JP3433454B2 - Base fabric for airbag and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved airbag base fabric which is inflated at the time of a collision of a vehicle, for example, an automobile, absorbs a shock of a seated occupant, and protects the same, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the practical use of airbags for ensuring the safety of passengers in automobiles has been rapidly increasing. In the event of a car collision, the sensor receives the shock of a collision to generate high-pressure gas, and the high-pressure gas momentarily inflates the airbag to protect the occupant's face, especially the face. To do. Conventionally, air bags have 400-1000 denier nylon 6
To improve heat resistance, flame retardancy, air barrier properties, etc., a plain woven fabric using 6 filament yarn is coated with synthetic rubber such as chloroprene or chlorosulfonated olefin, or an elastomer such as natural rubber, and the laminated base fabric is cut. It was made by sewing. The airbag is stored in a narrow space such as a steering wheel and an instrument panel until just before it is activated. The smaller the storage volume, the better, and the softer, lighter, and thinner base cloth is preferable.
However, the conventional airbag base fabric is thick and heavy because the elastomer is applied and laminated to a certain thickness in order to improve various performances as an airbag, and because it has a hard texture, it can be folded. Not only is it poor in performance and has a large storage capacity, but it also has a strong impact on the human body, especially the face during momentary expansion due to high temperature and high pressure gas, and receives a repulsion when it collides with an airbag, resulting in a vehicle structure. It was not preferable because it could collide with and be injured.

To address this problem, Japanese Patent Laid-Open No. 22525/1990
Japanese Patent Publication No. 5 discloses a knitted fabric airbag in which the central portion has a bag shape and all or part of the peripheral portion is integrated by a knitting structure.

[0004]

However, the base fabric for such an airbag has the characteristics that it is flexible and has elasticity with respect to elongation and can be manufactured with high productivity. However, in the so-called non-coated base fabric for airbag, In addition to the drawback that the air-permeable property required for an airbag cannot be obtained, after cutting, fraying and running easily occur from the cut portion, making handling extremely difficult.

The object of the present invention is to provide such a conventional airbag.
In view of the drawbacks of the base fabric for fabrics , it is flexible and has excellent storability, and the air-permeable base fabric for knitted fabric has a large air permeability, and it is possible to improve the drawbacks such that fraying and running from the cutting portion are likely to occur. An object of the present invention is to provide a base fabric for an air bag , which has a small impact particularly on the face when the bag is instantaneously inflated.

[0006]

The present invention has the following constitution in order to achieve the above object. That is, the airbag base fabric of the present invention is a wrap using filament yarn.
A composite sheet comprising a cell knitted and nonwoven, said double
A composite sheet is a non-woven fabric on at least one side of the Russell knitted fabric.
It is intended, characterized in that by inserting those constructed by knitting warp knitting, also, the manufacturing method of such an air bag base fabric <br/>, due raschel knitting machine, the yarns
Used, on at least one surface of the fabric, it is characterized in organizing the warp knitting by inserting a nonwoven.

[0007]

The filament yarn in the present invention is represented by, for example, polyamide fibers such as nylon 6, nylon 6.6, nylon 12, nylon 4.6 and the like, and copolymers with paraphenylene terephthalamide and aromatic ether. Aramid fiber, polyester fiber typified by polyalkylene terephthalate, vinylon fiber, rayon fiber, ultra high molecular weight polyethylene fiber, sulfone-based fiber such as paraphenylene sulfone and polysulfone, synthetic fiber such as polyetherketone fiber, and carbon fiber Continuous fibers made of inorganic fibers such as glass fibers, metal fibers, etc. can be used. Among these fibers, nylon 6.6 or nylon 6 is particularly preferable from the viewpoints of impact strength, flexibility, cost, etc., which are properties required as a base fabric for airbags.

The strength of the single fiber constituting the knitting yarn is not particularly limited, but is preferably 6 g / denier or more, more preferably 7 g / denier or more. The fineness and the total fineness of the single fibers constituting the knitting yarn are not particularly limited as long as they satisfy the mechanical properties required for the airbag base fabric, but the total fineness is preferably 100 to 1
000 denier and a single yarn fineness of 0.1 to 7 denier can be used.

Constituting the airbag base fabric of the present invention
That the knitting structure of the warp knitting is Russell knitting structure der the nonwoven fabric was inserted into one or both sides of the knitted fabric by La Sseru knitting machine
It In the airbag base fabric of the present invention , in particular, from the viewpoint of storability, it is desired that the fabric is lightweight, flexible, and thin, so that a structure in which a lightweight non-woven fabric is inserted as much as possible on only one side is preferably used . If necessary, the weft yarn, the warp yarn, and the bias yarn can be further inserted by inserting an insertion yarn.

The fibers as the non-woven fabric in the present invention include, for example, polyamide fibers such as nylon 6 and nylon 6.6, aramid fibers typified by copolymers with paraphenylene terephthalamide and aromatic ether, and polyalkylene terephthalate. Polyester fiber, vinylon fiber, rayon fiber, ultra high molecular weight polyethylene fiber, sulfone fiber such as paraphenylene sulfone and polysulfone, and polyimide fiber may be used alone or in combination.

These non-woven fabric fibers may be used as short fibers or continuous long fibers. The fineness of the single fiber used as the non-woven fabric is not particularly limited, but preferably about 0.1 to 20 denier.

The method for producing the non-woven fabric is not particularly limited, but a method of thermocompression bonding the sheet-shaped fibers, a method of joining with a needle punch, a method of joining with a high-pressure water stream, a method of joining with an adhesive, etc. manufactured had for appropriate
It can be Rukoto. The thickness of the non-woven fabric is preferably 0.0
It is about 5 to 2.0 mm, more preferably about 0.05 to 0.5 mm.

The Russell knitted fabric composited with the nonwoven fabric of the present invention can be used as it is as an airbag .
Preferably , for the purpose of reducing the air flow rate from the needle hole during knitting, a material whose air flow rate is reduced by heat treatment after knitting is preferred.
To use . Heat treatment method, a pin tenter, can be adopted such as a roller setter, from the viewpoint of air permeability of reduction, thermal calendering is particularly preferred. Knitted articles and knitting after heat treated knitted fabric, used without a coating, it is preferable to use as the base fabric for uncoated airbags, elastomer also be used as a base fabric for an air bag that is stacked on a part of the knitted fabric or the entire surface You can

[0014]

The present invention will be further described with reference to the following examples.

The method of measuring the characteristic values in the examples is as follows. (1) Unit weight: Weight per unit area of JIS L-1096 (2) Thickness: JIS L-1096 (3) Aeration rate: JIS L-1096 (Flagille method) (4) Impact on human body: airbag A base fabric ( knitted fabric that is a composite of non-woven fabrics ) is cut and sewn to form a circular airbag having a radius of 34.5 cm, and a hole having a radius of 4 cm is formed as an inflator attachment portion. Then
As shown in Fig. 1, put an ultra-thin rubber balloon in the air bag, inject air, inflate it to an internal pressure of 0.2 kg / cm ² , and release a lead pendulum of 500 g from 45 °, The angle at which the pendulum returned due to repulsion was measured by colliding with an airbag.

Example 1 Nylon 6.6 filament yarn having a total fineness of 210 denier, a single yarn fineness of 5.8 denier and a strength of 9.1 g / denier was used, and a basis weight of 50 g /
Air of 32 gauge tricot (Russell knitted fabric) in which Tyvek (polyethylene fiber thermocompression bonded nonwoven sheet) having m ² and thickness of 0.15 mm is inserted on one side.
A base fabric for bags was obtained. The characteristic values of this airbag base fabric
The characteristic values of and the airbag comprising the same are shown in Table 1.

COMPARATIVE EXAMPLE 1 Using a nylon 6.6 filament yarn having a total fineness of 210 denier, a single yarn fineness of 5.8 denier, and a strength of 9.1 g / denier, a tricot knitting machine was used to produce a 32 gauge tricot base fabric for an airbag. Obtained. The characteristic values of the airbag are shown in Table 1.

Example 2 As a knitting yarn, 70 denier, 18 filaments, nylon 6.6 filament yarn having a strength of 9.0 g / denier,
As a weft insertion yarn, 210 denier, 36 filaments, nylon 6.6 filament yarn with a strength of 9.1 g / denier, and as an inserted non-woven fabric, a weight of 50 g / m ² and a thickness of 0.15 mm, made by DuPont Tyvek (polyethylene fiber). Using the thermocompression bonded non-woven fabric sheet) and a Russell knitting machine, a 32 gauge tricot (Russell knitted fabric) base fabric for air bags in which weft yarn and non-woven fabric were inserted was obtained. The characteristic values of this airbag base fabric and
The characteristic values of the air bag shown in Table 1 that.

Comparative Example 2 A plain woven fabric having a total fineness of 420 denier, 36 filaments, nylon 6.6 filament yarn having a strength of 9.1 g / denier and having a density of 46 warps / inch for each weft.
A base fabric for an airbag was obtained. Special features of this airbag base fabric
Table 1 shows the sex values and the characteristic values of the airbags made of them.

[0020]

[Table 1]

As is clear from Table 1 , the air bag of Comparative Example 1 having only the knitted fabric has a small basis weight and a small impact on the human body, but has a large air flow rate, and is instantaneous as an air bag. At the time of inflation, there was a risk of high temperature and high pressure gas leaking from the airbag, and at the same time, it was difficult to inflate into a preferable shape as an airbag. In addition, the conventional airbag made of the woven fabric of Comparative Example 2 has a hard texture, has a high impact on the human body, and has an excessively large ventilation amount as in the case of the airbag having only the knitted fabric, and thus swells into a preferable shape. It was difficult. The product of the present invention was flexible, had an extremely small air flow rate, was excellent in storability and swelling property, and had excellent characteristics as an airbag having a small impact on the human body.

[0022]

According to the present invention, it is possible to reduce the impact on the human body due to the expansion of the airbag, the risk of injury in a collision to the vehicle structure by repelled by <br/> inflation of the air bag A base fabric for airbags having a low rate can be obtained. at the same time,
Since coatings for reducing aeration amount like conventional base fabric for an air bag is not necessary, texture soft, it is excellent in storability, it is possible to miniaturize the steering wheel or instrument panel. In addition, compared with non-coated base fabrics for woven fabrics and knitted fabrics alone, there is less fraying from the cut portion.

[Brief description of drawings]

FIG. 1 is a schematic view of a measuring device for measuring impact resistance.

[Explanation of symbols]

1: Airbag 2: Ultra-thin rubber balloon 3: Pendulum

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-4-287743 (JP, A) JP-A-48-30246 (JP, A) JP-A-2-185843 (JP, A) JP-A-2- 225155 (JP, A) JP-A-4-56650 (JP, A) JP-B-48-30292 (JP, B1) International publication 90/11914 (WO, A1) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) B60R 21/16 D04B 21/20

Claims (4)

(57) [Claims] 1. A filament yarn is used.RussellWith knitting
Non-wovenConsists ofA composite sheet,Composite sheet
But, Insert a non-woven fabric on at least one side of the Russell knitted fabric
Made by knitting warpIs characterized by
Air bagBase cloth. 2. The airbag base according to claim 1 , wherein the airbag is a non- coated airbag .
Cloth . 3. A filament yarn produced by a Russell knitting machine
A method for producing a base fabric for an air bag , wherein a non-woven fabric is inserted into at least one surface of a knitted fabric to knit a warp knit by using. 4. After knitting the warp knitting, 3. method of manufacturing a base fabric for an air bag, wherein the heat treatment.