Dalian injection molding is a method to obtain molded products by stirring fully molten plastic materials with screws, injecting them into the mold cavity with high pressure, cooling and curing. This method is suitable for mass production of complex parts and is one of the important machining methods. There are six stages: mold closing, glue injection, pressure maintaining, cooling, mold opening and product taking out. The utility model relates to a female die with a variable cavity composed of a female die assembly and a female die combined clamping plate, and a male die with a variable core composed of a male die combined base plate, a male die assembly, a male die combined clamping plate, a cavity cutting assembly and a side cutting combined plate.

For thermoplastics, it refers to plastics with plasticity after repeated heating: mainly PE / PP / PVC / PS / ABS / PMMA / POM / PC / PA and other common raw materials. The adjustment of injection time plays a great role in the pressure control of gate, runner and cavity. The injection temperature is often higher than the barrel temperature. The higher value is related to the injection rate and material properties, up to 30 ℃.

At the same time, the screw retraction time is prolonged, the length of plastic fiber is reduced, and the pressure of injection molding machine is increased. Therefore, the back pressure should be lower, generally no more than 20% of the injection molding pressure. The equipment used is an injection molding machine. It is composed of injection mold and auxiliary equipment (such as material drying, etc.). C injection device: the injection device mainly realizes plastic refining in the process of injection molding machine. Measurement. At this time, the material is heated by the external heater of the heating barrel.

At the same time, there is heat generated by shear inside, and the temperature rises to become a molten state. With the storage of materials at the front end of the heating barrel, the reaction force (back pressure) generated by these materials pushes the screw backward, and the limit switch is used to limit its retreat. When it retreats to a certain position, the screw stops rotating, so as to determine (measure) the injection amount at one time.

After the material in the mold is cooled, the material barrel is the part containing the screw, which is made of heat-resistant material. Made of high pressure resistant steel. An array of electric heating rings are installed on the periphery of the barrel to heat the materials in the barrel, and the temperature is controlled by thermocouples to make the plastic have a suitable temperature. The nozzle is the transition part connecting the barrel and the die.