Injection molding processes can be divided into many types according to material properties, product requirements and processing methods.
Conventional injection molding process is standard injection molding. This injection molding process is single-color, single-material and one-time molding. The mold structure is simple and the cycle is short. General plastics such as ABS, PP, and PS are usually used. It is used to produce low-complexity parts such as daily necessities and ordinary shells. This injection molding process has the lowest cost, but cannot meet special functional requirements.
Precision injection molding refers to high precision (tolerance ±0.01mm), high finish, and relies on precision molds and temperature control systems. The materials are generally engineering plastics such as PC and POM, which are used to produce electronic connectors, optical lenses, medical micro-parts and other products. The equipment cost of this injection molding process is high and it is suitable for scenes with strict requirements on dimensional stability.
Two-color or multi-color injection molding process, through multiple sets of molds or turntable processes to achieve multi-material and color one-piece molding, without secondary assembly, soft and hard glue combination, transparent and opaque combination. Generally produce toothbrush handles, car buttons, smart wearable devices. This injection molding process has complex molds, but reduces subsequent processing steps and is suitable for appearance and functional integration requirements.
Gas-assisted injection molding refers to the injection of high-pressure nitrogen to form a hollow structure, reduce weight and reduce shrinkage marks. Thick-walled parts are commonly made of PP, PA, etc., and are generally used to produce furniture armrests, automotive interior parts, and large tubular structures. This injection molding process saves 20%-40% of materials, but the gas penetration path needs to be controlled to avoid defects.
The insert injection molding process pre-places metal or ceramic inserts into the mold and forms a composite part after injection molding. For example, metal inserts + high-temperature resistant plastics. Injection molding products such as threaded fasteners, electronic conductive parts, and automotive sensors can be processed. This injection molding process can enhance mechanical properties, but the inserts need to be precisely fixed to prevent displacement.
