1. Plastic molding: injection molding
It is a method in which the plastic is heated and melted in the heating barrel of the injection molding machine, and then the melt is pushed into the cavity of the closed mold by the reciprocating screw.
It can not only produce high-precision, high-quality products under high productivity, but also can process a variety of plastics, and it has a large output (about 1/3 of the total plastic) and wide use, so injection molding is one of the important plastic molding methods in plastic processing.
2. Plastic molding: extrusion molding
Extrusion is a method in which plastic is continuously formed through a die in a flowing state by heating and pressing in an extruder.
It is generally used for plastic molding of the sheet, pipe, monofilament, flat wire, film, wire, cable covering, etc. It has a wide range of uses and high output. Therefore, it is one of the important molding methods in plastic processing.
3. Plastic molding: foam molding
It refers to the method of adding an appropriate foaming agent to foamed materials to produce porous or foamed products. Foamed products have the advantages of low relative density, high specific strength, less amount of raw materials, sound insulation, and heat insulation. Foaming materials include PVC, PE, PS, etc.
Products include film, sheet, pipe, profile, etc. Foaming can be divided into chemical foaming and physical foaming.
4. Plastic molding: blow molding
Blow (expanded film) molding (or hollow blow molding) refers to a molding method in which a thermoplastic parison or sheet in a closed mold is blown into a hollow product using fluid (compressed air) pressure.
Plastic containers produced by this method, such as various bottles, square, round or flat barrels, gasoline tanks have been widely used, and newly developed various industrial parts and daily products, such as double-walled box-shaped products, L-ring drums, palletizing boards, surfboards, seat backs, and desks, as well as front spoilers for automobiles, belt covers, instrument panels, air-conditioning ventilation pipes, etc., have been applied in practice. The processed materials have developed from daily-use plastics to engineering plastics. Now blow molding has become one of the important plastic molding services in plastic processing.
5. Plastic molding: injection blow molding
Injection blow molding is a blow molding method in which plastic is first made into a bottomed parison by injection molding, and then it is moved to a blow mold and blown into a hollow product.
This method can produce packaging containers for daily necessities, cosmetics, medicine, food, etc., but the volume should not exceed 1L. Commonly used plastics include polyethylene, polystyrene, and polyvinyl chloride.
6. Plastic molding: extrusion blow molding
Extrusion blow molding is a blow molding method, and unlike injection blow molding, its parison is manufactured by extrusion.
7. Plastic molding: stretch blow molding
Stretch blow molding is a blow molding method, which is to form a parison by extrusion, injection molding, etc. Then the parison is heated to the drawing temperature and stretched longitudinally under the action of internal (such as mandrel) or external (such as fixture) mechanical force. At the same time or later, it is expanded by compressed air and stretched laterally.