Fabrication of circular and Profiled Conformal Cooling Channels in aluminum filled epoxy injection mould tools

Abstract

The purpose of this paper is to present a technique of fabricating Profiled Conformal Cooling Channels (PCCC) in an Aluminum filled epoxy mould using Rapid Prototyping (RP) and Rapid Tooling (RT) techniques. The cooling channels in injection mould tools have a circular cross section. In a PCCC, the cross sectional shape is so designed that the flat face surface of the channel facing the cavity follows the profile of the cavity. These types of channels can be manufactured through RP techniques. A part to be moulded was designed and modeled. Two moulds were then designed with the part cavity, one having a circular channel and the second with a profiled channel, both having the same cross sectional area for coolant flow. The channel patterns were designed with supports according to their position regarding height and distance from the cavity as designed earlier. Both channels have the same distance from the cavity wall. RP patterns were produced for both channels and part using the Thermojet 3D printer. The cooling channel and the moulded part were then assembled as designed in the moulds. Moulding frames were fabricated with aluminium plates and the pattern was placed in the frames. Epoxy was poured on the pattern and then cured. The moulded part and the channel patterns embedded inside epoxy were melted out during the final curing cycle, leaving behind the circular- and profiled-cooling channels in the moulds. The RT fabrication technique adopted in the current work was to make the profiled channels which cannot be fabricated through conventional manufacturing methods.