Fabric creped absorbent sheet with variable local basis weight

• US 7,494,563 B2
• Filed: 05/16/2007
• Issued: 02/24/2009
• Est. Priority Date: 10/07/2002
• Status: Expired due to Term

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia-Pacific Consumer Products LP (KOCH Industries Incorporated)
• Inventors: Reeb, Ronald R., Super, Guy H., Chou, Hung Liang, McCullough, Stephen J., Edwards, Steven L., Harper, Frank D., Dwiggins, John H., Yeh, Kang Chang
• Primary Examiner(s): FORTUNA, JOSE A
• Application Number:
  US11/804,246
• Publication Number:
  US 20080029235A1
• Time in Patent Office: 650 Days
• Field of Search: 162/109, 162111-113, 162115-117, 162123-133, 156/183, 264282-283, 428/156, 428/212
• US Class Current: 162/109
• CPC Class Codes: D21F 11/006 Making patterned paper
• CPC Class Codes: D21F 11/14 Making cellulose wadding, filter or blotting paper
• CPC Class Codes: D21F 11/145 including a through-drying process
• CPC Class Codes: D21H 21/20 Wet strength agents
• CPC Class Codes: D21H 25/005 Mechanical treatment D21H25/08, D21H25/18 take precedence
• CPC Class Codes: D21H 27/40 at least one of the sheets being non-planar, e.g. crêped crêping or corrugating paper B31F
• CPC Class Codes: Y10T 428/24455 Paper
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

An absorbent cellulosic sheet having variable local basis weight includes a papermaking-fiber reticulum provided with (i) a plurality of cross-machine direction (CD) extending, fiber-enriched pileated regions of relatively high local basis weight interconnected by (ii) a plurality of elongated densified regions of compressed papermaking fibers. The elongated densified regions have relatively low local basis weight and are generally oriented along the machine direction (MD) of the sheet and have an MD/CD aspect ratio of at least 1.5. The products are most preferably prepared by way of a compactive dewatering/wet crepe process.

Claims

1. An absorbent cellulosic sheet having variable local basis weight comprising a patterned papermaking-fiber reticulum provided with:

(a) a plurality of generally machine direction (MD) oriented elongated densified regions of compressed papermaking fibers having a relatively low local basis weight as well as leading and trailing edges, the densified regions being arranged in a repeating pattern of a plurality of generally parallel linear arrays which are longitudinally staggered with respect to each other such that a plurality of intervening linear arrays are disposed between a pair of CD-aligned densified regions; and

(b) a plurality of fiber-enriched, pileated regions having a relatively high local basis weight interspersed between and connected with the densified regions, the pileated regions having crests extending generally in the cross-machine direction of the sheet;

wherein the generally parallel, longitudinal arrays of densified regions are positioned and configured such that a fiber-enriched region between a pair of CD-aligned densified regions extends in the CD unobstructed by leading or trailing edges of densified regions of at least one intervening linear array thereof, and wherein the sheet has a void volume of equal to or greater than 7 grams/gram and up to 15 grams/gram.

2. The absorbent cellulosic sheet according to claim 1, wherein the generally parallel, longitudinal arrays of densified regions are positioned and configured such that a fiber-enriched region between a pair of CD-aligned densified regions extends in the CD unobstructed by leading or trailing edges of densified regions of at least two intervening linear arrays.

3. The absorbent cellulosic sheet according to claim 1, wherein the generally parallel, longitudinal arrays of densified regions are positioned and configured such that a fiber-enriched region between a pair of CD-aligned densified regions is at least partially truncated in the MD and at least partially bordered in the MD by the leading or trailing edges of densified regions of at least one intervening linear array of the sheet at an MD position intermediate an MD position of the leading and trailing edges of the CD-aligned densified regions.

4. The absorbent cellulosic sheet according to claim 1, wherein the generally parallel, longitudinal arrays of densified regions are positioned and configured such that a fiber-enriched region between a pair of CD-aligned densified regions is at least partially truncated in the MD and at least partially bordered in the MD by the leading or trailing edges of densified regions of at least two intervening linear arrays of the sheet at an MD position intermediate an MD position of the leading and trailing edges of the CD-aligned densified regions.

5. The absorbent cellulosic sheet according to claim 1, wherein the leading and trailing MD edges of the fiber-enriched pileated regions are generally inwardly concave such that a central MD span of the fiber-enriched regions is less than an MD span at the lateral extremities of the fiber-enriched areas.

6. The absorbent cellulosic sheet according to claim 1, wherein the elongated densified regions occupy from about 5% to about 30% of the area of the sheet.

7. The absorbent cellulosic sheet according to claim 1, wherein the elongated densified regions occupy from about 5% to about 25% of the area of the sheet.

8. The absorbent cellulosic sheet according to claim 1, wherein the elongated densified regions occupy from about 7.5% to about 20% of the area of the sheet.

9. The absorbent cellulosic sheet according to claim 1, wherein the fiber-enriched pileated regions occupy from about 95% to about 50% of the area of the sheet.

10. The absorbent cellulosic sheet according to claim 1, wherein the fiber-enriched pileated regions occupy from about 90% to about 60% of the area of the sheet.

11. The absorbent sheet according to claim 1, wherein the linear arrays of densified regions have an MD repeat frequency of from about 50 meter⁻

1 to about 200 meter<sup>−

1</sup>.

12. The absorbent sheet according to claim 11, wherein the linear arrays of densified regions have an MD repeat frequency of from about 75 meter⁻

1 to about 175 meter<sup>−

1</sup>.

13. The absorbent sheet according to claim 11, wherein the linear arrays of densified regions have an MD repeat frequency of from about 90 meter⁻

1 to about 125 meter<sup>−

1</sup>.

14. The absorbent sheet according to claim 1, wherein the densified regions of the linear arrays thereof have a CD repeat frequency of from about 100 meter⁻

1 to about 500 meter<sup>−

1</sup>.

15. The absorbent sheet according to claim 1, wherein the densified regions of the linear arrays thereof have a CD repeat frequency of from about 150 meter⁻

1 to about 300 meter<sup>−

1</sup>.

16. The absorbent sheet according to claim 1, wherein the densified regions of the linear arrays thereof have a CD repeat frequency of from about 175 meter⁻

1 to about 250 meter<sup>−

1</sup>.

17. The absorbent cellulosic sheet according to claim 1, wherein the MD/CD aspect ratios of the densified regions are greater than 2.

18. The absorbent cellulosic sheet according to claim 1, wherein the MD/CD aspect ratios of the densified regions are greater than 3.

19. The absorbent cellulosic sheet according to claim 1, wherein the MD/CD aspect ratios of the densified regions are between about 2 and 10.

20. The absorbent cellulosic sheet according to claim 1, wherein the fiber-enriched pileated regions have fiber orientation bias along the CD of the sheet.

21. The absorbent cellulosic sheet according to claim 1, wherein the densified regions of relatively low basis weight extending in the machine direction have fiber orientation bias along the CD of the sheet.

22. The absorbent cellulosic sheet according to claim 1, wherein the elongated densified regions are substantially identical.

23. The absorbent cellulosic sheet according to claim 1, wherein the sheet has a basis weight of from 8 lbs per 3000 square-foot ream to 35 lbs per 3000 square-foot ream.

24. The absorbent cellulosic sheet according to claim 23, wherein the sheet has a void volume of equal to or greater than 8 grams/gram and up to 12 grams/gram.

25. The absorbent cellulosic sheet according to claim 1, wherein the sheet has a basis weight of from 20 lbs per 3000 square-foot ream to 35 lbs per 3000 square-foot ream.

26. The absorbent cellulosic sheet according to claim 25, wherein the sheet has a void volume of equal to or greater than 7 grams/gram and up to 15 grams/gram.

27. The absorbent cellulosic sheet according to claim 25, wherein the sheet has a void volume of equal to or greater than 8 grams/gram and up to 12 grams/gram.

28. The absorbent cellulosic sheet according to claim 1, having a CD stretch of greater than 5%, up to about 10%.

29. The absorbent cellulosic sheet according to claim 28, having a CD stretch of greater than 6%.

30. The absorbent cellulosic sheet according to claim 28, having a CD stretch of greater than 7%.

31. The absorbent cellulosic sheet according to claim 28, having a CD stretch of greater than 8%.

32. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is at least about 10% by weight recycle fiber.

33. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is at least about 25% by weight recycle fiber.

34. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is at least about 35% by weight recycle fiber.

35. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is at least about 45% by weight recycle fiber.

36. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is 50% or more by weight recycle fiber.

37. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is 75% or more by weight recycle fiber.

38. The absorbent cellulosic sheet according to claim 1, wherein the papermaking fiber is 100% by weight recycle fiber.