US3577360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for pre-expanding polymer beads
Assignee: Atlantic Richfield Co
•
Filing: 1968-10-07
•
Granted: 1971-05-04
•
Expires: 1988-10-07
Abstract
Abstract AN APPARATUS AND PROCESS ARE PROVIDED FOR EXPANDING POLYMERIC PARTICLES TO A PREDETERMINED DENSITY, WHICH PARTICLES ARE SUBJECTED TO FURTHER EXPANSION. AGITATED PARTICULATE EXPANDABLE POLYMER IS HEATED IN A DRY ATMOSPHERE IN A CLOSED VESSEL, UNDER VACUUM, TO A PREDETERMINED DENSITY. TO ACHIEVE ULTRA-LOW DENSITY EXPANDABLE PREPUFF, A COOLANT SUCH AS WATER IS INTRODUCED INTO THE CLOSED VESSEL AFTER THE PREDETERMINED DENSITY IS REACHED, BUT PRIOR TO THE RELEASE OF THE VACUUM. FOLLOWING RELEASE OF THE VACUUM, THE BEADS ARE REMOVED FROM THE CLOSED VESSEL AND MAY BE MOLDED DIRECTLY, WITHOUT ANY AGING PERIOD SUCH AS THAT NECESSARY FOLLOWING STEAM PREEXPANSION.
Inventors
- 👤 Richard H Immel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:59
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/3461; Y; Y10; Y10S; Y10S264/00; Y10S264/09
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |