Structurizer mold

Claim 1

In an injection mold comprising a plurality of sections separable for the removal of an organic thermoplastic article from a mold cavity, the improvement which consists of: a frame adapted to withstand clamping pressures in a reciprocating molding press for injection molding of a giant cellular thermoplastic article weighing more than five pounds; a plate combining with the frame to create an open box; a thin contoured wall for imparting at least a portion of the desired shape to the mold cavity and to the article, said contoured wall having a relatively low specific heat; a plurality of independent sets of heat transfer conduits in heat transfer relationship to various zones of the rear of the contoured wall; a plurality of independent sets of tubes extending from the frame for directing heat transfer fluid to and from the independent sets of heat transfer conduits, whereby programming of differential heat transfer for various zones of the mold is feasible; a ceLlular polyurethane thermally insulating foundation filling a significant portion of the box and contacting the contoured wall, heat transfer conduits, and plate; a second corresponding section comprising a frame, plate, contoured wall, heat transfer conduits, tubes, and insulating foundation, and having orifices for the entry of an injected mixture comprising hot molten organic plastic and gas at a plurality of locations in the mold cavity defined by the two contoured walls, said two sections cooperating to provide a structurizer mold in which the heat transfer characteristics applied to one zone of the cavity can differ from the heat transfer characteristics applied to another zone of the cavity by reason of the independent functioning of the independent sets of heat transfer conduits for the various zones of the structurizer mold.