Flash-spun sheet material
View Patent ↗This invention relates to improved plexifilamentary sheet material useful in protective apparel and filtration media, which material is comprised of substantially continuous polyethylene plexifilamentary fiber strands and has a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 2 cfm/ft 2 .
1. A flash-spun plexifilamentary fiber strand having a surface area of less than 10 m 2 /g and a crush value of at least 1 mm/g.
2. The flash-spun plexifilamentary fiber strand of claim 1 , wherein the surface area is less than 8 m 2 /g.
3. The flash-spun plexifilamentary fiber strand of claim 1 , wherein the surface area is less than 5 m 2 /g.
4. The flash-spun plexifilamentary fiber strand of claim 1 , wherein the crush value is at least 1.5 mm/g.
5. A nonwoven sheet comprising substantially continuous, flash-spun plexifilamentary fiber strands, the strands having surface areas of less than 10 m 2 /g and crush values of at least 1 mm/g.
6. The nonwoven sheet of claim 5 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 2 cfm/ft 2 .
7. The nonwoven sheet of claim 5 having a Gurley Hill Porosity of less than 6 seconds.
8. The nonwoven sheet of claim 6 having a hydrostatic head of at least 30 cm.
9. The nonwoven sheet of claim 6 having a hydrostatic head of at least 75 cm.
10. The nonwoven sheet of claim 6 having a hydrostatic head of at least 100 cm.
11. The nonwoven sheet of claim 6 having a hydrostatic head of at least 130 cm.
12. The nonwoven sheet of claim 5 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 4 cfm/ft 2 .
13. The nonwoven sheet of claim 5 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 10 cfm/ft 2 .
14. The nonwoven sheet of claim 5 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 20 cfm/ft 2 .
15. The nonwoven sheet of claim 5 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 25 cfm/ft 2 .
16. The nonwoven sheet of claim 5 , wherein the sheet has a whole surface bonded portion of a first side of the sheet and a point bonded portion on the second side of the sheet, the point bonded portion of the sheet comprising at least 50% by weight of the nonwoven sheet.
17. The nonwoven sheet of claim 16 , wherein the point bonded portion of the sheet comprises at least 60% by weight of the nonwoven sheet.
18. The nonwoven sheet of claim 17 , wherein the point bonded portion to the sheet is bonded with a ribbed bonding pattern and the whole surface bonded portion of the sheet is bonded with a linen pattern.
19. A nonwoven sheet comprising substantially continuous, flash-spun plexifilamentary fiber strands and having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 2 cfm/ft 2 .
20. The nonwoven sheet of claim 19 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 4 cfm/ft 2 .
21. The nonwoven sheet of claim 19 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 10 cfm/ft 2 .
22. The nonwoven sheet of claim 19 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 20 cfm/ft 2 .
23. The nonwoven sheet of claim 19 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 25 cfm/ft 2 .
24. The nonwoven sheet of claim 19 having a hydrostatic head of at least 30 cm.
25. The nonwoven sheet of claim 19 having a hydrostatic head of at least 85 cm.
26. The nonwoven sheet of claim 19 having a hydrostatic head of at least 130 cm.
27. The nonwoven sheet of claim 19 having a Gurley Hill Porosity of less than 6 seconds.
28. A garment comprised of the nonwoven sheet of claim 5 or 19 .
29. A flash-spun plexifilamentary fiber strand having a surface area of less than 10 m 2 /g.
30. The flash-spun plexifilamentary fiber strand of claim 29 , wherein the surface area is less than 8 m 2 /g.
31. The flash-spun plexifilamentary fiber strand of claim 29 , wherein the surface area is less than 5 m 2 /g.
32. A nonwoven sheet comprising substantially continuous, flash-spun plexifilamentary fiber strands, the strands having surface areas of less than 10 m 2 /g.
33. The nonwoven sheet of claim 32 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 2 cfm/ft 2 .
34. The nonwoven sheet of claim 32 having a Gurley Hill Porosity of less than 6 seconds.
35. The nonwoven sheet of claim 33 having a hydrostatic head of at least 30 cm.
36. The nonwoven sheet of claim 33 having a hydrostatic head of at least 75 cm.
37. The nonwoven sheet of claim 33 having a hydrostatic head of at least 100 cm.
38. The nonwoven sheet of claim 33 having a hydrostatic head of at least 130 cm.
39. The nonwoven sheet of claim 32 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 4 cfm/ft 2 .
40. The nonwoven sheet of claim 32 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 10 cfm/ft 2 .
41. The nonwoven sheet of claim 32 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 20 cfm/ft 2 .
42. The nonwoven sheet of claim 32 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 25 cfm/ft 2 .
43. The nonwoven sheet of claim 32 , wherein the sheet has a whole surface bonded portion of a first side of the sheet and a point bonded portion on the second side of the sheet, the point bonded portion of the sheet comprising at least 50% by weight of the nonwoven sheet.
44. The nonwoven sheet of claim 43 , wherein the point bonded portion of the sheet comprises at least 60% by weight of the nonwoven sheet.
45. The nonwoven sheet of claim 44 , wherein the point bonded portion to the sheet is bonded with a ribbed bonding pattern and the whole surface bonded portion of the sheet is bonded with a linen pattern.
46. A garment comprised of the nonwoven sheet of claim 32 .
47. A flash-spun plexifilamentary fiber strand having a crush value of at least 1 mm/g.
48. The flash-spun plexifilamentary fiber strand of claim 47 , wherein the crush value is at least 1.5 mm/g.
49. A nonwoven sheet comprising substantially continuous, flash-spun plexifilamentary fiber strands, the strands having crush value of at least 1 mm/g.
50. The nonwoven sheet of claim 49 , the strands having crush value of at least 1.5 mm/g.
51. The nonwoven sheet of claim 49 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 2 cfm/ft 2 .
52. The nonwoven sheet of claim 49 having a Gurley Hill Porosity of less than 6 seconds.
53. The nonwoven sheet of claim 51 having a hydrostatic head of at least 30 cm.
54. The nonwoven sheet of claim 51 having a hydrostatic head of at least 75 cm.
55. The nonwoven sheet of claim 51 having a hydrostatic head of at least 100 cm.
56. The nonwoven sheet of claim 51 having a hydrostatic head of at least 130 cm.
57. The nonwoven sheet of claim 49 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 4 cfm/ft 2 .
58. The nonwoven sheet of claim 49 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 10 cfm/ft 2 .
59. The nonwoven sheet of claim 49 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 20 cfm/ft 2 .
60. The nonwoven sheet of claim 49 having a Frazier Permeability, normalized to 1.0 oz/yd 2 basis weight, of at least 25 cfm/ft 2 .
61. The nonwoven sheet of claim 49 , wherein the sheet has a whole surface bonded portion of a first side of the sheet and a point bonded portion on the second side of the sheet, the point bonded portion of the sheet comprising at least 50% by weight of the nonwoven sheet.
62. The nonwoven sheet of claim 61 , wherein the point bonded portion of the sheet comprises at least 60% by weight of the nonwoven sheet.
63. The nonwoven sheet of claim 62 , wherein the point bonded portion to the sheet is bonded with a ribbed bonding pattern and the whole surface bonded portion of the sheet is bonded with a linen pattern.
64. A garment comprised of the nonwoven sheet of claim 47 .