| 摘要 |
Packaging containers are produced by deep drawing heated plastic film, which has at the beginning of shaping a different temp. at different positions in order to alter the extensibility of the film. The temp. of the film parts which are extended most during deep drawing is lower than the other parts. When the temp. of the film parts which are subjected to the greatest extension during deep drawing, is less than that at the other parts, then the reduction in wall strength of these parts is less than for a uniformly heated film. Consequently the container has a more uniform wall strength. |
