Moist Crepe Process

• US 20110146924A1
• Filed: 12/07/2010
• Published: 06/23/2011
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia-Pacific Consumer Products LP (KOCH Industries Incorporated)
• Inventors: Chou, Hung Liang, Hunter, Mark S., Peters, Christopher J., Geddes, Daniel J., Yeh, Kang Chang
• Granted Patent: US 8,398,819 B2
• Time in Patent Office: Days
• US Class Current: 162/111
• 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: D21H 17/36 Polyalkenyalcohols; Polyalkenylethers; Polyalkenylesters
• CPC Class Codes: D21H 17/55 Polyamides; Polyaminoamides; Polyester-amides
• CPC Class Codes: D21H 21/146 Crêping adhesives

Abstract

The present invention relates to the creation of toweling with surprisingly high absorbency using a furnish comprising a major proportion of recycle furnish when the furnish is creped from a Yankee dryer coated with a creping adhesive comprising polyvinyl alcohol and an epichlorohydrin crosslinked polyamide creping adhesive at a consistency corresponding to a sheet temperature (immediately prior to the creping blade) of between 225° F. and 255° F. (107° C. and 124° C.), preferably ranging from about 230° F. (110° C.) up to about 250° F. (121° C.).

Claims

1. A method of moist creping absorbent paper base sheet comprising the steps of:

a. forming a nascent web comprising at least a major portion, on a length-weighted basis, of flattened ribbonlike cellulosic fibers;

b. applying a creping adhesive coating comprising an admixture of polyvinyl alcohol and a polyamide crosslinked with epichlorohydrin to a Yankee dryer;

c. passing the nascent web through a nip defined between a suction pressure roll and said Yankee dryer;

d. adhering the nascent web to said Yankee dryer with a controlled loading between said suction pressure roll and said Yankee dryer;

e. drying the nascent web on said Yankee dryer to a moisture content corresponding to a sheet temperature (immediately prior to the creping blade) of from about 110°

C. to about 121°

C.;

f. creping the nascent web at a sheet temperature of from about 110°

C. to about 121°

C. from said Yankee dryer with an undulatory creping blade bearing against said Yankee dryer to form a moist biaxially undulatory web, the contact area between said undulatory creping blade and said Yankee dryer defining an undulatory ribbon shape across the width of said Yankee dryer;

g. thereafter drying said moist biaxially undulatory web.

2. The moist creping method of claim 1 wherein the steam pressure within said Yankee dryer, the dryer hood parameters, the Yankee dryer speed, creping adhesive composition and the pressure with which the suction pressure roll bears against the Yankee dryer are controlled such that:

the basis weight of the dry biaxially undulatory web is between about 24 and 30 lbs/3000 ft²;

the caliper of the web exceeds 48 mils per 8 sheets; and

, in the case where the furnish comprises primarily unbleached fibers, the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.2 g/g and the WAR is less than 50 seconds, while in the case that the sheet comprises primarily bleached fibers, the SAT absorbency of the biaxially undulatory base sheet is at least 2.0 g/g and the WAR is less than 55 seconds.

3. The moist creping method of claim 2 wherein the geometric mean breaking length of the resulting web is no more than 1300 m.

4. The moist creping method of claim 3 wherein the MD bending length of the resulting web is at least 3.0 cm and the geometric mean breaking length of the resulting web is from about 900 m to about 1300 m.

5. The moist creping method of claim 4 wherein:

the basis weight of the dry biaxially undulatory web is between 24 and 30 lbs/3000 ft²;

the caliper of the web exceeds 50 mils per 8 sheets;

the geometric mean breaking length of the resulting web is no more than 1250 m;

in the case where the furnish comprises primarily unbleached fibers, the specific SAT absorbency of the biaxially undulatory basesheet is at least 2.4 g/g; and

the WAR is less than 45 seconds while in the case that the furnish comprises primarily bleached fibers, the specific SAT is at least 2.2 g/g and the WAR is less than 50 seconds.

6. The moist creping method of claim 5 wherein the CD wet tensile measured by the Finch cup method is at least 650 g/3″

.

7. A method of moist creping absorbent paper base sheet comprising the steps of:

a. forming a nascent web comprising at least a major portion on a length-weighted basis of flattened ribbonlike cellulosic fibers;

b. applying a creping adhesive coating comprising an admixture of polyvinyl alcohol and a polyamide crosslinked with epichlorohydrin to a Yankee dryer;

c. passing the nascent web through a nip defined between a suction pressure roll and said Yankee dryer;

d. adhering the nascent web to said Yankee dryer with a pressure controlled by controlling the loading between said suction pressure roll and said Yankee dryer;

e. drying the nascent web on said Yankee dryer to a moisture content corresponding to a sheet temperature (immediately prior to the creping blade) of from about 110°

C. to about 121°

C.;

f. creping the nascent web at a sheet temperature of from about 110°

C. to about 121°

C. from said Yankee dryer with a creping blade bearing against said Yankee dryer to form a moist web;

g. thereafter drying said moist web.

8. The moist creping method of claim 7 wherein the steam pressure within said Yankee dryer, the dryer hood parameters, the Yankee dryer speed, creping adhesive composition and the pressure with which the suction pressure roll bears against the Yankee dryer are controlled such that:

the basis weight of the dry web is less than 30 lbs/3000 ft²;

the caliper of the web exceeds 48 mils per 8 sheets;

the WAR is less than 50 seconds and the geometric mean breaking length of the dried web is from about 900 m to about 1300 m and the specific SAT absorbency of the dry web is at least 2.45 g/g in the case of where the web comprises primarily unbleached fibers and 2.25 g/m²; and

at least about 2.25 g/g in the case where the web comprises primarily bleached fibers.

9. The moist creping method of claim 8 wherein the MD bending length of the resulting web is at least 3.0 cm and the geometric mean breaking length of the dried web is from about 1050 m to about 1250 m.

10. The moist creping method of claim 7 wherein:

the basis weight of the dry biaxially undulatory web is between 24 and 29 lbs/3000 ft²;

the caliper of the web exceeds 50 mils per 8 sheets;

geometric mean breaking length of the resulting web is no more than 1250 m;

the WAR is less than 45 seconds; and

the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.5 g/g in the case where the web comprises primarily unbleached fibers and is at least 2.3 g/g in the case where the web comprises primarily bleached fibers.

11. The moist creping method of claim 10 wherein the CD wet tensile measured by the Finch cup method is at least 650 g/3″

.

12. The moist creping method of claim 7 wherein the web comprises at least about 75% on a length-weighted basis of flattened ribbonlike fibers.

13. The moist creping method of claim 7 wherein the web comprises at least about 90% on a length-weighted basis of flattened ribbonlike fibers.

14. A method of moist creping absorbent paper base sheet comprising the steps of:

a. forming a nascent web comprising at least a major portion of recycled cellulosic fibers;

b. applying a creping adhesive coating comprising an admixture of polyvinyl alcohol and a polyamide crosslinked with epichlorohydrin to a Yankee dryer;

c. passing the nascent web through a nip defined between a suction pressure roll and said Yankee dryer;

d. adhering the nascent web to said Yankee dryer with a pressure controlled by controlling the loading between said suction pressure roll and said Yankee dryer;

e. drying the nascent web on said Yankee dryer to a moisture content corresponding to a sheet temperature, as measured just prior to the creping blade, of from about 110°

C. to about 121°

C.;

f. creping the nascent web at a sheet temperature of from about 110°

C. to about 121°

C. from said Yankee dryer with an undulatory creping blade bearing against said Yankee dryer to form a moist biaxially undulatory web, the contact area between said undulatory creping blade and said Yankee dryer defining an undulatory ribbon shape across the width of said Yankee dryer;

g. thereafter drying said moist biaxially undulatory web to form a dried web having a geometric mean breaking length of between about 900 m and 1350 m.

15. The moist creping method of claim 14 wherein the steam pressure within said Yankee dryer, the dryer hood parameters, the Yankee dryer speed, creping adhesive composition and the pressure with which the suction pressure roll bears against the Yankee dryer are controlled such that:

the basis weight of the dry biaxially undulatory web is less than 30 lbs/3000 ft²;

the caliper of the web exceeds 48 mils per 8 sheets;

the WAR is less than 50 seconds; and

the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.25 g/g in the case where the web comprises primarily unbleached fibers, and 2.05 g/g in the case where the web comprises primarily bleached fibers.

16. The moist creping method of claim 14 wherein the geometric mean breaking length of the resulting web is from about 900 m to about 1300 m.

17. The moist creping method of claim 16 wherein the MD bending length of the resulting web is at least 3 cm and wherein the geometric mean breaking length of the resulting web is from about 1050 m to about 1250 m.

18. The moist creping method of claim 14 wherein:

the basis weight of the dry biaxially undulatory web is between 24 and 30 lbs/3000 ft²;

the caliper of the web exceeds 50 mils per 8 sheets;

the geometric mean breaking length of the resulting web is no more than 1250 m;

the WAR is less than 45 seconds; and

the SAT absorbency of the biaxially undulatory base sheet is at least 2.35 g/g in the case where the biaxially undulatory web comprises primarily unbleached fibers and at least about 2.15 g/g in the case where the biaxially undulatory web comprises primarily bleached fibers.

19. The moist creping method of claim 18 wherein the CD wet tensile measured by the Finch cup method is at least 650 g/3″

.

20. The moist creping method of claim 19 wherein the web comprises at least about 1.5% ash by weight and at least about 10% non-hardwood fibers having an average fiber length of less than about 0.2 mm on a weight weighted basis.

21. A method of moist creping absorbent paper base sheet comprising the steps of:

a. forming a nascent web comprising at least a major portion of recycled cellulosic fibers;

b. applying a creping adhesive coating comprising an admixture of polyvinyl alcohol and a polyamide crosslinked with epichlorohydrin to a Yankee dryer;

c. passing the nascent web through a nip defined between a suction pressure roll and said Yankee dryer;

d. adhering the nascent web to said Yankee dryer with a controlled loading between said suction pressure roll and said Yankee dryer;

e. drying the nascent web on said Yankee dryer to a moisture content corresponding to a sheet temperature, as measured just prior to the creping blade, of from about 107°

C. to about 124°

C.;

f. creping the nascent web at a sheet temperature of from about 107°

C. to about 124°

C. from said Yankee dryer with an undulatory creping blade bearing against said Yankee dryer to form a moist web;

g. thereafter drying said moist web; and

h. recovering a web comprising at least about 1.5% ash by weight and at least about 10% non-hardwood fibers having an average fiber length of less than about 0.2 mm on a weight weighted basis, wherein the recovered web has a geometric mean breaking length between 900 m and 1350 m;

the WAR of the biaxially undulatory base sheet is less than 50 seconds and the SAT absorbency is at least 2.3 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.1 g/g in the case where the web comprises primarily bleached fibers.

22. The moist creping method of claim 21 wherein the steam pressure within said Yankee dryer, the dryer hood parameters, the Yankee dryer speed, creping adhesive composition and the pressure with which the suction pressure roll bears against the Yankee dryer are controlled such that:

the basis weight of the dry web is less than 30 lbs/3000 ft²;

the caliper of the web exceeds 48 mils per 8 sheets;

the WAR is less than 50 seconds; and

the specific SAT absorbency of the dry web is at least 2.45 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.15 g/g in the case where the web comprises primarily bleached fiber.

23. The moist creping method of claim 22 wherein the MD bending length of the resulting web is at least 3.0 cm and wherein the geometric mean breaking length of the resulting web is from about 1050 m to about 1250 m.

24. The moist creping method of claim 23 wherein:

the basis weight of the dry biaxially undulatory web is between 26 and 30 lbs/3000 ft²;

the caliper of the web exceeds 50 mils per 8 sheets;

the WAR is less than 45 seconds;

the geometric mean breaking length of the resulting web is no more than 1250 m; and

the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.45 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.25 g/g in the case where the web comprises primarily bleached fiber.

25. The moist creping method of claim 24 wherein the CD wet tensile measured by the Finch cup method is at least 800 g/3″

.

26. The moist creping method of claim 25 wherein the web comprises at least about 1.5% ash by weight and at least about 10% non-hardwood fibers having a fiber length of less than about 0.2 mm as determined on a length-weighted basis.

27. A method of moist creping absorbent paper base sheet comprising the steps of:

a. forming a nascent web comprising at least a major portion of recycled cellulosic fibers;

b. applying a creping adhesive coating to a Yankee dryer;

c. passing the nascent web through a nip defined between a suction pressure roll and said Yankee dryer;

d. adhering the nascent web to said Yankee dryer with a pressure controlled by controlling the loading between said suction pressure roll and said Yankee dryer;

e. drying the nascent web on said Yankee dryer to a moisture content corresponding to a sheet temperature, as measured just prior to the creping blade, of from about 107°

C. to about 124°

C.;

f. creping the nascent web at a sheet temperature, of from about 110°

C. to about 121°

C. from said Yankee dryer with an undulatory creping blade bearing against said Yankee dryer to form a moist biaxially undulatory web, the contact area between said undulatory creping blade and said Yankee dryer defining an undulatory ribbon shape across the width of said Yankee dryer;

g. thereafter drying said moist biaxially undulatory web; and

h. recovering a web comprising at least about 3% ash by weight and at least about 10% non-hardwood fibers having an average fiber length of less than about 0.2 mm on a weight weighted basis, wherein the geometric mean breaking length of the web is between 900 and 1350 m,; and

the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.55 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.35 g/g in the case where the web comprises primarily bleached fibers.

28. The moist creping method of claim 27 wherein the steam pressure within said Yankee dryer, the dryer hood parameters, the Yankee dryer speed, creping adhesive composition and the pressure with which the suction pressure roll bears against the Yankee dryer are controlled such that:

the basis weight of the dry biaxially undulatory web is less than 30 lbs/3000 ft²;

the caliper of the web exceeds 48 mils per 8 sheets;

the geometric mean breaking length of the resulting web is from about 1000 m to about 1300 m;

the WAR of the biaxially undulatory base sheet is less than 50 seconds; and

the specific SAT absorbency is at 2.6 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.4 g/g in the case where the web comprises primarily bleached fibers.

29. The moist creping method of claim 28 wherein the MD bending length of the resulting web is at least 3.0 cm and wherein the geometric mean breaking length of the resulting web is from about 1050 m to about 1250 m.

30. The moist creping method of claim 29 wherein:

the basis weight of the dry biaxially undulatory web is between 24 and 30 lbs/3000 ft²;

the caliper of the web exceeds 50 mils per 8 sheets;

the geometric mean breaking length of the resulting web is no more than 1250 m;

the WAR is less than 45 seconds and;

the specific SAT absorbency of the biaxially undulatory base sheet is at least 2.6 g/g in the case where the web comprises primarily unbleached fibers and at least about 2.4 g/g in the case where the web comprises primarily bleached fibers.