JPH09291465A - Production of fabric for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lightweight and soft fabric for air bag, low in air permeability and having moderate mechanical strength, intended for non-coat use, by heat treatment, with superheated steam, of a humid synthetic textile fabric woven by a water jet loom. SOLUTION: Nylon 66 multifilament yarns are woven by a water jet loom into a high-density or low-density plain textile fabric, which is then wound up into a roll once, and heat-treated in a humid state with superheated steam at 100-170 deg.C, thus obtaining the objective air bag base fabric with an air permeability of <=0.5cc/cm<2> /s at 124 Pa intended for non-coat use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an airbag fabric used for an airbag equipped as a safety device in a vehicle such as an automobile (hereinafter, an automobile will be described as a typical example).

[0002]

2. Description of the Related Art An air bag is housed in a steering wheel or a dashboard portion during steady operation, and when a car collides, a sensor detects the shock to generate a high pressure gas, and the gas causes the above air to be emitted. The bag is instantly inflated, and the inflated airbag prevents the occupant from colliding with the steering wheel or the like.

Therefore, as a bag material used for the above-mentioned airbag, firstly, high airtightness capable of preventing gas leakage as much as possible is required, secondly, appropriate strength is required, and thirdly. In addition, since the airbag is stored in a small place as described above, it is required to be compact and easy to fold.

As a conventional material for an airbag, there is a resin-coated airbag cloth in which a resin such as rubber is coated on a base fabric made of a synthetic fiber woven fabric (conventional example). By applying the resin, airtightness and heat resistance can be obtained. We are trying to improve.

However, in the above-mentioned conventional example, since the bag material is thick and the weight of the bag is large, it is difficult to fold it into a small size. Therefore, it is inferior in the storability in the handle and the texture is hard. However, when the inflated airbag comes into contact with the occupant's face, the face may be damaged, which is not preferable. In addition, the above-mentioned conventional example has a problem that the processing cost is increased because a step of applying rubber or the like is required.

Therefore, as a solution to these problems, a non-coated airbag cloth which does not require a resin coat has been proposed, for example, as in the following conventional examples. Conventional examples are
After weaving a high-density woven fabric, shrinkage processing, heat-setting calendering, etc. are performed to crimp the yarns constituting the fabric to obtain a low air-permeable fabric (Japanese Patent Laid-Open No. 1-122752).
issue).

[0007] In the conventional example, a chemical shrinkage treatment is applied to a woven fabric to swell the filaments constituting the fabric to narrow the gaps between the yarns and to obtain a low air-permeable fabric (Japanese Patent Laid-Open No. 6-62). 41844).

In the conventional example, immediately after the weaving operation by the loom,
Continuously shrinking the fabric in an aqueous bath at 20-100 ° C. and then running the fabric through a drying zone, which gives a fabric with the desired breathability, for example low breathability. (JP-A-7-145552).

By the way, as a loom for the base cloth of these non-coated airbag cloths and the above-mentioned resin-coated airbag cloths,
Water jet looms, air jet looms, and rapier looms are generally used. Among them, the water jet looms have a high production amount per hour, the damage of constituent yarns during weaving is small, and the energy required for production. It is especially widely used because of its low cost.

In the manufacturing process using a water jet loom, the woven wet fabric is wound up once,
The wound state is passed through a drier to be dried, or the woven fabric in a wet state woven by a water jet loom is wound while being continuously dried by a heating roller or the like. If left unwetted after weaving, it will cause fabric defects such as mold generation and wrinkles, and also carry unnecessary moisture when transporting to the processing plant for the next treatment. There are problems such as things that happen, and in order to avoid this problem, drying is always performed. Then, in the next step, various treatments such as scouring, drying, and heat treatment are performed on the wound dried green machine.

[0011]

As described above, various non-coated airbag cloths have been proposed. In the above-mentioned conventional example, however, the threads are pressed against each other as described above, so that the texture of the cloth is firm. However, the conventional example has a problem that the strength is lowered because the yarn is swollen.

[0012] In the conventional example, since the two steps of the treatment step in the aqueous bath and the step of the drying zone are required in succession, the equipment for the above-mentioned two steps must be installed in each loom, and therefore the equipment is complicated. In addition, there is a problem that a large installation area is required and the operation is complicated. Even if the woven fabrics woven from several looms are put together and treated in one aqueous bath treatment step and one drying zone step, the equipment becomes complicated and large. in addition,
Since the weaving process, the aqueous bath treatment process, and the drying zone process are performed continuously, when the loom stops for some reason, the processing time in the aqueous bath and drying zone increases,
This causes a problem such as generation of defective products.

In any case, the conventional method for producing a non-coated airbag cloth requires many steps,
As a result, the risk of wrinkles occurring on the way increases, and in addition, the manufacturing cost cannot be reduced so much.

Therefore, the present applicant invented a method for manufacturing a fabric for an airbag which has low air permeability, is lightweight, can be folded compactly, and has a low manufacturing cost, and has already applied for it (September 28, 1995). Patented invention of application; hereinafter referred to as prior invention).

A water jet loom, an air jet loom, a rapier loom, or the like is used as the loom in the above-mentioned prior invention, and the inventors of the present invention have further studied the above-mentioned invention. It has been found that there is room for further improvement in the case of weaving. Further, when the base fabric of the resin-coated airbag is woven by a water jet loom, it was found that there is room for improvement in the same manner, and as a result of the study, the present invention was completed.

That is, in the method using the water jet loom, as described above, since the process of rewinding must be repeated many times, defects such as wrinkles are likely to occur in the woven fabric, and in addition, the number of processes is large. There is a problem of high cost.

Therefore, in view of the above problems, the present invention provides low air permeability, light weight and softness when manufacturing a non-coated airbag fabric using a water jet loom.
It is a first object of the present invention to provide a method capable of producing a fabric for an airbag, which has strength, can be compactly folded, and is unlikely to cause defects such as wrinkles, with a small equipment area and further reduced manufacturing cost. A second object is to provide a method for producing a fabric for an air bag, which is useful as a base fabric for a resin-coated air bag.

[0018]

According to the method for manufacturing an airbag fabric of the present invention, a yarn made of synthetic fibers is woven using a water jet loom, and the fabric is kept in a wet state without being dried. The gist is to perform heat treatment with superheated steam at 170 ° C.

As described above, it is important that the woven fabric woven by the water jet loom is subjected to the superheated steam treatment in a wet state without being dried, and the fibers are contracted and dried by the superheated steam treatment. be able to. That is, when treated with superheated steam at 100 to 170 ° C., a sufficient shrinkage effect is exhibited, heat resistant dimensional stability is excellent, residual shrinkage is small, and a flexible woven fabric can be obtained, and a woven fabric in a wet state is obtained. Will be dried. Therefore, the drying step after weaving can be eliminated, the cost can be reduced by reducing the number of steps, and the risk of wrinkles and the like can be reduced.

On the other hand, from the viewpoint of shrinkage by heat and drying, it is conceivable to apply heat in a dry atmosphere, but when heat shrinking treatment is performed by dry heat, shrinkage is insufficient and residual shrinkage rate Was found to be a large and stiff fabric. Therefore, it was examined to further reduce the residual shrinkage by further increasing the dry heat temperature and performing heat shrinkage treatment, but it was found that discoloration of the fabric occurs due to the high temperature, which is not preferable.

As described above, the temperature of the shrink heat treatment with superheated steam is 100 to 170 ° C. Above 170 ° C,
The contraction effect commensurate with the increase in consumed energy does not appear, resulting in large energy loss and high cost. In addition, for fabrics made of synthetic fibers with high heat shrinkability, 1
When a shrinkage heat treatment of over 70 ° C. is performed, the fibers are sufficiently shrunk, but the shrinkage causes the yarn to bend and escapes in the thickness direction, rather creating a space between the yarns of the woven fabric and increasing the air permeability. The fabric for air bags has a low air permeability and cannot be obtained. On the other hand, when the temperature is lower than 100 ° C, the fibers are shrunk, but the woven fabric after the treatment is not sufficiently dried, and it is necessary to add a drying step as the next step, which increases the number of steps, which leads to rationalization and cost reduction. I can't go down. In addition, the increase in the number of steps increases the risk of wrinkles and stains as described above. Therefore, the above temperature range is set. More preferably 110
１６０160 ° C.

Further, in the method for manufacturing an airbag fabric according to the present invention, it is preferable that the step of weaving using the water jet loom and the step of performing shrinkage heat treatment with the superheated steam are discontinuously performed. That is, specifically, a water jet loom and a superheated steam processing machine are provided separately,
It is desirable to process them separately.

In the case of such a discontinuous treatment, since the processing speed of the superheated steam processing machine can be made higher than the weaving speed of the loom, the processing amount per superheated steam processing machine should be increased. And processing efficiency is good. In addition, in the case of continuous processing, when the loom is stopped for some reason, the overheat treatment time increases, which causes defective products,
In the case of discontinuity, the superheated steam processing machine is not affected by troubles of the loom, so that there is no risk of defective products as described above.

In the production method of the present invention, as described above, it is sufficient that the woven fabric is subjected to the shrinkage heat treatment with superheated steam at 100 to 170 ° C. in a wet state, and is continuously performed immediately after the weaving operation by the water jet loom. It is not excluded to carry out superheated steam treatment.

Further, in the method for manufacturing an airbag fabric according to the present invention, it is preferable to use polyamide fiber as the synthetic fiber. The polyamide fiber has excellent impact resistance,
It has excellent properties such as withstanding high temperature gas from the inflator.

Further, in the present invention, in the case of the non-coated airbag woven fabric, the woven fabric after the shrinkage heat treatment is 124 Pa.
It is preferable that the air permeability is 0.5 cc / cm ² / sec. Or less. This is because if the air permeability exceeds 0.5 cc / cm ² / sec., The amount of gas released to the outside through the fabric will increase and the responsiveness when the airbag is inflated will decrease, which is not preferable. Of 0.5 cc / cm ² / sec. Or less can be used as it is as a fabric for an airbag. The air permeability is measured using a Frazier tester of JIS-L1096 6.27.1 A method.

When the woven fabric obtained by the method of the present invention is used as a base fabric and a rubber-based resin or the like is coated to form a resin-coated airbag, the woven fabric after shrinkage heat treatment is 124P.
The air permeability is preferably 3.0 cc / cm ² / sec. or less under a, and more preferably more than 0.5 to 3.0 cc / cm ² / sec. This is because when the air permeability exceeds 3.0 cc / cm ² / sec., The resin may come out to the back surface of the base fabric (woven fabric). On the other hand, a high airtightness of 0.5 cc / cm ² / sec. Or less is not particularly necessary when coating the rubber resin. Examples of the rubber resin to be coated include chloroprene rubber and silicone rubber.

Some airbags are provided with a low breathable material portion as well as a filter portion having a relatively high breathability. As a woven fabric for such a filter portion, the method of the present invention is used. Among the manufactured airbag fabrics, those having a certain degree of air permeability, for example, an air permeability of 0.
Textiles of more than 5 to 3.0 cc / cm ² / sec. Are useful. The filter portion is provided for adjusting the amount of gas in the bag.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION An example of the manufacturing method of the present invention will be described below. First, a yarn made of polyamide fiber is woven using a water jet loom, and the woven fabric is treated in a superheated steam at 135 ° C. for 1 minute in a wet state to shrink and dry the woven fabric. Get the fabric.

The superheated steam can be obtained by superheating saturated steam with a heat source (for example, an electric heater), and as a typical superheated steam processor, HIGH TEMPERATURE
STEAMER (hereinafter referred to as HTS) and the like.

As the state of the superheated steam treatment, the woven fabric may be fixed, such as holding the woven fabric with a tenter, or may be free and not fixed. There is no problem in subjecting the woven fabric after the above superheated steam treatment to ordinary scouring and drying treatments. in addition,
Although sizing may be applied during the warping step before weaving with a water jet loom, the warping step without sizing is preferable from the viewpoint of cost reduction.

Polyamide fibers include 46 nylon and 6
Nylon, 66 nylon, 610 nylon, 11 nylon, 12
Aliphatic polyamides such as nylon, aromatic polyamides such as terephthalic acid and isophthalic acid, such as hexamethylene isophthalamide and tetramethylene isophthalamide,
Further, a copolyamide, a mixed polyamide and the like containing these as main constituents can be mentioned. Of these, 46 nylon, 6 nylon and 66 nylon are particularly preferable. As the synthetic fiber used in the present invention, polyester fiber, aramid fiber, wholly aromatic polyester fiber, etc. may be used in addition to the above polyamide fiber.

The synthetic fiber yarn used in the present invention may be a low shrinkage yarn or a high shrinkage yarn. That is, even a highly shrinkable synthetic fiber yarn having a dry heat shrinkage rate of 160 ° C. (measured by the JIS-L1013 7.15 (1) B method) of 5 to 15%, a low shrinkage synthetic fiber yarn of less than 5% Even fiber yarns can be applied to the method of the present invention. Especially, air permeability 0.5cc
In order to manufacture a fabric for an air bag having a low air permeability of less than / cm ² / sec., the highly shrinkable synthetic fiber yarn (dry heat shrinkage of 5
15%), the synthetic fiber yarns are woven with a water jet loom at a high density, and the woven fabric is made into a more dense woven fabric by the method of the present invention. It is preferable because a woven fabric can be obtained.

The fineness of the synthetic fiber yarn is 150 to
900 denier multifilament yarn is preferred, and more preferably 200 to 500 denier. If it is less than 150 denier, only a fabric having insufficient mechanical properties required for an airbag fabric, such as tensile strength or tear strength, can be obtained. On the other hand, if it exceeds 900 denier, it is difficult to obtain a flexible fabric. , Because the foldability is poor.

With respect to the heat-resistant dimensional stability of the fabric for an air bag, it is desirable that the heat shrinkage rate when left in a dryer at 190 ° C. for 15 minutes is 3% or less. When the heat shrinkage rate exceeds 3%, the size of the airbag is greatly changed by the high temperature gas from the inflator, which is not preferable, and the car may become extremely hot during parking. If the heat shrinkage rate exceeds 3% when left for a long time under the conditions, the dimensions of the airbag change, which is not preferable.

The stiffness of the airbag fabric is JIS-
L1096 6.19 A method (45 ° cantilever method)
It is preferably 125 mm or less. Bending degree is 125 mm
This is because a woven fabric having a weight of more than 100% is stiff, and the occupant may be damaged when the airbag is inflated and comes into contact with the occupant, and in addition, the foldability is deteriorated.

[0037]

[Example] As a yarn used for manufacturing an airbag fabric,
Using nylon 66 multifilament yarn consisting of 72 filaments, as shown in Table 1 below, high density or low density plain weave fabrics were woven using a water jet loom and once wound into rolls. In addition, each woven fabric No. 1-7
The dry heat shrinkage (%) and the fineness (denier) of the filament yarn used in Table 1 are shown in Table 1 below. The dry heat shrinkage is measured at 160 ° C according to JIS-L1013 7.15 (1) B method.
It was performed under dry heat. Table 1 also shows the moisture content of these woven fabrics Nos. 1 to 7 in the undried state immediately after weaving.

Next, regarding the woven fabric Nos. 1 to 6,
Using HTS in the wet state without drying, Table 1
Heat treatment was performed under the heat treatment conditions shown in (1), and the material was shrunk at a stretch.
In Table 1, "holding and fixing" means that the HTS with a tenter holding function was used to fix the fabric with the tenter, and "not fixed" means that the tenter was used. It was done in a free state without fixing the frame by. For the woven fabric No. 7, as shown in Table 1, the wet woven fabric was not fixed and was kept at 140 ° C.
A dry heat drying treatment for 1 minute was performed.

Regarding the shrink-treated woven fabric obtained as described above, Table 1 also shows the woven density, air permeability, shrinkage ratio, and bending resistance. The air permeability was measured with a Frazier tester at 124 Pa, and the heat shrinkage was 190
The woven fabric after being left in a dryer at 15 ° C. for 15 minutes is shown in comparison with the woven fabric before being left.

[0040]

[Table 1]

As can be seen from Table 1, the fabric Nos. 1 and 3 are
It was a soft woven fabric with low air permeability and excellent heat resistance and dimensional stability. Woven fabric No. 2 has a high air permeability of the woven fabric after the treatment because the woven fabric before the shrinkage treatment has a low density, but it has excellent heat resistance and dimensional stability, and has a soft characteristic.
A product suitable for use as a base fabric for resin-coated airbags was obtained. The woven fabric No. 4 was unsuitable as a non-coated airbag woven fabric because the woven fabric after the treatment had a high air permeability even though the woven fabric before the shrinkage treatment had a high density. Woven fabrics Nos. 5 and 6 were not dried sufficiently, and thus required a further drying process. By increasing the number of processes in this way, the risk of wrinkles and the like increasing, and the number of processes was reduced. The result did not lead to rationalization. Woven fabric No. 7 had a high heat shrinkage ratio and a poor heat-resistant dimensional stability, was a stiff woven fabric, and was unsuitable for airbags.

[0042]

According to the manufacturing method of the present invention, when a woven fabric for non-coated airbags or a base fabric for resin-coated airbags is manufactured by using a water jet loom, low air permeability, light weight, softness and strength are obtained. A sufficient and compactly foldable airbag fabric can be manufactured at a low cost and with a small equipment area in a manufacturing process in which defects such as wrinkles are unlikely to occur and without enormous investment.

Claims (5)

[Claims] 1. An air bag characterized in that a yarn made of synthetic fiber is woven using a water jet loom, and the woven fabric is heat-treated by superheated steam at 100 to 170 ° C. in a wet state without being dried. Method for manufacturing textiles. 2. The method for manufacturing an airbag fabric according to claim 1, wherein the weaving step and the shrinkage heat treatment step are discontinuously performed. 3. The method for manufacturing an airbag fabric according to claim 1, wherein a polyamide fiber is used as the synthetic fiber. 4. The airbag fabric according to claim 1, wherein the fabric after shrinkage heat treatment has an air permeability of 0.5 cc / cm ² / sec. Or less under 124 Pa. Production method. 5. The air according to any one of claims 1 to 3, wherein the woven fabric after shrinkage heat treatment has an air permeability of more than 0.5 to 3.0 cc / cm ² / sec. A method for manufacturing a bag fabric.