US 5,849,339 A · Apparatus for producing biodegradable resin foam

Abstract

Foam forming techniques are capable of permitting foaming of biodegradable resin to be positively and uniformly accomplished to provide a biodegradable resin foam with satisfactory quality. The biodegradable resin including foam is made of biodegradable resin a main biodegradable resin ingredient of 100.degree. C. or more in melting point and a low-melting biodegradable resin ingredient of 100.degree. C. or less in melting point. The biodegradable resin foam is produced by placing a starting material of at least biodegradable resin and a substantial amount of moisture in a heated and pressurized environment, releasing the starting material from the environment to foam the biodegradable resin, and subjecting the foamed resin to forming by a forming mold. An apparatus for producing the foamed biodegradable resin foam includes a pressure adjusting chamber, an air-permeable forming mold, a pressure reducing tank and an injection machine.

Claims15

Dependent claims

An apparatus for producing a biodegradable resin foam, comprising:

a pressure adjusting chamber constructed so as to be able to be opened and hermetically closed;
a pressure reducing means connected to said pressure adjusting chamber for rapidly reducing pressure in said pressure adjusting chamber;
an air-permeable forming mold in said pressure adjusting chamber;
and
an injection machine comprising a cylinder having a narrow opening at a front portion thereof, said cylinder being for heating and fluidizing biodegradable resin such that moisture is trapped therein, forcibly transferring the biodegradable resin toward said narrow opening, and extruding the biodegradable resin therefrom into said air-permeable forming mold so as to rapidly release the biodegradable resin from heat and pressure in said cylinder, whereby the biodegradable resin is foamed by an expansion force due to the vaporization of the moisture.

2 more elements

Dependencies are inferred from the claim text.

Apparatus for producing biodegradable resin foam

Life of this patent

Apparatus for producing biodegradable resin foam

Life of this patent

Abstract

Claims15