Mold temperature in the injection mold machine

SanLian Mould states the heat balance injection mold injection molding machine and mold control of thermal conductivity are the key to the production of injection molded parts. Internal mold, made of plastic brought about by heat transfer through thermal radiation to the material and mold steel, heat conduction through convection to the fluid. In addition, the heat through the thermal radiation was delivered to the atmosphere and moldbase. By thermal conductivity of fluid absorption of heat by the mold temperature machine to take away.Mold thermal equilibrium can be described as: P = Pm-Ps. Medium P-type machine for the mold temperature heat away; Pm for the plastics introduction of heat; Ps for mold heat circulated into the atmosphere.

Control the purpose of mold temperature and mold temperature on the effects of injection molded parts injection molding process, control the main purpose of mold temperature will die first, heated to operating temperature, and the other is to maintain a constant die temperature in the operating temperature. Does the success of these two points, you can optimize the cycle time and thus guarantee the stability of high-quality injection molded parts. Mold temperature will affect the surface quality, liquidity, shrinkage, deformation, such as injection molding cycle, as well as several-fold. Mold temperature too high or less on the different materials will have different effects. Of thermoplastics, the mold temperature is usually a little higher will improve the surface quality and liquidity, but it will extend the cooling time and injection molding cycle. Lower mold temperature will reduce the shrinkage in the mold, but will increase after the release of the contraction rate of injection molded parts. Of thermosetting plastics, the high point of the mold temperature is usually will reduce the cycle time, and the time required by the cooling time to determine parts. In addition, plastics processing, the higher mold temperature will reduce the plasticization time, reduce cycle times.

Control mold temperature of various points within the non-uniform, but also and injection cycle time-related. In the injection mold cavity after the temperature rose to the highest, when the hot melt encountered cold cavity wall, when the parts after removal of the temperature to a minimum. Mold Temperature Machine role is to keep the temperature constant θ2min and θ2max in between, that is to prevent the temperature difference △ θw gap in the production process or fluctuating. Following several control methods applicable to control mold temperature: the control of fluid temperature is the most commonly used method, and the control precision can meet the requirements of the majority of cases. The use of this control method, displayed in the controller’s temperature and mold temperature is not uniform; mold considerable temperature fluctuations, the impact of mold because there is no direct measurement of hot factors and compensation These factors include changing the injection cycle, injection speed, melt temperature and at room temperature. Second, the direct control of mold temperature. This method is loaded in the mold internal temperature sensor, which in the mold temperature control precision is relatively high use of the circumstances under which it will. Mold temperature control of the main features include: controller set temperature and mold temperature consistent; hot factors affect the mold can be directly measured and compensation. Under normal circumstances, mold temperature stability than by controlling the fluid temperature better. In addition, the mold temperature control in the production process control repeatability better. The third is joint control. Joint control of the above methods are integrated, it can also control the temperature of fluid and mold. In the joint control, temperature sensor position in the mold is extremely important to place temperature sensors, one must consider the shape, structure and location of cooling channels. In addition, the temperature sensor should be placed on the quality of injection molded parts in place play a decisive role. Connect one or more machine mold temperature controller to the injection molding machine has a lot of ways. From the interoperability, reliability and anti-jamming to consider the best use of digital interfaces such as RS 485. In the control unit and between the injection molding machine can transmit information through the software. Mold temperature machine can also be automatic.