Injection moulding is a method that plastic material is heated and melted in the heating barrel of injection moulding machine, and then pushed by reciprocating screw into the closed die cavity.

It can not only produce high-precision and high-quality products with high yield, but also can process many kinds of plastics, with large output (about 1/3 of the total amount of plastics) and wide application. Therefore, injection molding is one of the most important moulding methods in plastics processing. Extrusion moulding is a method of continuous moulding of plastics by heating and pressurizing in the extruder.

Generally used in sheet, tube, flat wire, film, wire and cable coating, etc., with wide application and high output. Therefore, it is one of the most important forming methods in plastics addition. Foaming is one of the important forming methods. Foaming means that foaming products with proper foaming agent in the foaming data, which can produce porous or foamed products, have relatively low density, high specific strength, less material consumption, sound insulation, heat insulation and other volt points, foaming data. There are PVC, PE and PS.

Products include: thin films, sheets, pipes, and profiles. Foaming can be divided into chemical foaming and physical foaming. Blowing moulding blowing (expanding film) plastic (or hollow blow moulding) refers to the use of fluid (compressed air) pressure to blow hot thermoplastic billets or sheets in closed moulds into hollow products.

Plastic containers produced by this method, such as bottles, square, round or flat barrels, gasoline tanks, etc., have been widely used. Newly developed industrial components and daily products, such as double-walled box products, L-ring drums, pallets, surfboards, seat backs and desks, and front baffles for cars, belt covers, dashboards, air conditioning ventilation tubes, etc., have been used in practice and processed information has been obtained. From daily plastics to engineering plastics, blow moulding has become one of the most important moulding methods in plastic processing.

But the basic process of blow moulding is:

1. Melting data.

2. The melt resin is formed into tubular or parison.

3. Melt and seal the hollow billet in blow moulding.

4. Blow up the billet in the die.

5. Cooling blow moulding products.

6. Remove the product from the die.

7. Dressing injection blow moulding injection blow moulding injection moulding is a blow moulding method. First, plastic is made into bottom billet by injection moulding, then it is moved to blow moulding to make hollow products.

This method can be used to produce packaging containers for daily necessities, cosmetics, pharmaceuticals, food, etc. But its volume should not exceed 1L. Commonly used plastics are polyethylene, polystyrene and polyvinyl chloride. Extrusion blow moulding is a blow moulding method. Unlike injection blow moulding, its parison is made by extrusion method. Drawing blow moulding is a blow moulding method. It is by extrusion. The billet is made by plastics, etc. Then the billet is heated to the drawing temperature. The billet is stretched longitudinally through the mechanical effect of the internal (e.g. mandrel) or external (e.g. fixture). At the same time, the billet is stretched horizontally by blowing with compressed air later.