US3620909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reclaiming pulp from waste papers
Assignee: Waste Paper Reclamation Corp
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Filing: 1970-05-01
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Granted: 1971-11-16
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Expires: 1990-05-01
Abstract
Abstract The reclamation of purified and reusable pulps from various types of waste papers by first shredding the paper into fine pieces, boiling the shredded paper in a chemical solution containing sodium hydroxide, sodium carbonate, sodium or ammonium phosphate and sodium borate, water washing the chemicals from the cooked paper and then bleaching the pulp with a chemical bleach at elevated temperature.
Inventors
- 👤 C Roy Gleason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:29
CPC Classifications
D; D21; D21C; D21C5/00; D21C5/02; D21C5/025; D21C5/027; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
191 words
In a process for the recovery of pulp from waste paper comprising the steps of reducing the paper into segments of smaller dimension, boiling the paper in a solution containing as essential ingredients an alkali metal hydroxide, an alkali metal carbonate, an alkali metal or ammonium phosphate and an alkali metal borate, in which such chemicals are present in the ratio of 227 + or - 10 percent parts by weight of alkali metal hydroxide, 115 + or - 10 percent parts by weight of alkali metal carbonate, 56 + or - 10 percent parts by weight of the phosphate and 56 + or - 10 percent parts by weight of the sodium borate, with the chemical solids being present in the solution in an amount within the range of 1 part by weight dissolved chemical solids per 5 to 20 parts by weight of paper, separating the chemically treated paper from the solution, washing the paper with water, pulping the washed product, and bleaching the washed pulp with a chemical bleach at a temperature within the range of 100* - 140* F., and then washing the bleached pulp with water.
Claim 2
Dependent Claim
25 words
The process as claimed in claim 1 in which the treatment of the waste paper in the chemical solution is carried out with vigorous agitation.
Claim 3
Dependent Claim
38 words
The process as claimed in claim 2 in which the dissolved chemical solids in the solution are present in the ratio of 1 part by weight chemical solids to 10 + or - 10 percent by weight paper.
Claim 4
Dependent Claim
19 words
The process as claimed in claim 2 in which the separated chemically treated paper is washed with cold water.
Claim 5
Dependent Claim
17 words
The process as claimed in claim 2 in which the bleached pulp is washed with cold water.
Claim 6
Dependent Claim
33 words
The process as claimed in claim 2 in which the paper is boiled in the cooking solution for at least 10 minutes at a temperature within the range of 180* - 212* F.
Claim 7
Dependent Claim
37 words
The process as claimed in claim 2 in which the paper is boiled in the cooking solution for at least 10 minutes at a temperature above 200* F. up to the boiling point temperature for the solution.
Claim 8
Dependent Claim
27 words
The process as claimed in claim 2 in which the alkali metal hydroxide is sodium hydroxide and in which the phosphate is sodium phosphate or ammonium phosphate.
Claim 9
Dependent Claim
26 words
The process as claimed in claim 2 in which the alkali metal carbonate is sodium carbonate and in which the alkali metal borate is sodium borate.
Claim 10
Dependent Claim
65 words
The process as claimed in claim 2 in which the chemicals are present in the boiling solution in an amount per 10 pounds of paper of 227 + or - 10 percent graMs sodium hydroxide, 115 + or -10 percent grams sodium carbonate, 56 + or - 10 percent grams sodium phosphate or ammonium phosphate and 56 + or - 10 percent grams sodium borate.
Claim 11
Dependent Claim
33 words
The process as claimed in claim 2 in which the paper is boiled in the cooking solution in the ratio of 1 gallon of cooking solution per 1/4 to 2 pounds of paper.
Claim 12
Dependent Claim
33 words
The process as claimed in claim 2 in which the paper is boiled in the cooking solution in the ratio of 1 gallon of cooking solution per 1/2 to 1 pound of paper.
Claim 13
Dependent Claim
24 words
The process as claimed in claim 2 in which the boiled and washed paper is pulped with cold water in a Hydropulper or beater.
Claim 14
Dependent Claim
31 words
The process as claimed in claim 2 in which the pulp is bleached under vigorous agitation with a chemical bleach at a temperature within the range of 110* - 140* F.
Claim 15
Dependent Claim
25 words
The process as claimed in claim 15 in which the bleach is carried out for a time within the range of 2 to 5 minutes.
Claim 16
Dependent Claim
15 words
The process as claimed in claim 2 in which the bleach is a chlorine bleach.
Claim 17
Dependent Claim
40 words
The process as claimed in claim 2 in which the materials are employed in the ratio of 0.5 to 2 pounds of chemicals per 20 gallons of solution and 1 pound of chemicals per 5 to 20 pounds of paper.
Claim 18
Dependent Claim
34 words
The process as claimed in claim 2 in which the materials are employed in the ratio of 0.8 to 1.2 pounds of chemicals per 20 gallons of aqueous solution and 10 pounds of paper.
References Cited (Backward Citations)
US1870358A
Cited
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 |