JP3928110B2 - Hollow monofilament for fabric and industrial fabric using the same - Google Patents

Description

【００５２】
【発明の効果】
以上説明したように、本発明の中空モノフィラメントは、繊維の軸方向に延びる４つ以上の中空孔を有し、潰れによる変形が大きく、かつ回復性が小さいため、この中空モノフィラメントを工業用織物の緯糸の少なくとも一部に使用した場合に、人為的に織物を圧縮して中空モノフィラメントを潰し中空構造を破壊することにより、織り組織、つまり織り密度を変えて、目的にあった通気性を有する織物とすることができる。
【００５３】
また、モノフィラメントを使用した織物は、一般にマルチフィラメントの紡績糸を使用した工業用織物に比べて比表面積が小さいため、織物表面に汚れが付着しにくく通気性に優れているが、通気性を得るため織り構造を複雑にすると汚れが付着しやすくなる。これに対し、本発明の中空モノフィラメントを使用した織物は、そうした織り構造を必要とせずに汚れが付着しにくいという優れた特性を発揮する。
【００５４】
したがって、本発明の中空モノフィラメントを緯糸の少なくとも一部に使用した工業用織物は、抄紙用ドライヤーカンバスに代表される各種工業用途に極めて有用である。
【図面の簡単な説明】
【図１】図１（ａ）〜（ｐ）は本発明の中空モノフィラメントの断面形状を示す断面説明図である。
【図２】図２は実施例における織物の通気度調整の容易度の評価に使用する三重織の織り構造を示す説明図である。
【符号の説明】
１ 中ヨコ糸（本発明の中空モノフィラメント）
２ 表面・裏面ヨコ糸
３ タテ糸[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow monofilament for industrial fabric (hereinafter simply referred to as a hollow monofilament) that is most suitable for use in a fabric that requires particularly wide air permeability adjustment, and an industrial fabric using the same.
[0002]
[Prior art]
The main role of the dryer part in the paper machine is to dry the wet paper. That is, the amount of dewatering in the dryer part of the paper machine is generally only about 0.6% of the total, but the drying cost of the wet paper is said to require about 5 times the mechanical watering cost in the press part. Efficient drying is an important issue for papermaking applications. Furthermore, in recent years, the speed of paper machines has been increasing, and the adjustment of the air permeability of the dryer canvas has been regarded as important.
[0003]
Conventionally, synthetic resin monofilaments have been mainly used for dryer canvases, and polyester (polyethylene terephthalate) monofilaments having a good balance of mechanical properties such as strength and rigidity, thermal properties, and durability have been used.
[0004]
In addition, as a means for adjusting the air permeability of the paper dryer dryer canvas, there are adjustment methods using a canvas weaving structure such as plain weaving, double weaving, triple weaving, and a method of driving multifilament or span yarn into a weft center. There are adjustment methods using the characteristics of monofilaments such as differences in heat shrinkage characteristics, differences in dimensions and shapes such as yarn diameter and irregular cross section, and adjustment methods using both.
[0005]
For example, in Japanese Patent Laid-Open No. 10-1893, by using a monofilament with a square cross section for the warp, the cross-sectional area can be larger than that of the flat yarn, and it becomes easy to crimp the weft by increasing the warp strength. There has been proposed a paper dryer drier canvas that can adjust the air permeability over a wide range by increasing the weaving density.
[0006]
Japanese Patent Application Laid-Open No. 10-317295 discloses a warp and weft density of 4 to 15 / 2.54 cm using a monofilament having an elliptical cross-sectional shape for the warp and a monofilament having a diameter of 0.6 to 1.2 mm for the weft. And a paper making dryer canvas having an air permeability of 35000 cc / min / cm ² or more has been proposed.
[0007]
Furthermore, Japanese Patent Application Laid-Open No. 11-269991 discloses a two-layer structure comprising a front surface layer and a back surface layer in which flat yarn is used as a warp, the surface layer has a 3/1 broken twill structure, and the weft yarn has a dry heat shrinkage rate. There has been proposed a papermaking dryer canvas in which two types of yarns of high and different sizes are arranged alternately on at least the surface layer.
[0008]
Furthermore, in Japanese Utility Model Publication No. 58-55280, dirt such as gum pitch of adhesive oil and paper paste and coating liquid contained in the paper powder loss in the dryer part of the paper machine are on the surface of the canvas. In order to prevent adhesion and deterioration of air permeability, a coarse porous papermaking dryer canvas woven into a single-layer plain weave structure has been proposed.
[0009]
Fabrics using monofilaments are less likely to have dirt on the weave and excellent air permeability as compared to industrial fabrics using multifilament spun yarns. However, the above-mentioned JP-A-10-317295 and JP-A-11 The paper making dryer canvas described in Japanese Patent Publication No. -269791 has a problem that it has a complicated woven structure, so that dirt is easily adhered to the weave and easily causes a decrease in air permeability.
[0010]
Further, a fabric using a monofilament with a square cross section described in Japanese Patent Application Laid-Open No. 10-1893 is not only inferior to that using a flat yarn but also has a thickness on the fabric. There was a problem that stretch was added to the wet paper running on the outside of the fabric in groups, and paper dust was likely to be generated due to slip or the like. And this paper dust adhered to the weave, causing the air permeability to deteriorate. If the monofilament diameter is reduced, these problems can be improved, but conversely, there is a trade-off problem in that it is difficult to crimp the weft because the strength of the yarn is reduced.
[0011]
[Problems to be solved by the invention]
The present invention has been achieved as a result of studying the solution of the problems in the prior art described above as an issue.
[0012]
Therefore, the object of the present invention is to provide a hollow monofilament that is most suitable for textile applications that require a wide range of air permeability adjustment, and by using it, it is possible to effectively prevent the adhesion of dirt without the need for air permeability adjustment by a complicated woven structure. Another object of the present invention is to provide an industrial fabric that is prevented.
[0013]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a monofilament having a specific compression displacement rate and a compression displacement recovery rate is a monofilament whose air permeability can be widely controlled when used as a woven fabric. In addition, the industrial fabric made of this monofilament can control the weaving density over a wide range to obtain appropriate air permeability, effectively preventing dirt from adhering without the need for air permeability adjustment with a complicated weaving structure. We have found that this is possible and have reached the present invention.
[0014]
That is, the present invention is a hollow monofilament having four or more hollow holes extending in the axial direction of the fiber, wherein the compression displacement rate is 20% or more and the compression displacement recovery rate is 50% or less. A hollow monofilament is provided.
[0015]
(However, the compression displacement rate and the compression displacement recovery rate are values measured using the Shimadzu Corporation “Shimadzu Powder Compression Tester PCT-200” under the following conditions: 20 ° C., 65 The side surface of a hollow monofilament that has been allowed to stand for 24 hours or more in an environment of% RH is compressed with a diamond disk-shaped pressurizer having a diameter of 500 μm under the conditions of an origin load of 15 gf, a maximum load of 200 gf, and a load applied speed of 1.44 gf / sec.・ The yarn diameter displacement at the time of recovery was read, and the compression displacement rate and the compression displacement recovery rate were calculated from the following formula: Three samples were taken from the same hollow monofilament, and n3 was measured and averaged. Asked.
[0016]
(1) Compression displacement rate (%) = (L1 / D) × 100
(2) Recovery rate of compression displacement (%) = (Restoration rate / Compression displacement rate) × 100
Here, D in the above formula is the diameter or representative diameter (μm) of the raw yarn before being subjected to the test, and L1 is the displacement difference between the displacement at the initial load of 15 gf applied to the sample and the displacement at the maximum load of 200 gf. L2 is the absolute value (μm) of the difference (residual displacement) between L1 and the restored displacement when the load is reduced from the maximum load 200 gf to the origin load 15 gf, and the restoration rate is the D , L1, L2, and a value (%) calculated by the formula [(L1-L2) / D] × 100. )
In the hollow monofilament of the present invention,
A preferable condition is that the ratio of the total area occupied by the hollow holes to the total cross-sectional area of the yarn cross section is 20 to 80%, and that the number of the hollow holes present in the yarn cross section is 4 to 10 As mentioned.
[0017]
The industrial fabric of the present invention is characterized in that the hollow monofilament is used for at least a part of the weft.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[0019]
The hollow monofilament proposed in the present invention is a monofilament having four or more hollow holes extending in the axial direction of the fiber and capable of widely controlling air permeability when used in at least a part of a weft of a woven fabric. .
[0020]
Specifically, the industrial fabric using the hollow monofilament of the present invention for at least a part of the weft is moderately controlled by widely controlling the weave density by artificially crushing the yarn to destroy the hollow structure and deforming the shape. It has an epoch-making feature that has never been achieved.
[0021]
Synthetic resins constituting the hollow monofilament of the present invention include polyamide resins such as 6 nylon, 66 nylon, 610 nylon, 612 nylon, 6/66 copolymer and copolymers thereof, polyethylene terephthalate (hereinafter referred to as PET), Polybutylene terephthalate (hereinafter referred to as PBT), polyethylene naphthalate, polyesters such as polycyclohexanedimethylene terephthalate and copolymers thereof, polyvinylidene fluoride, ethylene / tetrafluoroethylene copolymer, tetrafluoroethylene / hexafluoropropylene / Examples include fluororesins such as vinylidene fluoride copolymers, polyolefins such as polyphenylene sulfide (hereinafter referred to as PPS), polyethylene, and polypropylene. Among the above-mentioned polyesters that are balanced in terms of mechanical properties, thermal properties, and durability, PET and PPS having both heat resistance and heat and moisture resistance are particularly preferred polymers for papermaking dryer canvas materials. .
[0022]
Furthermore, in PET and PBT among the polyesters, a part of the dicarboxylic acid component terephthalic acid is mixed with isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacin. Acid, dimer acid and sulfonic acid metal salt substituted isophthalic acid may be substituted, and a part of glycol component ethylene glycol or 1,4-butanediol is replaced with diethylene glycol, neopentyl glycol, 1,4-cyclohexane It may be replaced with diol, 1,4-cyclohexanedimethanol, polyalkylene glycol or the like.
[0023]
In particular, industrial fabrics using polyester are likely to undergo a hydrolysis reaction depending on the use conditions. Therefore, a compound having one or more carbodiimide groups in one molecule, for example, N, N′-di-o-triylcarbodiimide, N, N′-diphenylcarbodiimide, N, N′-dioctyldecylcarbodiimide, N, N'-di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N, N'-di-2,6-diisopropylphenylcarbodiimide, N, N'-di-2,6 -Di-tert.-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N, N'-di-p-nitrophenylcarbodiimide, N, N'-di-p-aminophenylcarbodiimide, N, N ' -Di-p-hydroxyphenylcarbodiimide, N, N'-di-cyclohexylcarbodiimide, N, N'-di-p 1 such as triylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, and aromatic polycarbodiimide Hydrolysis resistance can also be improved by arbitrarily selecting and containing a seed or two or more compounds and lowering the carboxyl end group carboxyl group concentration.
[0024]
In addition, when the industrial fabric of the present invention is used as a papermaking dryer canvas, various papermaking raw materials such as fillers, sizing agents, paper strength enhancing agents, etc. added to the papermaking stock solution adhere to the surface.・ It may accumulate and reduce air permeability. Therefore, a random copolymer mainly composed of tetrafluoroethylene and ethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, vinylidene fluoride / tetrafluoroethylene copolymer, polytetrafluoroethylene, tetrafluoroethylene / Perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyperfluoroalkyl acrylate, polyperfluoroalkyl methacrylate, perfluoroalkyl alkylate and / or perfluoroalkyl methacrylate Random or block copolymers with acrylates and / or methacrylates, including those containing hydroxyalkyl groups, o- or m-perful One or more compounds such as a fluorine-containing polymer having a fluorine atom in the side chain of a polymer molecule such as polyester or polyether polyester containing rooxyisophthalic acid in at least a part of the dicarboxylic acid component is arbitrarily selected. The method of inclusion is also effective.
[0025]
Furthermore, in addition to the above synthetic resins, various inorganic particles such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin and diliconium acid, particles such as crosslinked polymer particles and various metal particles, and the like Known antioxidants, sequestering agents, ion exchangers, anti-coloring agents, antistatic agents, various colorants, waxes, silicone oils, various surfactants and various reinforcing fibers may be added. .
[0026]
The production of the hollow monofilament of the present invention can be carried out by a known hollow spinning method without requiring any special method. For example, the polymer resin is melt-extruded from a hollow spinneret using a kneading extruder such as an extruder, or a melt spinning machine such as a pressure melter type, and then cooled, hot-drawn, and thermally set.
[0027]
The hollow monofilament of the present invention obtained by the production method described above needs to have the following characteristics.
[0028]
The thickness of the monofilament of the present invention is appropriately selected depending on the application and is not particularly limited, but the range of 0.05 to 3 mm is most often used.
[0029]
Moreover, the cross-sectional shape of the hollow monofilament to be molded is not particularly specified, and if there are at least four hollow holes extending in the axial direction of the monofilament, the shape is round, square, flat, elliptical, half-moon, triangle, five-point The above polygons, multilobes, saddles, and the like may be used, and examples include monofilaments having various cross-sectional shapes as shown in FIGS.
[0030]
However, when there are too many hollow holes in one hollow monofilament, the discharge holes of the die become complicated, and when the resin is melt-extruded, the pressure increases rapidly, which may cause problems in work. Further, immediately after being melt-extruded from the die hole, the hollow hole may be blocked by the ballast effect.
[0031]
Therefore, in the hollow monofilament of the present invention, the number of hollow holes present in the cross section of the yarn is preferably 4 to 10, more preferably 4 to 6 per monofilament.
[0032]
Further, in the hollow monofilament of the present invention, if the ratio of the total area occupied by the hollow holes to the total cross-sectional area of the yarn cross section is too small, the collapse and collapse of the hollow structure is small, and the features and effects intended by the present invention are not exhibited. Further, even if the ratio of the total area occupied by the hollow holes is too large, the hollow structure is crushed so that when it is used in a woven fabric, it tends to collapse, and further, the tensile properties tend to be lowered. For these reasons, the ratio of the total area occupied by the hollow holes to the total cross-sectional area of the yarn cross section is preferably in the range of 20 to 80%, and more preferably in the range of 30 to 70%.
[0033]
Depending on the composition of the synthetic resin constituting the hollow monofilament, the number of hollow holes, and the ratio of the total area occupied by the hollow holes to the total cross-sectional area of the yarn cross-section, the hollow structure collapse method and the yarn hardness may vary. Furthermore, as an evaluation criterion that meets the purpose of the present invention, the compression displacement rate and the compression displacement recovery rate measured using Shimadzu Corporation “Shimadzu Powder Compression Tester PCT-200” satisfy specific values. It is necessary.
[0034]
However, the compression displacement rate and the recovery rate of the compression displacement are measured under the following conditions.
[0035]
That is, the side surface of a hollow monofilament that was allowed to stand for 24 hours or more in an environment of 20 ° C. and 65% RH was formed with a diamond disk-shaped pressurizer having a diameter of 500 μm and an origin load of 15 gf, a maximum load of 200 gf, and a load applied speed of 1.44 gf. The yarn diameter displacement when compressed / recovered under the conditions of / sec was read, and the compression displacement rate and the compression displacement recovery rate were determined from the following equations. Three samples were collected from the same hollow monofilament, and n3 was measured to obtain an average.
[0036]
(1) Compression displacement rate (%) = (L1 / D) × 100
(2) Recovery rate of compression displacement (%) = (Restoration rate / Compression displacement rate) × 100
Here, D in the above formula is the diameter or representative diameter (μm) of the raw yarn before being subjected to the test, and L1 is the displacement difference between the displacement at the initial load of 15 gf applied to the sample and the displacement at the maximum load of 200 gf. L2 is the absolute value (μm) of the difference (residual displacement) between L1 and the restored displacement when the load is reduced from the maximum load 200 gf to the origin load 15 gf, and the restoration rate is the D , L1, L2, and a value (%) calculated by the formula [(L1-L2) / D] × 100.
[0037]
In the hollow monofilament of the present invention, it is important that the pressure displacement rate is 20% or more and / or the compression displacement recovery rate is 50% or less, and the pressure displacement rate is less than the above range and / or compression. When the recovery rate of displacement exceeds the above range, the hollow structure is less crushed, and the features and effects intended by the present invention tend not to be exhibited.
[0038]
When the hollow monofilament thus obtained is used in at least a part of the weft of an industrial fabric, in particular, a dryer canvas for papermaking, the yarn is crushed artificially to break the hollow structure and deform the shape. Appropriate air permeability can be obtained by controlling the density widely. Furthermore, finer weaving density control can be achieved by mixing and using monofilaments having different ways of crushing, thickness and shape in the same fabric.
[0039]
【Example】
Hereinafter, examples of the present invention will be described in detail. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
[0040]
The physical properties of the hollow monofilament of the present invention described above and below are values measured by the following method.
[Compression displacement rate and compression displacement recovery rate]
As mentioned above.
[Total ratio of hollow area and representative diameter]
The monofilament sample was cut into 15 μm thicknesses with a microtome, and the cross section of the section was measured using the area measurement function of a digital HD microscope VH-7000 manufactured by KEYENCE Corporation. Area measurement of odd-shaped cross-sections such as elliptical, half-moon-shaped, multi-leafed, and saddle-shaped, with at least a part of a curved section or a complex shape is approximated to a polygon of 30 or more, and n: average of three measured values The value was the ratio of the total area of the hollow part of each sample.
[0041]
Similarly, using the same company's digital HD microscope VH-7000, the diameter of a circle circumscribing the cross-sectional shape was measured three times, and the average value was taken as the representative diameter.
[Ease of adjustment of fabric air permeability]
The hollow monofilaments obtained in each Example and Comparative Example were used as the middle weft 1 of the triple-woven fabric shown in FIG. 2, and the air permeability of the fabric was measured according to the JIS-L-1096 Frazier method. did. The warp yarn 3 and the front and back weft yarns 2 are solid monofilaments having the same wire diameter as the middle weft yarn 1 and have a weaving density of 63 warps / inch and 36 weft yarns / inch. Inch x 3 stages. After weaving, the fabric is set by applying a tension of 60 N / cm in the vertical direction for 1 hour, and then the air permeability is measured using Ain Penmeability Testen FX3300 (manufactured by Swiss TEXTEST AG). did.
[Example 1]
The dried PET resin (manufactured by Toray Industries, Inc., T750M) was supplied to a uniaxial extruder type melt spinning machine having a diameter of 40 mm, melted and kneaded at a temperature of 285 ° C., and then spun from the spinneret. Next, after the melted spun yarn was introduced into warm water and cooled and solidified, it was stretched by a total of 5.50 times in two stages of 88 ° C. and 180 ° C. without being wound, and subsequently 230 ° C., 0.9 Heat treatment was carried out twice, and a known oil agent was applied and wound around a bobbin to obtain a hollow monofilament having four hollow holes and a total area ratio of 34% of hollow portions as shown in FIG. . Table 1 shows the physical properties of the obtained hollow monofilament and the results of measuring the air permeability of the fabric using the hollow monofilament.
[0042]
As a result, it had a high compression displacement rate and a low recovery rate, and was good against crushing. Further, the air permeability of the woven fabric was reduced by 60% compared to the unset woven fabric, and it was possible to control the air permeability that can be used in the wet end portion of the paper machine dryer part.
[Example 2]
The dried 6 nylon resin (M1021T manufactured by Toray Industries, Inc.) was supplied to a uniaxial extruder type melt spinning machine with a diameter of 40 mm, melt-kneaded at a temperature of 260 ° C., and then spun from the spinneret. Next, after the molten spun yarn was introduced into water and allowed to cool and solidify, it was stretched to a total of 4.70 times in two stages of 60 ° C. and 130 ° C. without being wound up, and subsequently 180 ° C. and 0.95 times Was subjected to heat treatment, and a known oil agent was applied and wound around a bobbin to obtain a hollow monofilament having five hollow holes and a total area ratio of hollow portions of 60% as shown in FIG. Table 1 shows the physical properties of the obtained hollow monofilament and the results of measuring the air permeability of the fabric using the hollow monofilament.
[0043]
As a result, the recoverability was slightly high, but the compression displacement rate was very good. In addition, the air permeability of the fabric was reduced by 55% compared to the unset fabric, and the air permeability could be greatly controlled.
[Example 3]
The dried PPS resin (E2080 manufactured by Toray Industries, Inc.) was supplied to a uniaxial extruder type melt spinning machine with a diameter of 40 mm, melted and kneaded at a temperature of 320 ° C., and then spun from the spinneret. Next, after the melted spun yarn was introduced into warm water and cooled and solidified, it was stretched to a total of 4.20 times in two stages of 100 ° C. and 140 ° C. without being wound up, and subsequently 150 ° C., 0.95 Heat treatment was carried out twice, and a known oil agent was applied and wound on a bobbin to obtain a hollow monofilament having four hollow holes and a total area ratio of 40% of hollow portions as shown in FIG. . Table 1 shows the physical properties of the obtained monofilament and the results of measuring the air permeability of the fabric using the monofilament.
[0044]
As a result, it was substantially the same as the hollow monofilament of Example 1 with a high compression displacement rate and a low recovery rate. In addition, the air permeability of the fabric was reduced by 60% compared to the unset fabric, and the air permeability could be greatly controlled.
[Example 4]
With the resin and the production method described in Example 1, hollow monofilaments having 6 hollow holes and a total area ratio of 52% of hollow holes as shown in FIG. 1 (o) were obtained. Table 1 shows the physical properties of the obtained hollow monofilament and the results of measuring the air permeability of the fabric using the hollow monofilament.
[0045]
As a result, a hollow monofilament having a high compression displacement rate and a low recovery rate as compared with the PET monofilament of Example 1 and a quality different from the hollow monofilament of Example 1 was obtained due to the cross-sectional shape even with the same material. . In addition, the air permeability of the fabric could be greatly controlled.
[Example 5]
With the resin and the production method described in Example 1, hollow monofilaments having five hollow holes and a total area ratio of the hollow holes of 25% as shown in FIG. 1 (n) were obtained. Table 1 shows the physical properties of the obtained hollow monofilament and the results of measuring the air permeability of the fabric using the hollow monofilament.
[0046]
Compared with the hollow monofilament of Example 1, the hollow monofilament of this example has a slightly smaller compression displacement rate, a slightly higher recovery rate, and a slightly smaller change in the air flow rate of the fabric. I was able to control it.
[Example 6]
With the resin and the production method described in Example 2, hollow monofilaments having 8 hollow holes and a total area ratio of 18% of hollow holes as shown in FIG. 1 (f) were obtained. Table 1 shows the physical properties of the obtained hollow monofilament and the results of measuring the air permeability of the fabric using the hollow monofilament.
[0047]
The hollow monofilament of this example had a small compression displacement rate and a high recovery rate, so that the change in the air flow rate of the fabric was small, but the air permeability could be controlled more finely.
[Comparative Example 1]
A solid monofilament with a round cross section having a diameter of 0.5 mm was obtained by the resin and the production method described in Example 1. Table 1 shows the physical properties of the obtained solid monofilament and the results of measuring the air permeability of the fabric using the solid monofilament.
[0048]
As a result, because of the low compression displacement rate and the high recovery rate, the change in the air flow rate is extremely small as compared with the fabric using the hollow monofilament of Example 1, and the intended performance of the present invention is not exhibited.
[Comparative Example 2]
A solid monofilament having a true circular cross section with a diameter of 0.5 mm was obtained by the resin and the production method described in Example 2. Table 1 shows the physical properties of the obtained solid monofilament and the results of measuring the air permeability of the fabric using the solid monofilament.
[0049]
As a result, because of the low compression displacement rate and the high recovery rate, the change in the air flow rate is extremely small as compared with the fabric using the hollow monofilament of Example 2, and the intended performance of the present invention is not exhibited.
[Comparative Example 3]
A hexagonal cross-section solid monofilament having a circumscribed circle radius of 0.5 mm was obtained using the resin and the manufacturing method described in Example 1. Table 1 shows the physical properties of the obtained solid monofilament and the results of measuring the air permeability of the fabric using the solid monofilament.
[0050]
As a result, because of the low compression displacement rate and the high recovery rate, the change in the air flow rate is extremely small as compared with the fabric using the hollow monofilament of Example 4, and the intended performance of the present invention is not exhibited.
[0051]
[Table 1]

[0052]
【The invention's effect】
As described above, the hollow monofilament of the present invention has four or more hollow holes extending in the axial direction of the fiber, is largely deformed by crushing, and has low recoverability. When used for at least part of the weft, artificially compress the woven fabric to crush the hollow monofilaments and destroy the hollow structure, thereby changing the woven structure, that is, the weaving density, and having the desired breathability It can be.
[0053]
In addition, fabrics using monofilaments generally have a small specific surface area compared to industrial fabrics using multifilament spun yarns, so that dirt is less likely to adhere to the fabric surface and has excellent breathability, but obtains breathability. Therefore, if the woven structure is complicated, dirt is likely to adhere. On the other hand, the woven fabric using the hollow monofilament of the present invention exhibits an excellent characteristic that it does not require such a woven structure and is difficult to adhere dirt.
[0054]
Therefore, the industrial fabric using the hollow monofilament of the present invention as at least a part of the weft is extremely useful for various industrial uses represented by a papermaking dryer canvas.
[Brief description of the drawings]
FIGS. 1A to 1P are cross-sectional explanatory views showing a cross-sectional shape of a hollow monofilament of the present invention.
FIG. 2 is an explanatory view showing a triple weave weave structure used for evaluating the ease of adjusting the air permeability of the fabric in the examples.
[Explanation of symbols]
1 Middle weft yarn (hollow monofilament of the present invention)
2 Front / back weft 3 Warp

Claims (4)

A hollow monofilament for industrial textiles having four or more hollow holes extending in the axial direction of the fiber, wherein the compression displacement rate is 20% or more and the recovery rate of compression displacement is 50% or less.
(However, the compression displacement rate and the compression displacement recovery rate are values measured using the Shimadzu Corporation “Shimadzu Powder Compression Tester PCT-200” under the following conditions: 20 ° C., 65 The side surface of a hollow monofilament that has been allowed to stand for 24 hours or more in an environment of% RH is compressed with a diamond disk-shaped pressurizer having a diameter of 500 μm under the conditions of an origin load of 15 gf, a maximum load of 200 gf, and a load applied speed of 1.44 gf / sec.・ The yarn diameter displacement at the time of recovery was read, and the compression displacement rate and the compression displacement recovery rate were calculated from the following formula: Three samples were taken from the same hollow monofilament, and n3 was measured and averaged. Asked.
(1) Compression displacement rate (%) = (L1 / D) × 100
(2) Recovery rate of compression displacement (%) = (Restoration rate / Compression displacement rate) × 100
Here, D in the above formula is the diameter or representative diameter (μm) of the raw yarn before being subjected to the test, and L1 is the displacement difference between the displacement at the initial load of 15 gf applied to the sample and the displacement at the maximum load of 200 gf. L2 is the absolute value (μm) of the difference (residual displacement) between L1 and the restored displacement when the load is reduced from the maximum load 200 gf to the origin load 15 gf, and the restoration rate is the D , L1, L2, and a value (%) calculated by the formula [(L1-L2) / D] × 100. ) The hollow monofilament for industrial textiles according to claim 1, wherein the ratio of the total area occupied by the hollow holes to the total cross-sectional area of the yarn cross section is 20 to 80%. The hollow monofilament for industrial textiles according to claim 1 or 2, wherein the number of the hollow holes existing in the yarn cross section is 4 to 10. An industrial fabric, wherein the hollow monofilament for industrial fabric according to claim 1 is used for at least a part of a weft.

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