Engageability of fibrous surfaces for use with touch fasteners
View Patent ↗A method for forming a hook-engageable landing zone on a fibrous surface by selecting a region of the surface to form the landing zone, by raising fibers from the surface in the selected region to form fibrous loops extending from the surface, and by anchoring the fibrous loops in the selected region to secure the loops and resist pullout during hook engagement.
1. A method of forming a hook-engageable landing zone on an exposed fibrous surface, the method comprising:
selecting a region of the surface to form the landing zone;
raising fibers of the fibrous surface from the surface in the selected region to form raised fibrous loops extending from the surface, while leaving other areas of the exposed fibrous surface without such raised fibers; and then
bonding the raised fibrous loops in the selected region to secure the loops to resist pullout during hook disengagement,
wherein raising the fibers comprises pulling fibers away from the exposed fibrous surface, and
wherein pulling the fibers away from the surface comprises brushing, napping or carding the selected region.
2. The method of claim 1 , wherein the surface comprises a broad outer surface of a garment.
3. The method of claim 2 , wherein the garment is a disposable diaper.
4. The method of claim 1 , wherein the fibers are raised only in the selected regions.
5. The method of claim 4 , wherein the raised fibers have an overall loft “L 2 ” that is at least 25 percent greater than overall loft “L 1 .”
6. The method of claim 4 , wherein the raised fibers have an overall loft “L 2 ” that is at least 75 percent greater than overall loft “L 1 .”
7. The method of claim 4 , wherein the raised fibers have an overall loft “L 2 ” that is at least 150 percent greater than overall loft “L 1 .”
8. The method of claim 1 , wherein the fibrous surface comprises a non-woven material.
9. Method of claim 8 , wherein the non-woven material is bonded to an underlying substrate.
10. The method of claim 9 , wherein the underlying substrate is a film.
11. The method of claim 9 , wherein the selected region corresponds to visible landing zone indicia on the substrate.
12. The method of claim 1 , wherein the surface carries landing zone indicia.
13. The method of claim 9 , further comprising raising the underlying substrate in the selected region.
14. The method of claim 13 , wherein the underlying substrate is raised by embossing the substrate.
15. The method of claim 1 , wherein the fibrous surface is longitudinally continuous, the method comprising selecting a series of discrete, longitudinally spaced-apart regions of the surface for landing zones, and sequentially raising and anchoring fibers in the selected regions.
16. The method of claim 15 , further comprising segmenting the surface into discrete sections, each section containing at least a portion of a respective one of the selected regions.
17. The method of claim 1 , wherein the fibrous surface is of a spun-bonded material.
18. The method of claim 1 , wherein the fibrous surface comprises fibers of a denier less than about 3.
19. The method of claim 1 , wherein the fibrous surface comprises fibers of a tenacity less than about 6 g/d.
20. The method of claim 1 , wherein raising the fibers comprises engaging the selected region with an array of male touch fastener elements.
21. The method of claim 1 , wherein raising the fibers comprises applying a vacuum to the selected region.
22. The method of claim 1 , wherein raising the fibers forms a pattern of raised areas within the selected region.
23. The method of claim 1 , wherein anchoring the raised fibers comprises embossing the selected region to form a pattern of bond areas.
24. The method of claim 23 , wherein the pattern of bond areas are formed by passing the fibrous surface through an embossing nip.
25. The method of claim 24 , wherein the pattern of bond areas is formed with a roller having a heated, patterned surface.
26. The method of claim 23 , wherein the pattern of bond areas is formed with an ultrasonic horn fashioned to form the pattern of bond areas.
27. The method of claim 23 , wherein the pattern of bond areas is formed by applying pressure with an array of pins to discrete spots positioned against an energy source.
28. The method of claim 23 , wherein embossing comprises activating an adhesive in the bond areas.
29. The method of claim 28 , further comprising, prior to embossing, depositing the adhesive on the fibrous surface.
30. The method of claim 29 , further comprising applying the adhesive to the selected region in a predetermined pattern.
31. The method of claim 23 , wherein embossing comprises melting resin of the fibers in the bond areas.
32. The method of claim 23 , wherein the bond areas are contiguous across the selected region.
33. The method of claim 23 , wherein the bond areas are discrete spots separated by non-bond areas within the selected region.
34. The method of claim 23 , wherein the bond areas comprise only about 10 to 35 percent of an overall area of the selected region of raised loops.
35. The method of claim 23 , wherein the bond areas comprise only about 20 percent of an overall area of the selected region of raised loops.
36. The method of claim 1 , further comprising, after raising the fibers, processing the raised fibers in a manner that increases their crush resistance.
37. The method of claim 36 , wherein processing the fibers comprising applying a stiffening agent to the raised fibers.
38. The method of claim 37 , wherein the stiffening agent comprises starch.
39. The method of claim 37 , wherein the stiffening agent comprises urethane.
40. The method of claim 37 , wherein the stiffening agent comprises ink.
41. The method of claim 40 , wherein the ink is applied by printing.
42. The method of claim 36 , wherein said processing is performed after anchoring the fibers.