| abstract |
An object of the present invention is to inexpensively provide a method and device of producing a high viscosity polylactic acid composition, which composition is appropriate for foam molding having a high expansion ratio and is stable, and a foam molded article having a high expansion ratio formed of said high viscosity polylactic acid composition. A method of producing a polylactic acid foam molded article of the present invention which can achieve the above-described object is characterized by comprising a step of mechanically grinding a polylactic acid composition by applying a shear force, using a device equipped with an injection molding machine (B) or an extrusion molding machine (G), an orifice portion (S) and a foaming mold (P), in a foaming gas atmosphere in the orifice portion (S). The above-described polylactic acid composition is obtained by mechanically grinding polylactic acid, which polylactic acid is cross-linked by polyisocyanate, by applying a shear force in an inert gas atmosphere, said polylactic acid composition obtained by the grinding being characterized by having an MI value of 0.05 or more and 5 or less, which MI value is measured at 190° C. under a load of 21.6 kg in accordance with JIS K7210 (ISO 1133) (FIG. 2 ). |