What is the injection molding production process of plastic hollow panels?

Compared with cardboard structural products, hollow boards have the advantages of moisture resistance and corrosion resistance. However, most people do not know the molding process very well. The following plastics will popularize the injection molding production process of plastic hollow panels for you:

Closing the mold - high pressure and low-speed mold clamping - the forward movement of the injection seat - melt injection - holding pressure - cooling of the molten material into the mold Raw material) - the molten material in the mold is cooled and solidified, the mold is opened (the product is ejected at the same time) - the mold is closed (the next cycle of injection molding product production begins).

The raw materials for the plastic hollow board are added to the barrel of the injection molding machine from the hopper according to the number of plastic products used at one time. Since the raw material is heated and heated in the barrel, it is also compressed due to the gradual reduction of the volume of the thread on the screw. In addition, the continuous rotation of the screw thread causes the material to move forward and the friction between the material and the barrel. Conditioning, the raw material is gradually plasticized into a molten state while being pushed forward. The molten material to the front end of the screw generates a reverse screw thread thrust force due to the resistance of the nozzle. As the screw pushes the molten material forward, the generated melt material's reverse thrust pressure also gradually increases. When the reverse thrust pressure When is greater than the thrust and friction resistance of the cylinder piston to the screw (this resistance is the back pressure of the screw), the screw starts to retreat, and the feeding and metering of the hopper start at the same time. The distance that the screw retreats is determined by the injection volume of the injection molded product at one time, and is controlled by the travel limit switch adjusted before production. After the retreating screw touches the travel switch, it stops rotating and retreats to complete a pre-plasticizing raw material procedure.

After the pressure holding, cooling and shaping reach the preset time, the solid forming of the product is completed. The injection seat is pulled back by the cylinder piston, starting the second pre-plasticization of the screw, the molding die is opened, the product is ejected from the cavity, and the whole process of injection molding of the plastic hollow plate is completed.

After the clamping action of the clamping part is completed, the injection seat is pushed forward by the cylinder piston until the nozzle is close to the bushing mouth; then the injection cylinder piston pushes the screw to move forward rapidly, according to the pressure and flow speed required for the molten material to enter the molding die, inject the melt into the cavity of the forming mold. In order to prevent the molten material from filling the cavity of the molding die from returning and replenishing the shrinkage of the molten material before the molten material is cooled and solidified in time, the injection nozzle is still close to the bushing mouth and maintains a certain pressure. This process is called. Pressure-holding, cooling, and setting.