 
Injection molds made completely from copper alloys, instead of steel
or aluminum, are gaining acceptance in the plastics industry. Along
with increased production rates, copper alloy molds reduce warping,
surface finishing problems, and operating costs for manufacturers.
The main function of an injection mold, beside defining a part's shape,
is to remove heat from the plastic as quickly as possible. The mold
should be thought of as a heat transfer device much like an automobile
radiator. The faster the mold can transfer heat out of the molten
plastic and solidify it, the faster the mold can be run.
Reduced cycle time equates to reduced manufacturing cost. This is
where copper alloys outperform other metals used for molds.
Copper alloys provide the best combination of high thermal conductivity
and hardness for molds used in the plastic industry today. Copper
alloys have thermal conductivities three- to nine-times greater than
the commonly used Type 420 stainless steel. |
