A wide range of engineering plastics and its wide range of applications, its excellent performance is often used to replace metal materials.Many friends in the plastics industry in the choice of raw materials when the type, often because it can not correctly distinguish the characteristics of different varieties of plastic and worry. Basic performance, processing performance and use of three aspects for you to detail the variety of engineering plastics.
1, polyamide PA
Basic nature
proportion: PA6-1.14 g / cm³, PA66-1.15 g / cm³, PA1010-1.05 g / cm³
Shrinkage: PA6-0.8-2.5%, PA66-1.5-2.2%
Molding temperature: 220-300 ° C
Drying conditions: 100-110 ° C, 12 hours
Material properties:
Nylon 66 is better than nylon 6, high strength, good wear resistance; nylon 610 with nylon, nylon, nylon, nylon, nylon, nylon, nylon, nylon, nylon, nylon, nylon, nylon, 66 similar, but the water is small, low stiffness; nylon 1010 translucent, small water absorption, cold resistance is better.
Forming characteristics
1, the melting point of the crystallization material is higher, the melting temperature range is narrow, the thermal stability is poor, the material temperature is more than 300 degrees, the residence time is more than 30min, the decomposition is easy to absorb moisture, dry, water content should not exceed 0.3%
2, good liquidity, easy to flash material. It is appropriate to use self-locking nozzle, and should be heated;
3, forming shrinkage range and shrinkage, directional obvious, prone to shrinkage, deformation, etc .;
4, the mold temperature according to the plastic wall thickness in the range of 20-90 degrees, the injection pressure by injection machine type, material temperature, plastic parts size, mold casting system selected, the molding cycle selected by the plastic wall thickness. Viscosity, injection, cooling time should be taken long, and with white oil as release agent;
5, mold pouring system in the form and size, increase the flow channel and gate size can reduce the shrinkage.
The scope of application
Production of general mechanical parts, wear-resistant wear parts, transmission parts, and chemical, electrical, instrumentation, and so on.
2, polycarbonate PC
Basic nature
proportion: 1.18-1.20 g / cm³
Shrinkage: 0.5-0.8%
Molding temperature: 230-320 ° C
Drying conditions: 110-120 ° C, 8 hours
Material properties:
High impact strength, good color stability, colorless, good coloring, electrical insulation, corrosion resistance, good wear resistance, but poor self-lubricating, stress cracking tendency, high temperature easy hydrolysis, poor compatibility with other resins The
Forming characteristics
1, amorphous material, good thermal stability, wide molding temperature range, poor mobility. Moisture is small, but sensitive to water, subject to drying treatment. Shrinkage is small, prone to melt cracking and stress concentration, it should be strictly controlled molding Conditions, plastic parts subject to annealing;
2, the melting temperature is high, high viscosity, more than 200g of plastic parts is appropriate to use heating extension nozzle;
3, the cooling speed, mold pouring system to coarse and short principle, should be set up cold wells, gates should take large, mold should be heated;
4, the material temperature is too low will cause lack of material, plastic parts dull, material temperature is too high easy to overflow edge, plastic parts foam. Mold temperature low shrinkage, elongation, impact strength, bending, , Tensile strength is low. Mold temperature over 120 degrees when the plastic parts slow cooling, easy deformation of sticky mold.
The scope of application
Production of small parts of the instrument, transparent insulation and impact resistance parts.
3, POM POM
Basic nature
proportion: 1.41-1.43g / cm³
Shrinkage: 1.2-3.0%
Molding temperature: 170-200 ° C
Drying conditions: 80-90 ° C for 2 hours
Material properties
Good overall performance, strength, high rigidity, wear and wear resistance, small water absorption, good dimensional stability, but the thermal stability is poor, easy to burn, in the atmosphere exposure to aging.
Forming characteristics
1, crystal material, melting range is narrow, melting and solidification fast, the material temperature is slightly lower than the melting temperature that occurs crystallization. Mobility medium. Moisture is small, can not dry;
2, the friction coefficient is low, good elasticity, plastic parts of the surface prone to wrinkle surface defects;
3, easy to break down, the decomposition temperature of 240 degrees. Decomposition of the irritation and corrosive gases occur, so the mold steel should be made of corrosion resistance of the material system.
The scope of application
Production wear wear parts, transmission parts, as well as chemical, instrumentation and other parts.
4, polyphenylene oxide PPO
Basic nature
proportion: 1.07 g / cm³
Shrinkage: 0.3-0.8%
Molding temperature: 260-290 ° C
Drying conditions: 130 ° C for 4 hours
Material properties
1, for the white particles. Comprehensive performance is good, can be used in 120 degrees of steam, electrical insulation is good, small water absorption, but the tendency of stress cracking. Modified polyphenylene ether can eliminate stress cracking;
2, has outstanding electrical insulation and excellent water resistance, good dimensional stability. Its dielectric properties in the first plastic;
3, MPPO for PPO and HIPS blends made of modified materials, the current market materials are such materials;
4, a higher heat resistance, glass transition temperature of 211 degrees, the melting point of 268 degrees, heated to 330 degrees have a tendency to decompose, the higher the content of PPO its heat resistance better, hot deformation temperature of up to 190 degrees;
5, good flame retardant, with the self-interest, and HIPS mixed with a medium flammable. Light, non-toxic can be used in food and pharmaceutical industry. Lightfastness, long time in the sun will use color;
6, with ABS, HDPE, PPS, PA, HIPS, glass fiber, such as blending modified treatment.
Forming characteristics
1, non-crystalline material, moisture absorption is small;
2, poor mobility, similar to the Newtonian fluid, the viscosity of the temperature is more sensitive, the product thickness is generally above 0.8mm. Easily decomposed, decomposition of corrosive gases. Should strictly control the molding temperature, the mold should be heated, pouring system on the flow resistance Should be small
3, polyphenylene ether water absorption is very low about 0.06%, but the amount of water will lead to the product surface silver wire and other non-smooth phenomenon, it is best for drying, the temperature can not be higher than 150 degrees, otherwise the color will change;
4, the molding temperature of the polyphenylene ether is 280-330 degrees, and the molding temperature of the modified polyphenylene ether is 260-285 degrees.
The scope of application
Production of heat-resistant parts, insulation, wear-resistant wear parts, transmission parts, medical and electronic parts; can be used for higher temperature gears, blades, valves and other parts, can replace the use of stainless steel; Parts and connectors; electrical parts of motors, rotors, enclosures, transformers.
5, thermoplastic polyester
Polyethylene terephthalate PET
Basic nature
Previously used mostly as fiber, that is, polyester fiber, and now to the engineering plastics, plastic packaging, the rapid development of different according to the use of PET can be divided into fiber grade, film grade, blowing grade and enhanced.
Material properties
1, colorless transparent or milky white translucent solid;
2, has a high tensile strength, stiffness and hardness, but there is a certain flexibility, good wear resistance, creep resistance, and can be in a wide temperature range to maintain these good mechanical properties;
3, with excellent electrical insulation;
4, with excellent weather resistance, exposure to outdoor for six years, its mechanical properties can still maintain the initial 80%;
5, resistant to weak acid, organic solvents and oils have good chemical stability.
The scope of application
1, the production of film, photosensitive film, such as film film film, photographic film film;
2, as a food, medicine, textiles, precision instruments, electrical components and other packaging, the production of hollow containers of high strength, good transparency, non-toxic and tasteless, carbonated beverages, beer, edible oil and other widely used plastic packaging materials; material;
3, for the production of various electrical insulation materials, such as wires, switches, electrical enclosures and so on.
Polybutylene terephthalate PBT
Basic nature
PBT used as engineering plastics has been modified and modified two kinds of unmodified grade molding shrinkage, mechanical properties less than other engineering plastics, so rarely used alone. Nearly 80% of the PBT are modified.
Material properties
1, for the milky white crystalline solid, tasteless, odorless, non-toxic, the product surface shiny. Flexibility better than PET, melting temperature and rigidity are relatively small;
2, with excellent electrical insulation, even in humid and harsh environments can be maintained;
3, have good weather resistance;
4, can resist the general chemical corrosion, such as weak acid.
The scope of application
1, the production of various auto parts, such as door handles, bumper, rearview mirror shell;
2, the production of electrical and electronic parts, such as connectors, sockets, plugs, fuse boxes, etc .;
3, the production of various electrical enclosures and components, such as telephones, indoor and outdoor lighting appliances shell, hair dryer components.
6, ultra-high molecular weight polyethylene UHMWHPE
Basic nature
Relative molecular mass of more than 1.5 million, the overall performance of conventional molecular weight polyethylene does not have special engineering plastics. Molecular structure and ordinary polyethylene is exactly the same, but the molecular weight is particularly high in the relative molecular mass of more than 1.5 million UHMWPE, there are relative Molecular weight of 2 million, 300 million, or even up to 5 million or more grade.
Material properties
1, the average molecular weight of about 350,000 to 8 million, due to high molecular weight and other plastic unparalleled excellent impact resistance, wear resistance, self-lubricating, chemical resistance and other properties;
2, excellent low temperature performance, -40 ℃ still has a high impact strength, or even at -269 ℃ use;
3, with electrical insulation, low water absorption and physiological inertia;
4, with excellent resistance to stress cracking, creep resistance and fatigue resistance.
The scope of application
It is widely used in the fields of machinery, transportation, textile, papermaking, mining, agriculture, chemical industry and sports equipment. Among them, the application of large-scale packaging containers and pipelines is the most extensive. Because of its excellent physiological inertia, it has been used as heart valve, orthopedic , Artificial joints and so on in clinical medicine.
7, Thermoplastics
Polyacrylonitrile - Butadiene - Styrene ABS
Basic nature
Specific gravity: 1.05g / cm³
Molding shrinkage: 0.4-0.7%
Molding temperature: 200-240 ° C
Drying conditions: 80-90 ° C, 2 hours
Material properties
1, the overall performance is better, higher impact strength, chemical stability, good electrical properties;
2, and 372 plexiglass weld well, can be made of two-color plastic parts, and the surface chrome, paint treatment;
3, a high impact, high heat, flame retardant, enhanced, transparent level;
4, liquidity almost worse than HIPS, better than PMMA, PC, etc., good flexibility.
Molding characteristics
1, amorphous material, medium fluidity, large moisture absorption, must be fully dried, the surface of the plastic parts require a long time to preheat the dried 80-90 degrees, 3 hours;
2, should take high feed temperature, high mold temperature, but the material temperature is too easy to decompose (decomposition temperature of> 270 degrees), the plastic parts of higher precision, mold temperature should take 50-60 degrees, high gloss, resistance Thermoplastic parts, mold temperature should take 60-80 degrees;
3, If you need to solve the watermark, you need to improve the fluidity of the material, adopt high temperature, high mold temperature, or change into the water level and other methods;
4, such as forming heat-resistant grade or flame-retardant materials, the production of 3-7 days after the mold surface will remain plastic decomposition products, resulting in shiny mold surface, the mold needs to be promptly cleaned, while the mold surface to increase the exhaust position.
The scope of application
Production of general mechanical parts, wear-resistant wear parts, transmission parts and telecommunications components.
8, polyphenylene sulfide PPS
Basic nature
proportion: 1.36g / cm³
Molding shrinkage: 0.7%
Molding temperature: 300-330 ° C
Material performance
1, electrical insulation (especially high-frequency insulation) excellent, white, hard and brittle, dropped to the ground with metal sound, light transmittance second only to plexiglass, tinting water resistance, good chemical stability. Flammability, non-combustible plastic;
2, the strength of the general, very good rigidity, but crisp, easy to produce stress brittle crack; not benzene, gasoline and other organic solvents; long-term use temperature up to 260 degrees, 400 degrees in air or nitrogen to maintain stability by adding glass After the modification of fiber or other reinforcing materials, the impact strength can be greatly improved, the heat resistance and other mechanical properties have also been improved, the density is increased to 1.6-1.9g / cm³ and the molding shrinkage is as small as 0.15-0.25%.
Molding characteristics
1, amorphous material, hygroscopic, but should be dried after forming;
2, Mobility between ABS and PC, fast solidification, small shrinkage, easy to decompose, use a higher injection pressure and injection speed. Mold temperature to take 100-150 degrees. Main channel taper should be large, runner should be short.
The scope of application
Manufacture of heat-resistant parts, insulation and chemical equipment, optical instruments and other parts such as: TV, high-voltage components on the computer, shell, motor starting coil, blades, brush bracket and rotor insulation components, relays, F-class film, etc. The automobile can be made exhaust gas recirculation valve and pump impeller, bearings, sensing parts and so on.
9, polysulfone PSF or PSU
Basic nature
proportion: 1.25-1.35 g / cm³
Shrinkage: 0.5-0.7%
Molding temperature: 290-350 ° C
Drying conditions: 130-150 ° C, hours
Material properties
1, polysulfone for the amber transparent solid material, hardness and impact strength, non-toxic, heat and cold resistance to aging resistance, and can be used at -100--175 degrees long-term use. Resistance to inorganic acid salt corrosion, but not Aromatic and halogenated;
2, through the glass fiber reinforced modified materials can make a significant increase in wear resistance;
3, can be polysulfone and ABS, polyimide, polyether ether ketone and fluorine plastic made of polysulfone modified products, mainly to improve its impact strength and elongation, solvent resistance, environmental resistance, processing Performance and electroplability such as PSF / PBT, PSF / ABS, PSF + mineral powder.
Forming characteristics
1, amorphous material, moisture absorption, water absorption of 0.2% -0.4%, before use to be fully dry, and to prevent reabsorption to ensure that the water content of 0.1% or less;
2, forming performance and PC similar to the thermal stability is poor, 360 degrees began to break down;
3, poor mobility, fast cooling, it is appropriate to use high temperature and high pressure molding. Mold should have sufficient strength and stiffness, set the cold material wells, flow channel should be short, gate size to take plastic parts wall thickness of 1 / 2-1 / 3;
4, in order to reduce the stress caused by injection molding products, mold temperature should be controlled at 100-140 degrees. After molding can be taken to deal with glycerol bath annealing, 160 degrees, 1-5 minutes; or take the air bath 160 degrees, 1-4 Hour. The annealing time depends on the size and wall thickness of the product;
5, polysulfone in the molten state close to the Newton body, similar to polycarbonate, from the mobility of the temperature is more sensitive, in the 310 degrees -420 degrees, the temperature increased by 30 degrees, the mobility increased by 1 times. Molding mainly through improving the temperature to improve the processing of liquidity.
The scope of application
1, suitable for the production of heat-resistant parts, insulation, wear-resistant wear parts, instrumentation parts and medical equipment parts, but also for the production of low-temperature work parts;
2, polysulfone in the electrical and electronic industry commonly used in the manufacture of integrated circuit boards, coil racks, contactors, casing, capacitor film, high-performance alkaline battery shell;
3, polysulfone in the field of household appliances for microwave oven equipment, coffee heaters, humidifiers, hair dryer, cloth dryers, beverages and food dispensers, etc. Also can replace non-ferrous metals for watches, copiers, cameras, etc. Precision structural parts;
4, polysulfone has been through the US pharmaceutical, food field of the relevant norms, can replace the stainless steel products, used as surgical tool tray, sprayer, fluid controller, heart valve, pacemaker, gas mask, dental care and so on.
10, fluorine plastic
Fluoroplastics are partially or fully hydrogen-substituted paraffinic polymers containing polytetrafluoroethylene (PTFE), perfluoroethylene propylene (FEP) copolymers, poly perfluoroalkoxy (PFA) resins, polytrifluoro Vinyl chloride (PCTFF), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene tetrafluoroethylene (ETFE) copolymer, polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF).
Teflon PTFE
Basic nature
proportion: 2.1-2.2g / cm³
Shrinkage: 3.1-7.7%
Molding temperature: 330-380 ° C
Material properties
1, long-term use temperature -200--260 degrees, excellent chemical resistance, corrosion resistance to all chemicals, the lowest coefficient of friction in the plastic, there are good electrical properties, the electrical insulation from temperature Influence, there is 'plastic king' said;
2, was transparent or translucent state, the higher the crystallinity, the worse the transparency of raw materials are mostly powdery resin or concentrated dispersion, with high molecular weight, high crystallinity for the thermoplastic polymer.
Forming characteristics
1, crystal material, moisture absorption is small;
2, poor mobility, easy to break down, decomposition of corrosive gases should be strictly controlled molding temperature, the mold should be heated, pouring system on the flow resistance should be small;
3, the powder resin often powder powder metallurgy molding, the use of sintering method. Sintering temperature 360-380 degrees, not more than 475 degrees. Emulsion resin is usually cold extrusion and re-sintering process, can form a coating on the surface of the product. If you need to ask for transparency, toughness, should take a quick cooling. Can also take extrusion molding, you can squeeze out the tube,
4, PTFE melt viscosity is high, the viscosity of the body decreases with the increase of shear stress, showing the characteristics of its non-Newtonian fluid;
5, the second processing, you can hot-press composite, welding, bonding, enhanced, mechanical processing, etc., in order to obtain the final product.
The scope of application
Production of corrosion-resistant parts, wear-resistant wear parts, seals, insulation and medical equipment parts.
Polytetrafluoroethylene - ethylene copolymer ETFE
Basic nature
proportion: 1.7g / cm³
Shrinkage: 3.1-7.7%
Molding temperature: 300-330 ° C
Material performance
1, long-term use temperature -80--220 degrees, excellent chemical resistance, corrosion resistance to all chemicals, the lowest friction coefficient in plastic, as well as good electrical properties, the electrical insulation from temperature Influence, there is 'plastic king' said;
2, its chemical resistance and PTFE similar, better than vinylidene fluoride;
3, its creep resistance and compressive strength are better than Teflon, high tensile strength, elongation up to 100-300%, good dielectric properties, excellent radiation resistance.
Molding characteristics
1, crystal material, hygroscopicity can be processed by the usual thermoplastic processing methods into products;
2, poor mobility, easy to break down, decomposition of corrosive gases should be strictly controlled molding temperature should not exceed 350 degrees, the mold should be heated to 100
11, poly aryl ether ketone PEAK
Poly (aryl ether ketone) (PEAK) is a kind of phenylene ring through the ether bond and carbonyl group connected to the polymer. At present, there are polyether ether ketone (PEEK), polyether ketone (PEK), polyether ketone ketone (PEKK ), Polyether ether ketone ketone (PEEKK) and polyether ketone ether ketone ketone (PEKEKK), etc. The lower the proportion of ether bond and ketone (E / K) in the molecular chain, Its melting point and the higher the glass transition temperature.The polyether ether ketone molecular structure of the ether bond and make it flexible, so you can use thermoplastic engineering plastics processing methods for forming processing.
Material properties
1, with good high temperature performance, long-term use temperature above 240 ℃;
2, high mechanical properties. Resistance to chemical corrosion is excellent, there is a good anti-radiation, can withstand 10MGy γ-ray irradiation;
3, the combustion performance can reach UL94V-0 level, and when burning very little smoke and non-toxic, the heat released when burning is also very little, which is the aircraft interior decoration is a very important technical performance;
4, in a wide operating temperature and frequency range has good electrical properties, high frequency dielectric loss is small, is excellent high temperature, high strength C-class electrical insulation material.
The scope of application
1, and more used in the field of high-tech aerospace, or more demanding technical requirements of the automotive industry, electrical and electronic industry and the machinery industry, some structural components;
2, for the aircraft on the fire, oil of the various connectors; weather, creep resistance of the radome;
3, for the automotive industry and the machinery industry can withstand a variety of dynamic load components, such as bearing retainers, gears, hot water pumps, turbine blades, wear-resistant seal ring;
4, in medical equipment, PPEK hemodialysis machine in the manufacture of heaters and pressure sensor shell and the need for sterilization of dental equipment, PPEK can also replace metal, the production of human bones, the potential application of the prospect is very attractive.
12, polyarylate PAR
Basic nature
proportion: 1.2-1.26g / cm³
Shrinkage: 0.8%
Molding temperature: 300-350 ° C
Drying conditions: 100 to 120 ° C for 5 hours
Material properties
1, for the transparent amorphous thermoplastic engineering plastics, with excellent heat resistance, flame retardant and non-toxic. Can be directly used in ordinary thermoplastic molding process into products;
2, with excellent thermal performance, under the load of 1.86MPA, the thermal deformation temperature of up to 175 degrees, the decomposition temperature of 443 degrees. Its various mechanical properties affected by the temperature is small.
Forming characteristics
1, with the product wall thickness increases, forming shrinkage increases;
2, less hygroscopicity, about 0.1-0.3%, but the injection of trace moisture will cause polyarylene decomposition. Therefore, the material must be dried before molding to make its moisture content of less than 0.02%;
The scope of application
1, suitable for the production of heat, fire and dimensional stability of high electrical parts. Connector, coil holder, relay shell;
2, lighting parts. Can be made transparent shade, lighting, car reflector and so on.
13, liquid crystal polymer LCP
Liquid crystal polymer refers to a certain conditions can form a liquid crystalline polymer material, referred to as LCP, is one of the fastest growing new materials in recent years can be divided into soluble type (LLCP) and thermal type (TLCP) two Thermotropic liquid crystal refers to the liquid state can be presented in the molten state, as the application of engineering plastics is mainly in this category. According to the temperature level can be divided into super heat-resistant, heat-resistant, low heat-resistant three The
Material properties
1, LCP is high strength, high modulus, creep resistance, high impact resistance of polymer materials, its mechanical properties much higher than the ordinary engineering materials;
2, excellent abrasion resistance, high surface hardness, low wear, low molding shrinkage, excellent flowability, high thermal stability and heat resistance, excellent electrical insulation,
3, with excellent chemical stability, the UV radiation is also very stable. Has a prominent flame retardant, generally do not need to add flame retardant UL94V-0 level can achieve the level of flame retardant, smoke is also very low;
4, also has excellent vibration absorption characteristics, used as audio components can reduce noise.
The scope of application
1, high-density connectors, bobbins, spools, sockets, etc .; audio-visual devices in the speaker vibration board, headset switch; office equipment in the floppy disk, hard drive, copy and other parts;
2, in the chemical industry, for a variety of devices and parts, such as distillation tower packing, valves, oil wells equipment;
3, in the aerospace, aviation, military industry and other cutting-edge technology, has a wide range of applications, such as the use of its high temperature, flame retardant, low smoke characteristics, can be used for various parts within the aircraft;
4, for the medical device has a unique advantage.As the LCP material surgical instruments invasive is very low, will become the master of medical miniaturization technology;
5, LCP other applications in microwave oven stove containers, packaging materials, sports equipment and so on.
14, polyimide PI
Polyimide, referred to as PI, is the earliest emerging engineering plastics with high temperature resistance and high strength, occupying an extremely important position in heat-resistant engineering plastics and is an aromatic heterocyclic polymer containing an imide group in its main chain The general name of the products have been industrialized and the size of the major varieties are benzene-based polyimides, polyamidoimide (PAI), polyetherimide (PEI) and bismaleimide (BMI).
Material performance
1, excellent mechanical properties, high tensile strength, creep resistance, wear resistance is also very good;
2, excellent heat resistance, long-term use temperature is above 200 ℃. Low temperature resistance is also very prominent, at -269 ℃ low temperature can maintain mechanical strength;
3, is a flame retardant polymer, combustion smoke density is low, toxic gas content is small;
4, excellent resistance to radiation, resistance to corona better than other engineering plastics