Airbag made from a fabric substrate coated on an exterior side and on an opposite interior side
View Patent ↗A dual coated fabric that is well suited for producing vehicle airbags. The coated fabric includes a first coating on one side and a second coating on a second and opposite side. The first coating may comprise an elastomeric coating, such as a cured rubber. The second coating on the opposite side, however, may comprise a non-elastomeric coating. The non-elastomeric coating provides dimensional stability and provides an excellent counterbalance to the elastomeric coating.
1. A vehicle airbag, comprising:
a first fabric panel attached to a second fabric panel, the first fabric panel and the second fabric panel being attached together to form an airbag having an exterior surface and an interior surface, the interior surface being configured to receive an inflation gas for inflating the airbag, the first fabric panel and the second fabric panel comprising:
(a) a woven fabric substrate having a first interior side and an opposite second exterior side, the first side of the woven fabric substrate comprising the interior surface of the airbag and the second side of the woven fabric substrate comprising the exterior surface of the airbag;
(b) a first coating directly applied to the first interior side of the fabric substrate, the first coating comprising an elastomeric material, the elastomeric material comprising a polyorganosiloxane containing, per molecule, at least two C2-C6 alkenyl groups linked to silicon, the first coating being a one-layer coating and forming the interior surface of the airbag;
(c) a second coating directly applied to the second exterior side of the fabric substrate, the second coating comprising a non-elastomeric thermoplastic polymer, the second coating being a one-layer coating and forming the exterior surface of the airbag; and
(d) the first fabric panel and second fabric panel being attached together such that the first interior side of the first panel and the first interior side of the second panel are in contact along the seam of the airbag such that the first coating comprising the elastomeric material on the first fabric panel contacts the first coating comprising the elastomeric material on the second fabric panel.
2. A vehicle airbag as defined in claim 1 , wherein the elastomeric material comprises a cured rubber.
3. A vehicle airbag as defined in claim 1 , wherein the elastomeric material was cured using a metal catalyst.
4. A vehicle airbag as defined in claim 1 , wherein the second coating restricts the stretch properties of the fabric substrate.
5. A vehicle airbag as defined in claim 1 , wherein the non-elastomeric polymer comprises an acrylic polymer or urethane.
6. A vehicle airbag as defined in claim 1 , wherein the first coating is present on the first interior side of the fabric substrate in an amount from about 15 gsm to about 50 gsm.
7. A vehicle airbag as defined in claim 1 , wherein the second coating is present on the second exterior side of the fabric substrate in an amount from about 8 gsm to about 15 gsm.
8. A vehicle airbag as defined in claim 1 , wherein the woven substrate contains yarns comprising a polyester, a polyimide, or mixtures thereof.
9. A vehicle airbag as defined in claim 8 , wherein the yarns have a denier of from about 210 to about 630.
10. A vehicle airbag as defined in claim 1 , wherein the woven fabric substrate has a yarn count in a warp direction and in a fill direction of from about 40 to about 55.
11. A vehicle airbag as defined in claim 1 , wherein the airbag is not vented.
12. A vehicle airbag as defined in claim 1 , wherein the airbag comprises a side-curtain airbag.
13. A vehicle airbag as defined in claim 1 , wherein the airbag has a Cosmo leak down of greater than 100 kPa.
14. A vehicle airbag as defined in claim 1 , wherein the first fabric panel and the second fabric panel have a warp dimensional stability and a weft dimensional stability of less than about 1.0% when tested according to ISO Test 3759.
15. A vehicle airbag as defined in claim 1 , wherein the first fabric panel and the second fabric panel have a static air permeability of less than about 0.5 L/m 2 , when tested according to ISO Test 9237.
16. A vehicle airbag as defined in claim 1 , wherein the first fabric panel and the second fabric panel have a warp comb strip of greater than about 700 N when tested according to ASTM Test D6479.
17. A vehicle airbag as defined in claim 1 , wherein the yarns have a denier of 210 and the woven fabric substrate has a yarn count in a warp direction and in a fill direction of from about 60 yarns per inch to about 75 yarns per inch.
18. A vehicle airbag as defined in claim 1 , wherein the yarns have a denier of 350 and the woven fabric substrate has a yarn count in a warp direction and in a fill direction of from about 50 yarns per inch to about 65 yarns per inch.
19. A vehicle airbag as defined in claim 1 , wherein the yarns have a denier of 420 and the woven fabric substrate has a yarn count in a warp direction and in a fill direction of from about 40 yarns per inch to about 55 yarns per inch.
20. A vehicle airbag as defined in claim 1 , wherein the yarns have a denier of 630 and the woven fabric substrate has a yarn count in a warp direction and in a fill direction of from about 35 yarns per inch to about 45 yarns per inch.
21. A vehicle airbag as defined in claim 1 , wherein the first fabric panel is sewn to the second fabric panel to form a seam where the first fabric panel and the second fabric panel are attached together.