| 摘要 |
1,026,552. Sheet forming. M. GOURNELLE. Jan. 31, 1963 [Feb. 1, 1962], No. 4065/63. Heading B5A. An open container is made from a peripherally clamped blank of thermoplastic material by a pressing process involving a punch 7 which engages the material blank at a peripheral rim 5 on its bottom. The temperature to which the blank is heated and the speed of operation of the punch are so selected that uniform thickness of the container wall is obtained as the blank slides over the edge of the punch. The punch may comprise an upper support part 21, Fig. 7, which is fixed to a press rod (not shown) and is secured to but axially movable with respect to a body part 24, a washer 23 being interposed between the parts 21, 24. A ring 26 of metallic fabric which is clamped between the parts 25, 27 is the only part of the punch which bears on the thermoplastic material during pressing. Vent passages 281, 221, 301 in fixing screws 28, 22, 30 and the passage 244 permit evacuation of air entrapped during pressing and the passages 21, 221 allow the supply of compressed air to detach the container from the press. A paper washer is interposed between the ring 26 and the part 25. A counter punch or puncher may be provided. |
