Determining Mold Core Steel Thermal Expansion Gradients
Determining mold core thermal expansion gradients requires measuring temperature deltas from melt face to cooling lines to offset axial steel growth.
Finite Element Thermal Analysis
Meaning
Numerical simulation provides a prediction of heat distribution and cooling rates across complex geometries during the solidification phase of injection moulding. The software divides the part and the tool into a mesh of small discrete elements to solve heat transfer equations. This finite element thermal analysis allows engineers to identify areas where the plastic stays molten for too long.
Simulation Scope
Input variables include the melt temperature and the cooling water flow rate. By adjusting these parameters, the model shows how different cooling circuit designs affect the temperature of the plastic. Accurate finite element thermal analysis identifies potential sink marks or voids before the tool is ever cut.
Cooling Efficiency
Heat must be removed quickly to maintain a short cycle time and high production efficiency. If the water channels are too far from the cavity, the part will cool slowly and unevenly. Running a finite element thermal analysis highlights the difference between the core and the cavity temperatures.
Warp Prediction
Uneven cooling leads to internal stresses that cause the part to bend or twist after ejection. Because different areas of the part shrink at different rates, the final shape may deviate from the design. Engineers use finite element thermal analysis to balance the cooling and minimize the risk of post-moulding deformation.
This analysis often leads to the redesign of cooling lines or the addition of copper beryllium inserts to move heat away from thick sections.