Method for manufacture of regenerated synthetic resin product

Abstract

A method which is capable of manufacturing regenerated synthetic resin products, particularly slide fastener parts of regenerated synthetic resin, with good quality by using as a raw material such waste synthetic resin materials as emanate from the production line of slide fasteners of synthetic resin or arise from waste plastic products. This method includes granulating the waste synthetic resin material with a rotary blade kept in motion at a high speed and, at the same time, heating the resin material by the heat of friction with the rotary blade, heating and melting the hot granulated synthetic resin and deaerating and extruding the hot molten resin to obtain a strand, and pelletizing the extruded strand thereby forming primary pellets, subjecting the resultant primary pellets to solid-phrase polymerization in a vacuum or in an atmosphere of an inert gas at a prescribed temperature thereby forming regenerated pellets, and then forming the regenerated pellets into the shape of a product or the shape of a part aimed at. Preferably, the hot molten resin is subjected to a treatment of filtration for removal of extraneous substance at the step for forming the primary pellets.

Dependencies are inferred from the claim text.