Process for sheet forming polyethylene terephthalate
Abstract
Abstract 1,124,488. Drawing sheet material. GLANZSTOFF A.G. 2 Dec., 1965 [3 Dec., 1964], No. 51243/65. Heading B5A. A process for the production of an article from polyethylene terephthalate having a solution viscosity between 1À7 and 2À0 and a degree of crystallization between 5% and 25% comprises heating a sheet, plate or film of said material to a temperature between 85‹ C. and 200‹ C., vacuum deep-drawing the thus heated sheet, plate, or film and thereafter heating the article thus formed in the mould to a temperature between 140‹ C. and 220‹ C. During the heat treatment the shaping vacuum is preferably maintained. The vacuum deep-drawing may be effected using a male or female mould assisted by mechanical or pneumatic prestretching if desired.
Inventors
- 👤 Erhard Siggel
- 👤 Walter Rein
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-16 | 1973-08-18 | 1974-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-16 | 1977-08-18 | 1978-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-16 | 1981-08-18 | 1982-02-17 | $7700.00 | Window Closed / Lapsed |