A method of and an apparatus for thermally processing crystalline thermoplastic resin film

摘要

A method of and an apparatus for biaxially orienting a crystalline thermoplastic resin film and subsequently thermally processing the film with first and second heating devices, in which the temperatures of respective heaters for biaxially orienting are divisionaly controlled, the first heating device being operated by a tubular method or a tenter method, and the second heating device being operated, under a tenter method, above the temperature in the first heating device, whereby a melting and sticking of the film is prevented and the bowing ratio is decreased.