COMPOSITE WEBS AND METHODS OF MANUFACTURING SAME

• US 20080070464A1
• Filed: 09/14/2006
• Published: 03/20/2008
• Est. Priority Date: 09/14/2006
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wood, Leigh E., Jackson, Byron M., Alberg, Randall L., Becker, Dennis L., McDonald, Daniel S.
• Application Number:
  US11/531,825
• Publication Number:
  US 20080070464A1
• Time in Patent Office: Days
• US Class Current: 442/327
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2309/02 Temperature
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 37/0053 Constructional details of laminating machines comprising rollers; Constructional features of the rollers
• CPC Class Codes: B32B 37/1292 selectively, e.g. in stripes, in patterns B32B37/0076 takes precedence
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: Y10T 156/1737 Discontinuous, spaced area, and/or patterned pressing
• CPC Class Codes: Y10T 428/249982 With component specified as adhesive or bonding agent
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/601 Nonwoven fabric has an elastic quality
• CPC Class Codes: Y10T 442/674 Nonwoven fabric with a preformed polymeric film or sheet

Abstract

Composite webs having a structured web attached to a carrier web and methods of manufacturing the composite webs are disclosed. The structured web may include a plurality of structures that protrude from the structured web. The methods may involve delivering a molten polymeric composition onto the outer surface of a forming tool that includes a plurality of depressions formed in the outer surface. The molten polymer enters depressions in the outer surface of the forming tool and is solidified therein such that a plurality of structures are formed in the shape of the depressions. A skin layer of the polymeric composition may extend between the depressions, such that the structured web formed on the forming tool includes a skin layer connecting the structures. The structured web is removed from the forming tool after solidification of the polymeric composition by adhering the structured web to a carrier web using adhesive located between the carrier web and structured web.

Claims

1. A method for forming a composite web in a continuous process, the method comprising:

delivering molten polymeric composition onto an outer surface of a forming tool, wherein the molten polymeric composition enters a plurality of depressions formed into the outer surface, and wherein a skin layer of molten polymeric composition extends between the plurality of depressions over the outer surface of the forming tool;

forming a structured web on the forming tool by solidifying the molten polymeric composition in the skin layer and within the plurality of discrete depressions on the forming tool, wherein the structured web comprises a plurality of structures formed in the shape of the plurality of depressions and a skin layer interconnecting the plurality of structures; and

removing the formed structured web from the forming tool while the structured web is in a relaxed state on the forming tool, wherein the removing comprises adhering the skin layer and the plurality of structures to a first major surface of a carrier web using adhesive exposed on the first major surface of the carrier web;

wherein the carrier web and the structured web adhered thereto form a composite web comprising an indefinite length.

2. A method according to claim 1, wherein a ratio of structure thickness to skin layer thickness is 5:

1or more and wherein the skin layer has a thickness of 10 micrometers or less.

3. A method according to claim 1, wherein the carrier web is under tension when the carrier web is adhered to the structured web.

4. A method according to claim 1, wherein the carrier web is permanently elongated before adhering the structured web to the carrier web.

5. A method according to claim 1, wherein the adhesive is a pressure sensitive adhesive.

6. A method according to claim 1, wherein the adhesive is coextensive with the first major surface of the carrier web.

7. A method according to claim 1, wherein the adhesive is located on only a portion of the first major surface of the carrier web.

8. A method according to claim 1, wherein the first major surface of the carrier web is porous, and wherein the polymeric composition of the structured web does not infiltrate the porous surface.

9. A method according to claim 1, wherein the first major surface of the carrier web is fibrous, and wherein the polymeric composition of the structured web does not encapsulate fibers of the fibrous first major surface.

10. A method according to claim 1, wherein two or more depression of the plurality of depressions on the forming tool comprise a non-uniform depth, and wherein each structure of the plurality of structures comprises a non-uniform thickness corresponding to the non-uniform depth.

11. A method according to claim 1, wherein two or more depressions of the plurality of depressions comprise one or more islands located therein.

12. A method according to claim 1, wherein each structure of the plurality of structures comprises a shaped profile facing away from the first major surface of the carrier web.

13. A method according to claim 1, wherein the plurality of depressions comprises depressions with different shapes, whereby the plurality of structures comprise different shapes.

14. A method according to claim 1, wherein the molten polymeric composition comprises an elastomeric component such that at least portions of the structured web exhibit elastic behavior.

15. A method according to claim 1, wherein the molten polymeric composition comprises an elastomeric component such that at least some structures of the plurality of structures exhibit elastic behavior, and wherein the method further comprises stretching the composite web after adhering the structured web to the first major surface of the carrier web such that the carrier web exhibits permanent elongation after the stretching.

16. A method according to claim 1, wherein delivering the molten polymeric composition onto the outer surface of the forming tool comprises:

delivering a first molten polymeric composition to a first set of depressions of the plurality of depressions, wherein the plurality of structures comprises a first set of structures having a first shape;

delivering a second molten polymeric composition to a second set of depressions of the plurality of depressions, wherein the plurality of structures comprises a second set of structures having a second shape.

17. A method according to claim 16, wherein the first shape and the second shape are different.

18. A method according to claim 16, wherein the first molten polymeric composition and the second molten polymeric composition are different.

19. A method according to claim 1, the method further comprising attaching a coverweb to the composite web, wherein the coverweb faces the first major surface of the carrier web such that the structured web is located between the first major surface of the carrier web and the coverweb.

20. A method according to claim 19, wherein the coverweb is adhesively attached to the composite web.

21. A method according to claim 19, wherein the coverweb is adhesively attached to the composite web using a pressure sensitive adhesive.

22. A method according to claim 19, wherein the molten polymeric composition comprises an elastomeric component such that at least some structures of the plurality of structures of the structured web exhibit elastic behavior, and wherein the method further comprises stretching the composite web and the coverweb after attaching the coverweb to the composite web such that the carrier web and the coverweb exhibit permanent elongation after the stretching.

23. An elastic composite web comprising:

an extensible carrier web;

a structured web adhesively attached to a first major surface of the carrier web by adhesive located between the first major surface of the carrier web and the structured web, the structured web comprising a skin layer interconnecting a plurality of structures;

wherein the structures of the plurality of structures exhibit elastic behavior;

wherein the plurality of structures are in a selected arrangement on the first major surface of the carrier;

and wherein the structured web is in a relaxed state on the first major surface of the carrier web.

24. An elastic composite web according to claim 23, wherein the plurality of structures comprise a thickness of 75 micrometers or more and the skin layer comprises a thickness of 10 micrometers or less.

25. An elastic composite web according to claim 23, wherein a ratio of structure thickness to skin layer thickness is 5:

1 or more and wherein the skin layer thickness is 10 micrometers or less.

26. An elastic composite web according to claim 23, wherein the carrier web comprises a nonwoven web that is permanently elongated before the structured web is adhesively attached to the carrier web.

27. An elastic composite web according to claim 23, wherein the pattern comprises uniform spacing between all of the structures of the plurality of structures.

28. An elastic composite web according to claim 23, wherein the adhesive is a pressure sensitive adhesive.

29. An elastic composite web according to claim 23, wherein the first major surface of the carrier web is porous, and wherein the polymeric composition of the structured web does not infiltrate the porous surface.

30. An elastic composite web according to claim 23, wherein the first major surface of the carrier web is fibrous, and wherein the polymeric composition of the structured web does not encapsulate fibers of the fibrous first major surface.

31. A composite web comprising:

a carrier web;

a structured web adhesively attached to a first major surface of the carrier web by adhesive located between the first major surface of the carrier web and the structured web, the structured web comprising a skin layer interconnecting a plurality of structures;

wherein the plurality of structures comprise a thickness of 1 millimeter or less and the skin layer comprises a thickness of 50 micrometers or less;

wherein the plurality of structures are in a selected arrangement on the first major surface of the carrier;

and wherein the structured web is in a relaxed state on the first major surface of the carrier web.

32. A composite web according to claim 31, wherein a ratio of the structure thickness to the skin layer thickness is 5:

1 or more and wherein the skin layer thickness is 10 micrometers or less.

33. A composite web according to claim 31, wherein the carrier web comprises a nonwoven web that is permanently elongated before the structured web is adhesively attached to the carrier web.

34. A composite web according to claim 31, wherein the adhesive is a pressure sensitive adhesive.

35. A composite web according to claim 31, wherein the first major surface of the carrier web is porous, and wherein the polymeric composition of the structured web does not infiltrate the porous surface.

36. A composite web according to claim 31, wherein the first major surface of the carrier web is fibrous, and wherein the polymeric composition of the structured web does not encapsulate fibers of the fibrous first major surface.