| 摘要 |
PURPOSE:To operate lateral stretching of a film maintaining its length direction in a constant state and obtain a uniformly stretched film by making a direction transfer line of the U shape stretching path which pinches the edge of film by the pulley and the belt along the tangential line adjacent to the lowest part of the pulley. CONSTITUTION:The right and left edges of the twice folded tubular film 10 are fed via the nip rollers 9, 9' to the pulleys 2, 2' of the same shape and size which rotate reversely each other on a same plane, and are pinched by the pulleys and the circulating belts 7, 8, 7', 8'. When two sheets of obverse and reverse films are stretched along the U shape paths of the lower semicircular part of the pulley respectively, heating and pressing fluid is blown out from the opening holes 17, 17' at the tips of the fishtail tube 15, 15' which are arranged tangentially to the lowest end of the pulley. The film, being stretched, changes its direction smoothly by lubricating flow of blown out fluid following the U shape paths and is stretched laterally, maintaining a constant state longitudinally. Thus, uniformly stretched film 19 is obtained. |
