Patent US3822331A successfully refreshed from Google Patents.
US3822331A
Expired / Lapsed
US
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Continuous process for making low density thermoplastic foam
Assignee: WR Grace and Co Conn
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Filing: 1971-12-10
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Granted: 1974-07-02
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Expires: 1991-12-10
Abstract
Abstract THE PRESENT INVENTION IS DIRECTED TO A CONTINOUS PROCESS FOAR MAKING HIGHLY EXPANDED FOAM THERMOPLASTIC MATERIAL INCLUDNG THE STEP OF EXTRUDING A FOAMABLE THERMOPLASTIC COMPOSITION INTO A ZONE AT SUBATMOSPHERIC PRESSURE. APPARATUS SUITABLE FOR EFFECTING SAID PROCESS COMPRISING AN XTRUDER AND A CHAMBER HAVING VACUUM MEANS ASSOCIATED THEREWITH IS ALSO DISCLOSED. THE CHAMBER COMMUNICATES WITH THE EXTRUDER FOR EXPANDING A THERMOPLASTIC EXTRUDATE TO LOW DENSITY FOAM UNDER SUBATMOSPHERIC PRESSURE.
Inventors
- 👤 J Cogliano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:52
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J9/141; B; B29; B29C; B29C44/00; B29C44/34; B29C44/3403; B29C44/36; B29C44/46; B29C44/50; B29C44/507; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06
Claims Analysis
Total Claims: 0
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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) | 1977-07-01 | 1977-12-31 | 1978-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-01 | 1981-12-31 | 1982-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-01 | 1985-12-31 | 1986-07-02 | $7700.00 | Window Closed / Lapsed |