US 7,070,720 B2 · Die-expanded molding apparatus and method for synthetic resin, and die-expanded molded foam obtained thereby

Abstract

A die-expanded molding apparatus comprising starting material bead supply for supplying beads on a current of air from a tank through a packer into a cavity formed by a core and cavity molds; a plurality of air expulsion devices having air pressure-adjusting components communicating with the cavity, a dual-system air expulsion device being such that steam chambers on the back side of the core mold and the cavity mold are used as the air pressure-adjusting components, each communicating with the cavity through through-holes formed in the core and cavity molds, respectively; an air expulsion device having one or more air pressure-adjusting components communicating with a clearance between the core and cavity molds; and a control for controlling the air pressure in each of the air pressure-adjusting components to be pressurized less than the pressure in the tank.

Claims17

Dependent claims

A die-expanded molding method for synthetic resins in which starting material beads are packed into a cavity formed by a core mold and cavity mold, the material is heated, expanded, and fused to form a molded product, and the molded product is cooled and released from the mold, said die-expanded molding method for synthetic resins comprising

the manipulation of various service fluids for the supply of steam to the cavity, pressurization and depressurization, and the supply of compression air, by using an inter-mold clearance, formed in such a way as to communicate with external service piping, at the seam of said core mold and cavity mold located at the circumference of the cavity when the two molds are closed.

at least a chamber on the back side of a mold side, where narrow, bottomed portions that are difficult to pack with the starting material beads are formed, is held at a negative pressure relative to the atmospheric pressure of the starting material beads packed into the cavity by a packer;
and part of the predetermined packing amount of the starting material beads is delivered and packed in a concentrated manner in said difficult-to-pack portions, then the internal pressure of a pair of chambers on the back side of both molds is respectively held at a negative pressure relative to the atmospheric pressure of the starting material beads, and the remainder of the predetermined packing amount is delivered to pack all of the starting material beads in the cavity.

Dependencies are inferred from the claim text.

Die-expanded molding apparatus and method for synthetic resin, and die-expanded molded foam obtained thereby

Life of this patent

Die-expanded molding apparatus and method for synthetic resin, and die-expanded molded foam obtained thereby

Life of this patent

Abstract

Claims17