, preferably 80 to 120 mm, it is preferable in that the occurrence rate of defective products can be suppressed low.

  Moreover, a suitable aspect is shown below about the woven / knitted fabric used for the pre filter of a cleaner. Compared to air conditioners and the like, large dust particles are supplemented and cleaning is often performed frequently. In such a case, it is preferable that the aperture ratio is 30 to 60%, and the fiber diameters of the conductive synthetic fiber and the non-conductive synthetic fiber are 20 to 50 μm, particularly 30 to 50 μm. If the aperture ratio is 30 to 50% and the aperture ratio is relatively low, it is preferable to use a monofilament as the non-conductive synthetic fiber. If the aperture ratio exceeds 50%, the filter performance is not misaligned. In order to improve, it is preferable to use a core-sheath type composite fiber multifilament in which a low melting point component such as low melting point polyester is used for the sheath and a high melting point component having a higher melting point than the sheath component such as regular polyester is used for the core.

  The physical properties and evaluation were as follows.

A. Electrical resistance value About conductive synthetic fiber, the fiber length was cut off to 11 cm, and 0.5 cm of both ends of the fiber and a 1 cm square aluminum foil side were adhered with a conductive adhesive containing silver paste to prepare a sample. This sample was washed with water and left in a room at a temperature of 25 ° C. and a humidity of 60% for 24 hours. The electrical resistance was measured at a voltage of 100 V, and the electrical resistance value per 1 cm was calculated.
As for non-conductive synthetic fibers, those having an electric resistance value of 1.0 × 10 ¹³ Ω / cm or more cannot be measured. Therefore, the above sample is measured in a bundle of 100 pieces, and the electric resistance value between 10 cm is measured. After measuring, it converted into the electrical resistance value per one.

B. Surface electrical resistance value Two 10 cm long copper terminals were separated in parallel at 10 cm intervals, and the woven or knitted fabric was allowed to stand at a voltage of 100 V at both ends of the copper terminals at a temperature of 25 ° C. and a humidity of 60% for 24 hours. And the surface resistance per 1 cm ² was determined.

C. Dust removal performance (when dry)
The filters obtained in Examples and Comparative Examples were lightly rubbed about 10 times.
Next, the tip of the suction cylindrical hose of a cyclone type vacuum cleaner made in Japan (maximum suction work rate 580w type) using a mixed powder of 15 kinds of JIS-Z-8901 test powder in a room at room temperature of 20 ° C. and humidity of 40% ( The filter was attached to an inner diameter of 35 mm), and the dust adhesion state was evaluated.
Good (◎) with little dust adhering, slightly attached but good (○) with easy removal by brushing, only fine powder adhered even with brushing A thing ((triangle | delta)) was evaluated as a defect (*) with the thing with which (((triangle | delta))) applied a brush and dust remained even if it applied a brush.
At this time, the paper pack was subjected to a suction test while being replaced with a new one for each test.

D. Dust removal performance (after applying water washing friction)
The filters obtained in Examples and Comparative Examples were lightly rubbed with warm water at 30 ° C. with a brush (polybutylene terephthalate brush Lion toothbrush “Denta System Marion Ibrush Clear Type”) about 10 times.
Next, the tip of the suction cylindrical hose of a cyclone type vacuum cleaner made in Japan (maximum suction work rate 580w type) using a mixed powder of 15 kinds of JIS-Z-8901 test powder in a room at room temperature of 20 ° C. and humidity of 40% ( The filter was attached to an inner diameter of 35 mm), and the dust adhesion state was evaluated.
Good (◎) with little dust adhering, slightly attached but good (○) with easy removal by brushing, only fine powder adhered even with brushing A thing ((triangle | delta)) was evaluated as a defect (*) with the thing with which (((triangle | delta))) applied a brush and dust remained even if it applied a brush.
At this time, the paper pack was subjected to a suction test while being replaced with a new one for each test.

E. Strength of woven / knitted fabric The burst strength of the filter was determined by the Murren method of JIS L-1096. Those with less than 300 kPa were evaluated as bad (x), those with 300 or more and less than 400 kPa were allowed (Δ), and those with 400 kPa or more were evaluated as good (◯).

F. Manufacturability of knitted and knitted fabrics Good (◯), good (Δ), and no (×) in order of goodness for production without yarn breakage.

G. Bending softness of woven or knitted fabric The bending resistance was determined according to JISL1018 8.22 Bending Softness Method A (cantilever method).
F. Yield of filter The yield when producing a filter from a woven or knitted fabric was evaluated as good (◯), acceptable (Δ), and defective (×) in order of goodness.
G. Ease of dust removal from the prefilter of the air conditioning equipment After operating for about 8 hours every day in an 8 tatami Western-style room, remove the two prefilters from the air conditioner after 14 days, temperature 20 ° C, humidity 40 % Of dust was evaluated after leaving in a room for 24 hours. The evaluation was performed by sucking a Japanese-made cyclone type vacuum cleaner (maximum suction work rate 580w type) for 30 seconds and visually evaluating dust separation thereafter. The one with no dust remaining (◎), the one with slight residue (○), the one with dust remaining at the intersection of warp and weft (△), The case where dust remained in the opening was evaluated as (x).

Example 1
The intrinsic viscosity [η] is 0.65 polyethylene terephthalate, and the monofilament is drawn at a spinning speed of 1500 m / min and a draw ratio of 3.6 times, and is 33 dtex, breaking strength, 5.12 cN / dtex, breaking elongation, 30 % Polyethylene terephthalate monofilament was obtained and used as B yarn (non-conductive synthetic fiber). Next, using a slewer loom, the B yarns were arranged in a warp direction of 196 yarns / 2.54 cm, and in the weft direction, B yarns and A yarns (conductive synthetic fibers) were twisted at 80 times / m (S twist) ), 22 dtex / 6f, breaking strength 2.82 cN / dtex, conductive polyester fiber containing carbon black having an electric resistance value of 6.8 × 10 ⁷ Ω / cm (“Bertron” 22T / 6-B31 manufactured by Kanebo Gosei Co., Ltd.) ) With a weaving density of 196 pieces / 2.54 cm at intervals of 24: 1 (interval of about 3 mm) to produce a mesh fabric.

Next, this mesh fabric was heat-set at a temperature of 190 ° C. for 1 minute to obtain a mesh fabric having a warp density and a weft density of 200 / 2.54 cm, and used as a filter.
This filter had sufficient strength, and was excellent in dust removal performance even after drying and water washing friction.

(Examples 2-3)
A filter was obtained in the same manner as in Example 1 except that the weaving density of the mesh fabric when weaving was changed. This filter had sufficient strength, and was excellent in dust removal performance even after drying and water washing friction.

Example 4
As the A yarn, the A yarn of Example 1 and the polyester core-sheath type composite fiber (manufactured by Kanebo Gosei Co., Ltd .: trade name LHC) whose melting point of the sheath component of 56 dtex / 12f is higher than the melting point of the core component are combined 800 times. Using a twisted yarn with a S twist of / M and using as a B yarn a polyester core-sheath type composite fiber used for the A yarn 800 times / M, S twisted, except for the woven density at the time of weaving A filter was obtained. This filter had sufficient strength, and was excellent in dust removal performance even after drying and after washing with water, and also had excellent dust separation performance when used as a prefilter for an air conditioner. Also, when removing dust and dirt attached, the filter is fixed by fusing the crossing point of the fabric, so even if a little load is applied, it has sufficient strength, It can be used many times and has excellent recyclability.

(Example 5)
Instead of the polyester core-sheath type composite fiber used in Example 4, a polyester core-sheath type composite fiber (manufactured by Kanebo Gosei Co., Ltd .: trade name LHC) having a melting point of the sheath component of 84 dtex / 24f higher than the melting point of the core component is used. A filter was obtained in the same manner as in Example 4 except that the number of twists and the weaving density during weaving were changed. The same effect as in Example 4 was obtained.
Next, a polypropylene frame was attached to the filter to obtain a prefilter. This pre-filter is also excellent in dust removal performance when drying and washing friction is applied, and dust separation performance when used as a pre-filter for air conditioning, has no misalignment, and has sufficient strength. Can also be used, and has excellent recyclability.

(Examples 6 to 11)
A filter was obtained in the same manner as in Example 1 except that the A yarn, B yarn, woven density, and the like were changed as described in Table 1, Table 2, and Table 3 described later. The results are shown in Table 3.
In Example 6, a prefilter was obtained in the same manner as in Example 5. This pre-filter also has excellent dust removal performance and dust separation performance when used as a pre-filter for air conditioning, both during drying and when washed with water. Can also be used, and has excellent recyclability.

(Comparative Example 1)
A filter was obtained in the same manner as in Example 1 except that the A yarn was not used. The dustproof performance was inferior both when dry and when wet.

(Comparative Example 2)
Metal (copper) was deposited on the mesh fabric of Comparative Example 1. Temporarily, it was dustproof when it was dried, but it was weak against wear and was not durable. Moreover, even after the water washing friction was imparted, the dustproof property was not obtained.

(Comparative Examples 3-5)
A filter was obtained in the same manner as in Example 1 except that the A yarn, B yarn, woven density, and the like were changed as shown in Table 1, Table 2, and Table 3. The results are shown in Table 3.
In addition, with respect to Examples and Comparative Examples, physical properties and the like are described in Table 1, Table 2, and Table 3.

(Examples 11 to 16, Comparative Example 6)
As the A yarn, the same yarn as the A yarn of Example 4 is used except that the twist number is changed to 800 times / m. As the B yarn, the melting point of the sheath component of 56 dtex / 12f is higher than the melting point of the core component. Using sheath-type composite fibers (fiber diameter: 70 μm, number of twists: 800 times / m, electrical resistance: 7.60 × 10 ¹⁴ Ω / cm, strength: 4.30 cN / dtex), conductive thread spacing as shown in Table 4 A woven fabric in which the weaving density and the amount of conductive yarn were used and the aperture ratio was variously changed was produced in the same manner as in Example 4 to obtain a filter. Table 4 shows the surface resistance value, the aperture ratio, the bending resistance, the strength of the woven or knitted fabric, and the like. Next, a polypropylene frame was attached to the filter to obtain a prefilter.

  When Examples 14 to 16 having an opening ratio of 60% or more are used as prefilters for an air cleaner, it can be seen that the dust separation property is excellent. Comparative Example 6 having an excessively large aperture ratio was insufficient in strength and inferior in recyclability as a prefilter. In Examples 11 to 13, since the aperture ratio is lower than that of the other examples, the prefilter after the dust separation test is more dusty than that of Examples 14 to 16. It is necessary to clean the prefilter frequently.

(Examples 17 to 22, Comparative Examples 7 and 8)
As the A yarn, the same yarn as the A yarn of Example 1 was used, and as the B yarn, Examples 17 and 18 and Comparative Examples 7 and 8 were 28 dtex / 1f regular polyester (fiber diameter: 49 μm, electric resistance: 7 .60 × 10 ¹⁴ Ω / cm, strength: 5.84 cN / dtex), Examples 19 to 22 use the same yarn as the B yarn of Example 6, except that the weaving density is changed and the aperture ratio is changed. In the same manner as in Example 1, a filter was produced. The results are shown in Table 5.

(Examples 23 and 24, Comparative Example 9)
A filter was produced in the same manner as in Example 20 except that the interval between the conductive synthetic fibers was changed to 1 mm, 3 mm, 13 mm, and 22 mm. The results are shown in Table 6 together with the results of Example 20.

It is a schematic diagram for demonstrating the aperture ratio of the woven / knitted fabric of this invention. It is an example of the fiber cross-sectional shape of the electroconductive synthetic fiber of this invention.

Claims (14)

A filter comprising a woven or knitted fabric in which conductive synthetic fibers are arranged between non-conductive synthetic fibers, the woven / knitted fabric having a surface electrical resistance of 1.0 × 10 ¹¹ Ω / □ or less and an aperture ratio of 30 to 80% . The filter according to claim 1, wherein the conductive synthetic fiber has a fiber diameter of 10 to 50 μm. The conductive synthetic fibers have an electrical resistance value of 1.0 × 10 ¹⁰ Ω / cm or less, and the non-conductive synthetic fibers have an electrical resistance value of 1.0 × 10 ¹³ Ω / cm or more, and are adjacent in the same direction. The interval between the matching conductive synthetic fibers is 1 mm or more and 20 mm or less, and the amount of the conductive synthetic fibers used is 0.5 wt% or more and 10 wt% or less with respect to the entire woven or knitted fabric. filter. The said nonelectroconductive synthetic fiber is a filter as described in any one of Claims 1-3 containing what fused the sheath-core composite fiber which a sheath part consists of resin whose melting | fusing point is lower than a core part. The filter according to any one of claims 1 to 4, wherein the non-conductive synthetic fiber has a fiber diameter of 20 to 100 µm. The filter according to any one of claims 1 to 5, wherein a maximum gap length of the woven or knitted fabric is 40 to 800 µm. A filter comprising a woven or knitted fabric made of conductive synthetic fibers and non-conductive synthetic fibers in which a conductive component is kneaded into the fibers, and an aperture ratio of 30 to 80%. The filter according to claim 7, wherein a part of the conductive component is exposed in the conductive synthetic fiber. A prefilter for a dust collecting filter, wherein the filter according to any one of claims 1 to 8 is sandwiched and formed by a frame. A dust collecting filter comprising: a pre-filter that removes dust by sandwiching the woven or knitted fabric according to any one of claims 1 to 8 in a frame; and a main filter that passes through the pre-filter and further removes fine dust. An air conditioning collection comprising a pre-filter that removes dust by sandwiching the woven or knitted fabric according to any one of claims 1 to 8 and a main filter that passes through the pre-filter and further removes fine dust. Dust filter. A vacuum cleaner comprising a pre-filter that removes dust and a main filter that further removes fine dust that has passed through the pre-filter by sandwiching the woven or knitted fabric according to any one of claims 1 to 8 in a frame. Filter for dust collection. The filter for dust collection according to any one of claims 10 to 12, wherein the woven or knitted fabric is mainly made of polyester, and the frame is formed by fusing and molding a thermoplastic resin having a melting point of polyester or lower. An opening ratio is 30 to 80%, and the conductive synthetic fiber is a woven or knitted fabric in which a sheath component is arranged between non-conductive fibers including a core-sheath type composite fiber having a melting point lower than that of the core component. A method for producing a dust prefilter for fusing and molding a frame made of a synthetic resin having a low melting point.

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