US2823421A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stretching of polyethylene terephthalate film
Assignee: EIDP Inc
•
Filing: 1952-05-12
•
Granted: 1958-02-18
•
Expires: 1972-05-12
Abstract
No abstract record available.
Inventors
- 👤 Arthur C Scarlett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:56
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/005; B29C55/02; B29C55/10; B29C55/12; B29C55/14; B29K; B29K2067/00; Y; Y10; Y10S; Y10S260/00; Y10S260/23; Y10S264/00; Y10S264/73; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
96 words
A PROCESS FOR PREPARING POLYETHYLENE TEREPHTALATE FILM WHICH COMPRIESE CONTINUOUSLY CASTING A SUBSTANTIALLY AMORPHOUS POLYETHYLENE TEREPHTALATE FILM, CONTINUOUS LONGITUDIALLY STREACHING SAID AMORPHOUS FILM AT THE RATE OF AT LEAST 400% PER MINUTE NO GREATER THAN 3.25X AT A TEMPERATURE WITHIN THE RANGE OF 80*-90*C. THEREAFTER COMTINUOUSLY TRANVERSLY STRETCHING SAID FILM TO SUBSTANTIALLY THE SAME EXTENT AT A RATE OF AT LEAST 400% PER MINUTE AT A TEMPERATURE WITHIN THE RANGE OF 95*-110* C., AND CONTINUOUSLY HEAT-SETTING THE RESULTING BIAXIALLY STRETCHED FILM AT A TEMPERATURE WITHIN THE RANGE OF 150*C250*C. WHILE MAINTAINING SAID FILM UNDER TRANSVERSE TENSION.
References Cited (Backward Citations)
US2497376A
Cited
US2578899A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-02-17 | 1961-08-19 | 1962-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-17 | 1965-08-19 | 1966-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-17 | 1969-08-19 | 1970-02-18 | $7700.00 | Window Closed / Lapsed |