Twenty Kinds of Plastics and Their Properties—(11) PEI
11. PEI polyether
Typical application range:
The automobile industry (such as engine temperature sensor, fuel and air processor etc.), electrical and electronic equipment (electrical connector, printed circuit board, chip shell, explosion-proof box), product packaging, aircraft interior equipment, pharmaceutical industry (surgical instruments, instrument shell, non-invasive devices).
Injection molding process conditions:
Drying process: PEI has a hygroscopic property and can lead to degradation of the material. The value of humidity should be less than 0.02%. It is suggested that drying conditions are 150 and 4 hours.
Melting temperature: the common type material is 340~400 °C; the reinforced type material is 340~415 °C.
Mold temperature: 107~175 °C, it is suggested that the mold temperature is 140 degrees °C.
Injection pressure: 700~1500bar.
Injection speed: use as high as possible injection speed.
Chemical and physical properties:
PEI has a strong high temperature stability, even if it is a non reinforced PEI, it still has good toughness and strength. Therefore, the use of PEI’s superior thermal stability can be used to make high temperature and heat-resistant devices. PEI also has good flame retardancy, anti chemical reaction and electrical insulation properties. The glass conversion temperature is very high, up to 215 °C. PEI also has very low shrinkage and good mechanical properties in the same direction.