Fabric creped absorbent sheet with variable local basis weight
View Patent ↗An absorbent cellulosic sheet having a variable local basis weight. The sheet includes a papermaking-fiber reticulum having (a) a plurality of fiber-enriched pileated regions of a relatively high local basis weight each extending a distance in the cross-machine direction (CD) of the sheet, and (b) a plurality of elongated densified regions of compressed papermaking fibers that interconnect the plurality of fiber-enriched pileated regions. The elongated densified regions (i) have a relatively low local basis weight and each extend a distance in the machine direction (MD) of the sheet, (ii) are arranged in a repeating pattern having leading and trailing edges, such that the elongated densified regions are longitudinally staggered with respect to each other, and (iii) have MD/CD aspect ratios of at least 1.5.
1. An absorbent cellulosic sheet having a variable local basis weight, the sheet comprising:
a papermaking-fiber reticulum having:
(a) a plurality of fiber-enriched pileated regions of a relatively high local basis weight each extending a distance in the cross-machine direction (CD) of the sheet; and
(b) a plurality of elongated densified regions of compressed papermaking fibers that interconnect the plurality of fiber-enriched pileated regions, the elongated densified regions (i) having a relatively low local basis weight and each extending a distance in the machine direction (MD) of the sheet, (ii) being arranged in a repeating pattern having leading and trailing edges, such that the elongated densified regions are longitudinally staggered with respect to each other, and (iii) having MD/CD aspect ratios of at least 1.5.
2. The absorbent cellulosic sheet according to claim 1 , wherein the MD/CD aspect ratios of the densified regions are greater than 2.
3. The absorbent cellulosic sheet according to claim 1 , wherein the MD/CD aspect ratios of the densified regions are greater than 3.
4. The absorbent cellulosic sheet according to claim 1 , wherein the MD/CD aspect ratios of the densified regions are between about 2 and 10.
5. The absorbent cellulosic sheet according to claim 1 , wherein the fiber-enriched pileated regions have a fiber orientation bias along the CD of the sheet.
6. The absorbent cellulosic sheet according to claim 1 , wherein the elongated densified regions have a fiber orientation bias along the CD of the sheet.
7. The absorbent cellulosic sheet according to claim 1 , wherein the elongated densified regions are substantially identical.
8. The absorbent cellulosic sheet according to claim 1 , wherein the fiber-enriched pileated regions are bordered at lateral extremities in the CD by a CD-spaced pair of CD-aligned densified regions.
9. The absorbent cellulosic sheet according to claim 8 , wherein the fiber-enriched regions are at least partially bordered in the MD by the leading and trailing edges of an MD-staggered pair of densified regions.
10. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a basis weight in a range of 8 lbs per 3000 square-foot ream to 35 lbs per 3000 square-foot ream and a void volume greater than 7 grams/gram.
11. The absorbent cellulosic sheet according to claim 10 , wherein the sheet has a void volume of at least 7 grams/gram and up to 15 grams/gram.
12. The absorbent cellulosic sheet according to claim 10 , wherein the sheet has a void volume of at least 8 grams/gram and up to 12 grams/gram.
13. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a basis weight in a range of 20 lbs per 3000 square-foot ream to 35 lbs per 3000 square-foot ream and a void volume greater than 7 grams/gram.
14. The absorbent cellulosic sheet according to claim 13 , wherein the sheet has a void volume of at least 7 grams/gram and up to 15 grams/gram.
15. The absorbent cellulosic sheet according to claim 13 , wherein the sheet has a void volume of at least 8 grams/gram and up to 12 grams/gram.
16. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a CD stretch of greater than 5%, and up to about 10%.
17. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a CD stretch of greater than 6%.
18. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a CD stretch of greater than 7%.
19. The absorbent cellulosic sheet according to claim 1 , wherein the sheet has a CD stretch of greater than 8%.
20. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least about 10% by weight recycle fiber.
21. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least about 25% by weight recycle fiber.
22. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least about 35% by weight recycle fiber.
23. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least about 45% by weight recycle fiber.
24. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least 50% by weight recycle fiber.
25. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is at least 75% by weight recycle fiber.
26. The absorbent cellulosic sheet according to claim 1 , wherein the sheet comprises papermaking fiber that is 100% by weight recycle fiber.
27. The absorbent cellulosic sheet according to claim 1 , wherein the sheet is in the form of a tissue base sheet that has a bulk of at least 5 ((mils/8 plies)/(lb/ream)) and comprises papermaking fiber that is predominantly hardwood fiber.
28. The absorbent cellulosic sheet according to claim 27 , wherein the tissue base sheet has a bulk of at least 6 ((mils/8 plies)/(lb/ream)).
29. The absorbent cellulosic sheet according to claim 27 , wherein the tissue base sheet has a bulk of at least 5 and up to about 8 ((mils/8 plies)/(lb/ream)).
30. The absorbent cellulosic sheet according to claim 27 , wherein the tissue base sheet is incorporated into a two-ply tissue product.
31. The absorbent cellulosic sheet according to claim 1 , wherein the sheet is in the form of a tissue base sheet that has a normalized geometric mean (GM) tensile strength of greater than 21 ((g/3″)/(lbs/ream)) and a bulk of at least 5 ((mils/8 plies)/(lb/ream)) and up to about 10 ((mils/8 plies)/(lb/ream)), and comprises papermaking fiber that is predominantly hardwood fiber.
32. The absorbent cellulosic sheet according to claim 31 , wherein the tissue base sheet has a normalized GM tensile strength of greater than 21 ((g/3″)/(lbs/ream)) and up to about 30 ((g/3″)/(lbs/ream)).
33. The absorbent cellulosic sheet according to claim 32 , wherein the tissue base sheet has a normalized GM tensile strength of 25 ((g/3″)/(lbs/ream)) or greater.
34. The absorbent cellulosic sheet according to claim 31 , wherein the tissue base sheet is incorporated into a two-ply tissue product.
35. The absorbent cellulosic sheet according to claim 1 , wherein the sheet is in the form of a towel base sheet incorporating mechanical pulp and papermaking fiber, wherein at least 40% by weight of the papermaking fiber is softwood fiber.
36. The absorbent cellulosic sheet according to claim 1 , wherein the sheet is in the form of a towel base sheet comprising papermaking fiber, wherein at least 40% by weight of the papermaking fiber is softwood fiber and at least 20% by weight of the papermaking fiber is recycle fiber.
37. The absorbent cellulosic sheet according to claim 36 , wherein at least 30% by weight of the papermaking fiber is recycle fiber.
38. The absorbent cellulosic sheet according to claim 36 , wherein at least 40% by weight of the papermaking fiber is recycle fiber.
39. The absorbent cellulosic sheet according to claim 36 , wherein at least 50% by weight of the papermaking fiber is recycle fiber.
40. The absorbent cellulosic sheet according to claim 36 , wherein at least 75% by weight of the papermaking fiber is recycle fiber.
41. The absorbent cellulosic sheet according to claim 36 , wherein 100% by weight of the papermaking fiber is recycle fiber.
42. The absorbent cellulosic sheet according to claim 36 , wherein the towel base sheet has a basis weight in the range of 12 to 22 lbs per 3000 square-foot ream and an 8-sheet caliper of greater than 90 mils, and up to about 120 mils.
43. The absorbent cellulosic sheet according to claim 36 , wherein the towel base sheet is converted into a towel with a CD stretch of at least about 6%.
44. The absorbent cellulosic sheet according to claim 43 , wherein the towel has a CD stretch in the range of from 6% to 10%.
45. The absorbent cellulosic sheet according to claim 44 , wherein the towel has a CD stretch of at least 7%.
46. The absorbent cellulosic sheet according to claim 1 , wherein the sheet is in the form of a towel base sheet that has an MD bending length from about 3.5 cm to about 5 cm and comprises papermaking fiber, wherein at least 40% by weight of the papermaking fiber is softwood fiber and at least 20% by weight of the papermaking fiber is recycle fiber.
47. The absorbent cellulosic sheet according to claim 46 , wherein the MD bending length of the towel base sheet is from about 3.75 cm to about 4.5 cm.
48. The absorbent cellulosic sheet according to claim 46 , wherein at least 30% by weight of the papermaking fiber is recycle fiber.
49. The absorbent cellulosic sheet according to claim 46 , wherein at least 40% by weight of the papermaking fiber is recycle fiber.
50. The absorbent cellulosic sheet according to claim 46 , wherein at least 50% by weight of the papermaking fiber is recycle fiber.
51. The absorbent cellulosic sheet according to claim 46 , wherein at least 75% by weight of the papermaking fiber is recycle fiber.
52. The absorbent cellulosic sheet according to claim 46 , wherein 100% by weight of the papermaking fiber is recycle fiber.
53. The absorbent cellulosic sheet according to claim 46 , wherein the towel base sheet has a bulk of greater than 2.5 ((mils/8 plies)/(lb/ream)).
54. The absorbent cellulosic sheet according to claim 46 , wherein the towel base sheet has a bulk of greater than 2.5 ((mils/8 plies)/(lb/ream)) up to about 3 ((mils/8 plies)/(lb/ream)).
55. The absorbent cellulosic sheet according to claim 54 , wherein the towel base sheet has a bulk of at least 2.75 ((mils/8 plies)/(lb/ream)).