The general molding process of the screw injection molding machine is as follows: firstly, the granular or powdery plastic is added into the barrel, and the plastic is melted by the rotation of the screw and the heating of the outer wall of the barrel, and then the machine is clamped and the injection seat is moved forward. Make the nozzle close to the gate of the mold, and then inject pressure oil into the injection cylinder to advance the screw, so that the molten material is injected into the closed mold with a low temperature at a high pressure and a fast speed. Time and pressure are maintained (also known as pressure holding), cooled to solidify and form, and then the mold can be opened and the product can be taken out (the purpose of pressure holding is to prevent the backflow of the melt in the mold cavity, replenish the material into the mold cavity, and ensure the product. with certain density and dimensional tolerances). The basic requirements of injection molding are plasticizing, injection and molding. Plasticization is the premise to realize and ensure the quality of molded products, and in order to meet the requirements of molding, injection must ensure sufficient pressure and speed. At the same time, due to the high injection pressure, a correspondingly high pressure is generated in the mold cavity (the average pressure in the mold cavity is generally between 20 and 45MPa), so there must be a sufficient clamping force. It can be seen that the injection device and the clamping device are the key components of the injection molding machine.
Post time: Sep-17-2022