Injection molding is a method for manufacturing molding of industrial products. Rubber injection molding and plastic injection molding are usually used for products. Injection molding can also be divided into injection molding and die-casting. Injection molding machine (injection machine or injection molding machine for short) is the main molding equipment that uses plastic molding molds to make thermoplastic or thermosetting materials into plastic products of various shapes. Injection molding is realized through injection molding machines and molds.

It is a processing method for extruding materials to be processed into products or semi products of various sections continuously through the die by heating and plasticizing them while being pushed forward by the screw through the action between the extruder barrel and the screw.

Coating molding is a process that uses plastic sol or organic sol to coat the surface of substrate such as cloth or paper to make imitation leather products, lacquered cloth or plastic wallpaper, or powder plastic to coat metal surfaces. Common plastic coating products include artificial leather, varnished cloth, plastic wallpaper and various metal coating products.

Foaming agents are divided into two categories: physical agents and chemical agents. Various gases and volatile liquids are used as crop hair conditioners. Chemical foaming agents (CFA) can be organic or inorganic compounds, which will release gas during thermal decomposition. CFA is usually used to obtain foam with medium density to high density, and is usually used together with physical blowing agent to obtain foam with low density. This paper introduces the basic processing information of CFA in extrusion and injection molding.

Extruded thermoplastics usually foam to reduce density. The same method shall be used for extruded sections or plates. If possible, start with a stable process without CFA. The foaming agent shall be added at a relatively low dosage and slowly increased until the required extrudate density is obtained. Each increased dose should be given a time to reach a stable state. It is desirable to increase the production line speed of the downstream equipment to compensate for the expansion of the three-dimensional foam.