Injection moulds are the main process equipment for industrial production, the use of moulds to produce plastic parts, with a range of advantages such as providing production efficiency, easy to ensure the quality, low production costs, injection moulds are increasingly widely used in industrial production. As the most important process of injection moulding, the quality of its moulds directly affects the quality of products, while the production cost of moulds occupy a large proportion of the development costs of enterprises. So improve the service life/shot life of injection moulds to reduce the cost of plastic products, improve enterprise productivity and competitiveness has a significant impact.
Plastic injection molding process is mainly plastic raw materials in the injection machine barrel after heating plasticization, in the injection machine screw propulsion, after the plastic reaches a certain temperature, with a certain pressure and speed through the injection machine nozzle into the mold cavity, and then the mold after the pressure, the product cooling and open the mold and get plastic parts.
During the injection moulding process, the surface of the mould has to bear the pressure when the mould is closed, the pressure of the plastic melt in the mould cavity and the pulling force when the mould is opened, of which the pressure of the plastic melt on the cavity is the most important. At the same time, the mould must be maintained at a certain temperature conditions, mould temperature should try to achieve cyclical changes, customer requirements mould temperature should be high, which can effectively reduce the dissolution of the trace, and plastic parts off the mould temperature should be low. Otherwise the product deformation will be relatively large. Under such working conditions, the mould is susceptible to excessive deformation and hot and cold fatigue rupture, mainly under the action of temperature and pressure.
Plastic in the process of filling the mould cavity, mould forming parts by the high temperature and high pressure melt scouring, flow friction, in the process of product demoulding, cavity and core and plastic parts in the work process is easy to produce friction, resulting in the phenomenon of mould wear. At the same time, due to the frequent opening and closing of the mould, the mould guide parts and moulding parts are prone to wear and tear resulting in loosening.
In the moulding process, some plastics will decompose under high temperature and pressure to produce corrosive gases, which will easily corrode and damage the surface of the mould, causing damage to the surface of the mould.
When the production of injection moulds reaches a certain number, the surface quality of the product due to excessive wear of the mould cannot reach the requirements, the product overflow and flying edge is serious, and the mould cavity and core can not be repaired, the life of the mould expires. The total number of plastic parts completed before the mould fails is also known as the life of the mould.
Post time: Jul-26-2022