PURPOSE: To effectively reuse the plastic waste by putting previously selected and then compression-destroyed plastic wastes into a melt-heating bath of high boiling point petroleum liquid or inorganic salt, or putting selected plastic wastes into a melting furnace, and pouring down plastics melted by indirect heating from a nozzle, or pulling them up in use of rolls for rolling, and further forming and then molding them by means of a vacuum molding machine.

CONSTITUTION: By means of a shredder 1, plastic wastes including foam styrene are compression-destroyed, and thus granulated matters are introduced by rolls 2 into the lower part and then put into the medium in an oil or inorganic salt bath, and the medium is heated by means of a heating device for melting the wastes. Melted polyethylene and polypropylene are led by means of a pulling up roll 5 and a pulling up roll 6 and then cooled by a fan 9, and finally, wound up by a winding machine 7. In the next place, foam styrene melted matters are pulled up by pulling up rolls and then introduced therefrom by rolls, and matters severed by a cutter 11 are laminated on a lamination table 12 and then formed by means of a vacuum forming machine 13 so as to be molded. The molded matters are processed into a heat insulation building material, agricultural material, wrapping material for fish boxes or the like, storage pump, separation-oscillating filter or the like for muddy water.