Polylactide resin compositions and biaxial stretching process for the polylactide resin compositions

A process for producing a biaxially oriented polylactide film, comprising (a) forming a polylactide resin composition by melt- or solution-blending, the polylactide resin composition comprising

• (i) 40 to 95 weight percent based on the weight of all polylactides in the composition, of a crystallizable polylactide having a number-average molecular weight as measured by gel permeation chromatography against a polystyrene standard of at least 5000 g/mol and containing at least 95% by weight lactic units, wherein the lactic units are L-lactic units and D-lactic units in a ratio of ≥93:7 or ≤7:93 and (ii) 60 to 5 weight percent based on the weight of all polylactides in the composition of a non-crystallizable polylactide having a number-average molecular weight as measured by gel permeation chromatography against a polystyrene standard of at least 5000 g/mol and at least 90% by weight lactic units, and wherein the lactic units are L-lactic units and D-lactic units in a ratio of ≥20:80 or ≤80:20;
• (b) extruding the polylactide resin composition through an extrusion die in a machine direction to produce a polylactide sheet having a machine direction corresponding to the direction of movement of the polylactide blend through the extrusion die, and an orthogonal transverse direction, and
• (c) sequentially or simultaneously stretching the sheet in orthogonal directions at a temperature of 50° C. to 120° C. to produce the biaxially oriented polylactide film.