JPH08199448A - Woven fabric for industrial purpose - Google Patents

Abstract

PURPOSE: To produce a woven fabric of high quality for industrial purpose, which is excellent in tensile strength, tearing strength and flexibility and can easily be designed so that these properties may become almost equal in both warp and weft directions, thus has such a high isotropy that the fabric can be handled equally in both warp and weft directions on cutting and sewing. CONSTITUTION: This woven fabric comprises multifilament yarns of less than 4.0 denier filament fineness, where the strength of the filaments therefrom is higher than 6.5g/d in both warp and weft and the absolute value of the difference between the warp and the weft is less than 0.5g/d. The woven fabric is produced by using the same filament yarns as the warp and weft, setting the yarn counts equally, and adjusting their tensions. Since this fabric has good processability such as cutting and sewing, products of high qualities can be produced for the industrial purposes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in fabrics suitable for industrial materials. More specifically, the present invention relates to a woven fabric for industrial materials, which is a soft cloth, has excellent isotropic properties such as mechanical strength, and has good processability such as cutting and sewing, and can produce high-quality industrial material products.

[0002]

2. Description of the Related Art Textiles for industrial materials are used for seat belts, airbags, canvas, nets for construction / civil engineering, bags, etc., and their use has been remarkably expanding in recent years.

General required properties of the woven fabric for industrial materials include mechanical strength, surface properties such as friction and slippage, heat resistance, dimensional stability and the like according to use. In addition, air bag base fabrics and the like are required to have the property of being lighter and more flexible, and therefore, it is proposed to manufacture a fabric for industrial materials by using filament yarns having a reduced total fineness or single yarn fineness. Has been done.

On the other hand, in terms of mechanical properties such as tensile strength and tear strength of the woven fabric and physical properties such as the flexibility of the woven fabric, it is necessary that the warp direction and the weft direction of the woven fabric have substantially the same properties. It is desired from the standpoint of easiness of design at the time of cutting and quality assurance.

Therefore, from the viewpoint of the isotropy of the airbag base fabric, Japanese Unexamined Patent Publication (Kokai) No. 3-137245 discloses that the warp and weft are essentially the same by using the same yarn for both warp and weft. A method of forming a symmetric structure is proposed, and it is described that the obtained woven fabric has substantially the same mechanical properties in the weft direction. However, since the single yarn fineness of the filaments constituting this woven fabric is as thick as 4.3 d or more, it is inferior in terms of flexibility and the like.

Further, in Japanese Laid-Open Patent Publication No. 4-2835, as an example of weaving of a base fabric for airbags, weaving in which the same yarns are simply used for the warp and weft raw yarns and the number of driven yarns is made equal The conditions are shown. However, this example does not impart isotropicity to the airbag base fabric, and neither the warp direction property nor the weft direction property of the obtained base fabric is described at all.

[0007]

However, in general, in a woven fabric for industrial materials, the smaller the fineness of the single yarns constituting the woven fabric, the more the characteristics of the warp direction and the weft direction of the finally woven fabric are likely to be different.

That is, even when a multifilament yarn having the same tenacity is used for the warp yarn and the weft yarn and weaving the fabric with the same number of hammers in both the warp direction and the weft direction, the weaving machine used, the weaving method, and the applied tension during weaving. The mechanical properties of the woven fabric differ depending on the level and the like in the warp direction and the weft direction. In addition, recently, due to the progress of the loom, it is often the case that weaving is performed at high speed and high density using a water jet loom or an air jet loom, but in these cases, the strength of the warp and the weft in the woven fabric manufacturing process is improved. Differences are likely to occur. In particular, when weaving using fine single-filament filament yarns having a single-filament fineness of 4.0 d or less, the difference in strength is likely to be further increased, and as a result, not only strength characteristics but also other properties such as flexibility are In terms of characteristics, the woven fabric has anisotropy in the warp direction and the weft direction.

As described above, it has been difficult to impart isotropy to a filament yarn fabric having a fine single yarn fineness of 4.0 d or less by the conventional method.

In order to make the strength of the fabric in the warp direction and the weft direction isotropic, the number of warp and weft yarns is adjusted, that is, the number of warp yarns or weft yarns is increased or decreased. Alternatively, a method of adjusting the yarn quality such as the yarn fineness of the warp and weft can be considered. However, according to this method, since the constituent single yarn densities are different in the warp direction and the weft direction, other characteristics such as flexibility are different in the warp direction and the weft direction. Therefore, even if the strength is isotropic in the warp and weft, it is still difficult to obtain a woven fabric that can handle the warp and weft directions equally during cutting and sewing.

Therefore, the present invention solves the above-mentioned problems in the prior art, and even a woven fabric for industrial materials composed of filament yarn having a small single yarn fineness has mechanical strength such as tensile strength and tear strength. We provide fabrics for industrial materials that can be easily designed so that both physical properties such as flexibility and flexibility are almost the same in the warp direction and the weft direction, and make the warp direction and the weft direction equal when cutting or sewing. The main purpose is to provide a treatable fabric.

[0012]

In order to achieve the above-mentioned object, the woven fabric for industrial materials of the present invention is a woven fabric in which both warp and weft are composed of multifilament yarns having a single yarn fineness of 4.0d or less. The strength of the warp and the strength of the warp are both 6.5 g / d or more, and the difference (absolute value) between the strength of the warp and the strength of the weft is 0.5 g / d or less. Characterize.

Further, in the woven fabric for industrial materials, it is preferable that the warp yarn and the weft yarn are composed of the same filament yarn, and the difference between the warp direction and the weft direction of the weaving density is 2 or less per inch.

Kutta, the filaments that make it up,
It is preferable that the polyester filament is composed of ethylene terephthalate units in an amount of 85% by weight or more, and the total fineness of the multifilament yarn forming the warp and the weft is 1
It is preferably from 00 to 700d.

Further, it is preferable that the woven structure is a plain woven fabric, the cover factor thereof is 1700 or more, and the flexibility of the woven fabric by the cantilever method is 150 mm or less in both the warp and weft directions and the difference is 20 mm or less.

The woven fabric is particularly useful as a base fabric for airbags.

The single-filament fineness of the multifilament yarn constituting the woven fabric for industrial materials of the present invention is 4.0 d or less, preferably 0.1 to 0.1 in terms of the single-filament fineness of the decomposed yarn obtained by decomposing from the woven fabric.
It is 4.0 d, more preferably 0.2 to 2.0 d.
In order to make the single yarn fineness of the decomposed yarn within the above range, usually,
The single yarn fineness at the raw yarn stage may be designed to be equal or slightly smaller.

When the single yarn fineness of the decomposed yarn exceeds 4.0 d, the flexibility of the woven fabric becomes poor and it is difficult to obtain a high quality woven fabric. The finer the single yarn fineness is, the better. . However, if it is too thin, such as less than 0.1 d, it is not preferable because it is difficult to produce a yarn by the direct spinning method and there is a problem in practical use in industrial practice.

Further, the multifilament yarn constituting the woven fabric for industrial materials is required to have a decomposed yarn strength of 6.5 g / d or more for both warp and weft, and more preferably 7.0 g / d or more. is there. If either or both of the warp and the weft are less than 6.5 g / d, in order to increase the mechanical strength of the woven fabric itself to a level according to the application,
It is necessary to increase the number of threads to be driven in more than necessary and to make the total fineness of the filament yarns thicker than necessary. On the contrary, the flexibility and the lightness are impaired and the weavability is impaired. There is a problem and it is inappropriate.

In the present invention, it is important that the difference in the strength of the decomposed yarn between the warp and the weft is 0.5 g / d or less. When the difference exceeds 0.5 g / d, various physical properties such as tensile strength, tear strength and flexibility of the woven fabric may be designed to be isotropic, that is, the warp direction and the weft direction are almost the same. It is difficult and the intended purpose of the present invention cannot be achieved.

In particular, in the case of the present invention, by the woven fabric design in which the number of warp wefts is approximately the same level such that the difference between the warp direction and the weft direction is 2 or less per inch,
It is possible to easily design an isotropic woven fabric in which the physical properties in the warp direction and the weft direction are almost the same.

The filament yarn constituting the woven fabric for industrial materials in the present invention is not particularly limited as long as it has the above-mentioned characteristics.
Known filament yarns can be used. For example, polyester such as polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyhexamethylene adipamide, polytetramethylene adipamide,
It is possible to use a filament yarn made of polyamide such as polycapramide or polyolefin such as polyethylene or polypropylene. From the viewpoint of high-strength fibers, it is also possible to use wet spinning, dry spinning, or filament yarn made of polyvinyl alcohol or aromatic polyamide having a high degree of polymerization obtained by dry spinning.

Among them, in consideration of easiness of production and function, a filament yarn capable of being melt-spun and having excellent mechanical properties and heat resistance, for example, a filament yarn made of polyester or polyamide is preferable. In particular, a polyethylene terephthalate polyester filament yarn in which 85% by weight or more is composed of ethylene terephthalate units is most preferable from the viewpoint of dimensional stability.

The polymer to be used may contain other copolymerization components or additives for the purpose of enhancing the spinnability as long as it does not impair their original excellent properties. In addition, flame retardants, antioxidants and the like may be added for the purpose of enhancing the performance of the woven fabric as long as the spinnability is not impaired.

The total fineness of the filament yarn is 100 to 700 d, preferably 200 to 500 d, for the decomposed yarn.

If the total fineness of the decomposed yarn exceeds 700 d, the thickness of the woven fabric becomes too thick, tending to impair the flexibility and lightness, and further, the compactness becomes poor. Conversely, the total fineness is 1
If it is less than 00d, it is difficult to increase the mechanical strength of the woven fabric to the level required for industrial materials, no matter how densely weaved, at the present strength level.

The woven fabric for industrial materials of the present invention can have a woven structure according to the intended use, but a plain weave is preferred from the viewpoint of ease of weaving. In addition, weaving density can be widely used from open type to high density low breathable fabric depending on the purpose, and the number of hammered in is adjusted according to the required tensile strength, tear strength, burst strength, etc. of the cloth. However, in the case of a high-density fabric, the effect of the present invention can be more greatly exhibited.

Specifically, in the case of plain weave, the cover factor is preferably 1700 or more, more preferably 19
This is the case of 00 or more.

Furthermore, the fabric for industrial materials according to the present invention has a flexibility of 150 as measured by the cantilever method.
Excellent flexibility of not more than mm can be obtained, and further, the difference in flexibility between the warp direction and the weft direction is not more than 20 mm, and thus the flexibility can be excellent isotropic.

As described above, when the single yarn fineness of the filament yarn constituting the woven fabric for industrial materials is small, attention is paid to the strength characteristics of the warp and the weft in the woven fabric so that the strength characteristic satisfies a specific value. By weaving under various conditions, it is possible to easily design a woven fabric excellent in isotropicity of the background. In addition, the anisotropy of the warp and weft characteristics that occur during weaving can be accurately grasped, and it becomes possible to easily design an appropriate woven fabric in consideration of lightness and flexibility.

In particular, when the same filament yarn is used for the warp and the weft, and the number of woven fabrics is almost the same in the warp direction and the weft direction, the isotropic woven fabric has high strength and excellent flexibility. Is easily obtained.

Such a fabric for industrial materials of the present invention can be easily manufactured by the following method.

The filament yarn constituting the woven fabric may be produced by a usual spinning method. The strength of the decomposed yarn is 6.5g
In order to obtain a high-strength yarn of not less than / d, it is usually preferable that the yarn has a strength of 8.0 g / d at the stage of the raw yarn. In order to obtain a fiber having such strength, it is generally desirable to use a polymer having a high degree of polymerization. In the case of polyethylene terephthalate, a polymer having an intrinsic viscosity of 1.0 or more, and in the case of polyhexamethylene adipamide, Has 9
What has a relative viscosity of 8% sulfuric acid of 2.7 or more may be used.
If the viscosity is lower than this, it may be difficult to obtain sufficient strength and elongation characteristics even if the spinning conditions are optimized and improved. However, if the viscosity is too high, industrial spinning becomes difficult. Therefore, it is preferable to set the intrinsic viscosity to 1.7 or less and the 98% sulfuric acid relative viscosity to 5.0 or less at the highest.

The spinning temperature varies depending on the type of polymer used, but in the case of polyethylene terephthalate or polyhexamethylene adipamide, the range of 280 ° C. to 310 ° C. is usually used.

In the case of the above-mentioned polyethylene terephthalate, polyhexamethylene adipamide, and further polymers such as polycaprolactam, generally 10 to 10
It is preferable to use a heating cylinder having a length of 100 cm and whose temperature is controlled at 200 to 350 ° C. to delay the solidification of the molten polymer and develop high strength. The length and temperature conditions of the heating cylinder may be optimized depending on the fineness of the obtained yarn and the number of filaments.

The spun yarn is once wound or continuously stretched to give a desired high strength. The drawing conditions may be appropriately determined depending on the type of polymer used, the degree of polymerization thereof, and the physical properties of the undrawn yarn stage. Usually, it may be carried out by a conventional hot drawing, and a multi-step drawing of two or more steps is preferable.

Subsequently, the drawn yarn is heat set. The heat fixation may be carried out by a usual method such as bringing the yarn into contact with a heat roller or a heat plate, or passing it through a high temperature gas. At this time, the dry heat shrinkage ratio can be controlled by changing the tension and temperature during heat setting.

The filaments constituting the woven fabric for industrial materials in the present invention are preferably subjected to an entanglement treatment in the drawing step and the heat setting step in order to further suppress the generation of fluff. For the entanglement, a normal method such as air entanglement can be adopted. For example, in the case of air entanglement, the desired degree of entanglement can be achieved by appropriately changing the pressure of the supply air according to the fineness and tension of the yarn to be used. In this case, the degree of entanglement is preferably 30 or more, more preferably 50 or more.

The filament yarn obtained by drawing and heat setting usually has a total fineness of 80 to 700 d and a single yarn fineness of 4.
It is preferable to have the characteristics that the tensile strength is 0 d or less and the tensile strength is 8.0 g / d or more.

In order to produce a woven fabric for industrial materials by using this multifilament yarn, the obtained filament yarn may be used as it is as a warp yarn and a weft yarn, and the tension conditions thereof may be optimized and weaving by a usual method. The loom is not particularly limited, and weaving methods such as rapier, water jet loom, and air jet loom can be used. At this time, processing such as twisting and sizing is not necessary, but may be performed as necessary. The weaving structure is not particularly limited, such as plain weave and diagonal weave, but a plain weave is preferred because of ease of production.

In order to set the strength of the decomposed yarn of the woven fabric to 6.5 g / d or more, the original yarn strength is usually 8.0 g / d as described above.
The above filaments may be used and woven so as not to damage the filaments. That is, excessive bending of the filament yarn during weaving causes a large decrease in strength, which makes it difficult to obtain a high-strength woven fabric.

Further, in the method of reducing the strength difference of the decomposed yarns in the warp direction and the weft direction to 0.5 g / d or less, the warp direction and the weft are adjusted in accordance with the characteristics of the filament yarn and the driving speed. It suffices to control the tension during weaving in one direction.

The tension control can be carried out, for example, by applying a load to the warp to be fed to give tension, or by slightly loosening the tension of the weft that had been applied just before the reed was driven. Good. In short,
The tension level of the warp may be higher than the conventional level and / or the tension level of the weft may be lower than the conventional level. As for those tensions, the strength difference between the warp and the weft in the obtained woven fabric is 0.5 g.
It may be a level that is less than / d. In particular,
When the same filament yarn is used as the warp yarn and the weft yarn and the same number of yarns is driven into the fabric, the tension level may be controlled so that the warp yarn and the weft yarn in the woven fabric have the same crimp.

When a filament yarn having a large single yarn fineness is used, the strength difference between the warp yarn and the weft yarn hardly occurs at the time of weaving even by the conventional method without controlling the tension at the time of weaving. For thin filament yarn,
As described above, the strength difference between the warp and the weft occurs during weaving. The cause of this difference in strength is not clearly clarified, but the finer the fiber, the more flexible the filament becomes, and the more easily it is affected by contact with a guide, etc. It is presumed that this is due to the fact that defects are likely to occur in the same manner and that defects when contacting a guide or the like are likely to occur. Furthermore, the polymer having a higher initial modulus such as polyethylene terephthalate tends to be more susceptible to the influence.

By properly controlling the tension level during weaving as described above, even when a fine-fineness filament yarn having a single yarn fineness of 4.0 d or less is used, the difference in mechanical characteristics between the warp and the weft during the weaving Can be sufficiently suppressed,
The strength level of the decomposed yarns of the obtained woven fabric can be made substantially the same level (the strength difference is 0.5 g / d or less).

According to the above weaving method, the same filament yarn is used for the warp yarn and the weft yarn, and the weaving density difference between warps and wefts is substantially equal to 2 or less per inch. When woven with, the resulting fabric is
The isotropy of the process becomes extremely excellent. For example, in the case of a plain woven fabric obtained by the above method, the flexibility of the woven fabric by the cantilever method in both the warp direction and the weft direction is 150 m.
In addition, the difference between the warp direction and the weft direction of the flexibility can be made extremely small such as 20 mm or less.

The woven fabric for industrial materials of the present invention thus obtained, if necessary, may be subjected to scouring, heat setting, and calendering on one or both sides by a known method within a range not impairing the characteristics of the present invention. There is no problem in applying.

Particularly when it is used as a base fabric for an air bag, it is preferable that the fabric is contracted by heat setting or calendering to the extent that the fabric is not hardened to further suppress the air permeability.

Even when another filament is mixed as a rip stop into a part of the woven fabric, the effect of the present invention can be exhibited if substantially all of the filament yarns used satisfy the requirements of the present invention.

[0050]

The present invention will be described in detail below with reference to examples. Each physical property in the present invention is a value measured as follows.

(1) Intrinsic viscosity (IV) of polyethylene terephthalate: Using an Ostwald viscometer, the relative viscosity ηrp of a solution of 3.0 g of a sample dissolved in 100 ml of orthochlorophenol was measured at 25 ° C. IV is calculated by

IV = 0.0242 ηrp + 0.2634 where ηrp = (t × d) / (t0 × d0),
Here, t: drop time of solution (second), t0: drop time of orthochlorophenol (second), d: density of solution (g / cc), d0: density of orthochlorophenol (g / cc) .

(2) Sulfuric Acid Relative Viscosity of Polyamide: A sample is dissolved in 98% sulfuric acid at a concentration of 1% by weight and measured at 25 ° C. using an Ostwald viscometer.

(3) Tensile strength and elongation at break of filament yarn: Measured according to JIS-L-1017.

(4) Cover factor K of woven fabric: Defined by the following equation.

K = N _W × D _W ^0.5 + N _F × D _F ^0.5 where N _W : warp density (pieces / inch), D _W : warp fineness (denier) at the time of fabric production, N _F : weft density (pieces) / Inch), _DF : Weft yarn fineness (denier) at the time of fabric production.

(5) Softness of woven fabric: JIS-L-10
The bending resistance is measured by 96 (45 ° cantilever method).

(6) Tensile strength of woven fabric: JIS-K-
According to 6328 (strip method), the sample width is 3 cm. The results are shown by the average value of the warp direction value and the weft direction value of the fabric.

(7) Tear strength of woven fabric: JIS-L-
It is measured according to 1096 (trapezoid method). The results are shown by the average value of the warp direction value and the weft direction value of the fabric.

(8) Fineness and strength of the decomposed yarn of the woven fabric: The yarn was taken out from the woven fabric, cut into a length of 25 cm under a load of about 1/3 of the fineness of the original yarn stage, and then weighed,
It was converted to 9000 m and used as the decomposed yarn fineness. Then, a tensile test was carried out by using RTM-100 manufactured by Orientec Co., Ltd. at a test length of 15 cm and a tensile speed of 30 mm / min, and the strength at the maximum strength point was read on the chart. The value obtained by dividing the value by the decomposed yarn fineness was defined as the decomposed yarn strength, and the average of 5 measurements was calculated.

[Examples and Comparative Examples] From polyethylene terephthalate (PET) or polyhexamethylene adipamide (N66), filament yarns having the yarn characteristics shown in Table 1 were prepared by a conventional method of melt spinning, drawing and heat setting. Manufactured. Using the obtained filament yarn, a woven fabric was produced under the weaving conditions shown in Table 1 using an air jet loom. At the time of this weaving, in Examples 1 to 4 and Comparative Examples 1 and 2,
A means for relaxing the tension of the weft yarn at the moment of driving the reed was provided so that the strength levels of the warp yarn and the weft yarn in the woven fabric were almost the same.

In the case of Example 4 and Comparative Example 5, P
It was prepared as a sea-island type composite fiber containing ET as an island component, and was subjected to sea-removal treatment after weaving. The yarn properties were shown after the sea-removal except for the values of strength and elongation.

The fineness, strength and fabric characteristics of the decomposed yarn of the obtained woven fabric were measured and the results are shown in Table 1.

[0064]

[Table 1]

In Examples 1 to 4, since the original yarn strength was high, the decomposed yarn strength of the woven fabric also showed a high value of 6.5 g / d or more. Further, since the tension of the weft yarn is controlled to be low at the time of weaving, even though the fine yarn filament yarn having a single yarn fineness of 4d or less is used, the warp and weft directions of the decomposed yarn strength of the obtained woven fabric are The difference is extremely small at 0.0 to 0.2 g / d. As a result, a woven fabric having excellent tensile strength, tear strength, flexibility, warp and weft balance and excellent isotropy was obtained.

On the other hand, Comparative Example 1 has a low yarn strength, and therefore has poor mechanical properties when formed into a woven fabric and is unsuitable as an industrial woven fabric. Further, in Comparative Example 2, the filament used had an excessively large single yarn fineness, so that the woven fabric was thick and inferior in flexibility. Furthermore, in Comparative Examples 3 to 5, since tension control during weaving was not performed, there was a large difference between the warp direction and the weft direction of the decomposed yarn strength of the woven fabric, and a highly anisotropic woven fabric was obtained.

[0067]

EFFECTS OF THE INVENTION The woven fabric for industrial materials according to the present invention is composed of filament yarns having a specific fine single yarn fineness, and the warp and weft thereof have the same high strength in the woven fabric. Excellent tensile strength, tear strength, and flexibility. Furthermore, since it can be easily designed to have the same excellent strength and flexibility in the longitudinal direction and the weft direction,
It is excellent in isotropy so that the warp and weft directions can be handled equally during cutting and sewing, and it can be made into a high quality woven fabric for industrial materials, and it is possible to manufacture high quality industrial material products with good processability such as cutting and sewing .

For example, in the case of an airbag base fabric, it is possible to cut the fabric without distinction in the weft and weft directions, the cutting efficiency of the base fabric can be improved, and the design and processing during cutting and sewing are facilitated. It becomes possible to manufacture an airbag which is further inflated uniformly and further improved in safety.

Specifically, seat belts, airbags,
Preferable for various industrial materials such as canvas, nets for construction and civil engineering, bags, etc., especially as a base fabric for airbags that is isotropic and requires low density and high density and flexibility. Suitable for

Claims (7)

[Claims] 1. The single yarn fineness of both warp and weft is 4.
A woven fabric composed of multifilament yarns of 0d or less, both the strength of the warp and the strength of the warp are 6.5 g / d or more, and the difference between the strength of the warp and the strength of the weft (absolute value). ) Is 0.5 g / d or less, a woven fabric for industrial materials. 2. The warp yarn and the weft yarn are composed of the same filament yarn, and the difference between the warp direction and the weft direction of the weaving density is 2 or less per inch.
Woven fabric for industrial materials described. 3. The woven fabric for industrial materials according to claim 1, wherein the multifilament yarn comprises a polyester filament in which 85% by weight or more of the constituent polymer units are ethylene terephthalate units. 4. The woven fabric for industrial materials according to claim 1, wherein the total fineness of the multifilament yarn is 100 to 700 d. 5. The woven fabric for industrial materials according to claim 1, wherein the woven fabric is a plain woven fabric having a cover factor of 1700 or more. 6. The fabric cantilever has a flexibility value of 150 mm or less in both the warp direction and the weft direction, and a difference (absolute value) in flexibility value between the warp direction and the weft direction is 20.
The fabric for industrial materials according to claim 1, wherein the fabric is less than or equal to mm. 7. The woven fabric for industrial materials according to claim 1, wherein the woven fabric is a base fabric for an airbag.