In the field of machine parts machining industry, plastics are often used as raw materials for further machining. Now there are many kinds of plastics on the market, so what kind of plastics should be selected when machining machine parts?
1. ABS Plastic
ABS resin is one of the five synthetic resins. It has excellent impact resistance, heat resistance, low temperature resistance, chemical resistance and electrical performance. It also has the characteristics of easy processing, stable product size, good surface gloss, easy painting and coloring. It can also carry out secondary processing such as surface spraying metal, electroplating, welding, hot pressing and bonding. It is widely used in machinery, automobiles, electronic appliances, instruments and meters Textile, construction and other industrial fields, is a very wide range of thermoplastic engineering plastics. ABS is usually light yellow or milky white granular amorphous resin. ABS is one of the most widely used engineering plastics。
2. Nylon PA6
The material has the most superior comprehensive properties, including mechanical strength, stiffness, toughness, mechanical shock absorption and wear resistance. These characteristics, together with good electrical insulation capacity and chemical resistance, make nylon 6 a “universal” material for the manufacture of mechanical structural parts and maintainable parts.
3. Nylon PA66
Compared with nylon 6, it has better mechanical strength, stiffness, heat resistance, wear resistance and creep resistance, but its impact strength and mechanical shock absorption performance are reduced, so it is very suitable for automatic lathe machining. PA66 is more widely used in the automotive industry, instrument housings and other products requiring impact resistance and high strength.
4. Nylon PA12
The scientific name of PA12 is polydodecalactam, also known as nylon 12. The basic raw material for polymerization is butadiene, which can depend on petrochemical industry. It is a semi crystalline crystalline thermoplastic material. Its characteristics are similar to PA11, but its crystal structure is different. PA12 is a good electrical insulator and like other polyamides, it will not affect the insulation performance due to moisture. It has good impact resistance and mechanical and chemical stability. PA12 has many improved varieties in plasticizing and strengthening properties. Compared with PA6 and PA66, these materials have lower melting point and density, and have very high moisture regain. PA12 has no resistance to strong oxidizing acids. Typical application scope of nylon 12: water meter and other commercial equipment, cable sleeve, mechanical cam, sliding mechanism, photovoltaic backplane and bearing, etc.
Polyvinyl chloride (PVC for short) is the initiator of vinyl chloride monomer (VCM for short) in peroxide, azo compound, etc; Or polymers polymerized under the action of light and heat according to the mechanism of free radical polymerization. Vinyl chloride homopolymer and vinyl chloride copolymer are collectively referred to as vinyl chloride resin. PVC used to be the most common plastic in the world, and it was widely used. It is widely used in building materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.
6. POM Saigang
POM is a tough and elastic material, which has good creep resistance, geometric stability and impact resistance even at low temperatures. POM has both homopolymer and copolymer materials. Homopolymer materials have good ductility and fatigue strength, but are not easy to process. Copolymer materials have good thermal stability, chemical stability and are easy to process. Both homopolymer materials and copolymer materials are crystalline materials and not easy to absorb water. The high crystallinity of POM results in a very high shrinkage, which can be as high as 2%~3.5%. There are different shrinkage rates for different reinforced materials. POM has very low friction coefficient and good geometric stability, which is particularly suitable for making gears and bearings. Because of its high temperature resistance, it is also used for pipeline devices (valves, pump shells), lawn equipment, etc. Audio machines such as video recorders, CD, LD, MD players, radios, headphones, stereos, OA machines such as printers, keyboards, CD-ROM drives, household appliances such as washing machines, dryers, hair dryers, automotive parts such as seat belt mechanical parts, exterior door handles, reflectors, engine rooms, as well as precision parts such as cameras, clocks, and building materials, Materials for forming toys such as game consoles and stationery.
7. PMMA Acrylic
Polymethyl methacrylate is a popular name, abbreviated as PMMA. The chemical name of this polymer transparent material is polymethyl methacrylate, which is a polymer compound polymerized from methyl methacrylate. It is an important thermoplastic developed earlier. Organic glass is divided into colorless transparent, colored transparent, pearlescent and embossed organic glass. PMMA is commonly known as Acrylic, Zhongxuan Acrylic and Acrylic. PMMA has good transparency, chemical stability, mechanical properties and weather resistance, easy dyeing, easy processing, beautiful appearance and other advantages. Organic glass is also called gelatin glass, acrylic, etc. The material is widely used in the production of advertising light boxes, nameplates, etc.
Polycarbonate (PC for short) is a polymer containing carbonate group in the molecular chain. According to the structure of the ester group, it can be divided into aliphatic, aromatic, aliphatic aromatic and other types. The application of aliphatic and aliphatic aromatic polycarbonate in engineering plastics is limited due to their low mechanical properties. The three major application fields of PC engineering plastics are glass assembly industry, automobile industry, electronics and electrical appliances industry, followed by industrial machinery parts, optical disks, packaging, computer and other office equipment, medical and health care, film, leisure and protective equipment, etc
Polypropylene is a thermoplastic resin made from propylene polymerization. The relative density is only 0.89-0.91, which is one of the lightest plastics. Because of its high crystallinity, this material has good surface stiffness and scratch resistance. PP has no environmental stress cracking problem.
PPS plastic (polyphenylene sulfide) is a kind of thermoplastic special engineering plastic with excellent comprehensive properties. Its outstanding characteristics are high temperature resistance, corrosion resistance and superior mechanical properties. The electrical insulation (especially high-frequency insulation) is excellent, white hard and brittle, there is a metallic sound when falling to the ground, the light transmittance is second only to that of organic glass, the coloration is water resistant, and the chemical stability is good. It has excellent flame retardancy and is non combustible plastic. The strength is general, the rigidity is good, but the quality is brittle, and the stress embrittlement is easy to occur; Not resistant to benzene, gasoline and other organic solvents; The long-term use temperature can reach 260 ℃, and it is stable in 400 ℃ air or nitrogen. After modification by adding glass fiber or other reinforcement materials, the impact strength, heat resistance and other mechanical properties can be greatly improved. The density is increased to 1.6-1.9, and the molding shrinkage is smaller to 0.15-0.25%. It is suitable for making heat resistant parts, insulating parts, chemical instruments, optical instruments and other parts.
Polyether ether ketone (PEEK) resin is a kind of special engineering plastics with excellent performance. Compared with other special engineering plastics, it has more significant advantages, such as positive high temperature resistance of 260 degrees, excellent mechanical properties, good self-lubrication, chemical corrosion resistance, flame retardancy, peel resistance, wear resistance, non resistance to strong nitric acid, concentrated sulfuric acid, radiation resistance, and super mechanical properties, which can be used in high-end machinery, nuclear engineering, aviation and other technologies.
12. Teflon PTFE
Polytetrafluoroethylene (PTFE for short) (commonly known as “plastic king, Hara”), trademark Teflon ®， In China, because of its pronunciation, the trademark “Teflon” is also called “Teflon”, “Teflon”, “Teflon”, “Teflon”, “Teflon”, “Teflon”, “Teflon” and so on, all of which are transliterations of “Teflon”. Products of this material are generally referred to as “non stick coatings”; It is a synthetic polymer material that uses fluorine to replace all hydrogen atoms in polyethylene. This material has the characteristics of acid resistance, alkali resistance and resistance to various organic solvents, and is almost insoluble in all solvents. At the same time, PTFE has the characteristics of high temperature resistance, its friction coefficient is extremely low, so it can be used as a way of lubrication, and also become an ideal coating that does not stick to the inner layer of pots and water pipes.
13. Polyurethane PU
Polyurethane is a kind of polymer with – NHCOO – repeating structural unit in the main chain, abbreviated as PU, which includes rigid polyurethane plastics, soft polyurethane plastics, polyurethane elastomers and other forms, and is divided into two categories: thermoplastic and thermosetting. Its raw materials are generally presented in resin state.
Polyethylene terephthalate is the most important variety of thermoplastic polyester, commonly known as polyester resin. It is prepared by transesterification of dimethyl terephthalate with ethylene glycol or esterification of terephthalic acid with ethylene glycol to synthesize dihydroxyethyl terephthalate first, and then by polycondensation. Together with PBT, it is called thermoplastic polyester, or saturated polyester. It has excellent physical and mechanical properties in a wide temperature range. Its long-term use temperature can reach 120 ℃. Its electrical insulation is excellent. Even under high temperature and high frequency, its electrical performance is still good, but its corona resistance is poor, creep resistance, fatigue resistance, friction resistance and dimensional stability are good.
One thought on “How To Choose The Plastic Material For Machining Mechanical Parts?”
This is a great blog! Acrylic, ABS, Acetal and ETFE are plastics with unparallel machining characteristics. They machine well and hold up much better than the soft and flexible ones. Plastics are mostly used as raw materials in CNC machining.