1.Injection molding - injection molding
Injection molding (injection molding) is a method to make thermoplastic or thermosetting molding materials uniformly plasticized in the heated barrel, then pushed into the closed mold cavity by plunger or moving screw and cooled and solidified.
The molding cycle of injection molding is short (seconds to minutes), and the quality of molding products can be from several grams to dozens of kilograms. It can mold products with complex shape, accurate size, metal or non-metal inserts at one time. Therefore, the method has strong adaptability, high production efficiency and can be mass produced. Injection molding is suitable for almost all thermoplastics.
Typical products: automobile plastic parts, plastic shell of consumer electronic products, etc.
2. Extrusion - extrusion
Extrusion molding, also known as extrusion molding or extrusion molding, is a method to make materials continuously flow through a specific shape of the die by heating and pressing in the extruder.
Extrusion method is mainly used for the molding of thermoplastics and also for some thermosetting plastics. Extrusion products are continuous profiles, such as tube, rod, wire, plate, film, wire and cable coating, etc. It is also used for mixing, plasticizing, granulating, coloring and blending of plastics.
3. Blow molding
Blow molding is a method to blow the closed hot billets into hollow products by gas pressure, or to blow the billets into tube membrane without mould. The method is mainly used for manufacturing various packaging containers and tubular membranes. All melt index of 0.04 ~ 1.12 are excellent hollow blow molding materials.
Typical products: chemical product packaging, consumer product packaging, drug packaging
4. Blister molding
With the aid of the blister machine, the heating piece on the blister mold is electrified to heat the plastic film and the blister oil on the blister machine, so as to achieve the melting in a short time, and complete the blister process through high pressure, pressure maintaining and cooling. In this process, heating and pressurization are carried out simultaneously. PVC is commonly used for packaging.
Typical products: plastic sheet packaging, disposable plastic lunch box, aerospace interior decoration, etc
5. Compression molding (Molding)
Compression molding, also known as compression molding, is the main method of molding thermosetting plastics and reinforced plastics. The technological process is to pressurize the raw materials in the mold heated to the specified temperature, so that the raw materials melt and flow and fill the mold cavity evenly. After a certain period of time under the conditions of heating and pressurization, the raw materials form products.
6. Rolling forming
Calendering is a forming method that the thermoplastic is connected into film or sheet by a series of heated rollers under the action of extrusion and calendering. There are film, sheet, artificial leather and other coating products. The raw materials used in calendering are mainly PVC, cellulose, modified polystyrene, etc. Rolling equipment includes rolling machine and other auxiliary machines. Calenders are usually classified by the number of rollers and their arrangement. According to the number of rollers, there are two rollers, three rollers, four rollers, five rollers or even six rollers in the calender, three rollers or four rollers are the most used.
7. Foam forming
Foaming is the process of making plastics have microporous structure. Almost all thermosets and thermoplastics can be made into foam plastics. The commonly used resins are polystyrene, polyurethane, polyvinyl chloride, polyethylene, urea formaldehyde, phenolic aldehyde and so on. According to the bubble structure, the foam plastics can be divided into two categories. If most stomata are interconnected, they are called open cell foam plastics. If most pores are separated from each other, they are called closed cell foam plastics. The foam structure with open or closed holes is determined by the manufacturing method. Foaming methods include chemical foaming, physical foaming and mechanical foaming.
Microcellular molding
Using the essence of low supercritical pressure and temperature of N2 or CO2, the supercritical fluid is injected into the feed pipe in supercritical state. By the diffusion effect of supercritical fluid with good diffusion and screw mixing, the supercritical fluid and molten plastic are mixed into a uniform single-phase body. In the process of injection, the supercritical fluid nucleates in the mold due to the instantaneous high pressure drop and grows into uniform micro bubbles. The plastic is cooled by the mold The bubbles are wrapped in the plastic to achieve the effect of micro foaming. It includes four processes: gas dissolution; nucleation; cell growth; shaping.
8. Winding
Winding forming refers to the forming of reinforced plastic products by winding continuous wires impregnated with resin glue onto the core mould or mould under the condition of controlling tension and predetermined line type. This method is only suitable for manufacturing cylindrical and spherical bodies of revolution. The commonly used resins are phenolic resin, epoxy resin, unsaturated polyester resin, etc. Glass fiber is a kind of reinforcement material commonly used in winding. It has two kinds: twist fiber and untwist fiber.
9. Lamination
Lamination refers to the method of combining two or more layers of the same or different materials into a whole by heating and pressing with or without binder. Lamination molding is usually operated by a laminating machine, in which a plurality of floating hot pressing plates are arranged between the moving pressing plate and the fixed pressing plate. The commonly used reinforcement materials for lamination are cotton cloth, glass cloth, paper, asbestos cloth, etc. the resins are phenolic, epoxy, unsaturated polyester and some thermoplastic resins.
10. Coating forming
Coating forming refers to the method of coating a thin layer of plastic (e.g. less than. 0.3mm) on the surface of fabric, paper, metal foil or plate in the form of liquid or powder for the purpose of anticorrosion, insulation, decoration, etc. The most commonly used plastics for coating are generally thermoplastic
