US3932209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low hemicellulose, dry crosslinked cellulosic absorbent materials
Assignee: Personal Products Co
•
Filing: 1971-08-09
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Granted: 1976-01-13
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Expires: 1991-08-09
Abstract
Abstract Dry crosslinked, fibrous cellulosic absorbent material having low hemicellulose content and low knot content, the fibers being internally crosslinked for the major part and being relatively free of intercrosslinking with adjacent fibers.
Inventors
- 👤 Pronoy Kumar Chatterjee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:10
CPC Classifications
C; C08; C08B; C08B15/00; C08B15/10; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
A method of making pulpboard for grinding into pulp fluff of improved dry and wet resilience and increased fluid absorption and retention capacity from cellulose fibers having a high hemicellulose content comprising: treating said cellulose fibers to reduce said hemicellulose content to no more than about 7%; forming a pulpboard from said treated cellulosic fibers; and dry crosslinking said fibers in said pulpboard form to result in a pulpboard having a knot content of less than 15%.
Claim 2
Independent Claim
77 words
A method of making pulpboard for grinding into pulp fluff of improved dry and wet resilience and increased fluid absorption and retention capacity from cellulose fibers having a high hemicellulose content comprising: treating said cellulose fibers to reduce said hemicellulose content to no more than about 7%; forming a pulpboard from said treated cellulosic fibers; and dry crosslinking said fibers in said pulpboard form to result in a pulpboard having a knot content of less than 15%.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein said cellulosic fibers are treated by extracting said hemicellulose with an aqueous solution of from about 5 percent to about 12 percent caustic at a temperature of from about 15° to about 35°C.
Claim 4
Dependent Claim
44 words
The method of claim 1 wherein said dry crosslinking is accomplished by introducing said pulpboard to an aqueous bath comprising crosslinking agent and catalyst, driving off the water in a heating step and reacting said crosslinking agent with said cellulose in a curing step.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-12 | 1979-07-14 | 1980-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-12 | 1983-07-14 | 1984-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-12 | 1987-07-14 | 1988-01-13 | $7700.00 | Window Closed / Lapsed |