Melting doing to push out the production

摘要

PROBLEM TO BE SOLVED: To obtain a smooth film without causing slackening or wrinkles.;SOLUTION: In this air cooling type manufacturing method for the inflation film, a raw material resin is extruded from an annular die in a molten state to form an annular film, air is supplied into the inner space of the annular film under cooling to inflate the film and the annular film solidified by cooling is taken over while flatly folded through a guide member. The temperature Tf(°C) of the annular film solidified at the time of contact with the guide member satisfies a relational expression [Tf≤Tr(5)]. Tr(5) shows a temperature at which a thermal deformation ratio of the solidified annular film becomes 5% when measurement is made by applying stress having magnitude same to frictional force receiving from the guide member under the condition at the time of production of the film.;COPYRIGHT: (C)2004,JPO