| 摘要 |
<p>1,213,269. Film fibrillation. CHEVRON RESEARCH CO. 1 July, 1969 [3 July, 1968], No. 33264/69. Heading B4B and B5B. A cutting device useful in fibrillating uniaxially oriented polymeric film 13 comprises a roller 16, on the surface of which are formed longitudinal rows of elevated substantially equidistant cutting elements 21, the lateral offset between successive elements in consecutive rows being 0À5-50 mils, and a roller 17 having circumferential longitudinal grooves 22. The rollers are positioned with their circumferential surfaces parallel such that elements 21 penetrate but do not touch grooves 22. In use the rollers are rotated synchronously in opposite directions while the film passes between them under controlled tension. The roller 16 may be formed by cutting one or more helical screw threads on a roller of the form of roller 17. The elements 21 may be triangular with an apex angle of 10-70 degrees, each element being 0À1-100 mils wide. The film may be, e.g. polypropylene, of uniform thickness and be drawn by at least 4 : 1 but not sufficiently to cause spontaneous fibrillation, the rollers being rotated at a peripheral speed 1À5-20 times that of the film, while the film is under a tension of 600-3000 p.s.i. The film produced may take a form which, in appearance, is akin to a plurality of ladders arranged side-by-side.</p> |
