Loop fastening material

1. A touch fastener loop material comprising a non-woven web of fibers forming both a base and a field of hook-engageable loops of a tenacity of at least 1.1 grams per denier extending outward from one broad side of the base, wherein the fibers are distributed such that the loop material has a Loop Loft Density of between 0.6 and 1.3 gram per cubic inch as determined based on a thickness of the loop material measured according to ASTM D1777.

2. The touch fastener loop material of claim 1 , wherein the Loop Loft Density is between 0.8 and 1.0.

3. The touch fastener loop material of claim 1 , having a Critical Fiber Volume Percentage of between 20 and 60 percent.

4. The touch fastener loop material of claim 1 , wherein the fibers are distributed such that the field of loops has a Maximum Fiber Volumetric Ratio of between 5 and 25 percent.

5. The touch fastener loop material of claim 4 , wherein the Maximum Fiber Volumetric Ratio is between 10 and 15 percent.

6. The touch fastener loop material of claim 4 , wherein the Maximum Fiber Volumetric Ratio occurs within a lower 30% of an elevation span between the Rising 5% Ratio Elevation and the Falling 5% Ratio Elevation.

7. The touch fastener loop material of claim 1 , wherein the tenacity is at least 5 grams per denier.

8. The touch fastener loop material of claim 7 , wherein the tenacity is at least 8 grams per denier.

9. The touch fastener loop material of claim 1 , having a Peel Strength of at least 500 grams force per inch width when mated with an HTH725 hook and tested according to ASTM D5170-98.

10. The touch fastener loop material of claim 1 , having a Shear Strength of at least 8,000 grams force per square inch when mated with an HTH725 hook and tested according to ASTM D5169-98.

11. The touch fastener loop material of claim 1 , having Frazier air permeability of at least 500 feet3/feet2/sec.

12. The touch fastener loop material of claim 1 , having an overall thickness of less than about 1.5 millimeters.

13. The touch fastener loop material of claim 1 , wherein the web has an overall basis weight of between 20 gsm and 70 gsm.

14. The touch fastener loop material of claim 1 , wherein the fibers comprise multicomponent fibers.

15. The touch fastener loop material of claim 14 , wherein the multicomponent fibers comprise bicomponent fibers having a sheath of a lower melting temperature than a core within the sheath, and wherein the fibers are bonded within the base by resin of the sheath.

16. The touch fastener loop material of claim 1 , further comprising a film permanently bonded to a side of the base opposite the field of loops.

17. The touch fastener loop material of claim 16 , wherein the loop material is air-impermeable.

18. The touch fastener loop material of claim 1 , consisting essentially of the non-woven web of fibers, bonded together by fused material of the fibers.

19. The touch fastener loop material of claim 1 , wherein the base is dimensionally stable.

20. A touch fastener comprising the loop material of claim 1 and a backing bonded across a surface of the base opposite the field of loops.

21. A touch fastener loop material comprising a non-woven web of fibers forming both a base and a field of hook-engageable loops of a tenacity of at least 1.1 grams per denier extending outward from one broad side of the base, wherein the fibers are distributed such that the field of loops has a Maximum Fiber Volume Ratio of between 5 and 25 percent, and the loop material has a Loop Loft Density of between 0.6 and 1.8 gram per cubic inch as determined based on a thickness of the loop material measured according to ASTM D1777.