Low permeability side curtain airbag cushions having extremely low coating levels

• US 6,701,971 B1
• Filed: 11/22/2000
• Issued: 03/09/2004
• Est. Priority Date: 06/17/1999
• Status: Expired due to Term

• Current Assignee: Mililken & Company
• Original Assignee: Mililken & Company
• Inventors: Li, Shulong, Sollars, John A. Jr.
• Primary Examiner(s): SINGH-PANDEY, ARTI R
• Application Number:
  US09/718,643
• Time in Patent Office: 1,203 Days
• Field of Search: 139/48, 139/50, 139/383.R, 139/384.R, 139/387.R, 139/389, 139/407, 139/408, 139/410, 139/414, 139/420, 139/384, 139/420.R, 280/728.1, 280/729, 280/743.1, 383/3, 428/34.3, 428/34.5, 428/34.6, 428/35.7, 428/35.9, 428/36.1, 428/36.9, 428/101, 428/106, 428/166, 442/76, 442/104, 442/149, 442/164, 442/168, 442/203, 442/205-207, 442/218, 442/220, 442/234, 442/236, 442/286
• US Class Current: 139/387.00R
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B60R 2021/23514 coated fabric
• CPC Class Codes: B60R 21/232 Curtain-type airbags deploying mainly in a vertical direction from their top edge
• CPC Class Codes: B60R 21/235 characterised by their material
• CPC Class Codes: D03D 1/02 Inflatable articles
• CPC Class Codes: D03D 11/02 Fabrics formed with pockets, tubes, loops, folds, tucks or flaps fabrics consisting of a single tube D03D3/02
• CPC Class Codes: D06N 3/186 one of the layers is on one surface of the fibrous web and the other layer is on the other surface of the fibrous web
• CPC Class Codes: Y10T 428/1307 Bag or tubular film [e.g., pouch, flexible food casing, envelope, etc.]
• CPC Class Codes: Y10T 428/1314 Contains fabric, fiber particle, or filament made of glass, ceramic, or sintered, fused, fired, or calcined metal oxide, or metal carbide or other inorganic compound [e.g., fiber glass, mineral fiber, sand, etc.]
• CPC Class Codes: Y10T 428/1317 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1359 Three or more layers [continuous layer]
• CPC Class Codes: Y10T 428/1362 Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/24025 Superposed movable attached layers or components
• CPC Class Codes: Y10T 428/24066 Wood grain
• CPC Class Codes: Y10T 442/2139 Coating or impregnation specified as porous or permeable to a specific substance [e.g., water vapor, air, etc.]
• CPC Class Codes: Y10T 442/2369 Coating or impregnation improves elasticity, bendability, resiliency, flexibility, or shape retention of the fabric
• CPC Class Codes: Y10T 442/2738 Coating or impregnation intended to function as an adhesive to solid surfaces subsequently associated therewith
• CPC Class Codes: Y10T 442/2861 Coated or impregnated synthetic organic fiber fabric
• CPC Class Codes: Y10T 442/2893 : Coated or impregnated polyamide fiber fabric
• CPC Class Codes: Y10T 442/3179 : Woven fabric is characterized by a particular or differential weave other than fabric in which the strand denier or warp/weft pick count is specified
• CPC Class Codes: Y10T 442/3195 : Three-dimensional weave [e.g., x-y-z planes, multi-planar warps and/or wefts, etc.]
• CPC Class Codes: Y10T 442/3203 : Multi-planar warp layers
• CPC Class Codes: Y10T 442/3211 : Multi-planar weft layers
• CPC Class Codes: Y10T 442/3301 : Coated, impregnated, or autogenous bonded
• CPC Class Codes: Y10T 442/3317 : Woven fabric contains synthetic polymeric strand material
• CPC Class Codes: Y10T 442/3431 : Plural fabric layers
• CPC Class Codes: Y10T 442/3447 : Including a preformed synthetic polymeric film or sheet [i.e., film or sheet having structural integrity prior to association with the woven fabric]
• CPC Class Codes: Y10T 442/3854 : Woven fabric with a preformed polymeric film or sheet

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 permeabilities. The inventive fabrics are primarily for use in automotive restraint cushions which 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 necessary low permeability levels. Thus, the inventive coated airbag possesses a coating of at most 3.0 ounces per square yard, most preferably about 0.8 ounces per square yard, and exhibits a leak-down time (a measurement of the time required for the entire amount of gas introduced within the airbag at peak pressure during inflation to escape the airbag at 10 psi) of at least 7 seconds. All coatings, in particular elastomeric, non-silicon coatings, and coated airbags, meeting these criteria are intended to reside within the scope of this invention.

Claims

1. A one-piece woven airbag cushion comprising a coated inflatable fabric, wherein said inflatable fabric is at least partially coated with an elastomeric composition;

wherein said airbag cushion exhibits a characteristic leak-down time after inflation of at least 5 seconds;

wherein said inflatable fabric comprises at least two layers of fabric in certain discrete areas of the fabric and at least one narrow single fabric layer at a discrete area within said fabric;

wherein said at least one narrow single fabric layer is the sole source of providing inflatable pillow structures within said airbag cushion; and

wherein said at least one narrow single fabric layer is formed solely from a basket weave pattern of an even number of yarns, at most 12 yarns in width.

2. The airbag cushion of claim 1 wherein said elastomeric composition is present on the surface of said inflatable fabric in an amount of at most 3.0 ounces per square yard of the fabric.

3. The fabric of claim 2 wherein the weave pattern of said at least two layers of fabric within said inflatable fabric is a plain weave pattern.

4. The airbag cushion of claim 2 wherein said elastomeric composition is costed on said inflatable fabric surface in an amount of at most 2.0 ounces per square yard.

5. The airbag cushion of claim 4 wherein said elastomeric composition is coated on said airbag fabric surface in an amount 1.5 ounces per square yard.

6. The airbag cushion of claim 5 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.2 ounces per square yard.

7. The airbag cushion of claim 6 wherein said elastomeric composition is coated on said airbag fabric surface in an amount at most 1.0 ounces per square yard.

8. The airbag cushion of claim 7 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 0.8 ounces per square yard.

9. The fabric of claim 1 wherein said at least two layers of fabric within said inflatable fabric are formed solely from one type of weave pattern, wherein said weave pattern is not a basket weave pattern.

10. The fabric of claim 1 wherein at least two discrete narrow areas of single fabric layers are present within said inflatable fabric, wherein said at least two single fabric layers are separated by an area of two layers of fabric, and wherein the lengths of each single layer is from 4 to 8 yarns in length.

11. The fabric of claim 10 wherein said at least two single fabric layer areas are constructed solely from basket weave patterns containing at least two yarns per basket pattern and at most four yarns per basket pattern.

12. The fabric of claim 11 said separator two layers of fabric between said two single layers of fabric comprises an even number of weft yarns.

13. The fabric of claim 12 wherein said separator two layers of fabric comprises at most 12 weft yarns and at least 2 weft yarns.

14. The fabric of claim 13 wherein said at least two single fabric layers are constructed solely from two-by-two basket weave patterns and said separator double fabric layer comprises four weft yarns.

15. The airbag cushion of claim 1 wherein said elastomeric composition comprises at least one elastomer exhibiting a tensile strength of at least 2,000 psi and an elongation at break of at least 180%.

16. The airbag cushion of claim 15 wherein said elastomeric composition is present in the form of a resin solution in an organic solvent.

17. The airbag cushion of claim 1 wherein said elastomeric composition comprises polyurethane.

18. The airbag cushion of claim 17, wherein said elastomeric polyurethane composition is polycarbonate polyurethane.

19. The airbag cushion of claim 1 wherein said coated fabric is woven from polyamide yarns.

20. The airbag cushion of claim 19 wherein said polyamide yarns are formed from nylon 6,6 fiber.

21. The airbag cushion of claim 19, wherein said polyamide yarns are multifilament yarns exhibiting a linear density of about 210-840 denier.

22. The airbag cushion of claim 21, wherein said multifilament yarns exhibit a filament linear density of about 4 denier per filament or less.

23. A one-piece woven airbag cushion comprising a coated inflatable fabric, wherein said inflatable fabric is at least partially coated with an elastomeric composition;

wherein said airbag cushion exhibits a characteristic leak-down time after inflation of at least 5 seconds;

wherein said inflatable fabric comprises at least two layers of fabric in certain discrete areas of the fabric and at least one single fabric layer at a discrete area within said fabric;

wherein said at least one narrow single fabric layer is the sole source of providing inflatable pillow structures within said airbag cushion;

wherein said at least one narrow single fabric layer is solely formed from a weave pattern of at most 12 yarns in width; and

wherein the weave diagram for such an inflatable fabric does not exhibit more than three consecutive unfilled blocks in any row or column.

24. The airbag cushion of claim 23 wherein said elastomeric composition is present on the surface of said inflatable fabric in an amount of at most 3.0 ounces per square yard of the fabric.

25. The airbag cushion of claim 24 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 2.0 ounces per square yard.

26. The airbag cushion of claim 25 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.5 ounces per square yard.

27. The airbag cushion of claim 26 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.2 ounces per square yard.

28. The airbag cushion of claim 27 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.0 ounces per square yard.

29. The airbag cushion of claim 28 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 0.8 ounces per square yard.

30. The airbag cushion of claim 23 wherein wherein said elastomeric composition comprises at least one elastomer exhibiting a tensile strength of at least 2,000 psi and an elongation at break of at least 180%.

31. The airbag cushion of claim 30, wherein said elastomeric composition is present in the form of a resin solution in an organic solvent.

32. The airbag cushion of claim 23 wherein said elastomeric composition comprises polyurethane.

33. The airbag cushion of claim 32, wherein said elastomeric polyurethane composition is polycarbonate polyurethane.

34. The airbag cushion of claim 23 wherein said coated fabric is woven from polyamide yarns.

35. The airbag cushion of claim 34 wherein said polyamide yarns are formed from nylon 6,6 fiber.

36. The airbag cushion of claim 35, wherein said multifilament yarns exhibit a filament linear density of about 4 denier per filament or less.

37. The airbag cushion of claim 34, wherein said polyamide yarns are multifilament yarns exhibiting a linear density of about 210-630 denier.

38. A one-piece woven airbag cushion comprising a coated inflatable fabric, wherein said inflatable fabric is at least partially coated with an elastomeric composition;

wherein said airbag cushion exhibits a characteristic leak-down time after inflation of at least 5 seconds;

wherein said inflatable fabric comprises at least two layers of fabric in certain discrete areas of the fabric and at least one narrow single fabric layer at a discrete area within said fabric;

wherein said at least one narrow single fabric layer is the sole source of providing inflatable pillow structures within said airbag cushion;

wherein said at least one narrow single fabric layer is solely formed from a weave pattern of at most 12 yarns in width; and

wherein only two separate weave densities are present within the area directly adjacent to said at least one narrow single fabric layer.

39. The airbag cushion of claim 38 wherein said elastomeric composition is present on the surface of said inflatable fabric in an amount of at most 3.0 ounces per square yard of the fabric.

40. The airbag cushion of claim 39 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 2.0 ounces per square yard.

41. The airbag cushion of claim 39 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.5 ounces per square yard.

42. The airbag cushion of claim 41 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.2 ounces per square yard.

43. The airbag cushion of claim 42 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.0 ounces per square yard.

44. The airbag cushion of claim 43 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 0.8 ounces per square yard.

45. The airbag cushion of claim 38 wherein said elastomeric composition comprises at least one elastomer exhibiting a tensile strength of at least 2,000 psi and an elongation at break of at least 180%.

46. The airbag cushion of claim 45, wherein said elastomeric composition is present in the form of a resin solution in an organic solvent.

47. The airbag cushion of claim 38 wherein said elastomeric composition comprises polyurethane.

48. The airbag cushion of claim 47, wherein said elastomeric polyurethane composition is polycarbonate polyurethane.

49. The airbag cushion of claim 38 wherein said coated fabric is woven from polyamide yarns.

50. The airbag cushion of claim 38 wherein said polyamide yarns are formed from nylon 6,6 fiber.

51. The airbag cushion of claim 50, wherein said polyamide yarns are multifilament yarns exhibiting a linear density of about 210-630 denier.

52. The airbag cushion of claim 51, wherein said multifilament yarns exhibit a filament linear density of about 4 denier per filament or less.

53. A one-piece woven airbag cushion comprising a coated inflatable fabric, wherein said inflatable fabric is at least partially coated with an elastomeric composition;

wherein said airbag cushion exhibits a characteristic leak-down time after inflation of at least 5 seconds;

wherein said inflatable fabric comprises at least two layers of fabric in certain discrete areas of the fabric and a plurality of narrow single fabric layers in at least two discrete areas within said fabric;

wherein said at least two narrow single fabric layers are the sole source of providing inflatable pillow structures within said airbag cushion; and

wherein the narrow single fabric layers present within said two discrete areas within said fabric are formed solely from a basket weave pattern of an even number of yarns, from 4 to 8 yarns in width.

54. The airbag cushion of claim 53 wherein said elastomeric composition is present on the surface of said inflatable fabric in amount of at most 3.0 ounces per square yard of the fabric.

55. The airbag cushion of claim 54 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 2.0 ounces per square yard.

56. The airbag cushion of claim 55 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.5 ounces per square yard.

57. The airbag cushion of claim 56 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.2 ounces per square yard.

58. The airbag cushion of claim 57 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 1.0 ounces per square yard.

59. The airbag cushion of claim 58 wherein said elastomeric composition is coated on said airbag fabric surface in an amount of at most 0.8 ounces per square yard.

60. The airbag cushion of claim 53 wherein said elastomeric composition comprises at least one elastomer exhibiting a tensile strength of at least 2,000 psi and an elongation at break of at least 180%.

61. The airbag cushion of claim 60, wherein said elastomeric composition is present in the form of a resin solution in an organic solvent.

62. The airbag cushion of claim 53 wherein said elastomeric composition comprises polyurethane.

63. The airbag cushion of claim 62, wherein said elastomeric polyurethane composition is polycarbonate polyurethane.

64. The airbag cushion of claim 53 wherein said coated fabric is woven from polyamide yarns.

65. The airbag cushion of claim 64 wherein said said yarns are formed from nylon 6,6 fiber.

66. The airbag cushion of claim 65, wherein said polyamide yarns are multifilament yarns exhibiting a linear density of about 210-630 denier.

67. The airbag cushion of claim 66, wherein said multifilament yarns exhibit a filament linear density of about 4 denier per filament or less.

68. A coated side curtain airbag exhibiting a rolled packing volume factor of from about 17 to about 24;

wherein said coated side curtain airbag exhibits a leak-down time after inflation of at least 7 seconds; and

wherein said inflatable fabric comprises at least two layers of fabric in certain discrete areas of the fabric and at least one narrow single fabric layer at a discrete area within said fabric;

wherein said at least one narrow single fabric layer is the sole source of providing inflatable pillow structure within said airbag cushion; and

wherein said at least one narrow single fabric layer is formed solely from a basket weave pattern of an even number of yarns, at most 12 yarns in width.

69. The airbag cushion of claim 68 wherein said rolled packing volume factor is about 21.6.