Sekisui Kaseihin Kogyo Kabushiki Kaisha

Sekisui Kaseihin Kogyo K.k.

Mikio Ishikawa

Motoshige Hayashi

Masahiro Tsubone

Motokazu Yoshii

Teruyoshi Akuzawa

Toshiro Kobayashi

Toshirou Kobayashi

An improved process and apparatus for producing a thermoplastic resin foam by mixing a thermoplastic resin, a blowing agent and other necessary components in a molten state and extruding the mixture to expand. The apparatus comprises a metering zone provided at the front end of the rotating shaft in an extruder, a kneading zone provided closer to the rear end than the metering zone, and a plurality of perforated plates mounted on the surface of the shaft in the kneading zone. The outside diameter of said shaft is made smaller than that of the screw in the metering zone as measured at the bottom of channels. This feature combines with the perforated plates to insure uniform mixing and consistent extruding operations.

Process for producing thermoplastic resin foams

A process for producing a polystyrene resin foam is disclosed, which comprises supplying an extruding machine with a polystyrene resin, a fine inorganic powder and a highly volatile foaming agent, heating them to melt, and extruding the melt from the nozzle into a zone of the lower pressure, wherein 0.01 to 2 parts by weight of an alcoholic ester of a higher fatty acid is added to 100 parts by weight of the polystyrene resin. The process insures that foams having a skin of good aesthetic appeal that are free from staining and malodor can be produced consistently for a prolonged time without any fire hazard.

Process for producing polystyrene resin foam

A method for preparing a multi-cellular foamed board of thermoplastic resin which comprises forming under pressure in a die a thermoplastic resin melt containing a foaming agent to give the resin melt a shape of a flat board having a broad width compared with a thickness thereof, extruding the resin melt from the die having the convex forward end with a middle portion in the width direction thereof protruding the greatest toward the extruding direction, introducing thus extruded resin melt immediately into a moulding passage having a concave end engaging with the said convex forward end of the die, allowing the resin melt to expand in the thickness direction at the portion adjacent to and extending along the concave end of the passage, and thereafter allowing the resin melt to expand in both the thickness and width directions of the board in the passage.

Method and apparatus for preparing multi-cellular foamed board of

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Tochigi, Japan

Mikio Ishikawa