MOLDING METHOD AND APPARATUS FOR EXPANDABLE POLYMER RESIN

摘要

Problems to be solved. A conventional molding method of an expandable polymer resin employs a high-temperature heat transfer medium to perform high-temperature fusion of expandable polymer resin particles and thus suffers from high energy and time consumption due to heating and cooling of a mold and thus reduced production efficiency. Solutions. As such, the present invention provides a method for molding an expandable polymer resin-molded material at a low temperature and a molding apparatus for use in practicing the same. In accordance with the present invention, pre-expanded particles of expandable polymer resin are coated with a solution of a coating resin having a softening temperature lower than that of the expandable polymer resin to form skin layers on surfaces of expanded particles and expanded resin is then molded by fusion of these skin layers. Additional expansion of the expandable polymer resin, or provision of external physical pressurizing force, or simultaneous use of both obtains pressure necessary for the molding process. In any case, it is possible to perform the molding process at significantly lower temperature than in conventional methods.