Modified kraft fibers

• US 20070051481A1
• Filed: 10/18/2006
• Published: 03/08/2007
• Est. Priority Date: 05/24/2005
• Status: Active Grant

• Current Assignee: International Paper Company
• Original Assignee: International Paper Company
• Inventors: Tan, Zheng, Goyal, Gopal, Koukoulas, Alexander
• Granted Patent: US 7,520,958 B2
• Time in Patent Office: Days
• US Class Current: 162/17
• CPC Class Codes: D21C 1/02 with water or steam
• CPC Class Codes: D21C 1/06 with alkaline reacting compounds
• CPC Class Codes: D21C 3/02 with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
• CPC Class Codes: D21C 9/10 Bleaching ; Apparatus therefor
• CPC Class Codes: D21H 11/20 Chemically or biochemically modified fibres

Abstract

A method of producing a modified pulp comprising treating wood chips in an extraction process to remove hemicellose to form treated wood chips; and subjecting said treated wood chips to chemical or semichemical pulping to form a modified Kraft pulp wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 5 to about 10% by dry weight of the modified pulp.

Claims

1. A method of producing a modified pulp comprising:

treating wood chips in an extraction process with steam, a liquid comprising water or a combination thereof to remove hemicellulose to form treated wood chips; and

subjecting said treated wood chips to chemical or semichemical pulping to form a modified Kraft pulp wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 3 to about 15% by oven dried weight of the modified pulp.

2. The method of claim 1 wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 5% to about 10% by oven dried weight of the modified Kraft pulp.

3. The method of claim 2 wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 6% to about 10% by oven dried weight of the modified Kraft pulp.

4. The method of claim 3 wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 6% to about 8% by oven dried weight of the modified Kraft pulp.

5. The method of claim 1 wherein the modified Kraft pulp includes enhanced properties define by higher bulk, higher brightness, better drainage and dewatering or drying or a combination.

6. The method of claim 1 wherein the step of treating wood chips is producing a modified Kraft pulp having at least about 1% by weight less hemicelluloses the same pulp when unmodified.

7. The method of claim 1 wherein the step of treating wood chips is producing a modified Kraft pulp having from about 1% to about 20% less hemicelluloses than the same pulp when unmodified.

8. The method of claim 7 wherein the step of treating wood chips is producing a modified Kraft pulp having from about 1% to about 16% less hemicelluloses than the same pulp when unmodified.

9. The method of claim 1 wherein the step of treating wood chips is producing a modified Kraft pulp having from about 2% to about 8% less hemicelluloses than the same pulp when unmodified.

10. The method of claim 1 the wood chips are treated with an aqueous acidic composition to and end pH of less than 7.

11. The method of claim 10 wherein the end pH is equal to or less than about 6.

12. The method of claim 11 wherein the end pH is equal to or less than about 5.

13. The method of claim 12 wherein the end pH is from about 2 to about 4.

14. The method of claim 12 wherein the modified pulp exhibits water retention about 0.1 g/g less than that of the same or substantially the same unmodified pulp

15. The method of claim 12 wherein the modified pulp exhibits water retention about 0.2 g/g less than that of the same or substantially the same unmodified pulp.

16. The method of claim 12 wherein the modified pulp exhibits water retention of from about 0.2 g/g to about 0.5 g/g less than that of the same or substantially the same unmodified pulp.

17. The method of claim 1 wherein the modified pulp exhibits freeness of at least about 20 CSF units greater than that of the same or substantially same un-modified pulp the increase in greater than that of the un-modified pulp.

18. The method of claim 17 wherein the modified pulp exhibits freeness of at least about 50 CSF units greater than that of the same or substantially same unmodified pulp.

19. The method of claim 17 wherein the modified pulp exhibits freeness of from about 50 to about 200 CSF units greater than that of the same or substantially same unmodified pulp.

20. The method of claim 1 which further comprises bleaching the modified modified chemical or semi-chemical pulp.

21. An absorbent personal hygiene article comprising:

at least one fluid permeable topsheet layer;

at least one fluid impervious backsheet layer coterminous with the topsheet layer; and

at least one absorbent sublayer between the at least one top sheet layer and the at least backsheet layer, the at least one absorbent layer comprising a bleached modified chemical or semi-chemical pulp wherein the amount of hemicellulose contained in the modified pulp is from about 4 to about 16% by dry weight of the same or substantially the same modified pulp.

22. A bleached modified chemical or semi-chemical pulp wherein the amount of hemicellulose contained in the modified pulp is from about 4 to about 16% by dry weight of the same or substantially the same modified pulp.

23. A paper or paperboard comprising a bleached modified chemical or semi-chemical pulp wherein the amount of hemicellulose contained in the modified pulp is from about 4 to about 16% by dry weight of the same or substantially the same modified pulp.

24. A method of producing a modified pulp comprising:

treating Kraft pulp in an extraction process with steam, a liquid comprising water or a combination thereof to remove hemicellulose to form treated wood chips to form a modified Kraft pulp wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 3 to about 15% by oven dried weight of the modified pulp.