Combined molding technique for plastic materials. Part I preventing the warp deformation and clamping failures for an outsert molding

摘要

A combined molding technique of outsert molding of plastic to plastic structures is very effective in reducing production costs and improving recycling of electrical products. Outsert molding can reduce the process for assembling parts and unify the materials to plastics by eliminating metallic joints such as bolts and nuts. The following results were experimentally obtained for plastic parts outsert molded to a thin plastic part: (1) The warp deformation of an outsert molding is mainly caused by the two following reasons; The difference between the mold shrinkage rate of the outsert molding resin from the expansion rate of the pre-heated thin part, The difference in cooling rate through the thickness of the outsert molding. (2) To prevent the warp deformation of an outsert molding, it is necessary to reduce the bending moment by balancing the mold shrinkage rate of the outsert molding resin and the expansion rate of the pre-heated thin part. (3) An ontsert molding with no flash and no plastic deformation can be obtained by a mold with clamping gaps that can be matched to the thickness distribution of the thin part using sliding blocks.