| 摘要 |
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. |
