Patent US3639557A successfully refreshed from Google Patents.
US3639557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and device for filtering melts of fiber-forming high molecular weight polymers
Assignee: Hoechst AG
•
Filing: 1970-04-01
•
Granted: 1972-02-01
•
Expires: 1990-04-01
Abstract
Abstract TOWARDS THE SPINNING MASS AND THE MEAN FINENESS OF GRAIN OF WHICH INCREASES IN THE DIRECTION TO THE SPINNERET ACCORDING TO AN EXPONENTIAL FUNCTION. TO REMOVE IMPURITIES AND INHOMOGENEITIES FROM SPINNING MASSES OF FIBER- AND FILM-FORMING HIGH MOLECULAR WEIGHT POLYMERS THE MASSES ARE FILTERED THROUGH A FILTER PACK CONTAINING A FINELY DIVIDED MATERIAL WHICH IS INERT
Inventors
- 👤 Otto Pfannenschmid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:53
CPC Classifications
D; D01; D01D; D01D1/00; D01D1/10; D01D1/106
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |