KR102153088B1 - Fabric for Airbag and Method for Manufacturing The Same - Google Patents

Abstract

Disclosed are a fabric for an air bag that satisfies the demand for weight reduction and has low air permeability, low strength, and excellent mechanical properties, and a method for manufacturing the same. The fabric for an airbag of the present invention includes a fiber base material of weft inserted warp knit construction: an adhesive polymer layer on the fiber base material having a melting point of 50 to 150°C; And a protective polymer layer on the adhesive polymer layer, having a melting point of 100 to 220°C.

Description

Fabric for Airbag and Method for Manufacturing The Same}

The present invention relates to a fabric for an airbag and a method for manufacturing the same, and more specifically, to a fabric for an airbag having low air permeability, low stiffness, and excellent mechanical properties while satisfying the demand for weight reduction, and a manufacturing method thereof.

When the impact sensor detects an impact applied to the vehicle when a vehicle running at a predetermined speed or more is collided or overturned, the airbag is expanded and deployed, thereby protecting the driver and passengers of the vehicle from accidents.

In general, the fabric for airbags further includes a coating layer for enhancing the airtightness of the fabric in addition to the textile substrate.

Polyamide yarns such as nylon 66 or polyester yarns are mainly used for the manufacture of fiber substrates. In general, the fibrous substrate is a fabric woven in a plain weave or a basket weave or a One Piece Woven (OPW) type fabric.

Neoprene rubber was used as the main material of the coating layer in the early days, but due to the coating weight of 60 g/m ² or more, the fabric for the air bag was too heavy and it was not easy to pack it in the air bag module. For this reason, the fabric coated with neoprene gradually disappears, and a relatively lightweight silicone-coated or polyurethane-coated fabric in which a silicone resin or polyurethane resin is coated on one or both sides of the fabric by a knife coating method replaces this. Are doing.

The fabric for airbags should have low air permeability for smooth deployment in case of a vehicle accident, and should have excellent mechanical properties (e.g., tensile strength, shape stability, etc.) to prevent damage to the airbag itself. It should have low stiffness to improve storage capacity. At the same time, as interest in the environment increases, the weight reduction of airbag fabrics is continuously required to improve fuel efficiency of vehicles.

However, a fabric for an airbag that satisfies a low weight per unit area, a low stiffness, and a high tensile strength and satisfies even high dimensional stability and high airtightness (ie, low air permeability) has not yet been developed.

Accordingly, the present invention relates to a fabric for an airbag and a manufacturing method thereof that can prevent problems due to limitations and disadvantages of the related technology as described above.

One aspect of the present invention is to provide a fabric for an airbag that satisfies the demand for weight reduction and has low air permeability, low stiffness, and excellent mechanical properties.

Another aspect of the present invention is to provide a method of manufacturing a fabric for an air bag with high productivity while satisfying the demand for weight reduction and having low air permeability, low stiffness, and excellent mechanical properties.

In addition to the viewpoints of the present invention mentioned above, other features and advantages of the present invention will be described below, or from such description will be clearly understood by those of ordinary skill in the art.

According to one aspect of the present invention as described above, the fiber base material of the weft inserted warp knit construction: an adhesive polymer layer on the fiber base material having a melting point of 50 to 150 ℃; And it has a melting point of 100 to 220 ℃, comprising a protective polymer layer on the adhesive polymer layer, airbag fabric is provided.

The melting point of the protective polymer layer may be 50 to 70° C. higher than the melting point of the adhesive polymer layer.

The fiber substrate, a plurality of warp; A plurality of weft yarns arranged to be perpendicular to the warps on the warps; And a ground yarn that binds the warps and weft yarns.

The warp yarns, weft yarns, and ground yarns each have a fineness of 420 to 1500 denier, the warp density of the fiber substrate is 9 to 24 th/inch, and the weft density of the fiber substrate may be 11 to 26 th/inch have.

The total thickness of the adhesive polymer layer and the protective polymer layer may be 20 to 200 μm.

The total weight per unit area of the adhesive polymer layer and the protective polymer layer may be 15 to 45 g/m ² .

The weight per unit area of the adhesive polymer layer may be 7 to 22 g/m ² .

Each of the warp yarns, weft yarns, and ground yarns may include at least one of polyamide, polyester, and polyolefin.

The adhesive polymer layer may include at least one of polyolefin, polyester, copolyester, thermoplastic polyurethane, polyamide, copolyamide, ethylene vinyl acetate polymer, and polyacrylate.

The protective polymer layer may include at least one of polyamide, copolyamide, thermoplastic polyurethane, and ethylene copolymer.

According to another aspect of the present invention, preparing a fiber base material of the weft-inserted warp knit structure; Laminating an adhesive polymer film having a melting point of 50 to 150°C on the fibrous substrate; And laminating a protective polymer film having a melting point of 100 to 220° C. on the adhesive polymer film.

In addition, preparing a fiber base material of the weft-inserted warp knit structure; Preparing a multi-layer film comprising an adhesive polymer layer having a melting point of 50 to 150 ℃ and a protective polymer layer having a melting point of 100 to 220 ℃; And laminating the multi-layer film on the fibrous substrate so that the adhesive polymer layer is positioned between the fibrous substrate and the protective polymer layer. A method of manufacturing an airbag fabric is provided.

The melting point of the protective polymer layer may be 50 to 70°C higher than the melting point of the adhesive polymer layer, and the laminating step may be performed at a temperature 30 to 40°C higher than the melting point of the adhesive polymer layer.

All of the above general description and the following detailed description are only for illustrating or explaining the present invention, and are to be understood as providing a more detailed description of the invention of the claims.

According to the present invention, a fabric for an airbag having a low weight per unit area, low stiffness, and high tensile strength can be manufactured with high productivity by adopting a fiber base having a warp knitting structure instead of a fiber base having a fabric structure. Therefore, the airbag made of the fabric for an airbag of the present invention can not only satisfy the industry's demand for weight reduction for improving vehicle fuel efficiency, but also exhibit excellent storage properties and mechanical strength.

In addition, according to the present invention, by applying a film laminating method instead of using a coating liquid, it can have excellent airtightness (that is, air barrier property) and high shape stability even though the fabric for airbag has a low weight per unit area.

The accompanying drawings are intended to aid understanding of the present invention and constitute a part of the present specification, illustrate embodiments of the present invention, and describe the principles of the present invention together with the detailed description of the present invention.
1 is a cross-sectional view of a fabric for an airbag according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments described below are provided for illustrative purposes only to help a clear understanding of the present invention, and do not limit the scope of the present invention.

As illustrated in FIG. 1, the fabric 100 for an airbag according to an embodiment of the present invention includes a fibrous substrate 110, an adhesive polymer layer 120, and a protective polymer layer 130.

The fibrous substrate 110 of the present invention has a weft inserted warp knit construction. That is, the fiber substrate 110 of the present invention includes a plurality of warp yarns 112, a plurality of weft yarns 111 arranged to be perpendicular to the warp yarns 112 on the warp yarns 112; And a ground yarn 113 tying the warp yarns 112 and the weft yarns 111 together. Depending on the arrangement of the ground yarns 113, the fiber substrate 110 of the present invention may be an X type, a Z type, or an I type.

Since the warp yarns 111 and 112 are hardly twisted, the fibrous substrate 110 of the present invention itself has a significantly lower stiffness (1 to 5 N) compared to the fibrous substrate of the plain weave structure, The airbag fabric 100 also has a low stiffness of 10N or less.

In addition, since the decrease in the strength of the yarn due to friction between the warp yarns 111 and 112 in the manufacturing process is minimized, the fiber substrate 110 of the present invention has higher mechanical properties (e.g., tensile Strength).

In addition, the fibrous substrate 110 of the present invention has a relatively simple manufacturing method, and thus has high productivity compared to the fibrous substrate of a fabric structure.

Each of the warp yarns 112, weft yarns 111, and ground yarn 113 is polyamide (for example, nylon 6, nylon 66, aramid, etc.), polyester (for example, polyethylene terephthalate), And it may include at least one of polyolefin (eg, polyethylene, polypropylene, etc.). In consideration of airbag deployment performance and cost, nylon fibers or polyester fibers are preferred.

According to an embodiment of the present invention, each of the warp yarns 112, the weft yarns 111, and the ground yarn 113 has a fineness of 420 to 1500 denier, preferably 840 to 1000 denier.

The fineness of the yarns should be 420 denier or higher in order for the airbag fabric 100 to have an absorption performance and excellent strength capable of absorbing the development energy of high temperature and high pressure when the airbag is deployed. On the other hand, it is preferable that the fineness of the yarns is 1500 denier or less in order to reduce the folding property and weight of the airbag.

In addition, from the viewpoint of flexibility and smoothness of the coated surface, each of the warp yarns 112, the weft yarns 111, and the ground yarn 113 is preferably a multifilament including 72 or more filaments.

According to an embodiment of the present invention, the fibrous substrate 110 has a warp density of 9 to 24 th/inch, preferably 14 to 22 th/inch, and 11 to 26 th/inch, preferably 16 to 24 th/inch. It has a weft density of th/inch. The warp density and the weft density must be 9 th/inch and 11 th/inch or more, respectively, to satisfy the minimum mechanical strength required by the industry. On the other hand, when the warp density exceeds 22 th/inch or the weft density exceeds 26 th/inch, the fibrous substrate 110 cannot satisfy the low stiffness of 1 to 5 N, so the folding and storage properties of the airbag This is degraded.

According to an embodiment of the present invention, the adhesive polymer layer 120 on the fibrous substrate 110 has a melting point of 50 to 150°C, and the protective polymer layer 130 on the adhesive polymer layer 120 is 100 It has a melting point of to 220 ℃.

The protective polymer layer 130 performs an air blocking function, and the adhesive polymer layer 120 mediates the pressure-pressure bonding between the fibrous substrate 110 and the protective polymer layer 130 of the present invention.

The adhesive polymer layer 120 may include at least one of polyolefin, polyester, copolyester, thermoplastic polyurethane, polyamide, copolyamide, ethylene vinyl acetate polymer, and polyacrylate. In consideration of the adhesiveness and elasticity to the surface of the fibrous substrate 110, the adhesive polymer layer 120 is preferably formed of polyolefin, thermoplastic polyurethane, polyamide, and/or copolyamide.

The protective polymer layer 130 may include at least one of polyamide, copolyamide, thermoplastic polyurethane, and ethylene copolymer. In consideration of the adhesiveness with the adhesive polymer layer 120 and the air blocking effect, the protective polymer layer 130 is preferably formed of polyamide, copolyamide, and/or thermoplastic polyurethane.

According to an embodiment of the present invention, the total thickness of the adhesive polymer layer 120 and the protective polymer layer 130 is 20 to 200 μm, preferably 30 to 150 μm, more preferably 40 to 100 μm. . If the total thickness is less than 20 μm, the minimum air tightness required for the airbag cannot be satisfied. On the other hand, when the total thickness exceeds 200 μm, the stiffness of the fabric 100 for the air bag exceeds 10 N, so that the folding and storage properties of the air bag manufactured by this are significantly deteriorated, as well as due to excessive use of materials. Economic feasibility worsens.

According to an embodiment of the present invention, the total weight per unit area of the adhesive polymer layer 120 and the protective polymer layer 130 is 15 to 45 g/m ² , preferably 20 to 40 g/m ² , more It is preferably 25 to 35 g/m ² . Here, the weight per unit area of the adhesive polymer layer 120 is 7 to 22 g/m ² , preferably 10 to 20 g/m ² , more preferably 12 to 17 g/m ² .

Only when the total weight per unit area is 15g/m ² or more, it is possible to secure a uniform thickness of the adhesive polymer layer 120 and the protective polymer layer 130, and desirable mechanical properties of the airbag fabric 100 can be obtained. have. On the other hand, when the total weight per unit area exceeds 45g/m ² , the stiffness of the fabric 100 for airbags exceeds 10N, so that the folding and storage properties of the airbags manufactured therefrom are significantly deteriorated, as well as excessive material. Economic feasibility worsens due to use.

Hereinafter, a method of manufacturing an airbag fabric according to an embodiment of the present invention will be described in detail.

The method according to an embodiment of the present invention comprises the steps of preparing a fibrous substrate 110 having a warp knitting structure of inserting weft yarn, and an adhesive polymer film 120 having a melting point of 50 to 150°C on the fibrous substrate 110 Laminating and laminating a protective polymer film 130 having a melting point of 100 to 220° C. on the adhesive polymer film 120.

As described above, the fiber substrate 110 of the weft-inserted warp knit structure is polyamide (for example, nylon 6, nylon 66, aramid) or polyamide having a fineness of 420 to 1500 denier, preferably 840 to 1000 denier. It may be manufactured using an ester (eg, polyethylene terephthalate) yarn as the warp 112, the weft 111, and the ground yarn 113. From the viewpoint of flexibility and smoothness of the coated surface, the yarn is preferably a multifilament comprising 72 or more filaments. For the above reasons, the fiber substrate 110 has a warp density of 9 to 24 th/inch, preferably 14 to 22 th/inch, and 11 to 26 th/inch, preferably 16 to 24 th/inch. It has a weft density.

By sequentially laminating the adhesive polymer film 120 and the protective polymer film 130 on the fibrous substrate 110, the airbag fabric 100 of the present invention has excellent airtightness despite having a low weight per unit area (That is, air barrier properties) and can have high shape stability.

The laminating processes may be each performed by a roll calendaring method, a flatbed calendaring method, a transfer calendaring method, a flame laminating method, etc., preferably Roll calendering method is applied.

The method according to another embodiment of the present invention includes the steps of preparing a fibrous substrate 110 having a warp knitting structure of inserting weft yarn, an adhesive polymer layer 120 having a melting point of 50 to 150°C, and a melting point of 100 to 220°C. Preparing a multi-layer film comprising a protective polymer layer 130, and the adhesive polymer layer 120 to be positioned between the fibrous substrate 110 and the protective polymer layer 130, the multi-layer And laminating a film on the fibrous substrate 110.

In this case, the laminating process is preferably performed in a temperature range capable of sufficiently melting the adhesive polymer layer 120, while preventing thermal damage to the protective polymer layer 130.

Accordingly, according to an embodiment of the present invention, the melting point of the protective polymer layer 130 is 50 to 70° C. higher than the melting point of the adhesive polymer layer 120, and the laminating step is performed by the adhesive polymer layer 120 It is performed in a temperature range of 30 to 40° C. higher than the melting point of and 20 to 30° C. lower than the melting point of the protective polymer layer 130. For example, by performing the laminating process at 80 to 180°C, preferably at 120 to 170°C, the adhesive polymer layer 120 is sufficiently melted to easily penetrate into the fiber base 110 and thus the fiber base material In addition to improving the adhesion to 110, the protective polymer layer 130 may maintain a uniform thickness.

Hereinafter, the effects of the present invention will be described through specific examples and comparative examples of the present invention. However, the following examples are only for helping understanding of the present invention, and these do not limit the scope of the present invention.

Example One

A fiber substrate of a warp-knit structure with a weft insertion type using a polyester (PET) yarn formed of 192 filaments and having a total fineness of 1000 denier as warp, weft, and ground yarn (warp density: 18th/inch, weft density: 18th/ inch) was prepared.

A 0.04 mm thick multi-layer film (manufacturer: Nolax, trade name: A23.2276C) comprising a polyolefin layer having a melting point of 150° C. and a polyamide layer (manufacturer: Nolax, trade name: A23.2276C) was deposited on one side of the fiber substrate at 170° C. 2 N/cm ² By thermocompression bonding at a pressure of (the polyolefin layer is in direct contact with the fiber substrate), the fabric for an airbag was completed.

Example 2

The fabric for airbags was completed in the same manner as in Example 1, except that both the warp density and the weft density of the fiber base were 16th/inch.

Comparative example One

The fabric for an airbag was completed in the same manner as in Example 1, except that a fiber base was manufactured by performing a plain weave with a warp yarn density of 18th/inch using the same yarn as in Example 1 above.

Comparative example 2

A fibrous substrate was prepared by performing plain weave with a warp yarn density of 18th/inch using the same yarn as in Example 1 above. Subsequently, a liquid silicone resin (manufacturer: Dow Corning, brand name: DC3730) was coated on one side of the fiber substrate through a knife coating method, pre-dried at 90°C, and then the drying temperature was gradually increased, and finally at 150°C. By performing a vulcanization process for 150 seconds, the coating agent was cured to complete the airbag fabric having a silicone resin coating layer.

The weight per unit area, tensile strength, elongation, stiffness, and air permeability of the fabrics for airbags of the Examples and Comparative Examples manufactured as above were measured by the following methods, respectively, and the results are shown in Table 1 below. Done.

* Weight per unit area

According to the ISO 3801 method, a circular specimen having a cross-sectional area of 1 m ² was collected using a circular cutter dedicated to sampling, and then the weight per unit area was measured using a scale for measuring the weight of the specimen.

* Tensile strength and elongation

Tensile strength was measured by the ISO 13934-1 cut strip method. After taking a specimen of 50 mm in width and 350 mm in length, a tensile test was performed using a universal tensile tester at a clamp length of 200 mm and a crosshead speed of 200 mm/min, and the strength and elongation at the time of failure of the specimen were measured, respectively.

* Stiffness

For a specimen of 100 mm × 200 mm, the stiffness of each airbag fabric was measured by the ASTM D 4032 test method, the Circularbend method. Specifically, when a specimen folded in half is placed on a pedestal having a hole of 38.1 mm diameter (102 mm × 102 mm × 6 mm) and the specimen is pressed with a bar from above, the force of pushing the fabric down through the hole of the pedestal was measured.

* Air permeability

According to the ASTM D 737 test method, the airbag fabric was left at 20°C and 65%RH for 1 day, and then the amount of air at 125Pa pressure passing through the 38cm ² circular side was measured.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Fiber substrate structure Weft insert warp Weft insert warp Plain weave Plain weave Warp/weft density (th/inch) 18×18 20 18×18 18×18 Coating method Laminating Laminating Laminating Knife coating Weight per unit area (g/m ² ) 216 196.4 232 233 Tensile strength (hard/weft) (N/5cm) 3148/2989 2798/2656 2619/2526 2710/2646 Elongation (hard/weft)(%) 25/23 26/23 27/25 26/24 Lecture (hard/weft)(N) 9.2/8.9 8.1/7.7 19.1/18.1 12.3/11.6 Air permeability (l/dm ² /min) 0 0 0 0.04

100: air bag fabric 110: fiber base
111: weft 112: warp
113: ground yarn 120: adhesive polymer layer
130: protective polymer layer

Claims (12)

Fiber base of weft inserted warp knit construction:
An adhesive polymer layer on the fibrous substrate, having a melting point of 50 to 150°C; And
It comprises a protective polymer layer on the adhesive polymer layer, having a melting point of 100 to 220 ℃,
The fiber substrate, a plurality of warp; A plurality of weft yarns arranged to be perpendicular to the warps on the warps; And a ground yarn that binds the warps and weft yarns,
The warp yarns, weft yarns, and ground yarns each have a fineness of 1000 to 1500 denier,
The warp density of the fiber substrate is 9 to 24 th/inch,
The weft density of the fiber substrate is 11 to 26 th / inch,
Fabric for air bags. The method of claim 1,
The melting point of the protective polymer layer is 50 to 70° C. higher than the melting point of the adhesive polymer layer,
Fabric for air bags. delete delete The method of claim 1,
The total thickness of the adhesive polymer layer and the protective polymer layer is 20 to 200 μm,
Fabric for air bags. The method of claim 5,
The total weight of the adhesive polymer layer and the protective polymer layer per unit area is 15 to 45 g/m ² ,
Fabric for air bags. The method of claim 6,
The weight per unit area of the adhesive polymer layer is 7 to 22 g/m ² ,
Fabric for air bags. The method of claim 1,
Each of the warp yarns, weft yarns, and ground yarns comprises at least one of polyamide, polyester, and polyolefin,
Fabric for air bags. The method of claim 8,
The adhesive polymer layer comprises at least one of polyolefin, polyester, copolyester, thermoplastic polyurethane, polyamide, copolyamide, ethylene vinyl acetate polymer, and polyacrylate,
The protective polymer layer comprises at least one of polyamide, copolyamide, thermoplastic polyurethane, and ethylene copolymer,
Fabric for air bags. Preparing a fiber base material of the weft-inserted warp knit structure;
Laminating an adhesive polymer film having a melting point of 50 to 150°C on the fibrous substrate; And
Comprising the step of laminating a protective polymer film having a melting point of 100 to 220 ℃ on the adhesive polymer film,
Manufacturing method of fabric for air bag. Preparing a fiber base material of the weft-inserted warp knit structure;
Preparing a multi-layer film comprising an adhesive polymer layer having a melting point of 50 to 150 ℃ and a protective polymer layer having a melting point of 100 to 220 ℃; And
Laminating the multi-layer film on the fibrous substrate such that the adhesive polymer layer is positioned between the fibrous substrate and the protective polymer layer,
The fiber substrate, a plurality of warp; A plurality of weft yarns arranged to be perpendicular to the warps on the warps; And a ground yarn that binds the warps and weft yarns,
The warp yarns, weft yarns, and ground yarns each have a fineness of 1000 to 1500 denier, the warp density of the fiber base is 16 to 24 th/inch, and the weft density of the fiber base is 16 to 26 th/inch,
Manufacturing method of fabric for air bag. The method of claim 11,
The melting point of the protective polymer layer is 50 to 70° C. higher than the melting point of the adhesive polymer layer,
The laminating step is performed at a temperature 30 to 40° C. higher than the melting point of the adhesive polymer layer,
Manufacturing method of fabric for air bag.

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