Brief introduction of several main molding process

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Introduction to several main molding processes for processing plastic products

at present, the output of general thermoplastic plastics in the world accounts for almost 80% of the total output of plastics, and China is no exception. The processing of these plastics is physical processing technology, such as extrusion, injection, calendering, etc., that is, plastic products are made through the process of heating, melting and cooling. In the past 20 years, the forming and processing technology has developed rapidly, but the tone has changed little, but it has developed from unidirectional type to combined type, such as extrusion drawing blowing, injection drawing blowing, extrusion thermoforming, extrusion compounding, and from general to special conditions, such as high pressure, high temperature, high vacuum, plasma spraying, etc

extrusion molding

thermoplastic resin and various additives are mixed and granulated and then added to the extruder. The material is melted and plasticized by the mechanical shear force, friction heat and external heating in the barrel, and at the same time, it becomes a dense melt under the push of the screw rotating forward. When the molten body passes through the filter plate and the sundries are removed, it must be shut down for different types of forming die, and become a profile with constant cross-section shape, and the product is obtained after cooling and shaping

the plates, rods, tubes, wire sheaths, wires, tapes, and some films we usually see are made by this method. China has been able to produce fine plastic pipes such as fishing silk and thick plastic pipes with a diameter of 0.2m, as well as profiled sections used in buildings, such as plastic doors and windows

extrusion molding has high production efficiency, simple operation and uniform product quality; The equipment can be large or small, simple or refined, easy to manufacture and easy to put into production; It can be multi-purpose or integrated. At the same time, good experience accumulation is still an indispensable part of production. In addition, the extruder can also be used for mixing, plasticizing, dehydration, granulation, feeding and other different processes

calendering molding

calendering molding is one of the main molding methods of thermoplastic. This method is mainly used to manufacture thin films and sheet materials. Thermoplastics suitable for calendering include PVC, PE, PP, ABS, CA, vc/eva, etc

injection molding

injection molding is also called injection molding, which is a molding method of injection and molding. The advantages of injection molding method are fast production speed, high efficiency, automation of operation, and molding of products with complex shapes. The disadvantage is that the mold cost is high and it is difficult to clean, so this method is not suitable for small batch products. The products formed by this method include: TV shell, semiconductor radio shell, connectors on electrical appliances, knobs, coil frames, gears, car lampshades, tea cups, rice bowls, soap boxes, bathtubs, sandals, etc

at present, injection molding is applicable to all thermoplastics. Its molding cycle is short, there are many varieties of designs and colors, the shape can be from simple to complex, the size can be from large to small, and the product size is accurate, and the product is easy to update

blow molding

blow molding includes blow molding film and blow molding hollow products

forming of foamed plastics

foamed plastics are plastic products made of resin with countless tiny bubbles inside, also known as microporous or porous plastics. Modern technology can process almost all thermoplastic and thermosetting resins into foamed plastics. At present, the resins commonly used in the manufacture of foamed plastics include polystyrene, polyvinyl chloride, polyethylene, polyurethane, urea formaldehyde resin and so on

foamed plastic is divided into the overall size of the design sample according to the different degree of hardness and softness of the product; Soft, hard and semi-rigid foamed plastics

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