Meaning
Ability of the mould metal to transport heat away from the plastic melt governs the cooling efficiency of the entire process. Tool steel thermal conductivity determines the rate at which the part reaches a temperature safe for ejection. This property varies significantly between different grades of steel and copper-based alloys.
Material Selection
Choice of metal impacts both the cycle time and the durability of the tool. Tool steel thermal conductivity is often a trade-off with hardness and wear resistance. While a high-conductivity alloy like beryllium copper can cool a part very quickly, it is much softer than a standard P20 tool steel and may wear down in high-glass-fiber applications.
Cooling Efficiency
Design of the water channels must be optimized to take advantage of the thermal properties of the metal. Tool steel thermal conductivity influences the thermal lag between the cavity surface and the cooling fluid. Metals with low conductivity can create hot spots in the tool that lead to uneven shrinkage and warpage in the finished parts.
Cycle Impact
Total production cost is heavily influenced by the cooling phase, which often makes up seventy percent of the cycle. Tool steel thermal conductivity allows the designer to shave seconds off the process by moving heat more effectively. This is especially important for thick-walled parts where the core remains hot for a long time.
In some cases, inserts made from high-conductivity materials are used only in the most difficult areas to balance the cooling. The use of these materials is a common strategy for increasing the output of a high-volume production line.
