Nissei Company, Ltd.

Akihisa Hashimoto

Akio Ozasa

Shinji Tanaka

Takeshi Shingu

Rumi Shinohara

A bowl-shaped container () which is as a biodegradable molded article adheres a coating film () mainly made of biodegradable plastic and having at least hydrophobicity to the surface of the main body () of the container mainly made of starch. The main body () is molded through steam expansion of a slurry or dough molding material containing high-amylose starch and water, or a slurry or dough molding material containing starch, polyvinyl alcohol and water. For these reasons, it is possible to accomplish sufficient strength and at least sufficient water resistance, to exert a very excellent biodegradability and further to provide a biodegradable molded article having excellent moisture absorption strength mainly made of starch even if the biodegradable molded article has a complicated shape.

Biodegradable molded article

Using a metal mold () consisting of a convex mold part () and a concave mold part (), a molding material () is placed between a pair of coating films (), and after clamping, the molding material () and the coating film () are heated and molded to make a biodegradable expanded molded article, and at the same time, the coating film () is softened and pressure-bonded to a surface of the biodegradable expanded molded article. An exhaust hole () and () are provided on the convex mold part () and the concave mold part (), respectively. At the time of heating and molding, gaseous matter existing between the coating film () and a surface of the metal mold () is discharged out of the metal mold () through the exhaust holes () and (). 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.

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Shiga, Japan

Akihisa Hashimoto