The Most Critical Factor in Mold Temperature Molding
The use of the mold and the temperature
Injection mold heat balance indulgence, injection molding machine and mold heat transfer are the key to injection molding. Heat formed by plastic, such as thermoplastics, rejects heat radiation to the material and mold and rejects convection to the heat transfer fluid. In addition, heat veto heat radiation is transferred to the atmosphere and the mold frame. The heat absorbed by the heat transfer fluid is carried away by the mold temperature.
the mold temperature indulgence of the injection molding process, the main purpose is to indulge the mold temperature is heated to the working temperature, and the second is to keep the temperature constant at the working temperature of the mold. If the above two points are successful, the cycle time cannot be optimized to ensure the stable quality of the injection molded parts.
Mold temperature infects surface quality, fluidity, shrinkage, injection molding cycle and deformation. If the mold temperature is too high or too low, different infections will be formed for different materials. For thermoplastics, higher mold temperatures generally do not improve surface quality and flow, but extend cooling time and injection cycle. Lower mold temperatures reduce the shrinkage of the mold but reduce the shrinkage of the molded part. For thermoset plastics, higher mold temperatures typically reduce cycle time and depend on the time required to cool the part. In addition, in plastic processing, the higher the mold temperature, the shorter the plasticizing time and the fewer the number of cycles.
The effective indulgence of the preparation temperature of the mold, the temperature indulgence system consists of three parts: mold, mold temperature machine and thermal fluid. To ensure that heat can be added or removed to the mold, each part of the system must meet the following conditions: The first is the cooling passage inside the mold, the surface area must be large enough to match the runner diameter pump (pump pressure) Ability.
The temperature distribution inside the chamber is highly contagious to the deformation and internal pressure of the part. Reasonable setting of the cooling passage can not reduce the internal pressure and improve the quality of the injection molded parts. Reduced cycle time and reduced product cost.
The mold temperature machine must be able to maintain the temperature of the heat transfer fluid in the temperature range of 1 degree Celsius to 3 degrees Celsius, depending on the quality requirements of the molded part. The third is that the thermal fluid must have good thermal conductivity and, most importantly, it can get in and out of the heat in a short time.
From a thermodynamic point of view, water is significantly better than oil.