초록 ▼

Using a metal mold (20a) consisting of a convex mold part (21a) and a concave mold part (22a), a molding material (14) is placed between a pair of coating films (12), and after clamping, the molding material (14) and the coating film (12) are heated and molded to make a biodegradable expanded molded

Using a metal mold (20a) consisting of a convex mold part (21a) and a concave mold part (22a), a molding material (14) is placed between a pair of coating films (12), and after clamping, the molding material (14) and the coating film (12) are heated and molded to make a biodegradable expanded molded article, and at the same time, the coating film (12) is softened and pressure-bonded to a surface of the biodegradable expanded molded article. An exhaust hole (31a) and (32a) are provided on the convex mold part (21a) and the concave mold part (22a), respectively. At the time of heating and molding, gaseous matter existing between the coating film (12) and a surface of the metal mold (20a) is discharged out of the metal mold (20a) through the exhaust holes (31a) and (32a). Accordingly, it is possible to provide a method and a mold to manufacture a biodegradable expanded molded article easily and with excellent accuracy of dimension, having enough strength, enough water resistance, very excellent biodegradability and excellent surface smoothness even if the biodegradable molded article has a complicated shape.

대표청구항 ▼

What is claimed is: 1. A method to manufacture a biodegradable molded article comprising the steps of:providing a slurry or dough molding material mainly made of starch or a derivative thereof and obtained by adding water therewith;providing a coating film distinct from the slurry or dough molding m

What is claimed is: 1. A method to manufacture a biodegradable molded article comprising the steps of:providing a slurry or dough molding material mainly made of starch or a derivative thereof and obtained by adding water therewith;providing a coating film distinct from the slurry or dough molding material and mainly made of a biodegradable plastic and having hydrophobicity;placing the slurry or dough molding material and the coating film into a mold having a given-shaped cavity to obtain a combination of the slurry or dough molding material and the coating film; andheating and molding the combination of the slurry or dough molding material and the coating film in the mold to mold the slurry or dough molding material through steam expansion, and at the same time soften and pressure-bond the coating film to a surface of a biodegradable expanded molded article obtained through steam expansion molding, whereina mold made up of a pair of a convex mold and a concave mold being used;said mold has an exhaust hole;the molding material and the coating film being placed between the convex mold and the concave mold before the heating and molding;in the heating and molding step, a central part of the coating film being deformed by moving at least either one of the convex mold and the concave mold in a direction wherein these two molds fit together;at least while the coating film is being deformed, a relative moving speed of the convex mold to a plane formed by connecting a surface of non-deforming parts on an outer periphery of the coating film being maintained from 8 mm/s to 12 mm/s; andin the heating and molding step, a gas existing between the coating film and a surface of the mold is discharged out of the cavity through the exhaust hole.