JP2003227025A - Multi-lobar cross-sectional monofilament and industrial woven fabric using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-lobar cross-sectional monofilament optimal for an industrial woven fabric where wide air permeability adjustment is especially required, and to provide an industrial woven fabric which is produced from the multi-lobar cross-sectional monofilaments and effectively prevents the adhesion of stains and whose air permeability adjustment is easy without needing air permeability adjustment with a complicated weaving structure. <P>SOLUTION: The tri-lobar or more multi-lobar cross-sectional monofilament has a compression displacement rate of ≥20% and a compression displacement recovery of ≤50%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monofilament having a multi-lobed cross section, which is most suitable for an industrial woven fabric which requires a wide range of air permeability adjustment, and an industrial woven fabric using the same.

[0002]

BACKGROUND OF THE INVENTION The main role of the dryer part in a paper machine is to dry wet paper. Generally, the amount of dehydration in the dryer part is only about 0.6% of the total amount, but it is said that the cost of drying wet paper is about 5 times the mechanical watering cost in the press part, and it can be dried efficiently depending on the papermaking application. This is an important issue.
Furthermore, since the speed of paper machines is increasing in recent years,
It has become important to adjust the air permeability of the dryer canvas.

Conventionally, a synthetic resin monofilament has been mainly used as a material for a dryer canvas, and a polyester (polyethylene terephthalate) monofilament in which mechanical properties such as strength and rigidity, thermal properties and durability are well balanced. Is used.

As a method for adjusting the air permeability of the dryer canvas, a plain weave, a double weave, a triple weave, and a weaving texture of the canvas, such as driving a multifilament or a spun yarn into the weft core, are typical. An adjusting method utilizing the characteristics of the monofilament such as a difference in heat shrinkage characteristic, a difference in size and shape such as a yarn diameter or a modified cross section, or an adjusting method using both of the above is also known.

For example, in Japanese Unexamined Patent Publication No. 10-1893, a monofilament having a square cross section is used for the warp, so that the cross section can be made larger than that of the flat yarn.
A dryer canvas for papermaking has been proposed in which the increase in the warp strength makes it easier to crimp the weft, and the weaving density is increased to adjust the air permeability over a wide range.

In Japanese Unexamined Patent Publication (Kokai) No. 10-317295, monofilaments having an elliptical cross-sectional shape are used for warps and monofilaments having a diameter of 0.6 to 1.2 mm are used for wefts, and the warp and weft densities are 4 to 15 filaments. /2.54cm dryer canvas with air permeability of 35000cc
/ Min. A dryer canvas for papermaking, which is characterized by having a density of not less than / cm ² , has been proposed.

Further, Japanese Patent Laid-Open No. 11-269791 discloses a two-layer structure comprising a front layer and a back layer using flat yarns as warps, and the surface layer has a 3/1 tear twill structure,
There has been proposed a papermaking dryer canvas in which weft yarns of two kinds, large and small, having high dry heat shrinkage and different sizes are alternately arranged on at least the surface layer.

[0008] Further, Japanese Utility Model Publication No. 58-55280 discloses that the gummable pitch of the sticky oil contained in the paper dust reduction in the dryer part of the paper machine and the stains such as the sizing agent and the coating liquid for papermaking are removed from the canvas. In order to prevent the air permeability from adhering to the surface and lowering the air permeability, a coarse porous papermaking dryer canvas woven in a single layer plain weave structure has been proposed.

Compared with industrial fabrics using multifilament spun yarn, fabrics using monofilaments are
Although it is difficult for dirt to adhere to the texture and has excellent breathability, the above-mentioned JP-A-10-317295 and JP-A-11-
The paper-making dryer canvas described in Japanese Patent No. 269791 has a problem that since the weaving structure is complicated, stains are likely to be attached to the texture and the air permeability is likely to be deteriorated.

A woven fabric using a square cross-section monofilament described in JP-A-10-1893 as a warp,
Not only is the flatness inferior to the one using flat yarn,
Since the woven fabric becomes thick, stretch is applied to the wet paper running outside the woven fabric in the paper dryer group in the paper manufacturing process, and paper dust is easily generated due to slips and the like, and the paper dust adheres to the weave to improve breathability. There was a problem of causing the decrease. In this case, such a problem can be solved by reducing the yarn diameter, but there is a trade-off problem that it is difficult to crimp the weft yarn because the tenacity of the yarn decreases.

[0011]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying as a subject to solve the above-mentioned problems in the prior art.

Therefore, an object of the present invention is to provide a multifilament monofilament which is most suitable for industrial textiles which requires a wide range of air permeability adjustment, and the use of the filament does not require air permeability adjustment due to a complicated weaving structure, and stains. An object of the present invention is to provide an industrial woven fabric which effectively prevents the adhesion of

[0013]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, have made a multi-lobed cross-section monofilament having a specific compression displacement rate and a recovery rate of the compression displacement into a woven fabric. In this case, it is a monofilament whose air permeability can be widely controlled.In addition, the industrial woven fabric made of this monofilament can control the weaving density widely to obtain appropriate air permeability, and it is necessary to adjust the air permeability by a complicated weaving structure. The inventors have found that it is possible to effectively prevent the adhesion of dirt without doing so, and have reached the present invention.

That is, the present invention is a multilobe monofilament having a cross-sectional shape of three or more leaves, and the compression displacement rate measured by the following method is 20% or more and the compression displacement recovery rate is 50% or less. The present invention provides a multifilament cross-section monofilament. (However, the measurement of the compression displacement rate and the recovery rate of the compression displacement is a value measured under the following conditions using “Shimadzu powder compression tester PCT-200” manufactured by Shimadzu Corporation. That is, 20 ° C. 65%
A diamond disk-shaped presser having a flat surface with a diameter of 500 μm on the side surface of a monofilament left for 24 hours or more in an RH environment, with an origin load of 15 gf and a maximum load of 200 g.
f, the yarn diameter displacement at the time of compression / recovery under the conditions of a load application speed of 1.44 gf / sec was read, and the compression displacement rate and the compression displacement recovery rate were calculated from the following equations. In addition, three samples were taken from the same monofilament, n3 was measured, and the average was obtained.

(1) Compression displacement rate (%) = (L1 / D) × 100 (2) Recovery rate of compression displacement (%) = (Restore rate / Compression displacement rate) × 100 where D in the above equation Is the diameter or representative diameter (μm) of the raw yarn before being subjected to the test, L1 is the yarn diameter displacement at the time of the origin load of 15 gf initially applied to the sample and the maximum load 20
Absolute value of displacement difference with yarn diameter displacement at 0 gf (μ
m) and L2 are absolute values (μm) of the difference (residual displacement) between the L1 and the restoration displacement when the load is reduced from the maximum load of 200 gf to the origin load of 15 gf, and the restoration ratios are D and L.
It is a value (%) calculated from the equation 1, (L2) by the formula [(L1−L2) / D] × 100. ) In addition, in the multi-leaf cross-section monofilament of the present invention,
When the area of the circle circumscribing the cross-sectional shape of the yarn is S ₁ and the actual area of the yarn cross-section is S ₂ , the area ratio R represented by the formula R = S ₂ / S ₁ is 0.2 to 0.8. Within the range, and the cross-sectional shape of the yarn is a multi-leaf cross-sectional shape of 3 to 10 leaves,
Both are mentioned as preferable conditions.

The industrial woven fabric of the present invention is characterized in that the above-mentioned monofilament having a multi-lobed cross section is used for at least a part of the weft.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

The multi-lobed cross-section monofilament proposed in the present invention has a multi-lobed cross-sectional shape of three or more lobes, and when used in at least part of the weft of a woven fabric, it is possible to widely control the air permeability. It is characterized by.

More specifically, an industrial woven fabric using the multifilament monofilament of the present invention in at least part of the weft is
By artificially crushing the yarn to destroy the multi-lobed cross-sectional shape and deforming the shape, it has a novel feature that is unprecedented in that weaving density is widely controlled and appropriate breathability is obtained. is there.

As the synthetic resin constituting the multifilament monofilament of the present invention, 6 nylon, 66 nylon, 6
Polyamide resins such as 10 nylon, 612 nylon, and 6/66 copolymer and their copolymers, polyethylene terephthalate (hereinafter referred to as PET), polybutylene terephthalate (hereinafter referred to as PBT), polyethylene naphthalate, polycyclohexane dimethylene terephthalate Such as polyesters and their copolymers, polyvinylidene fluoride, ethylene / tetrafluoroethylene copolymer, tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride copolymer, and other fluororesins, polyphenylene sulfide (hereinafter referred to as PPS) ), And polyolefins such as polyethylene and polypropylene, etc., but the above polyesters that are balanced in mechanical properties such as strength and rigidity, thermal properties and durability. PPS that and having heat resistance and moist heat resistance, particularly preferable as a material for papermaking drier canvas.

Furthermore, PET in the above polyesters
In PBT, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid and sulfonic acid metal salt are used as a part of terephthalic acid which is a dicarboxylic acid component. It may be replaced with another dicarboxylic acid component such as substituted isophthalic acid, or a part of ethylene glycol or 1,4-butanediol which is a glycol component may be replaced with diethylene glycol, neopentyl glycol,
It may be replaced with other glycol components such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and polyalkylene glycol.

In particular, industrial fabrics using polyester monofilaments are apt to undergo a hydrolysis reaction depending on the conditions of use. Therefore, a compound having one or more carbodiimide groups in one molecule, such as 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-triylcarbodiimide, p-phenylene-bis-di-o
-Triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide, ethylene-bis-
By optionally selecting one or more compounds selected from diphenylcarbodiimide, aromatic polycarbodiimide and the like to be contained in the polyester,
It is also possible to reduce the concentration of the carboxyl group of the polyester end group and improve the hydrolysis resistance.

When an industrial fabric is used as a dryer canvas for papermaking, various papermaking raw materials such as fillers, sizing agents and paper-strengthening agents added to the papermaking stock solution, and stains formed by other materials are used as the surface. May adhere to and accumulate on the to reduce breathability. 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 -A random or block copolymer of acrylate and / or methacrylate, including the case of containing a methacrylate and a hydroxyalkyl group, and o- or m-perfluorooxyisophthalic acid as at least a part of the dicarboxylic acid component. One or more compounds selected from fluorine-containing polymers having a fluorine atom in the side chain of a polymer molecule such as polyester or polyether polyester are arbitrarily selected and synthesized. By containing the fat, it may be less likely to contaminate.

Further, the above synthetic resin includes titanium oxide,
In addition to particles of various inorganic particles such as silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin and zirconium acid, and crosslinked polymer particles and various metal particles, conventionally known antioxidants, sequestering agents, Ion exchangers, anti-coloring agents, anti-static agents, various coloring agents, waxes, silicone oils, various surfactants, various reinforcing fibers and the like may be added.

The production of the multi-lobed monofilament of the present invention can be carried out by a known spinning method without requiring any special method. For example, it can be produced by melt-extruding a polymer resin from a spinneret using a kneading extruder such as an extruder or a melt spinning machine such as a pressure melter type, and then cooling, hot drawing and heat setting.

The monofilament of the present invention obtained by the above-mentioned production method is required to have the following characteristics.

That is, it is important that the cross-sectional shape of the multi-lobed monofilament of the present invention has a multi-lobed shape of three or more lobes, but at least one leaf of the multi-lobed shape has another lobe. The shape and size of the leaves may be different, and a specific example of such a multi-lobed shape is shown in FIG.
Various sectional shapes as shown in (f) to (f) can be mentioned.

However, if the number of leaves in the multi-leaf cross section is too large, the change in shape due to crushing will be small and the performance intended by the present invention will not be exerted, so the number of leaves will be 3 to 10.
It is preferably leaves, and more preferably 3 to 8 leaves.

The thickness of the multi-lobed monofilament of the present invention is appropriately selected depending on the application and is not particularly limited, but the monofilament circumscribed circle diameter is preferably in the range of 0.05 to 3 mm. used.

The multilobed monofilament of the present invention is
Shimadzu Corporation “Shimadzu powder compression tester PCT-20”
It is an essential requirement that the compression displacement rate and the compression displacement recovery rate measured using "0" satisfy specific values.

However, the compression displacement rate and the compression displacement recovery rate are measured under the following conditions.

That is, the side surface of the monofilament left for 24 hours or more in an environment of 20 ° C. and 65% RH has a diameter of 5
A diamond disk-shaped presser having a flat surface of 00 μm is used to read the yarn diameter displacement when compressed / recovered under the conditions of an origin load of 15 gf, a maximum load of 200 gf, and a load application speed of 1.44 gf / sec. And the recovery rate of compressive displacement was obtained. Note that three samples were taken from the same monofilament, n3 was measured, and the average was obtained.

(1) Compression displacement rate (%) = (L1 / D) × 100 (2) Recovery rate of compression displacement (%) = (Restore rate / Compression displacement rate) × 100 Here, D in the above equation Is the diameter or representative diameter (μm) of the raw yarn before being subjected to the test, L1 is the yarn diameter displacement at the time of the origin load of 15 gf initially applied to the sample and the maximum load 20
Absolute value of displacement difference with yarn diameter displacement at 0 gf (μ
m) and L2 are absolute values (μm) of the difference (residual displacement) between the L1 and the restoration displacement when the load is reduced from the maximum load of 200 gf to the origin load of 15 gf, and the restoration ratios are D and L.
It is a value (%) calculated from the equation 1, (L2) by the formula [(L1−L2) / D] × 100.

In the multi-lobed monofilament of the present invention, it is important that the compression displacement rate is 20% or more and the compression displacement recovery rate is 50% or less, and the pressure displacement rate is less than the above range and / or Or, if the recovery rate of compression displacement exceeds the above range, the crushing of the yarn will be small,
The features and effects intended by the present invention tend not to be sufficiently exhibited.

In the multifilament monofilament of the present invention, the area of the circle circumscribing the cross-sectional shape of the yarn is S ₁ ,
If the actual area of the thread cross section is a S _2, wherein R = S ₂ / S area ratio R of S ₂ relative to S ₁ represented by ₁ is from 0.2 to 0.
It is desirable that it is in the range of 8, especially 0.3 to 0.7.
If the value of R is too large, the deformation due to crushing will be small, and the effect intended by the present invention will not be sufficiently exhibited. On the other hand, if the value of R is too small, the strength of the yarn decreases and the yarn tends to break.

The multi-lobed monofilament of the present invention having the above constitution exhibits the best effect when used as an industrial woven fabric. That is, the industrial fabric of the present invention in which the multi-lobed monofilament of the present invention is used for at least part of the weft, particularly the dryer canvas for papermaking, artificially crushes the yarn to destroy the leaf-shaped portion and deform the shape. Thereby, the weaving density can be widely controlled to obtain appropriate breathability. Furthermore, by mixing and using monofilaments having different thread crushing and different thicknesses and shapes in the same woven fabric, finer weaving density control becomes possible.

In general, a woven fabric using monofilaments has a smaller specific surface area than an industrial woven fabric using spun yarn of multifilaments, so that stains are less likely to adhere to the woven fabric surface and the breathability is excellent. When the weaving structure is complicated to obtain the property, dirt is likely to adhere. On the other hand, the industrial woven fabric using the multi-lobed monofilament of the present invention is characterized in that it does not require such a complicated weaving structure and that stains do not easily adhere to it.

[0038]

EXAMPLES Examples of the monofilament of the present invention will be described in more detail below, but the present invention is not limited to the following examples unless it exceeds the gist.

The physical properties of the multi-lobed monofilament of the present invention described above and below are values measured by the following methods. [Compression displacement rate and compression displacement recovery rate] As described above. [Area ratio R and representative diameter] A monofilament sample was sliced into 15 µm-thick sections with a microtome, and the section of the section was used for the area measurement function of KEYENCE Digital HD Microscope VH-7000. The actual area S ₂ of the yarn cross section was calculated by approximating a polygon having a shape of a triangle or more. Similarly, from the area S _{1 of} the circle circumscribing the cross-sectional shape and the actual area S _{2 of the} yarn cross section, the formula R = S ₂ / S
₁ The area ratio R of S ₂ with respect to S ₁ was obtained from (1).

Further, the diameter of the circle circumscribing the cross-sectional shape was measured three times with the company's Digital HD Microscope VH-7000, and the average was taken as the representative diameter. [Ease of Adjusting Air Permeability of Woven Fabric] The monofilament obtained in each of Examples and Comparative Examples was used as a weft yarn in the triple woven fabric shown in FIG.
It measured according to the Frazier method of SL-1096. In addition, the same linear linear cross-section solid monofilament as the middle weft thread is used as the warp thread and the front and back side of the fabric, and the weaving density is 63 warp threads / inch, 36 weft / inch × 3 steps did. After weaving, the fabric is set by applying a tension of 60 N / cm in the vertical direction for 1 hour, and then the Ain Penmability Tester F
The air permeability was measured using X3300 (manufactured by TEXTEST AG, Switzerland), and evaluated by comparison with an unset woven fabric. [Example 1] Dry PET resin (T7 manufactured by Toray Industries, Inc.)
50M) was fed to a uniaxial extruder type melt spinning machine having a diameter of 40 mm, melt-kneaded at a temperature of 285 ° C., and then spun from a spinneret. Then, the spun yarn in a molten state is introduced into warm water to be cooled and solidified, and then drawn in two stages of 88 ° C and 180 ° C to a total of 5.5 times without winding, and subsequently 230 ° C and 0.9 times. By performing a constant length heat treatment in (1), applying a known oiling agent, and winding the bobbin on a bobbin, a 5-leaf cross-section monofilament having an R of 0.48 as shown in FIG. 1 (c) was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, with a high compression displacement rate and a low recovery rate, the air permeability of the fabric is reduced by 55% as compared with the unset fabric,
It was possible to control the air permeability so that it could be used at the wet end of the paper machine dryer part. [Example 2] Dried 6 nylon resin (manufactured by Toray Industries, Inc.,
M1021T) was fed to a uniaxial extruder type melt spinning machine having a diameter of 40 mm and melt-kneaded at a temperature of 260 ° C.
It was spun from the spinneret. Then, the spun yarn in a molten state is introduced into warm water to be cooled and solidified, and then 60 without winding.
1B is drawn by stretching at a total of 4.7 times in two stages of ℃ and 130 ℃, followed by constant length heat treatment at 180 ℃ 0.95 fold, and applying a known oil agent and winding on a bobbin, as shown in FIG. 1 (b). A 4-leaf monofilament having an R of 0.40 was obtained.
The physical property results of the obtained monofilament are shown in Table 1.

As a result, although the compressive displacement rate and the recovery rate were higher than those of the multi-lobed monofilament of Example 1, the air permeability of the woven fabric was reduced by 50% as compared with the unset fabric, and the air permeability was significantly increased. Was able to control. [Example 3] Dry PPS resin (E2, manufactured by Toray Industries, Inc.)
080) was supplied to a uniaxial extruder type melt spinning machine having a diameter of 40 mm, melt-kneaded at a temperature of 320 ° C., and then spun from a spinneret. Then, the spun yarn in a molten state is introduced into warm water to be cooled and solidified, and then drawn to a total of 4.2 times in two stages of 100 ° C. and 140 ° C. without being wound up, and subsequently 150 ° C./0.95 times By performing a constant length heat treatment in (1), applying a known oiling agent, and winding the bobbin around, an 8-leaf monofilament having an R of 0.52 as shown in FIG. 1 (f) was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, the compressive displacement rate was low, but the recovery rate was low, and the breathability of the woven fabric was 63% as compared with the unset woven fabric.
It was reduced and could be controlled significantly. [Example 4] Using the resin and the manufacturing method described in Example 1, a 5-leaf monofilament having an R of 0.35 as shown in Fig. 1 (c) was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, although the same material as the multi-lobed cross-section monofilament of Example 1, since the area ratio R was small, the compression displacement rate was large and the recovery rate was low. Further, the breathability of the woven fabric could be controlled to a greater extent than the result of Example 1. [Example 5] By the resin and the manufacturing method described in Example 1,
An 8-leaf monofilament having an R of 0.80 as shown in FIG. 1 (f) was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, compared with the monofilament having a multi-lobed cross section of Example 1, since the compression displacement rate was slightly smaller, the change in the air permeability of the fabric was also slightly smaller, but the air permeability could be controlled more finely. . [Example 6] By the resin and the production method described in Example 2,
A 4-leaf monofilament having an R of 0.62 as shown in FIG. 1B was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, the degree of crushing was a little small because the recovery rate was a little high, and the change in the air permeability of the woven fabric was a little small, but the air permeability could be controlled more finely. [Comparative Example 1] By the resin and the manufacturing method described in Example 1,
A solid monofilament with a circular cross section having a diameter of 0.5 mm was obtained. The physical property results of the obtained monofilament are shown in Table 1.

Since this solid monofilament with a round cross section has a low compression displacement rate and a high recovery rate, the change in the air flow rate is much smaller than that of the woven fabric using the multileaf cross section monofilament of Example 1, and the performance intended by the present invention is obtained. Was not demonstrated. [Comparative Example 2] By the resin and the manufacturing method described in Example 2,
A solid monofilament with a circular cross section having a diameter of 0.5 mm was obtained.
The physical property results of the obtained monofilament are shown in Table 1.

Since this solid monofilament with a round cross section has a low compressibility and a high recovery rate, the change in the air flow rate is much smaller than that of the woven fabric using the multilobe cross section monofilament of Example 2, and the performance intended by the present invention is small. It was not demonstrated. [Comparative Example 3] By the resin and the manufacturing method described in Example 1,
A solid monofilament having a regular hexagonal cross-section with a circumscribed circle radius of 0.5 mm was obtained. The physical property results of the obtained monofilament are shown in Table 1.
Shown in.

This solid monofilament having a regular hexagonal cross section is
Due to the low compression rate and the high recovery rate, the change in the air flow rate was extremely smaller than that of the woven fabric using the multi-leaf cross-section monofilament of Example 1, and the performance intended by the present invention was not exhibited. [Comparative Example 4] By the resin and the production method described in Example 1,
An 8-leaf monofilament having an R of 0.87 as shown in FIG. 1 (f) was obtained. The physical property results of the obtained monofilament are shown in Table 1.

As a result, since the area ratio R was large, the compression displacement rate was small and the recovery rate was high. Therefore, the amount of change in the air permeability of the woven fabric was small, and the performance intended by the present invention was not sufficiently exhibited.

[0051]

[Table 1]

[0052]

As described above, the multifilament monofilament of the present invention has a multilobe cross section of three or more leaves, and is characterized by large deformation due to crushing and low recovery. Therefore, an industrial woven fabric using the multi-lobed cross-section monofilament of the present invention in at least part of the weft has a woven structure, that is, by artificially compressing the woven fabric to crush the multi-lobed cross-section monofilament to destroy the leaf shape. The weaving density can be changed, and as a result, a woven fabric having air permeability suitable for the purpose can be obtained.

In general, a woven fabric using monofilaments has a smaller specific surface area than an industrial woven fabric using spun yarn of multifilaments, so that dirt is less likely to adhere to the woven fabric surface and is excellent in breathability. When the weaving structure is complicated to obtain the property, dirt is likely to adhere. On the other hand, the industrial woven fabric using the multi-lobed monofilament of the present invention is characterized in that it does not require such a complicated weaving structure and that dirt is not easily attached.

[Brief description of drawings]

1 (a) to 1 (f) are cross-sectional explanatory views showing a specific example of the cross-sectional shape of the multi-lobed monofilament of the present invention.

FIG. 2 is an explanatory view showing a triple weave structure used for evaluation of the ease of adjusting the air permeability of the fabric in the example.

[Explanation of symbols]

1 Medium weft (multifilament monofilament of the present invention) 2 Front and back weft 3 warp yarn

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4L045 AA05 BA02 BA15 DA41 DA48                 4L048 AA19 AA20 AA24 AA37 AB10                       CA11 DA39                 4L055 CF30 EA15 EA19 FA20 FA30

Claims (4)

[Claims] 1. The cross-section of the yarn is a multi-leaf shape having three or more leaves, and the compression displacement rate measured by the following method is 20% or more and the compression displacement recovery rate is 50% or less. Multifilament cross-section monofilament. (However, the measurement of the compression displacement rate and the recovery rate of the compression displacement is a value measured under the following conditions using "Shimadzu powder compression tester PCT-200" manufactured by Shimadzu Corporation. , The side of the monofilament left for 24 hours or more under the environment of 65% RH,
With a diamond disk-shaped presser having a flat surface with a diameter of 500 μm, read the yarn diameter displacement when compressed / recovered under the conditions of origin load 15 gf, maximum load 200 gf, and load application speed 1.44 gf / sec. And the recovery rate of compressive displacement were obtained. In addition, three samples were taken from the same monofilament, n3 was measured, and the average was obtained. (1) Compressive displacement rate (%) = (L1 / D) × 100 (2) Recovery rate of compressive displacement (%) = (Restore rate / Compressive displacement rate) × 100 Here, D in the above equation is used for the test. The diameter or representative diameter (μm) of the raw yarn before being used, L1 is the yarn diameter displacement at the time of the origin load of 15 gf initially applied to the sample and the maximum load of 20
Absolute value of displacement difference with yarn diameter displacement at 0 gf (μ
m) and L2 are absolute values (μm) of the difference (residual displacement) between the L1 and the restoration displacement when the load is reduced from the maximum load of 200 gf to the origin load of 15 gf, and the restoration ratios are D and L.
It is a value (%) calculated from the equation 1, (L2) by the formula [(L1−L2) / D] × 100. ) 2. When the area of the circle circumscribing the cross-sectional shape of the yarn is S ₁ and the actual area of the yarn cross section is S ₂ , the formula R = S ₂ /
The multifilament cross-section monofilament according to claim ₁ , wherein the area ratio R represented by S ₁ is in the range of 0.2 to 0.8. 3. The multifilament monofilament according to claim 1 or 2, wherein the cross section of the yarn has a multilobal cross section of 3 to 10 leaves. 4. An industrial fabric comprising the monofilament having a multi-lobed cross section according to any one of claims 1 to 3 as at least a part of a weft.