NEEDLING LOOPS INTO CARRIER SHEETS

• US 20090203280A9
• Filed: 06/05/2008
• Published: 08/13/2009
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Velcro IP Holdings LLC
• Original Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Inventors: Provost, George A., Barker, James R.
• Granted Patent: US 8,753,459 B2
• Time in Patent Office: Days
• US Class Current: 442/360
• CPC Class Codes: A44B 18/0011 Female or loop elements A44B18/0007 takes precedence
• CPC Class Codes: D04H 1/46 by needling or like operations to cause entanglement of fibres D04H1/45 takes precedence; needling machines D04H18/00
• CPC Class Codes: D04H 1/485 in combination with weld-bonding
• CPC Class Codes: D04H 1/54 by welding together the fibres, e.g. by partially melting or dissolving in combination with needling D04H1/485
• CPC Class Codes: D04H 11/08 formed by creation of a pile on at least one surface of a non-woven fabric without addition of pile-forming material, e.g. by needling, by differential shrinking needling machines D04H18/00
• CPC Class Codes: Y10T 442/627 Strand or fiber material is specified as non-linear [e.g., crimped, coiled, etc.]
• CPC Class Codes: Y10T 442/636 Synthetic polymeric strand or fiber material is of staple length

Abstract

Methods of making a sheet-form loop product are provided. One method includes placing a layer of staple fibers against a first side of a substrate comprising a nonwoven web; needling fibers of the layer through the substrate by penetrating the substrate with needles that drag portions of the fibers through the substrate, leaving exposed loops of the fibers extending from a second side of the substrate; and anchoring fibers forming the loops by fusing the fibers to each other and to filaments of the nonwoven web on the first side of the substrate, while substantially preventing fusion of the fibers on the second side of the substrate. Sheet-form loop products are also provided, including for example a flexible nonwoven substrate and a layer of staple fibers disposed on a first side of the substrate, exposed loops of the fibers extending from a second side of the substrate, with bases of the loops being anchored on the first side of the substrate, wherein the fibers on the first side of the substrate are fused together to a relatively greater extent than the fibers on the second side of the substrate.

Claims

1. A method of making a sheet-form loop product, the method comprising placing a layer of staple fibers against a first side of a substrate, the substrate comprising a nonwoven web;

needling fibers of the layer through the substrate by penetrating the substrate with needles that drag portions of the fibers through the substrate during needling, leaving exposed loops of the fibers extending from a second side of the substrate; and

anchoring fibers forming the loops by fusing the fibers to each other and to filaments of the nonwoven web on the first side of the substrate, while substantially preventing fusion of the fibers on the second side of the substrate.

2. The method of claim 1 further comprising, prior to fusing, heating the fibers from the first side of the substrate.

3. The method of claim 1 wherein the fibers include bicomponent fibers having a core of one material and a sheath of another material, and wherein anchoring the fibers comprises melting material of the sheaths of the bicomponent fibers to bind fibers together.

4. The method of claim 1 wherein anchoring the fibers to the substrate comprises laminating the fibers to the substrate by a laminating process comprising passing the needled substrate through a nip defined between a compliant rubber roll and a hot can.

5. The method of claim 4 further comprising cooling the surface of the compliant rubber roll.

6. The method of claim 4 wherein the fibers are loose and unconnected to the substrate and each other until needled.

7. The method of claim 1 wherein after anchoring the fibers and filaments on the first side are fused together by a network of discrete bond points.

8. The method of claim 7 wherein the bond points are in a random distribution.

9. The method of claim 7 wherein the fibers comprise drawn staple fibers, and the fused fibers maintain a longitudinal molecular orientation throughout the bond points.

10. The method of claim 1 wherein needling fibers of the layer through the substrate and anchoring fibers forming the loops forms loops sized and constructed to be releasably engageable by a field of hooks for hook-and-loop fastening.

11. The method of claim 1 wherein the nonwoven web has a linear filament layer density of at least 25 filaments/layer.

12. The method of claim 11 wherein the nonwoven web has an overall nonwoven basis weight of less than about 0.75 osy.

13. The method of claim 1 wherein the nonwoven web consists essentially of filaments having a denier of 6 or less.

14. The method of claim 1 wherein the staple fibers and filaments of the nonwoven web are of substantially the same denier.

15. The method of claim 1 wherein the nonwoven web comprises a spunbond web.

16. The method of claim 15 wherein, prior to needling, the spunbond web comprises a non-random pattern of fused, spaced apart regions, each fused region surrounded by unfused regions.

17. The method of claim 1 wherein the nonwoven web comprises filaments formed of a polymer selected from the group consisting of polyesters, polyamides, polyolefins, and blends and copolymer thereof.

18. The method of claim 1 wherein the nonwoven web has a specific gravity of less than about 1.5 g/cm³.

19. The method of claim 18 wherein the nonwoven web comprises filaments having a specific gravity of less than about 1.0 g/cm³.

20. The method of claim 1 wherein the staple fibers are disposed on the substrate in a layer of a total fiber weight of less than about 2 ounces per square yard (67 grams per square meter).

21. The method of claim 20 wherein the staple fibers are disposed on the substrate in a layer of a total fiber weight of no more than about one ounce per square yard (34 grams per square meter).

22. The method of claim 1 wherein the staple fibers are disposed on the substrate in a carded, unbonded state.

23. The method of claim 1 further comprising, prior to disposing the fibers on the substrate, carding and cross-lapping the fibers.

24. The method of claim 1 wherein the loop product has an overall weight of less than about 5 ounces per square yard (167 grams per square meter).

25. A sheet-form loop product comprising:

a flexible nonwoven substrate; and

a layer of staple fibers disposed on a first side of the substrate, exposed loops of the fibers extending from a second side of the substrate, with bases of the loops being anchored on the first side of the substrate;

wherein the fibers on the first side of the substrate are fused together to a relatively greater extent than the fibers on the second side of the substrate.

26. The loop product of claim 25 wherein the fibers are fused on the first side of the substrate in a network of discrete bond points.

27. The loop product of claim 26 wherein the fibers on the first side are fused directly to one another and to filaments of the nonwoven web.

28. The loop product of claim 27 wherein the fibers are substantially unbonded on the second side of the web.

29. The loop product of claim 27 wherein the second side of the web includes embossed areas, and the fibers are bonded only in the embossed areas.

30. The loop product of claim 25 wherein the fibers include bicomponent fibers having a core of one material and a sheath of another material, the fibers fused by melted material of the sheaths of the bicomponent fibers.

31. The loop product of claim 25 wherein the fibers include first fibers having a relatively high melting temperature and second fibers having a relatively lower melting temperature, the melting temperature of the second fibers being selected to allow the second fibers to fuse and anchor the loops.

32. The loop product of claim 30 wherein the bicomponent fibers make up between about 5 and 40 percent of the fibers, by weight.

33. The loop product of claim 31 wherein the second fibers make up between about 5 and 40 percent of the fibers, by weight.

34. The loop product of claim 25 wherein the staple fibers have a total fiber weight of less than about 2 ounces per square yard (67 grams per square meter).

35. The loop product of claim 34 wherein the staple fibers have a total fiber weight of no more than about one ounce per square yard (34 grams per square meter).

36. The loop product of claim 25 wherein the loop product has an overall weight of less than about 5 ounces per square yard (167 grams per square meter).

37. The loop product of claim 25 wherein the loops are hook-engageable and the product comprises a loop fastener product.

38. The loop product of claim 25 wherein the nonwoven web has a linear filament layer density of at least 25 filaments/layer.

39. The loop product of claim 25 wherein the nonwoven web consists essentially of filaments having a denier of 6 or less.

40. The loop product of claim 25 wherein the nonwoven web comprises filaments formed of a polymer selected from the group consisting of polyesters, polyamides, polyolefins, and blends and copolymer thereof.

41. The loop product of claim 25 wherein the nonwoven web comprises filaments having a specific gravity of less than about 1.5 g/cm³.

42. The loop product of claim 41 wherein the nonwoven web comprises filaments having a specific gravity of less than about 1.0 g/cm³.

43. The loop product of claim 25 wherein the nonwoven web comprises filaments having a weight of about 12 g/m² to about 17 g/m².