| 摘要 |
PURPOSE:To provide the longitudinally stretching of thermoplastic resin film with no adhesion of roll-like blots and at the same time with no surface blemish such as scratch, wear and the like by a method wherein a pair of chains equipped with clips is employed as a transferring means A and a pair of chains equipped with clips or rolls are employed as a transferring means B. CONSTITUTION:Stretching is done by the difference between the transferring speeds of chains equipped with clips. Chains 4 and 4' equipped with clips driven at lower speed are set in a preheating oven 1. Film is preheated in the preheating oven up to a temperature, at which the film can be stretched. A radiation heater 2 is employed for uniform stretching. Chains 5 and 5' equipped with clips driven at higher speed are set in a cool air oven 3. The film, the stretch of which has finished, is cooled at this zone or rapidly cooled by being brought into contact with cooled rolls driven at higher speed simultaneous with the finish of stretching, resulting in reducing the blemish of the film nearly to zero.
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