| 摘要 |
Improved roll formation in regenerated cellulose film is obtained by a method for introducing randomized gauge variations in the film on the casting machine by varying the water content in the gel film in scattered areas across the film prior to drying. Those areas of the film containing more moisture before drying tend to be thicker than those areas containing less moisture resulting in gauge variations throughout the film. Since the gauge variations are randomly imparted to the film across its width, they do not pile up on top of one another to form gauge bands when the film is wound into rolls and the effect on roll formation of any gauge bands inherently present in the film from the casting operation are minimized due to the (superimposed) randomly imparted gauge variations. Preferably, the method comprises imparting the random gauge variations in the film by producing diagonal tracks of water on the film with a transversely moving squeegee band containing a plurality of slight indentations. The squeegee is positioned between the last bath on the casting machine and the dryer and moves transversely across the film. Any one indentation in its surface contacting the film leaves a small track of water extending diagonally across the film resulting in more moisture in that area of the film before drying and an increased thickness in that area after the film is dried.
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