Copper is the most thermally conductive (property of a material to conduct heat) of the common solids; only silver, cubic boron nitride and diamond are more conductive. This makes copper an excellent choice for plastic injection molds that must remove heat from the injected, molten plastic to make it solidify. However, copper is neither hard nor strong enough in its pure form to serve as an injection mold. Fortunately, metallurgists have developed alloys of copper that retain much of the conductivity while attaining strength and hardness that approaches or even exceeds that of steels.
The attributes of copper alloys that make them attractive to the mold industry are high thermal conductivity, ease of machining by a variety of processes, and corrosion resistance to water, cooling fluids and the plastics being injected. With thermal conductivity of two to 10 times that of common tool steels, these alloys can be used in injection mold core and cavity applications to remove hot spots, reduce warpage and reduce cycle time. This has been demonstrated in several studies
Copper alloys are traditionally used in core applications where the copper attains a lower temperature than would steel in a difficult-to-cool area, enabling the plastic in these areas to solidify more quickly. With proper design, inserts can be added to trouble spots in a steel mold after initial fabrication and first article operation of the mold so that hot spots can be reduced and dimensional stability from shot to shot can be improved.
We produce cast or forged copper alloys into variety of shapes for example rod, rings and disks.
The high thermal conductivity of Brocadur® alloys improved the heat transmission in the mould and provides a shortened cycle time.
Brocadur® high performance copper alloys