| 摘要 |
The invention of the parent Specification according to which films are made by flowing a stream of film-forming material on to a moving casting surface whilst maintaining a pressure differential between the two sides of the film to prevent fluttering, the pressure on the side coming into contact with the casting surface being 0.7-5 inches of water lower than on the other side, is modified by increasing the pressure differential to between 5 and 8 inches of water. The bigger pressure differential enables the film to be produced at higher speeds. |
