| 摘要 |
1,176,426. Stretching nylon sheet material. MOLDEX Inc. 21 Feb., 1967 [21 Feb., 1966], No. 8279/67. Heading B5A. The mechanical properties of nylon sheet or film are improved by submitting the film to a compressive force while at an elevated temperature to impart permanent elongation to the strip in a direction transverse to the direction of the compressive force, and then tension stretching the strip to produce additional orientation. In a particular embodiment (Fig. 3) nylon sheeting 28 passes from a spool 36 around a pair of preheated rollers 40 and 42, and then through compression rollers 44 and 46 which may be heated, the spacing between the rollers being substantially less than the thickness of the sheet. The sheet which has been elongated in the longitudinal direction then passes around cooling rollers 48 and 50 before being taken up on a spool 56. The tension stretching is effected on a modification of the machine above (see Fig. 6), the compressed nylon sheet 28a passing around rollers 140 and 142 which may be heated, and then through brake rollers 144 and 146 which hold the sheet under tension, stretching then being effected by rollers 152 and 154, and the sheet finally being wound on a roll 156.
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