Plastic Molds Are Classified According To Function

The structure of plastic mold is mainly classified by function: pouring system, temperature control system, molding parts system, exhaust system, guiding system, ejecting system and so on. Among them, the casting system and molded parts are the parts that are in direct contact with plastics and change with plastics and products, and are the most complex and the most varied parts of the plastic mold, requiring the highest finish and precision.

1. Pouring system:

It refers to the part of the flow path before the plastic enters the cavity from the nozzle, including the main flow path, cold feed hole, diverter path and gate.

2. Molding parts system:

It refers to the combination of various parts that constitute the shape of the product, including the dynamic die, the fixed die and the cavity (concave die), the core (punch die), the molding rod and so on. The core forms the inner surface of the product, and the cavity (concave die) forms the outer surface shape of the product. After closing the mold, the core and cavity form the mold cavity. According to the process and manufacturing requirements, sometimes the core and the die are composed of a number of pieces, and sometimes they are made as a whole, and only inserts are used in parts that are easily damaged and difficult to process.

3. Temperature control system:

In order to meet the requirements of injection process for mold temperature, it is necessary to have a temperature control system to adjust the temperature of the mold. For injection molds for thermoplastics, the cooling system is mainly designed to cool the mold (the mold can also be heated). The common method of mold cooling is to open a cooling water channel in the mold, and use the circulating cooling water to take away the heat of the mold; In addition to the use of cooling water to heat hot water or hot oil, electric heating elements can also be installed in and around the mold.

4. Exhaust system:

It is set up in order to exclude the air in the injection molding cavity and the gas generated by the plastic melting to the mold. When the exhaust is not smooth, the surface of the product will form gas marks (gas marks), burning and other bad; The exhaust system of the plastic mold is usually a trough air outlet opened in the mold to discharge the air of the original cavity and the gas brought by the molten material.