US4028452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Additives to improve wettability of synthetic paper pulp
Assignee: Sun Ventures Inc
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Filing: 1974-09-25
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Granted: 1977-06-07
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Expires: 1994-09-25
Abstract
Abstract Synthetic paper pulp is prepared by extruding a foam sheet of a synthetic thermoplastic fiber forming resin, which resin contains from 0.1 to 5.0 wt. % and preferably from 1 to 2 wt. % of a soap such as aluminum stearate, attenuating the foam sheet as it is extruded and applying either heat or a shearing action to the attenuated sheet to cause it to break down into short fibers containing numerous fibrils. This pulp is then either used directly or blended with natural pulp, wet laid to form a coarse paper and then formed into a final paper product by application of heat and pressure. The soap serves to improve the wettability of the resulting fibers.
Inventors
- 👤 Gary L. Driscoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:40
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/42; D21; D21H; D21H13/00; D21H13/10; D21H17/00; D21H17/63; D21H17/66; D21H5/00; D21H5/12; D21H5/1254; D21H5/20; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/08; Y10S264/47
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
176 words
A process for producing a synthetic thermoplastic resin pulp comprising: a. dry blending pellets or powder synthetic thermoplastic resin with 0.1 to 5.0 percent by weight of a solid soap of a metal salt of a fatty acid containing from 7 to 24 carbon atoms and wherein the metal is lithium, sodium, calcium or aluminum; b. blending a blowing agent in the amount of from 0.1 to 20 weight percent of the resin being extruded into a blend of resin, soap, and agent to form a foamable melt; c. melting the resulting foamable melt blend of the resin, the soap and the agent; d. extruding the foamable melt blend into an area of reduced pressure through a heated die which lips are set from 5 to 100 mls apart; e. immediately attenuating the molten extruded foamed sheet with attenuation at a rate of from 1.5 to 10 times the rate linear at which the melt is extruded to induce formation of fibrils; and f. breaking down said attenuated foamed sheet into short fibers containing numerous fibrils.
Claim 2
Dependent Claim
176 words
A process for producing a synthetic thermoplastic resin pulp comprising: a. dry blending pellets or powder synthetic thermoplastic resin with 0.1 to 5.0 percent by weight of a solid soap of a metal salt of a fatty acid containing from 7 to 24 carbon atoms and wherein the metal is lithium, sodium, calcium or aluminum; b. blending a blowing agent in the amount of from 0.1 to 20 weight percent of the resin being extruded into a blend of resin, soap, and agent to form a foamable melt; c. melting the resulting foamable melt blend of the resin, the soap and the agent; d. extruding the foamable melt blend into an area of reduced pressure through a heated die which lips are set from 5 to 100 mls apart; e. immediately attenuating the molten extruded foamed sheet with attenuation at a rate of from 1.5 to 10 times the rate linear at which the melt is extruded to induce formation of fibrils; and f. breaking down said attenuated foamed sheet into short fibers containing numerous fibrils.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein said attenuated sheet of foamed resin is broken down into fibers by immersion in a liquid and applying a shearing force thereto.
Claim 4
Dependent Claim
24 words
The process of claim 1 wherein the resin is selected from the group consisting of polystyrene, polypropylene, polyethylene, polyvinyl chloride, poly-ρ-caprolactam and blends thereof.
Claim 5
Dependent Claim
49 words
The process of claim 1 wherein said attenuated sheet of foamed resin is broken down into fibers by restraining said sheet and heating said sheet to a temperature slightly below the softening point of the resin whereby the attenuated foamed resin sheet heat shrinks and disintegrates into the fibers.
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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) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |