Process for producing reclaimed expandable polystyrene resin particle

A method of producing regenerated expandable polystyrene resin particles, comprising the steps of:

• dissolving a waste foamed polystyrene resin material made of an expanded polystyrene resin in a volume reducing agent having solubility with respect to said foamed polystyrene resin material and exhibiting a mutual solubility with a blowing agent to be used, thereby forming a compacted material;
• dispersing and kneading together said compacted material and an extraction solvent for extracting said volume reducing agent to extract said volume reducing agent, thereby forming a solid material;
• forming said solid material into a particulate material consisting of particles;
• and
• dipping said particulate material in the blowing agent for expanding said polystyrene resin at ordinary room temperature, and, at the same time, further extracting said volume reducing agent to regenerate said expanded polystyrene resin.

A method of producing regenerated expandable polystyrene resin particles, comprising the steps of:

• dissolving a waste foamed material made of an expanded polystyrene resin in a volume reducing agent having solubility with respect to said foamed polystyrene resin material and exhibiting a mutual solubility with a blowing agent to be used, thereby forming a compacted material;
• extruding said compacted material in a string-like form at room temperature;
• holding said compacted material extruded in said string-like form on a non-adhesive substrate for preventing adhesion of said compacted material;
• and
• dipping said compacted material held on said substrate in said blowing agent at a temperature at least 20° C. lower than a softening temperature of said polystyrene resin, thereby performing extraction of said volume reducing agent and impregnation with said blowing agent.

A method of producing regenerated expandable polystyrene resin particles, comprising the steps of:

• dissolving a waste foamed material made of an expanded polystyrene resin in a volume reducing agent having solubility with respect to said foamed polystyrene resin material and exhibiting a mutual solubility with a later-mentioned blowing agent to form a compacted material;
• dispersing and kneading together said compacted material and an extraction solvent under stirring, thereby forming a solid material having reduced adhesion;
• forming said solid material into a particulate material at room temperature;
• and
• dipping said particulate material in said blowing agent at a temperature at least 20° C. lower than a softening temperature of said polystyrene resin, thereby performing extraction of said volume reducing agent and impregnation with said blowing agent.