A Complete Collection of Commonly Used Plastic Characteristics （Part II）

1. PSU plastic (polysulfone)

Specific gravity: 1.25-1.35 grams/cubic centimeter

Molding shrinkage rate: 0.5-0.7%

Forming temperature: 290-350 ℃

Drying conditions: 130-150 ℃ for 4 hours

Material performance

1. Polysulfone is an amber transparent solid material with high hardness and impact strength, non-toxic, heat and cold resistance, and good aging resistance. It can be used for a long time at -100-175 degrees Celsius. It is resistant to corrosion by inorganic acids, alkalis, and salts, but not to aromatic and halogenated hydrocarbons. Polyarylsulfone has high hardness, radiation resistance, good heat and cold resistance, and has self immobility. It can be used for a long time at -100-175 degrees Celsius.

2. The wear resistance of the material can be greatly improved through glass fiber reinforcement and modification.

3. Polysulfone can be modified with ABS, polyimide, polyether ether ketone, and fluoroplastics to produce modified products of polysulfone, mainly to improve its impact strength and elongation, solvent resistance, environmental resistance, processing performance, and electrodability. For example, PSF/PBT, PSF/ABS, PSF+mineral powder.

purpose

1. Suitable for making heat-resistant parts, insulation parts, wear reducing and wear-resistant parts, instrument parts, and medical device parts, while polyarylsulfone is suitable for making low-temperature working parts.

2. Polysulfone is commonly used in the electronic and electrical industry to manufacture integrated circuit boards, coil racks, contactors, racks, capacitor films, and high-performance alkaline battery shells

3. Polysulfone is used in household appliances such as microwave ovens, coffee heaters, humidifiers, hair dryers, cloth steamers, beverage and food dispensers. It can also replace non-ferrous metals for precision structural components such as clocks, copiers, cameras, etc.

4. Polysulfone has passed relevant regulations in the fields of medicine and food in the United States and can replace stainless steel products. Due to its steam resistance, hydrolysis resistance, non-toxic, high temperature steam disinfection resistance, high transparency, good dimensional stability and other characteristics, polysulfone can be used as surgical tool tray, spray, fluid controller, heart valve, pacemaker, gas mask, dental support, etc.

Forming performance

1. Amorphous material, with high moisture absorption and a water absorption rate of 0.2% -0.4%, must be thoroughly dried before use and prevent further moisture absorption. Ensure that the water content is below 0.1%.

2. The molding performance is similar to that of PC, with poor thermal stability and decomposition starting at 360 degrees.

3. Poor fluidity, fast cooling, suitable for high-temperature and high-pressure molding. The mold should have sufficient strength and stiffness, with a cold well, a short flow channel, and a gate size of 1/2-1/3 of the wall thickness of the plastic part.

4. To reduce the internal stress generated by injection molded products, the mold temperature should be controlled between 100-140 degrees. After forming, annealing treatment can be carried out in a glycerol bath at 160 degrees Celsius for 1-5 minutes; Alternatively, take an air bath at 160 degrees for 1-4 hours. The annealing time depends on the size and wall thickness of the product. 5. Polysulfone is similar to a Newtonian body in a molten state, similar to polycarbonate, and its flow ability is relatively sensitive to temperature. Within 310-420 degrees, for every 30 degrees increase in temperature, its flow ability doubles. Therefore, during molding, the main method is to improve the processing flow ability by increasing the temperature.

2. PTFE plastic (F4) (polytetrafluoroethylene)

Specific gravity: 2.1-2.2 g/cm3

Molding shrinkage rate: 3.1-7.7%

Forming temperature: 330-380 ℃

Material performance

1. Long term use at temperatures ranging from -200 to 260 degrees Celsius, it has excellent resistance to chemical corrosion, is resistant to all chemicals, has the lowest friction coefficient among plastics, and has excellent electrical properties. Its electrical insulation is not affected by temperature, and is known as the "king of plastics".

2. It is in a transparent or semi transparent state, and the higher the crystallinity, the worse the transparency. The raw materials are mostly powdered resins or concentrated dispersions, which have extremely high molecular weight and are high crystallinity thermoplastic polymers.

Purpose

Suitable for making corrosion-resistant parts, wear reducing and wear-resistant parts, sealing parts, insulation parts, and medical device parts.

Forming performance

1. Crystalline material with low moisture absorption.

2. Poor fluidity and easy decomposition, producing corrosive gases during decomposition. The molding temperature should be strictly controlled, the mold should be heated, and the pouring system should have low resistance to material flow.

3. Powdered resins are often formed using powder metallurgy and sintering methods. The sintering temperature should be 360-380 degrees, and should not exceed 475 degrees. Lotion resin is usually processed by cold extrusion and then sintering, which can form an anti-corrosion coating on the surface of articles. If the transparency and toughness of the product are required, rapid cooling should be adopted. Extrusion molding can also be adopted, which can extrude pipes, rods, and profiles.

4. The viscosity of PTFE melt is very high, and the volume viscosity decreases with the increase of shear stress, indicating its non Newtonian fluid characteristics.

5. Secondary processing can include hot pressing, welding, bonding, reinforcement, mechanical processing, etc. to produce the final product.

3. ASA plastic (acrylic styrene acrylonitrile)

Specific gravity: 1.05 g/cm3

Molding shrinkage rate: 0.4-0.7%

Forming temperature: 170-230 ℃

Drying conditions: 80-90 ℃ for 2 hours

Material performance

ASA polymers are amorphous materials that can be processed by extrusion and injection molding to produce products with excellent resistance to climate impacts. The mechanical properties of the ternary copolymer ASA are usually similar to ABS resin, except that the performance of ASA is much less affected by outdoor climate than ABS resin.

purpose

Suitable for making general architectural fields, outdoor furniture, and exterior mirror shells for automobiles.

Forming performance

1. Amorphous material, with moderate fluidity and high moisture absorption, must be fully dried. Plastic parts with a glossy surface must be preheated and dried for a long time at 80-90 degrees Celsius for 3 hours.

2. It is recommended to use high material temperature and high mold temperature, but if the material temperature is too high, it is easy to decompose (decomposition temperature is> 250 degrees). For high-precision plastic parts, the mold temperature should be set at 50-60 degrees, and for glossy and heat-resistant plastic parts, the mold temperature should be set at 60-80 degrees.

3. The brands of ASA basic resins sold on the market are: Luran S (BASF Plastic Materials Company); Gelog brand (General Plastics); Centrex brand (Monsanto Corporation).

4. PPS plastic (polyphenylene sulfide)

Specific gravity: 1.36 g/cm3

Molding shrinkage rate: 0.7%

Forming temperature: 300-330 ℃

Drying conditions:---

Material performance

1. Excellent electrical insulation (especially high-frequency insulation), white hard and brittle, with metallic noise when dropped to the ground, second only to organic glass in terms of light transmittance, coloring, water resistance, and good chemical stability. It has excellent flame retardancy and is a non combustible plastic.

2. The strength is average and the rigidity is good, but the texture is brittle and prone to stress cracking. It is not resistant to organic solvents such as benzene and gasoline. It can be used at a temperature of 260 degrees Celsius for a long time and remains stable in air or nitrogen at 400 degrees Celsius. After modification with glass fiber or other reinforcing materials, the impact strength can be greatly improved, and the heat resistance and other mechanical properties can also be improved. The density can be increased to 1.6-1.9, and the molding shrinkage can be reduced to 0.15-0.25%.

Purpose

Suitable for making heat-resistant parts, insulation parts, chemical instruments, optical instruments, and other parts.

Forming performance

1. Amorphous material, with low moisture absorption, but should be formed after drying.

2. The fluidity is between ABS and PC, with fast solidification, small shrinkage, and easy decomposition. High injection pressure and speed are chosen. The mold temperature is taken as 100-150 degrees. The taper of the main flow channel should be large, and the flow channel should be short.

5. ETFE plastic (polytetrafluoroethylene ethylene ethylene copolymer)

Specific gravity: 1.7 g/cm3

Molding shrinkage rate: 3.1-7.7%

Forming temperature: 300-330 ℃

Material performance

1. Long term use at a temperature of -80 to -220 degrees Celsius, it has excellent chemical corrosion resistance, is resistant to all chemicals, has the lowest friction coefficient among plastics, and has excellent electrical properties. Its electrical insulation is not affected by temperature, and is known as the "king of plastics".

2. Its chemical resistance is similar to that of polytetrafluoroethylene, but better than that of vinylidene fluoride.

3. Its creep resistance and compressive strength are better than polytetrafluoroethylene, with high tensile strength and an elongation rate of 100-300%. Good dielectric properties and excellent radiation resistance.

purpose

1. Suitable for making corrosion-resistant parts, wear reducing and wear-resistant parts, sealing parts, insulation parts, and medical device parts.

2. Insulation layer for wires and cables, anti-corrosion equipment, sealing materials, pump valve bushings, and chemical containers.

Forming performance

1. Crystalline material with low moisture absorption. Products can be processed using the usual processing methods of thermoplastic.

2. Poor fluidity and easy decomposition, producing corrosive gases during decomposition. It is advisable to strictly control the molding temperature not to exceed 350 degrees, the mold should be heated to 100-150 degrees, and the pouring system should have low resistance to material flow. It could form thin-walled simple products with a thickness of 0.7-0.8 millimeters.

3. Transparent granular material, injection molding, extrusion molding. The molding temperature ranges from 300 to 330 degrees, and temperatures above 350 degrees can easily cause discoloration or bubbles. It is advisable to form at high speed and low pressure, and pay attention to the difficulty of demanding.

6. PFA plastic (soluble polytetrafluoroethylene)

Specific gravity: 2.13-2.167 g/cm3

Molding shrinkage rate: 3.1-7.7%

Forming temperature: 350-400 ℃

Material performance

1. A copolymer of a small amount of perfluoropropyl perfluoroethylene ether and polytetrafluoroethylene. The melt adhesion is enhanced, the viscosity of the solution decreases, and the performance remains unchanged compared to polytetrafluoroethylene. This resin can be directly processed into products using ordinary thermoplastic forming methods.

2. Long term use at a temperature of -80 to -260 degrees Celsius, it has excellent chemical corrosion resistance, is resistant to all chemicals, has the lowest friction coefficient among plastics, and has excellent electrical properties. Its electrical insulation is not affected by temperature, and is known as the "king of plastics". Its chemical resistance is similar to that of polytetrafluoroethylene, but better than that of vinylidene fluoride.

3. Its creep resistance and compressive strength are better than polytetrafluoroethylene, with high tensile strength and an elongation rate of 100-300%. Good dielectric properties and excellent radiation resistance. The flame retardancy reaches V0 level.

purpose

1. Suitable for making corrosion-resistant parts, wear reducing and wear-resistant parts, sealing parts, insulation parts, and medical device parts.

2. Insulation layer for high-temperature wires and cables, anti-corrosion equipment, sealing materials, pump valve bushings, and chemical containers.

Forming performance

1. Crystalline material with low moisture absorption. Products can be processed using the usual processing methods of thermoplastic.

2. Poor fluidity and easy decomposition, producing corrosive gases during decomposition. It is advisable to strictly control the molding temperature not to exceed 475 degrees, the mold should be heated to 150-200 degrees, and the pouring system should have low resistance to material flow.

3. Semi transparent granular material, injection molding, extrusion molding. The molding temperature is 350-400 degrees, and above 475 degrees can easily cause discoloration or bubbles. And pay attention to the difficulty of demolding.

4. Due to the corrosive effect of molten materials on metals, long-term production requires chromium plating treatment for molds.

7. PAR plastic (U plastic) (polyaromatic resin)

Specific gravity: 1.2-1.26 grams/cubic centimeter

Forming shrinkage rate: 0.8%

Forming temperature: 300-350 ℃

Drying conditions: 100~120 ℃ -5 hours

Material performance

1. It is a transparent amorphous thermoplastic engineering plastic with excellent heat resistance, flame retardancy, and non-toxic properties. It can be directly processed into products using ordinary thermoplastic forming methods.

2. It has excellent thermal performance, with a thermal deformation temperature of up to 175 degrees and a decomposition temperature of 443 degrees under a load of 1.86 MPA. Its various mechanical properties are less affected by temperature.

purpose

1. Suitable for making electrical components that are heat-resistant, flame resistant, and have high dimensional stability. Connector, coil holder, relay housing.

2. Lighting parts. It can be made into transparent lampshades, illuminators, car reflectors, etc.

Forming performance

1. As the wall thickness of the product increases, the molding shrinkage rate increases.

2. The hygroscopicity is relatively low, about 0.1-0.3%, but a small amount of water during injection molding can cause the decomposition of polyarylic resin. Therefore, the material must be dried before forming. Make its moisture content less than 0.02%.

8. Phenolic plastic

Specific gravity: 1.5-2.0 g/cm3

Molding shrinkage rate: 0.5-1.0%

Forming temperature: 150-170 ℃

Material performance

Phenolic plastic is a hard and brittle thermosetting plastic commonly known as bakelite powder. High mechanical strength, toughness and wear resistance, stable size, corrosion resistance, and excellent electrical insulation performance.

Suitable for making insulation mechanism components for electrical appliances and instruments, can be used in humid and hot conditions.

Forming performance

1. The formability is good, but the shrinkage and directionality are generally larger than those of amino plastics, and they contain volatile water. Before forming, preheating should be carried out, and exhaust should be discharged during the forming process. If not preheated, the mold temperature and forming pressure should be increased.

2. The mold temperature has a significant impact on fluidity, and generally when it exceeds 160 degrees, the fluidity will rapidly decrease.

3. The hardening speed is generally slower than that of amino plastics, and the heat released during hardening is greater. The internal temperature of large thick walled plastic parts is easily too high, leading to uneven hardening and overheating.

9. MF,UF Aminoplastics

Specific gravity: 1.5 grams per cubic centimeter

Molding shrinkage rate: 0.6-1.0%

Forming temperature: 160-180 ℃ Material performance

Good arc resistance and electrical insulation, water resistance and heat resistance, suitable for compression molding, suitable for making arc resistant electrical parts and explosion-proof electrical insulation parts

Forming performance

1. Good flow ability and fast hardening speed, therefore preheating and molding temperatures should be appropriate, and coating, mold closing, and pressurization speeds should be fast.

2. The molding shrinkage rate is high.

3. It contains a lot of moisture and volatile substances, which are prone to moisture absorption and agglomeration. When forming, it should be preheated and dried to prevent further moisture absorption. However, if it is too dry, its fluidity will decrease. During molding, there is moisture and decomposition products, which are acidic. The mold should be chrome plated to prevent corrosion, and exhaust should be used during molding.

4. The molding temperature has a significant impact on the quality of plastic parts. If the temperature is too high, it is prone to decomposition, discoloration, and uneven color of bubbles. If the temperature is too low, the fluidity is poor and the luster is not good.

5. When using pre pressed ingots to form large plastic parts with fine materials, large specific volume, and high inflation, it is easy to produce ripples and flow patterns, so it is generally not suitable to use.

10. Epoxy resin (EP)

Specific gravity: 1.9 g/cm3

Forming shrinkage rate: 0.5%

Forming temperature: 140-170 ℃

Material performance

Good mechanical properties, electrical insulation, chemical stability, and strong adhesion to many materials, but the performance is influenced by the variety and content of fillers. The heat resistance of alicyclic epoxy plastics is relatively high. Suitable for casting and low-pressure extrusion molding.

Suitable for sealing and fixing electricians, electronic components, and coils, and can also be used for repairs.

Forming performance

1. Castable. Good fluidity, small hardening shrinkage, but poor thermal rigidity, difficult to demould.

2. The hardening speed is fast, and there is generally no need to exhaust during hardening. After loading, pressure should be applied immediately.

11. Organic silicon plastic (IS)

Specific gravity: 1.75-1.95 g/cm3

Forming shrinkage rate: 0.5%

Forming temperature: 160-180 ℃ Material performance

High and low temperature resistance, good water resistance, high frequency insulation, radiation resistance, and ozone resistance are suitable for the encapsulation and fixation of electrical, electronic components, and coils

Forming performance

1. Good fluidity, slow hardening speed, and high molding temperature is required for compression molding.

2. After compression molding, it must undergo high-temperature curing treatment.

Drying conditions: 130-150 ℃ for 4 hours