PEI Vs.POM

About PEI we need know the following :

1): PEI is a thermoplastic engineering resin with excellent stability and performance.

2): One of the outstanding features of PEI resin is that it can withstand high temperature for a long period of time. This high heat resistance, coupled with excellent flammability and UL laboratory certification, makes PEI resin meet the demanding requirements of high temperature use.

(3): (Ductility) PEI resin is not only unparalleled in both high strength and high modulus characteristics, it also has outstanding ductility. Its yield stretch is so long that it can be freely combined with a variety of easy-to-assemble buckle fit program. Even when only 10% glass fiber reinforcement is added, PEI 2100 resin maintains ductility at temperatures ranging from below freezing to 200℃.

(4): (Impact Strength) PEI 1000 resin has wonderful practical impact resistance. In view of the fact that PEI resins show notch agility, it is recommended to follow the principles of the scale plan. Should minimize the use of force concentration points (such as sharp corners) in the injection molded parts to supply the maximum have a blow strength. PEI AT * 100 resins are used in the use of wanting high blow function. The notched Izod impact of this series is up to 15km/mз.

5): (Fatigue Resistance) Fatigue is a vital planning consideration for rotary loading or oscillating parts.

6): (Creep Behavior) When considering the machine function of any thermoplastic, the planner must be familiar with the effects of temperature, stress levels and load continuity on the function of the material. Even at temperatures and stress levels where many other thermoplastics cannot be utilized, PEI resins show excellent creep resistance.

(7): PEI resin has a wonderful motor performance, in the general environmental conditions can maintain a solid. Coupled with thermal and mechanical properties, this makes PEI resins an ideal choice for demanding electronic and electrical applications.

(8): (Relative dielectric constant) Although the use of absolute values of relative dielectric constant may want to be high or low, it is important that these values remain stable over the entire range of application temperatures and/or frequencies. PEI resins are high performance amorphous engineering thermoplastics.

(9): PEI resin has an inherent flame retardancy and low smoke generation characteristics. Certain trademark resins are rated UL 94V-0* at a thickness of 0.25mm. Other trademarked resins exhibit high dielectric constants and high dissipation factors over a wide range of temperatures and frequencies. As an amorphous thermoplastic polyetherimide, PEI resin combines high performance and excellent processing characteristics, high heat resistance and high strength, modulus and general chemical resistance in one.

The important characteristics of PEI

1, PEI Chinese name (polyetherimide) is Tiger Pura color bright solid, with superior flame retardancy and low smoke, extinguishing grade UL94-V-0 level.

2, PEI has a strong high-temperature stability. High temperature resistance, heat distortion temperature of 220 ℃, can be in -160-180 ℃ of the temperature of the long-term use of things.

3, hydrolysis stability is very good, high temperature resistance, steam resistance;

4.Polyetherimide has a very good resistance to ultraviolet rays, Y-ray function.

Ordinary function of polyformaldehyde is a kind of outside smooth, radiant hard and dense raw materials, light yellow or white, thin-walled localized semi-transparent. Extinguishing characteristics for easy to extinguish, off the fire after the succession of extinguishing, the flame is yellow at the upper end, the lower end of the blue, the occurrence of molten droplets, there is a violent irritating formaldehyde flavor, fishy odor.

Polyformaldehyde is a white powder, ordinary non-transparent, good coloring, specific gravity 1.41-1.43 g/cm3, molding shrinkage 1.2-3.0%, molding temperature 170-200 ℃, drying premise 80-90 ℃ for 2 hours.

POM's long-term heat-resistant function is not high, but a short time can reach 160 ℃, in which the homopolymerization of POM short-term heat-resistant than copolymerization of POM higher than 10 ℃, but long-term heat-resistant copolymerization of POM instead of homopolymerization of POM higher than the top and bottom of 10 ℃. Can be used in the -40 ℃ ~ 100 ℃ temperature range for a long time.

POM is very easy to analyze, analyze the temperature of 280 degrees, analyze the irritating and erosive gas occurs. Therefore, the mold steel should be used to produce erosion-resistant raw materials.

Mechanical function of POM strength, high stiffness, good elasticity, good wear resistance. Its mechanical function is excellent, than the strength of up to 50.5MPa.

Its mechanical function is excellent, the specific strength can reach 50.5MPa, than the stiffness can reach 2650MPa, and metal is very close to the mechanical function of POM with the temperature shift is small, copolymerization of POM than homopolymerization of POM shift is slightly larger.

POM's strike strength is higher, but the general strike is less than ABS and PC; POM is sensitive to the gap, out of the gap can make the strike strength landing as much as 90%.

POM's fatigue strength is very outstanding, 10 alternating load, fatigue strength up to 35MPa, while PA and PC is only 28MPa.

POM creep is similar to PA, at 20 ℃, 21MPa, 3000h when only 2.3%, and by the temperature is very small.

POM's friction factor is small, good wear resistance (POM>Pa66>Pa6>ABS>HPVC>PS>PC), the limit of the PV value is very large, self-smoothness is good.

POM products on the grinding, high load effect is prone to near-screaming noise.

Electrical function of POM's electrical insulation is better, nearly independent of temperature and humidity; dielectric constant and dielectric loss in a wide range of temperature, humidity and frequency shift is very small; arc resistance is excellent, and can be maintained at high temperatures.

The dielectric strength of POM is related to the thickness, the thickness of 0.127mm when 82.7kV/mm, thickness of 1.88mm when 23.6kV/mm.

Environmental function POM is not resistant to strong acids and oxidizers, enoic acid and weak acids have a certain degree of stability.POM solvent resistance is superior, can be resistant to hydrocarbons, alcohols, aldehydes, ethers, gasoline, smooth oil and weak alkali, etc., and can be maintained at high temperatures with considerable chemical stability. Small water absorption, good dimensional stability.

POM weathering is not good, long-term in the role of ultraviolet light, mechanical function of the landing, outside the occurrence of chalking and cracking. Forming crystalline material, narrow melting range, fast melting and solidification, material temperature slightly below the melting temperature that crystallization occurs. Medium activity. Moisture absorption is small, can not be disposed by drying.