A Practical. Low-tech Method of Producing Mold Tooling with Conformal Cooling Channels and High Thermal Conductivity Materials

摘要

A novel mold making technique, based on long-established technologies, is presented. A composite electroformed mold cavity shell, having thin nickel or nickel alloy cavity walls, backed by a thicker copper layer, is used as an EDM electrode to produce a mating surface in a conventional tool steel block. A slot pattern is milled into the EDMed surface of the block, corresponding to the desired cooling channel circuit. The mating back surface of the electroform is then joined to the block, by means of a structural adhesive, or with a sealing adhesive combined with threaded fasteners. This bonding of the electroform to the block caps off the slots and forms very efficient cooling channels, wherein the cooling medium is in direct contact with the copper of the electroformed shell. The cooling channels are conformal to the mold cavity, spaced away from the cavity walls only by the thickness of the electrodeposit. The joined electroform/block composite is then finish machined as one piece, to form a mold or mold insert. Potential uses include injection molding, blow molding, and micro-embossing. Significant cycle time reductions are enabled by the enhanced cooling efficiency of this design, as compared to those with conventional gun-drilled cooling circuits.