1. Heating and pre plasticization
Driven by the transmission system, the screw will transport and compact the materials from the hopper forward. Under the shear and friction of the heater outside the barrel, the screw and the barrel, the materials will gradually melt, and a certain amount of molten plastic has accumulated at the head of the barrel. Under the pressure of the melt, the screw will slowly retreat. The backward 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 backward
2. Clamping and locking
The mold locking mechanism pushes the template and the mold moving part installed on the moving template to close the mold 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. 3. The injection device moves forward
When the mold closing is completed, the whole injection seat is pushed and moved forward to make the nozzle of the injection machine fully fit with the main sprue opening of the mold
4. Injection and pressure maintaining
After the mold locking and nozzle completely fit the mold, the injection cylinder enters the high-pressure oil to push the screw forward relative to the barrel, inject the melt accumulated at the head of the barrel into the mold cavity with sufficient pressure, and the plastic volume shrinks due to the decrease of temperature. In order to ensure the tightness, 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
5. Pressure relief
When the melt at the mold gate freezes, the pressure can be relieved
6. The injection device retreats
Generally speaking, after pressure relief, the screw can rotate and retreat to complete the next feeding and pre plasticization process. (generally, in the existing injection molding, the action of the injection seat leaving the main gate of the mold has been cancelled, and this action is performed for materials with serious salivation, such as PA)
7. Mold opening and ejection of plastic parts
After the plastic parts in the mold cavity are cooled and shaped, the mold locking mechanism opens the mold and pushes out the plastic parts in the mold.