Copper alloy sprue bushings are used to achieve better temperature control of the contained melt inside. For those applications where the melt is prematurely freezing-off inside the sprue bushing, a copper alloy sprue bushing increases the rate at which heat can be transferred to the melt and keeps it molten. For those applications where the sprue and runner is thicker than the part and is limiting the cycle time, a copper alloy sprue bushing increases the rate at which heat can be transferred from the melt and solidifies the sprue faster. This produces a faster molding cycle which equates to reduced manufacturing cost.
Hot Runner Maniforld Heater
For more demanding applications, where a hot runner manifold is needed, a copper alloy heater module provides faster start-up times because of faster heat transfer to the melt. It will also provide better melt temperature control because of faster heat transfer response.
Engraving can be done with copper alloys. The same care has to be taken to provide draft angles and relief as with other mold materials.
Molds for Injection & Blow-Molding
Copper alloy molds provide faster cycle times for both injection- and blow-molded parts because of their superior heat transfer characteristics. Faster cycle times reflect better equipment utilization, forestalling the need to purchase additional equipment.
In most thermoplastic processing, the plastic shrinks onto the core and may separate from the cavity wall. When that happens, the majority of the cooling of the plastic is from the core. Molders have found that cycle times can be dramatically cut by inserting copper alloy cores in their molds. Copper alloy cores can be of any geometry-from simple cores to the most complex.
A wide range of resins and plastic products are molded using copper alloy tooling. These products range from high mechanical-property and tight dimensional tolerance requirements to those with lower requirements.