PRODUCTION OF STRETCHED FILM OF POLYLACTIC ACID

摘要

PURPOSE:To provide an easily stretchable film by a method wherein L-polylactic acid and/or D-polylactic acid is melted, extruded, quenched and stretched. CONSTITUTION:After polylactic acid is melted, extruded, formed into film and quenched, the film is uniaxially stretched or gradually or simultaneously stretched for a predetermined width in the range from at least glass transition point to at most crystallization temperature. The film may be treated with constant heat after stretching. The film thus obtained has a tensile strength of at least 6kgf/mm<2> in the stretching direction and a Young's modulus of at least 220kgf/mm<2> in the stretching direction and is excellent in transparency.