It is a method that the plastic material is first heated and melted in the heating barrel of the injection molding machine, and then pushed into the cavity of the closed mold by the reciprocating screw.
It can not only produce high-precision and high-quality products with high productivity, but also process a large variety of plastics with large output (about 1 / 3 of the total amount of plastics) and wide use. Therefore, injection molding is one of the important molding methods in plastic processing.
Extrusion molding
Extrusion is a process in which the plastic is continuously molded through the die in a flowing state by heating and pressing in the extruder.
It is generally used for the forming of plates, pipes, single wires, flat wires, films, wires and cables. It has a wide range of uses and high output. Therefore, it is one of the important forming methods in plastic processing.
Foam forming
It refers to the way of adding appropriate foaming agent into foaming materials to produce porous or foam products. The foaming products have the advantages of small relative density, high specific strength, small amount of raw materials, sound insulation and heat insulation. The foaming materials include PVC, PE and PS.
Products are: film, plate, pipe, and profile. Foaming can be divided into chemical foaming and physical foaming.
Blow molding
Blown (expanded film) plastic (or hollow blown plastic) is a kind of molding method that uses the pressure of fluid (compressed air) to blow the hot thermoplastic blank or sheet in the closed mold into hollow products.
A plastic container produced in this way. For example, various bottles, square, round or flat barrels, gasoline tanks, etc. have been widely used. Various newly developed industrial parts and daily products, such as double wall box shaped products, L-ring big barrels, palletizing boards, surfboards, seat backs and desks, as well as front baffles, belt covers, instrument boards, air conditioning and ventilation pipes for automobiles, have been applied in practice. The processed materials include: The development of domestic plastics to engineering plastics. Now blow molding has become one of the important forming methods in plastic processing.
But the basic steps of blow molding process are:
1. Melted materials
2. Forming the molten resin into a tube or mold
3. Melt and seal the hollow blank in the blowing mold
4. Blow out the mold blank
5. Cooling blow molded products
6. Take out the product from the mold
7. Finishing
Injection Blow Molding
Injection blow molding is a blow molding method. First, the plastic is made into a bottomed blank by injection molding, and then it is moved into a blow mold to blow it into a hollow product.
This method can be used to produce packaging containers for daily necessities, cosmetics, medicine, food, etc., but its volume should not exceed 1L. The commonly used plastics are polyethylene, polystyrene, PVC, etc.
extrusion blow molding
Extrusion blow molding is a blow molding method. Unlike injection blow molding, its parison is made by extrusion.
stretch blow molding
Stretch blow molding is a blow molding method. It uses extrusion, injection molding and other methods to make parison, and then heating parison to stretching temperature, longitudinal stretching is carried out under the mechanical force of internal (such as mandrel) or external (such as fixture), and transverse stretching is carried out at the same time or later through compressed air inflation.
