US3814240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of thermoplastic film and wastepaper
Assignee: United States Department of Agriculture
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Filing: 1972-09-13
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Granted: 1974-06-04
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Expires: 1992-09-13
Abstract
Abstract A process of transporting, in suspension, a mixture of wastepaper and thermoplastic film in a hot gas stream causing the thermoplastic film to contract upon itself and form particles, thereby decreasing its specific surface to such an extent as to allow removal of the contracted plastic particles from the mixture by standard mechanical methods, such as air classification or screening. The process effectively removes all thermoplastic film from the wastepaper thus allowing for more efficient paper utilization through higher recycling rates.
Inventors
- 👤 J Laundrie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:11
CPC Classifications
D; D21; D21B; D21B1/00; D21B1/02; D21B1/026; D21B1/028; B; B03; B03B; B03B9/00; B03B9/06; B03B9/061; B29; B29B; B29B17/00; B29B17/02; B29B2017/0213; B29B2017/0217; B29B2017/0231; B29B2017/0234; B29B2017/0255; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2711/00; B29K2711/12; B29L; B29L2007/00; B29L2007/008; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/62
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
48 words
A process for removing thermoplastic film from a mixture of wastepaper and thermoplastic film which comprises: a. heating said mixture in a stream of hot gas to cause said film to contract upon itself to form particles, and b. mechanically separating the paper from the contracted thermoplastic particles.
Claim 2
Dependent Claim
48 words
A process for removing thermoplastic film from a mixture of wastepaper and thermoplastic film which comprises: a. heating said mixture in a stream of hot gas to cause said film to contract upon itself to form particles, and b. mechanically separating the paper from the contracted thermoplastic particles.
Claim 3
Dependent Claim
84 words
A process for removing thermoplastic film from a mixture of wastepaper and thermoplastic film, comprising the steps of: a. comminuting said mixture; b. transporting said mixture into an enclosed heating zone; c. introducing a sufficiently hot gaseous stream into said zone to reduce the specific surface of said thermoplastic film by contraction upon itself to form particles; d. separating the mixture of wastepaper and contracted thermoplastic particles from said hot stream of gas; and e. mechanically separating the contracted thermoplastic particles from the wastepaper.
Claim 4
Dependent Claim
84 words
A process for removing thermoplastic film from a mixture of wastepaper and thermoplastic film, comprising the steps of: a. comminuting said mixture; b. transporting said mixture into an enclosed heating zone; c. introducing a sufficiently hot gaseous stream into said zone to reduce the specific surface of said thermoplastic film by contraction upon itself to form particles; d. separating the mixture of wastepaper and contracted thermoplastic particles from said hot stream of gas; and e. mechanically separating the contracted thermoplastic particles from the wastepaper.
Claim 5
Dependent Claim
22 words
The process of claim 2 wherein the gas temperature in said heating zone is kept below the kindling temperature of the paper.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |