Many molds, especially engineering thermoplastics, work at extremely high temperatures, such as 80 degrees Celsius or 176 degrees Fahrenheit. If the mold is not insulated, the heat loss of the air and the injection molding machine can easily be as much as the heat loss of the injection cylinder.
Therefore, the mold must be insulated from the machine board, and if possible, the mold surface must also be insulated. If you think about hot runner molds, minimize the heat exchange between the hot runner and the cooled injection parts. This method can increase energy loss and preheating time.
The need for temperature control
1. The purpose and effect of temperature control on formability
The appearance of the molded product, the physical properties of the material, the molding cycle, etc. Obviously affected by the core temperature. Under normal molding conditions, it is better to keep the mold core temperature low, so you can increase the number of injections, but the molding cycle is related to the shape of the molded product (mold core structure) and the type of finished material, and it also depends on whether the mold core needs to be improved. Filling temperature.
2. Temperature control to avoid stress
This is the result of the material of the molded product, and this requirement only requires the cooling rate. The cooling time is short, even if one part is hardened, the other part is still soft, which can still prevent the stress caused by uneven expansion. In other words, proper temperature control can improve the cooling stress characteristics.
3. Temperature control for crystallinity conditioning of molding materials
The adjustment of crystallinity and the improvement of the mechanical properties of crystalline materials such as polythiourethane/PA (nylon), polyacetate/PC and polypropylene/PP usually require higher core temperatures.
