The temperature control of the injection molding machine barrel is achieved by using a microcomputer control circuit and selecting appropriate control algorithms to control the heating sleeves outside the injection molding machine barrel. Ensuring that the working temperature of each section inside the barrel can be maintained within the set range according to the process requirements, precise temperature control is beneficial for improving product quality and raw material utilization in precision injection molding, which is a very important indicator.

The temperature control object of the barrel in the injection molding machine is a nonlinear, uncertain, strongly coupled, and large hysteresis system, which is one of the control difficulties. For such objects, there is currently a lack of a unified and effective control method, and conventional PID control methods cannot meet the requirements of high-precision injection.

The injection molding machine produces different products, with different pre molding quantities, environmental temperatures, and production cycles, and its barrel temperature object model parameters are different; There is a strong coupling phenomenon between the temperature control of each section of the barrel, making it very difficult to achieve complete decoupling control; In addition, the object is still a large hysteresis system, and conventional control methods may inevitably experience large overshoot and oscillation phenomena. Therefore, it is necessary to study adaptive temperature control strategies to achieve high-precision temperature control.

In the plastic processing, temperature control mainly includes temperature control of the material barrel, nozzle, and mold. The temperature of the material barrel refers to the surface heating temperature of the material barrel. Due to the thick wall of the material barrel, the selection of thermocouple detection points is crucial, and there are significant differences in temperature curves at different detection points. Therefore, dual point parallel detection, that is, setting thermocouples at both the surface and depth of the material barrel, will obtain a relatively stable temperature curve, which is conducive to the accuracy of temperature control.

The temperature of the nozzle directly affects the shear flow of the melt during passage, which has a significant impact on the quality of the product. Therefore, higher precision is required for controlling the temperature of the nozzle. Mold temperature refers to the surface temperature of the mold cavity in contact with the product, which significantly affects the filling, cooling, and pressure holding processes.