Patent US3620910A successfully refreshed from Google Patents.
US3620910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of groundwood pulp from a dicotyledonous plant
Assignee: US Plywood Champion Papers Inc
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Filing: 1969-06-23
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Granted: 1971-11-16
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Expires: 1989-06-23
Abstract
Abstract There is disclosed a process for the preparation of groundwood or mechanical pulp from a dicot material such as kenaf. The process as applied to kenaf comprises treating chopped kenaf at about atmospheric pressure and ambient temperature with an aqueous solution of alkaline sulfite and sodium carbonate at a pH of from about 10 to 11 for about 1-30 minutes, and thereafter mechanically refining said material to form a pulp.
Inventors
- 👤 Walter P Lawrence
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:45
CPC Classifications
D; D21; D21C; D21C5/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
17 words
The process of claim 1 wherein said solution has a pH of from about 10 to 11.
Claim 2
Dependent Claim
12 words
The process of claim 1 wherein said dicotyledonous plant is chopped kenaf.
Claim 3
Dependent Claim
17 words
The process of claim 3 wherein said chopped kenaf comprises pieces about 1/4 to 5 inches long.
Claim 4
Dependent Claim
40 words
The process of claim 3 wherein said aqueous treating solution comprises from about 1 to 10 percent by weight of Na2CO3 and from about 1 to 10 percent by weight of Na2SO3, based on the dry weight of the kenaf.
Claim 5
Dependent Claim
22 words
The process of claim 5 wherein the pieces of kenaf are soaked in said solution and the treated kenaf is subsequently compressed.
Claim 6
Dependent Claim
19 words
The process of claim 5 wherein said pieces of kenaf are compressed and then are treated with said solution.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |