Plastic injection molding mainly consists of two parts: injection molding machine and mold.
Main Components of an Injection Molding Machine An injection molding machine is the main equipment for melting, injecting, and clamping plastic. It mainly includes the following functional modules:
Injection Unit: Responsible for plasticizing the plastic into a molten state and injecting it into the mold.
Includes: Screw, barrel, nozzle, check ring, flow divider, etc.
Mold Closing Unit: Enables the opening, closing, locking, and ejection of the molded product.
Includes: Front and rear fixed platen sections, moving platen section, tie rods, mold closing cylinder, mold adjusting device, ejection mechanism, etc.
Hydraulic system: Provides power to drive injection and mold closing actions.
Electrical control system: Controls temperature, pressure, time, and the sequence of actions to ensure process stability.
Heating and cooling system: Regulates the temperature of the barrel and mold to ensure effective plasticizing and cooling.
Machine frame: Supports and secures all components.
Main Components of a Plastic Injection Mold
The mold is the core tool that gives shape to plastic products. A typical structure includes:
Molded parts: Directly form the inner and outer surfaces of the molded part, including cores (punches), cavities (dies), inserts, etc.
Gating system: Guides molten plastic from the nozzle into the mold cavity, including the main runner, cold slug well, branch runners, and gate.
Guiding system: Ensures precise alignment between the moving and fixed molds, typically composed of guide pillars and guide bushings.
Ejection mechanism: Used to eject the molded part, including ejector pins, ejector plates, return springs, ejector rods, etc.
Ventilation system: Expels air and volatile gases from the mold cavity, preventing air marks and scorching, usually achieved through the parting line gap or dedicated venting channels.
Temperature control system: Controls the mold temperature through cooling channels or heating elements.
Core-pulling mechanism (side parting mechanism): Used to handle side holes and side recesses, including sliders, angled guide pillars, hydraulic cylinders, etc.
