One minute understanding of the eight steps of plastic injection molding

One minute understanding of the eight steps of plastic injection molding

One minute understanding of the eight steps of plastic injection molding

Injection molding, also known as injection molding, is an injection molding method. The advantages of the injection molding method are fast production speed, high efficiency, automatic operation, a wide variety of patterns, shapes from simple to complex, and sizes from large to small. Moreover, the product size is accurate, the product is easy to be updated, and it can form parts with complex shapes. Injection molding is applicable to mass production, products with complex shapes and other molding processing fields.

What are the steps of plastic injection molding?

  1. Heating and pre plasticizing

  2. Driven by the drive system, the screw conveys and compacts the materials from the hopper forward. Under the shearing and friction of the heater outside the barrel, the screw and the barrel, the materials gradually melt. A certain amount of molten plastic has accumulated at the head of the barrel. Under the pressure of the melt, the screw slowly retreats. The retreating distance depends on the amount required for one injection of the metering device. When the predetermined injection amount is reached, the screw stops rotating and retreating.
  3. Mold closing and locking

  4. The mold locking mechanism pushes the template and the mold moving part installed on the moving template to close and lock with the mold moving part on the moving template, so as to ensure that sufficient clamping force can be provided to lock the mold during molding.
  5. Injection device moves forward

  6. When the mold closing is completed, the entire injection base is pushed forward to make the nozzle of the injection machine fully fit with the main runner of the mold.
  7. Injection and pressure maintaining

  8. After the mold locking and nozzle fully fit the mold, the injection pressure cylinder enters the high-pressure oil to push the screw forward relative to the barrel, injecting the melt accumulated at the head of the barrel into the mold cavity with sufficient pressure. The plastic volume shrinks due to the temperature drop. In order to ensure the compactness, dimensional accuracy and mechanical properties of the plastic parts, it is necessary to maintain a certain pressure on the melt in the mold cavity to supplement materials.
  9. Pressure relief

  10. When the melt at the mold gate freezes, the pressure can be relieved.
  11. Injection device retreats

  12. Generally speaking, after the pressure relief is completed, the screw can rotate and retreat to complete the next feeding and pre plasticizing process. (In general, the action that the injection base withdraws from the main gate of the mold has been canceled for existing injection molding. This action is performed for materials with serious salivation, such as PA).
  13. Mold opening

  14. After the plastic parts in the mold cavity are cooled and shaped, the clamping mechanism opens the mold and pushes out the plastic parts in the mold.
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