MANUFACTURE OF THERMOPLASTIC RESIN FILM

摘要

PURPOSE:To improve bowing and manufacture a biaxially-oriented thermoplastic resin film of superior heat dimension stability and improved flatness by carrying out a treatment for limpness in the longitudinal direction just after orientation in the axial direction. CONSTITUTION:An unoriented film 1 is oriented in the longitudinal direction in the longitudinal direction orientation process 2 in which a plurality of rolls and the like are disposed. The film is preheated in the preheating zone 4 of a stenter 3 and oriented in the width direction in the orientation zone 5. The limpness treatment is carried out for the biaxially-oriented thermoplastic film 6 by a longitudinal direction limpness treatment means 7 just after successive biaxially orientation. A film 6 fed from a guide roll 8 into the longitudinal direction limpness treatment process 7 is moved floatingly along the arc face of a hot air blowing means 10 provided with a plurality of hot air blow nozzles 9, during which the limpness treatment is carried out in the longitudinal direction.