Process for the production of polylactic acid film

摘要

The invention relates to the sequential biaxial stretching of a thin film made of a polylactic acid resin containing as large an amount of a plasticizer as 10 to 50 wt % and aims at solving the problematic grip failure in the widthwise stretching step which failure is caused by the lowering in film flatness occurring in gripping the film with clips continuously. A process for the production of polylactic acid film which comprises subjecting an unstretched film of a polylactic acid resin containing 10 to 50 wt % of a plasticizer to lengthwise stretching under such conditions as to give a lengthwise stretched film having a thickness of 12 to 100 mum and then subjecting the lengthwise stretched film to widthwise stretching with a tenter for widthwise stretching to form a sequentially biaxially stretched film, characterized in that the clip temperature of the tenter in bringing the lengthwise stretched film passed through guide rolls into contact with the clips and making the film bitten by the clips is adjusted to 70° C. or below.