Injection Molding products China manufacturer

1. The hopper

Thermoplastic material is supplied to molders in the form of samll pellets. The hopper on the injection molding machine holds these pellets. The pellets are gravity-fed from the hopper throat into the barrel and screw assembly.

2. The barrel

The barrel of the injection molding machine supports the reciprocating plasticizing screw. It is heated by the electric heater bands.

3. The reciprocating screw

The recipprocating screw is used to compress, melt, and convey the material. The reciprocating screw consists of three zones: the feeding zone; the compressing zone; the melting zone.

While the outside diameter of the screw remains contrast, the depth of the flights on the reciprocating screw decreases from the feed zone to the begainning of the meleting zone. These flights compress the material against the inside diameter of the barrel, which creates viscous heat. This shear heat is mainly responsible for meleting the material. The heat bands outside the barrel help maintain the material in the molten state. Typically, a molding machine can be have three or more heater bands or zones with different temperature settings.

For thermoplastics, the injection molding machine converts granular or pelleted raw plastic into final molded parts via a melt, injection, pack, and cool cycle. Atypical injection molding machine consists of the following major components:

 A. The Injection System

The injection system consists of a hopper, a reciprocating screw and barrel assembly, and an injection nozzle. This system confines and transports the plastic as it progresses through the feeding, compressing, degassing, melting, injection, and packing stage.