| 摘要 |
644,858. Compound sheet materials. BOSTON WOVEN HOSE & RUBBER CO. Oct. 4, 1946, No. 29615. Convention date, March 4, 1944. [Class 140] Two or more strips of thermoplastic material are laminated together by applying them under pressure on to an endless moving metal belt heated to a temperature at which the thermoplastic material adheres, heating the thermoplastic material while subjected to pressure to a non-decomposing, strain-relieving temperature above the heat-forming temperature, cooling the unitary laminated sheet to a non-adherent condition, and then stripping it from the belt. An endless pad of rubbercoated fabric may be interposed between the metal belt or the pressure - applying device and the thermoplastic material. As shown, strips 28 of thermoplastic material are fed to the bite between a heated drum 10 and an endless metal band 12 which presses the strips 28 against a substantial arcuate portion of the drum and also passes around rollers 14, 15 and 16. The metal band is heated by a heating jacket 22 and roller 16 may also be heated. From the drum 10 the united layers adhering to the steel band 12 are carried around roller 14 which is cooled and beneath a cooling jacket 24. Further cooling of the band 12 and the adhering thermoplastic strip may be effected by a water-circulating jacket 26. The thermoplastic strip, which becomes non-adherent on cooling, is stripped from the belt 12 and wound up into a roll 38. A second metal band 30 supported on rollers 32 and 34 may be provided to contact the other side of the thermoplastic material. The thermoplastic material may be vinyl chloride polymerized by itself, with vinyl acetate or vinylidene chloride, or a polyvinyl acetal. Specification 473,899 is referred to. |
