Twenty Kinds of Plastics and Their Properties—(6) PC
Typical application range:
Electrical and commercial equipment (computer components, connectors, etc.), appliances (food processing machines, fridge drawer, etc.), transportation industry (vehicle front and rear lights, dashboards, etc.)
Injection molding process conditions:
Drying process: the PC material is hygroscopic, and the drying before processing is very important. It is suggested that the drying condition is from 100 to 200, 3~4 hours. The humidity must be less than 0.02% before processing.
Melting temperature: 260~340 C.
Mold temperature: 70~120 C.
Injection pressure: use high injection pressure as much as possible.
Injection speed: low speed injection for smaller gate, and high speed injection for other types of gate.
Chemical and physical properties:
PC is a kind of amorphous engineering material. It has excellent impact strength, thermal stability, gloss, inhibition of bacterial characteristics, flame retardancy and pollution resistance. The gap of PC’s otched Izod impact stregth is very high, and the contraction rate is very low, generally 0.1%~0.2%. PC has very good mechanical properties, but the flow characteristics are poor, so the injection process of this material is difficult. The final expectation of the product should be based on the quality of the PC material. If the plastic parts require high impact resistance, low flow rate PC material is used, otherwise, high flow rate PC material can be used, so that the injection process can be optimized.