plastic classification
- Dec 28, 2018 -

(1) general plastic



It is to point to output is big commonly, use is wide, formative sex is good, the plastic with cheap price. General plastic


particles


particles


Is expected to have five varieties: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile ─ ─ butadiene styrene (ABS) polymer. The five types of plastic takes up the vast majority of plastic materials used, the rest of the basic can be classified as special plastic varieties, such as: PPS, PPO, PA, PC, POM, etc., their dosage is very few, in the daily life products mainly used in the engineering industry, national defense science and technology and other high-end areas, such as automobile, aerospace, construction, communications and other fields. Plastics can be classified into thermoplastics and thermosetting plastics according to their plasticity. Usually, thermoplastic products can be recycled, and thermosetting plastic is not, according to the optical properties of plastic, can be divided into transparent, translucent and opaque raw materials, such AS PS, PMMA, AS, PC and other plastic belongs to transparent plastic, and most other plastic are opaque plastic.



Properties and USES of common plastics



1. Polyethylene: common polyethylene can be divided into low-density polyethylene (LDPE) and high-density polyethylene (HD)


Special plastic


Special plastic


PE) and linear low-density polyethylene (LLDPE). Among the three, HDPE has better thermal, electrical and mechanical properties, while LDPE and LLDPE have better flexibility, impact properties and film forming properties. LDPE and LLDPE are mainly used for packaging film, agricultural film, plastic modification, etc., while HDPE is widely used, film, pipe, injection daily necessities and other fields.



2. Polypropylene, relatively speaking, more variety of polypropylene, use also is more complex, area is various, main varieties are polyethylene polypropylene (homopp), block copolymerization polypropylene (copp) and random copolymerization polypropylene (rapp), according to different purposes, the homopolymerization mainly used in wire drawing, fiber, injection, BOPP film, and other fields, copolymerization polypropylene is mainly used in household appliances injection parts, modified materials, daily injection products, pipes, etc., random polypropylene is mainly used for transparent products, high-performance products, high performance steel tubes, etc.



3. Polyvinyl chloride: due to its low cost, the product has the characteristics of self-flame retardant, so it is widely used in the construction field, especially the sewer pipe, plastic steel doors and Windows, plates, artificial leather and other USES are the most extensive.



4 polystyrene: as a transparent raw material, in the case of transparent demand, the use of a wide range of, such as car lampshade, daily transparent parts, transparent cups, cans and so on.



ABS: it is an engineering plastic with a wide range of USES. It has outstanding physical mechanical and thermal properties, and is widely used in household appliances, panels, masks, composite parts, accessories, etc., especially household appliances, such as washing machines, air conditioners, refrigerators, fans, etc., the amount of which is very large. In addition, it has a wide range of USES in plastic modification.



(2) engineering plastics



Generally refers to the ability to withstand certain external forces, with good mechanical properties and resistance to high and low temperature performance, dimensional stability, can be used as a plastic engineering structure, such as polyamide, polysulfone. In engineering plastics, it is divided into general engineering plastics and special engineering plastics. Engineering plastics in mechanical properties


Engineering plastics


Engineering plastics


Energy, durability, corrosion resistance, heat resistance and other aspects can achieve higher requirements, and processing is more convenient and can replace metal materials. Engineering plastics are widely used in electronic and electrical, automotive, construction, office equipment, machinery, aerospace and other industries, plastic for steel, plastic for wood has become an international trend.



General engineering plastics include: polyamide, polyformaldehyde, polycarbonate, modified polyphenyl ether, thermoplastic polyester, ultra-high molecular weight polyethylene, methyl pentene polymer, vinyl alcohol copolymer, etc.



Special engineering plastics can be divided into cross-linked and non-cross-linked plastics. Cross-linked: polyurethane bimaleamide, polytriazine, cross-linked polyimide, heat resistant epoxy tree fingers. Non-crosslinked: polysulfone, polyether sulfone, polyphenyl sulfide, polyimide, polyether ether ketone (PEEK).



(3) special plastic



It is to point to have special function commonly, can be used at aviation, aerospace the plastic of special application domain. For example, fluorine plastics and silicone have outstanding high temperature resistance, self-lubrication and other special functions, reinforced plastics and foam plastics have high strength, high buffer and other special properties, these plastics belong to the category of special plastics.



A. reinforced plastics:



Reinforced plastic raw materials can be divided into granular shape (such as calcium plastic reinforced plastic), fibrous shape (such as glass fiber or glass cloth reinforced plastic), flake shape (such as mica reinforced plastic) three kinds. According to the material can be divided into cloth base reinforced plastic (such as rags reinforced or asbestos reinforced plastic), inorganic mineral filled plastic (such as quartz or mica filled plastic), fiber reinforced plastic (such as carbon fiber reinforced plastic) three.



B. foam plastics:



Foamed plastics can be divided into hard, semi-hard and soft foamed plastics. Rigid foam plastic has no flexibility, compression hardness is very large, only to reach a certain stress value before deformation, stress relief can not be restored to its original state; Soft foam plastic is very flexible, the compression hardness is very small, it is easy to deformation, stress relief can be restored to its original state, the residual deformation is small; The flexibility and other properties of semi-rigid foams are between hard and soft foams.