Method of separating strands on a stretching surface

Patent metadata

Field	Value
Publication number	US-9314962-B2
Application number	US-201313891287-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	May 10, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A method of separating strands of a slit web is disclosed. The method includes providing a slit web having a length in a machine direction and running the slit web in the machine direction onto a stretchable surface. The slit web includes multiple strands provided by a plurality of slits extending in a first direction not parallel to a cross-machine direction. The slit web is in contact with the stretchable surface for a path length in the machine direction, and for at least a portion of the path length, the stretchable surface is stretching in the cross-machine direction. The traction between the slit web and the stretchable surface during the stretching at least partially separates at least some of the multiple strands of the slit web in a second direction transverse to the first direction. A method of increasing a width of a polymeric netting is also disclosed.

First claim

What is claimed is:

1. A method of separating strands of a slit web, the method comprising:
providing a slit web having a length in a machine direction, wherein the slit web comprises multiple strands provided by a plurality of slits extending in a first direction not parallel to a cross-machine direction; and
running the slit web in the machine direction onto a stretchable surface, wherein the slit web is in contact with the stretchable surface for a path length in the machine direction, wherein for at least a portion of the path length, the stretchable surface stretches in the cross-machine direction, and wherein traction between the slit web and the stretchable surface during stretching at least partially separates at least some of the multiple strands of the slit web in a second direction transverse to the first direction.

2. The method of claim 1 , wherein the slit web has a width after contacting the stretchable surface that is at least five percent greater than its width before it contacts the stretchable surface.

3. The method of claim 1 , wherein the slit web comprises mechanical fastening elements on at least one major surface.

4. The method of claim 3 , wherein the mechanical fastening elements are male fastening elements comprising upstanding posts having bases attached to the slit web.

5. The method of claim 3 , wherein the slit web is coated with adhesive on its major surface opposite the mechanical fastening elements.

6. The method of claim 1 , wherein the stretchable surface does not have a support surface contacting the stretchable surface on a side opposite a side of the stretchable surface that contacts the slit web.

7. The method of claim 1 , wherein the plurality of slits are interrupted by intact bridging regions of the web, wherein for at least some adjacent interrupted slits, the intact bridging regions are staggered in a direction transverse to the first direction, and wherein the stretching provides a spread web comprising multiple strands of the slit web attached to each other at least at some of the intact bridging regions and separated from each other between at least some of the intact bridging regions.

8. The method of claim 7 , wherein the intact bridging regions divide the interrupted slits into a series of slit portions aligned in the first direction, and wherein a ratio of a length of the slit portions to a width of one of the multiple strands is at least 2 to 1.

9. The method of claim 1 , wherein at least some of the multiple strands of the slit web are not attached to each other.

10. The method of claim 1 , wherein the stretchable surface is provided by at least one stretchable band, stretchable tubing, at least one coiled spring, or a combination thereof.

11. The method of claim 1 , wherein running the slit web in the machine direction comprises running the slit web onto a roller comprising two rotating diverging disks that are laterally spaced and have the stretchable surface between them that stretches in the cross-machine direction for a portion of a rotation of the two rotating diverging disks.

12. The method of claim 11 , wherein there are multiple stretchable bands, stretchable tubing, multiple coiled springs, or a combination thereof attached to the diverging disks that provide the stretchable surface.

13. The method of claim 11 , wherein the stretchable surface is a sleeve connected to the two rotating diverging disks.

14. The method of claim 11 , wherein a distance between the two diverging disks' peripheral surfaces at a point of greatest separation is at least 25 percent greater than a distance between the two diverging disks' peripheral surfaces at a point of least separation.

15. The method of claim 1 , wherein the stretchable surface is stretched on a conveyor belt apparatus.

16. The method of claim 1 , wherein stretchable surface comprises an elastomer.

17. The method of claim 1 , further comprising directing the slit web onto a high-friction surface after at least some of the multiple strands are at least partially separated.

18. The method of claim 1 , further comprising laminating the slit web to a carrier after at least some of the multiple strands are at least partially separated.

19. The method of claim 18 , wherein the carrier is provided with a layer of adhesive, wherein the slit web is bonded to the carrier with the adhesive to form a laminate, and wherein the adhesive is exposed between the multiple strands in the laminate.

20. The method of claim 19 , wherein the laminate is directed through a nip downweb from where the slit web is bonded to the carrier.

21. A method of increasing a width of a polymeric netting, the method comprising:
providing a polymeric netting having a length in a machine direction; and
running the polymeric netting in the machine direction onto a stretchable surface, wherein the polymeric netting is in contact with the stretchable surface for a path length in the machine direction, wherein for at least a portion of the path length, the stretchable surface stretches in the cross-machine direction, and wherein traction between the polymeric netting and the stretchable surface during stretching increases the width of at least a portion of the polymeric netting in the cross-machine direction.

Assignees

• 3M Innovative Properties Co

Inventors

• Rothwell Neal C
• Bugeja Peter J
• Gilbert Thomas J
• Biegler Kristopher K
• Peltier Mark A
• Luepke Ryan M
• Perron Steven J
• Diekmann Timothy J

Classifications

• D01D5/426

  by cutting films · CPC title

• B29C55/08 Primary

  transverse to the direction of feed · CPC title

• A44B18/0046

  Fasteners made integrally of plastics · CPC title

• D04H13/02

  Production of non-woven fabrics by partial defibrillation of oriented thermoplastics films · CPC title

• B29K2021/003

  Thermoplastic elastomers · CPC title