METHOD FOR COMMINUTING PET RESIN AT ROOM TEMPERATURE

摘要

PROBLEM TO BE SOLVED: To manufacture fine powder by mechanical comminuting at room temperature by heat-treating a comminuted raw material for recycling a PET resin pellet and a molding according to a specific crystallinity of a resin before comminuting. SOLUTION: As a raw material, in addition to a PET pellet sold in the market, a plastic bottle melt extruded to a pellet-like state can be used. This material is heat treated before comminuting, a crystallinity of a resin is set to 35% or more, and the material is mechanically comminuted at room temperature to manufacture fine powder particles. Its heating temperature is a range of 166±10 deg.C of crystallinity temperature. And, a time until its crystal phase is changed and finely comminuted is normally 3 to 40 hours. Since the particles obtained from the material having such a crystallinity of 35% or more do not almost have whisker-like protrusions, the particles can be further finely granulated by repeatedly circulating and supplying it, for example, to the same comminutor. Such particles can be applied to a fluid dipping powder paint.