Determining Polymer Wall Conductance on Smooth Tool Steel
Polymer wall conductance on smooth tool steel peaks above 3500 W/m²K under packing pressure and drops below 600 W/m²K upon thermal gap detachment.
Ampcoloy Copper Alloy
Meaning
Specialized copper alloys provide rapid heat dissipation in high-stress zones of injection moulds. Use of ampcoloy copper alloy allows a moulder to target hot spots where traditional tool steel fails to remove heat efficiently. This material family combines high thermal conductivity with sufficient hardness to withstand the rigours of high-volume production.
Unlike standard beryllium copper, these alloys often rely on specific alloying elements to achieve properties without the same health risks.
Thermal Conductivity
Values for thermal conductivity in an ampcoloy copper alloy often exceed 200 Watts per metre-Kelvin, allowing for extreme heat extraction. This property is measured against the lower rates of P20 or H13 tool steel which typically sit below 30 Watts per metre-Kelvin.
Moulding Application
Critical inserts or core pins often incorporate ampcoloy copper alloy to prevent defects like sink marks or warpage. Concentrating heat removal at the thickest section of a part ensures a more uniform cooling rate across the entire geometry. This localized approach prevents the build-up of residual stress.
Efficient heat transfer at the gate area also speeds up solidification and prevents drooling or stringing.
Economic Outcome
Improved cycle times resulting from the use of ampcoloy copper alloy lower the total cost per part over a long production run. Initial tooling costs are higher due to the price of the raw material and the specialized machining requirements. These expenses are recovered through increased throughput and lower scrap rates.
A reduction of even a few seconds in cooling time translates into thousands of additional units per week on a high-cavity tool. Total output remains stable because the alloy maintains its shape under pressure.