At present, the world's general thermoplastic plastic production accounts for almost 80% of the total output of plastic, China is no exception. These plastic processing is a physical processing technology, such as extrusion, injection, rolling, etc., which is a plastic by melting and heating and cooling process and products. Nearly 20 years, molding technology development very fast, but little change in tone, but has the one-way type to the combination type development, such as squeeze - pulling - blowing, injection stretch blow, extrusion - thermoforming, extrusion compound, from the general to the special conditions of the molding processing technology development, such as high pressure, high temperature, high vacuum, plasma spraying.
The extrusion molding
Thermoplastic resin and all kinds of additives after mixing granulation to add extruder. Materials in the barrel by mechanical shearing force and friction heat and heating to the melting plasticizing and in the screw to rotate forward shove the become dense melt. The molten material is then passed through the filter plate and the different types of molding die, and the section shape is constant.
We usually see the plate, rod, tube, wire sheath, wire, tape, some films are made with this method. The country has been able to produce the fine such as fishing nets and crude such as diameter of 0.2m of large diameter plastic pipe, but also in the production of building with special-shaped cross section profiles, such as plastic doors and windows.
Extrusion molding production efficiency, simple operation, uniform product quality; equipment can be large and small, can be simple, easy to manufacture, easy to put into production; can use a machine or a comprehensive production. The extrusion molding machine can also be used for mixing, plasticizing, dehydration, granulation, feeding different process.
The calendering
Calendering is one of the main thermoplastic molding method. The method is mainly made of thin film and sheet material. Suitable for rolling thermoplastic plastic PVC, PE, PP, ABS, CA, VC/EVA etc..
The injection molding
Injection molding, also known as injection molding, it is an injection molding method. The injection molding method has the advantages of high production speed and high efficiency, and the operation can be realized automatically. The disadvantage is that the mold cost is high, and cleaning difficult, so the small batch of products should not be used in this method. The forming method of product has: TV shell, semiconductor radio shell, on the electrical connector, a knob, a coil frame, gear, automobile lampshade, cup, bowl, dish, bath, sandals and so on.
At present, the injection molding is suitable for all thermoplastic plastic, its molding cycle is short, the variety of color, shape can be simplified to numerous, size can be large to small, and the product size is accurate, the product is easy to update.
The blow molding
Blow molding including blow molding and blow molding hollow products two.
The foam molding
Foam is made of resin as the main component of the internal contain numerous micro bubble hole of plastic products, also known as microporous or porous plastic. Modern technology can almost all of the thermoplastic and thermosetting resin processed into foam plastic. Currently used in the manufacture of foam plastics are polystyrene, polyvinyl chloride, polyethylene, polyurethane, urea formaldehyde resin, etc..
According to the degree of soft and hard, the plastic foam is divided into soft, hard and semi hard foam plastics.
|
|
