Working principle and operation of plastic injection molding machine

The plastic injection molding machine uses the thrust of the screw (or plunger) to inject the plasticized plastic in the molten state (that is, the viscous state) into the closed mold cavity, and obtain the product after solidification and shaping. Injection molding is a cyclic process. Each cycle mainly includes: quantitative feeding-melting and plasticizing-pressure injection-mold filling and cooling-mold opening and part removal. After taking out the plastic part, the mold is closed again for the next cycle.

Locking the mold: The mold board quickly approaches the fixed mold board, and after confirming that there is no foreign matter, the system is turned to high pressure and the template is locked.

The shooting platform moves forward: the shooting platform advances to the specified position.

Plastic injection: The screw can be set to inject the molten material at the front end of the barrel into the cavity at multiple speeds, pressures and strokes.

Cooling and pressure holding: According to the setting of various pressures and time periods, the pressure of the barrel is maintained while the cavity is cooled and formed.

Cooling and pre-molding: The products in the mold cavity continue to cool, and the hydraulic motor drives the screw to rotate to push the plastic particles forward. The screw retreats under the control of the set back pressure. When the screw retreats to the predetermined position, the screw stops rotating and the injection cylinder presses The setting is loosened and expected to end.

Shooting table retreat: After pre-plasticizing, the shooting table retreats to the designated position.

Open the mold: the mold pulls back to the original position.

Ejection: The thimble ejects the product.

The advantages of injection molding method are fast production speed, high efficiency, operation can be automated, variety of colors, shapes can be from simple to complex, size can be from large to small, and the product size is accurate, the product is easy to update, and it can be made into complex shapes. Parts and injection molding are suitable for mass production and molding processing fields such as products with complex shapes.