According to different processing objects, moulds are generally divided into plastic moulds, metal moulds and inorganic non-metallic moulds; according to the difference in mould forming process, they can be divided into plastic moulds, stamping moulds, forging moulds, casting moulds, rubber moulds, powder metallurgy moulds, etc. In terms of properties, injection moulds are also a type of plastic moulds, because plastic moulds can be divided into injection moulds, blow moulds, extrusion moulds, slush moulds, etc. according to different processing techniques. Among the above-mentioned mould types, plastic moulds and metal stamping moulds are the two most widely used mould types. According to the data released by the China Die & Mould Industry Association, the sales of plastic moulds account for about 45% of the total sales of moulds, and the stamping moulds account for about 37%.