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POM Japan DURACON GH-20 GF20 high temperature 160 degree rigid high specific gravity steel

Item No.: GH-20 GF20
Polyoxymethylene: Polyoxymethylene, polyoxymethylene (POM), also known as sai steel and special steel, is obtained by polymerization of formaldehyde and other raw materials. Pom-h (formaldehyde homopolymer), pom-k (formaldehyde copolymer) is a high-densit
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Description

 

(Polyoxymethylene) (Saigang ~ Trane)
English name: Polyoxymethylene (Polyformaldehyde)
POM (Polyacetal Resin) Definition: Polyoxymethylene is a linear polymer with no side chains, high density and high crystallinity. According to the chemical structure in the molecular chain, it can be divided into two types: homopolyformaldehyde and acetal copolymer. The important difference between the two is that the homopolyformaldehyde has high density, crystallinity and melting point, but the thermal stability is poor, the processing temperature range is narrow (about 10 ° C), the acid-base stability is slightly lower, and the copolymerized formaldehyde density, crystallinity, The melting point and strength are low, but the thermal stability is good, it is not easy to decompose, the processing temperature range is wide (about 50 ° C), and the acid-base stability is good. It is an engineering plastic with excellent comprehensive performance. Has good physical, mechanical and chemical properties, especially with excellent friction resistance. Commonly known as Saigang or Steel, it is the third largest general plastic. Suitable for making wear-resistant parts, transmission parts, and parts such as chemicals and instruments.
One of the synthetic resins, also known as polyacetal resin, POM plastic, steel, etc.; is a white or black plastic particle with high hardness, high rigidity and high wear resistance. Mainly used for gears, bearings, auto parts, machine tools, instrument internals and other products that act as skeletons.
Feature editing
(1) POM can be used without drying before drying. It is best to preheat in the process (about 80 °C), which is good for the stability of product size.
(2) The processing temperature of POM is very narrow (0~215°C). When the residence time in the barrel is slightly longer or the temperature exceeds 220°C, it will decompose and produce stimulating formaldehyde gas.
(3) When the POM material is injected, the holding pressure should be large (similar to the injection pressure) to reduce the pressure drop. The screw speed should not be too high, and the residual amount should be less;
(4) POM products have a large shrinkage rate and are prone to shrinkage or deformation. POM is larger than heat and has a high mold temperature (80 to 100 ° C). The product is very hot when it is released from the mold. It is necessary to prevent burns on the fingers.
(5) POM should be formed under the conditions of “medium pressure, medium speed, low material temperature and high mold temperature”, and the mold temperature should be controlled when molding precision products.
(6) High mechanical strength and rigidity
(7) The highest fatigue strength
(8) Good environmental resistance and organic solvent resistance
(9) Strong resistance to repeated impact, good electrical properties, good recovery, self-lubricating, good wear resistance, excellent dimensional stability.
Application editing
Can replace most non-ferrous metals, automobiles, machine tools, instrument parts, bearings, fasteners, gears, springs, pipes, conveyor belt accessories, electric water tanks, pump casings, drainers, faucets, etc.
Physical and chemical editing
General performance
POM is a hard, dense material with a smooth, shiny surface, light yellow or white, and the thin-walled portion is translucent. The combustion characteristics are easy to burn, and continue to burn after the fire. The upper end of the flame is yellow, the lower end is blue, and melted and dripped, and there is a strong irritating formaldehyde smell and fish odor. POM is a white powder, generally opaque, good coloring, specific gravity 1.41-1.43 g / cm3, molding shrinkage 1.2-3.0%, molding temperature 170-200 ° C, drying conditions 80-90 ° C 2 hours. The long-term heat resistance of POM is not high, but it can reach 160 °C in the short term. The short-term heat-resistant POM of homopolymerized POM is higher than 10 °C, but the long-term heat-resistant copolymerized POM is about 10 °C higher than the homopolymerized POM. It can be used for a long time in the temperature range of -40 ° C to 100 ° C. POM is easily decomposed and has a decomposition temperature of 240 degrees. Irritating and corrosive gases occur during decomposition, so the mold steel should be made of corrosion-resistant materials.
(1) POM is a crystalline plastic with a density of 1.42g/cm3. It has good steel properties and is commonly known as “Saigang”.
(2) It has excellent performances such as fatigue resistance, creep resistance, wear resistance, heat resistance and impact resistance, and has small friction coefficient and good self-lubricity.
(3) POM is not easy to absorb moisture, its water absorption rate is 0.22~0.25%, its dimensional stability is good in a humid environment, its shrinkage is 2.1% (larger), the size is difficult to control during injection molding, and the heat distortion temperature is 172 °C. POM has two kinds of homo-formaldehyde, the performance is different (homo-formaldehyde is better temperature resistance).
Mechanical properties
POM has high strength, high rigidity, good elasticity and good wear resistance. Its mechanical properties are excellent, the specific strength can reach 50.5MPa, the specific stiffness can reach 2650MPa, and it is very close to metal. The mechanical properties of POM change little with temperature, and the copolymerized POM changes slightly more than the homopolymerized POM. The impact strength of POM is higher, but the conventional impact is less than ABS and PC; POM is sensitive to the gap, and the gap can reduce the impact strength by as much as 90%. The fatigue strength of POM is very prominent. After 10 alternating loads, the fatigue strength can reach 35MPa, while PA and PC are only 28MPa. The creep of POM is similar to that of PA, which is only 2.3% at 20 °C, 21 MPa, and 3000 h, and is little affected by temperature. POM has a small friction coefficient and good wear resistance (POM>PA66>PA6>ABS>HPVC>PS>PC), the limit PV value is large, and the self-lubricating property is good. POM products are prone to scream-like noise when subjected to high loads.
Electrical performance
POM has good electrical insulation and is almost independent of temperature and humidity; dielectric constant and dielectric loss vary little over a wide range of temperatures, humidity and frequencies; excellent arc resistance and high temperature maintain. The dielectric strength of the POM is related to the thickness, which is 82.7 kV/mm at a thickness of 0.127 mm and 23.6 kV/mm at a thickness of 1.88 mm.
Environmental performance
POM is not resistant to strong bases and oxidants, and has certain stability to olefinic acids and weak acids. POM has good solvent resistance and is resistant to hydrocarbons, alcohols, aldehydes, ethers, gasoline, lubricating oils and weak bases, and maintains considerable chemical stability at high temperatures. Low water absorption and good dimensional stability.
The weather resistance of POM is not good. Under the action of ultraviolet rays for a long time, the mechanical properties are degraded, and the surface is pulverized and cracked.
Formability
The crystallized material has a narrow melting range, fast melting and solidification, and crystallization occurs when the temperature of the material is slightly lower than the melting temperature. Medium mobility. Low moisture absorption, no drying treatment.
Modified POM editor
1. Enhanced POM
The main reinforcing materials are glass fiber, glass ball or carbon fiber, and the glass fiber is most commonly used. The mechanical properties after reinforcement can be improved by 2 to 3 times, and the heat distortion temperature is increased by 50 °C or more.
2. Highly lubricated POM
Adding graphite, F4, molybdenum disulfide, lubricating oil and low molecular weight PE to POM can improve its lubricating performance. For example, adding 5 parts of F4 to the POM can reduce the friction factor by 60% and the wear resistance by 1-2 times. For example, the addition of a liquid lubricant to the POM can greatly improve the wear resistance and the ultimate PV value. In order to improve the dispersion effect of the oil, it is necessary to add an oil-absorbing carrier such as carbon black, aluminum hydroxide barium sulfate or ethylene-propylene rubber. The frictional property of adding 5% oil POM is increased by 72%, the ultimate PV value is up to 3.9 MPa·m/s (pure POM is 0.213 MPa·m/s), which is 3 to 20 times that of other engineering plastics.


 
Physical characteristics public English comment
density 1.36 g / cm 3 0.0491 psi ISO 1183
Water absorption rate 6.3 - 6.9% 6.3 - 6.9% ISO 62
Hygroscopicity at equilibrium 1.9 - 2.3% 1.9 - 2.3% 23 ° C / 50% RH; ISO 62
Viscosity measurement 140 140 Viscosity value; ISO 307
Linear mold shrinkage 0.0035 cm / cm 0.0035 inches / inch  
Melt flow 68 g / 10 minutes
@Load 5.00 kg,
temperature 275 ° C
68 g / 10 min
@Load 11.0 lbs,
melting point 527 °F
ISO 1133
 
Mechanical behavior public English comment
Tensile strength 185 MPa 26800 psi 50 mm/min; ISO 527
Yield elongation 3.5% 3.5% 50 mm/min; ISO 527
Elastic Modulus 9.50 GPa 1380 ksi ISO 527
Bending strength 270 MPa 39200 psi ISO 178
Flexural modulus 8.60 GPa 1250 ksi ISO 178
Izod impact, gap (ISO) 1.50 kJ / m2 0.714 ft - lb / inch 2 ISO 180 / A.
Charpy impact no gap 9.50 J /cm2 45.2 ft-lb /in2 ISO 179 / 1eU
8.00 J /cm2
@temperature -30.0 °C
38.1 ft-lb /in2
@temperature-22.0°F
ISO 179 / 1eU
Charpy Impact, gap 1.50 J /cm2 7.14 ft - lb / inch 2 ISO 179 / 1eA
1.10 J /cm2
@temperature -30.0 °C
5.24 ft - lb / inch 2
@temperature -22.0 °F
ISO 179 / 1eA
 
Electrical characteristics public English comment
Volume resistivity 1.00e + 14 ohm-cm 1.00e + 14 ohm-cm IEC 60093
Dielectric constant 3.8
@Frequency 1.00e + 6 Hz
3.8
@Frequency 1.00e + 6 Hz
IEC 60250
Dissipation factor 0.023
@Frequency 1.00e + 6 Hz
0.023
@Frequency 1.00e + 6 Hz
IEC 60250
Comparative tracking index 575 V 575 V IEC 60112
 
Thermal performance public English comment
CTE, linear, parallel to flow 20.0 - 25.0 microns / room
°C @temperature 23.0-80.0 °C
11.1 - 13.9 microinches/inch °F
@temperature 73.4 - 176°F
ISO 11359-1 / -2
CTE, linear, lateral flow 60.0 - 70.0 microns / room
°C @temperature 23.0-80.0 °C
33.3 - 38.9 microinches/inch °F
@temperature 73.4 - 176°F
ISO 11359-1 / -2
Specific heat capacity 1.50 J / g-°C 0.359 BTU / lb-°F  
Thermal Conductivity 0.360 W / mK 2.50 BTU-in / hr-ft2-°F DIN 52612
Melting point 220 °C 428 °F DIN 53765
Maximum use temperature, air 135 °C 275 °F 50% loss in tensile strength after 20,000 hours
  165 °C 329 °F 50% loss in tensile strength after 5,000 hours
  200 °C 392 °F  
Deflection temperature is 0.46 MPa (66 psi) 220 °C 428 °F ISO 75
Deflection temperature is 1.8 MPa (264 psi) 210 °C 410 °F ISO 75
Flammability, UL94 HB
@Thickness 1.60 mm
HB
@Thickness 0.0630 in
 
 
Processing attribute public English comment
Melt temperature 270 - 290 °C At 518-554 °F Injection molding / extrusion
Mold temperature Melting point 80.0 - 90.0 °C 176 - 194 °F Injection molding





 

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