Low permeability airbag cushionshaving film coatings of extremely low thickness

Abstract

Coated inflatable fabrics, more particularly airbags to which very low add-on amounts of coating have been applied, are provided which exhibit extremely low air permeability. The inventive inflatable fabrics are primarily for use in automotive restraint cushions that require low permeability characteristics (such as side curtain airbags). Traditionally, heavy, and thus expensive, coatings of compounds such as neoprene, silicones and the like, have been utilized to provide such required low permeability. The inventive fabric utilizes an inexpensive, very thin coating to provide such necessarily low permeability levels. Thus, the inventive coated inflatable airbag comprises a film laminated on at least a portion of the target fabric surface wherein the film possesses a tensile strength of at least 2,000 and an elongation at break of at least 180%. The film provides a low permeability airbag cushion exhibiting a leak-down time of at least 5 seconds as well as a very low packing volume (for more efficient use of storage space within a vehicle) for the target side curtain airbag.

Description

[0001] This application is a continuation-in-part of co-pending application Ser. No. 09 / 557,643, filed on Apr. 25, 2000, which is a continuation-in-part of co-pending application Ser. No. 09 / 501,467, filed on Feb. 9, 2000, which is a continuation-in-part of Ser. No. 09 / 350,620, filed on Jul. 7, 1999, which is a continuation-in-part of Ser. No. 09 / 335,257, filed on Jun. 17, 1999; this application is also a continuation-in-part of co-pending application Ser. No. 09 / 406,264, filed on Sep. 24, 1999. These parent applications are herein entirely incorporated by reference.[0002] This invention relates generally to coated inflatable fabrics and more particularly concerns airbag cushions to which very low add-on amounts of coating have been applied and which exhibit extremely low air permeability. The inventive inflatable fabrics are primarily for use in automotive restraint cushions that require low permeability characteristics (such as side curtain airbags). Traditionally, heavy, and thus...

AI Technical Summary

Benefits of technology

0032] Additionally, it has also been found that the inventive film coating compositions, at the inventive add-on amounts, etc., provide the same types of benefits with the aforementioned sewn, stitched, etc., side curtain airbags. Although such structures are highly undesirable due to the high potential for leakage at these attachment seams, it has been found that the inventive coating provides a substantial reduction in permeability (to acceptable leak-down time levels, in fact) with correlative lower add-on amounts than with standard silicone and neoprene rubber coating formulations. Such add-on amounts will approach the 2.7 ounces per square yard limit, but lower amounts have proven

Problems solved by technology

Such a coated low permeability airbag must provide a necessarily

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