Claims
- 1. Pulp produced by the process comprising the steps of:
- a. providing hardwood chips having dimensions of from about 0.6 to about 2.5 centimeter;
- b. introducing said chips into a digester;
- c. removing substantially all the free oxygen from said chips;
- d. providing a cooking liquor comprising from about 0.4% to about 3% by weight ammonia and from about 9% to about 14% by weight sulfur dioxide;
- e. reacting the lignin in said chips by maintaining the temperature within said digester at less than about 110.degree. C. to form lignin products, wherein said chips are reacted under substantially oxygen-free conditions and substantially all of said chips are immersed in said cooking liquor;
- f. increasing the temperature within said digester to from about 140.degree. C. to about 155.degree. C. at a rate of from about 0.75.degree. C. per minute to about 3.degree. C. per minute under substantially oxygen-free conditions;
- g. hydrolyzing said lignin reaction products at a temperature of from about 140.degree. C. to 155.degree. C. at a pH of from about 2 to about 3; and
- h. decreasing rapidly the temperature within said digester;
- wherein said pulp subsequent to Step h comprises hardwood cellulosic fibers and has a xylan content of between about 6% and about 8% by weight on a dry pulp basis, a xylan to mannan weight ratio of between about 2.5 and about 3.7 and a glucan content of between about 80% and about 92% by weight on a dry pulp weight basis.
- 2. The pulp described in claim 1, wherein said hydrolyzing continues for from about 30 minutes to about 80 minutes.
- 3. The pulp described in claim 2, wherein said hydrolyzing is accompanied by a side relief operation and said decreasing of temperature is accomplished by reducing the pressure on said chips to essentially atmospheric pressure in less than about 50 minutes.
- 4. A tissue paper web made from the pulp of claim 3.
- 5. A tissue paper web made from the pulp of claim 2.
- 6. The pulp described in claim 1, wherein said decreasing of temperature is accomplished by reducing the pressure on said chips to essentially atmospheric pressure in less than about 50 minutes.
- 7. A tissue paper web made from the pulp of claim 6.
- 8. A tissue paper web made from the pulp of claim 1.
- 9. The pulp described in claim 1, wherein said xylan content is between about 6.5% and about 7.5%.
- 10. A tissue paper web made from the pulp of claim 9.
- 11. The pulp described in claim 9, wherein said xylan content is between about 7.0% and 7.5%.
- 12. A tissue paper web made from the pulp of claim 11.
- 13. Pulp from hardwood fiber sources having a high tactile sense of softness, said pulp comprising hardwood cellulosic fibers having between about 6% and about 8% xylan by weight on a dry pulp basis, between about 80% and about 92% glucan by weight on a dry pulp basis, and an amount of mannan such that a weight ratio of xylan to mannan is between about 2.5 and about 3.7.
- 14. Pulp as described in claim 13, wherein said pulp comprises between about 6.5% and about 7.5% xylan.
- 15. Pulp as described in claim 14, wherein said pulp comprises between about 7.0% and about 7.5% xylan.
- 16. A tissue paper web made from the pulp of claim 15.
- 17. A tissue paper web made from the pulp of claim 14.
- 18. A tissue paper web made from the pulp of claim 13.
Parent Case Info
CROSS-REFERENCES TO PRIOR APPLICATIONS
This is a divisional of Application Ser. No. 766,063 filed Aug. 14, 1985 (now U.S. Pat. No. 4,634,499) which is a continuation-in-part of Application Serial No. 490,926, filed May 2, 1983 (now abandoned).
US Referenced Citations (5)
Non-Patent Literature Citations (2)
Entry |
Bulko; Abstract ABIPC, vol. 45, No. 6, Dec., 1974, #5925(u), p. 606. |
Parfinova; Abstract ABIPC, vol. 41, No. 6, Dec. 1970, #5374, p. 522. |
Divisions (1)
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Number |
Date |
Country |
Parent |
766063 |
Aug 1985 |
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Continuation in Parts (1)
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Number |
Date |
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490926 |
May 1983 |
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