ABS, PA, PC, POM are the four major engineering materials recognized by the national standard in the plastic injection mold industry.

1. ABS: It has excellent impact resistance and does not drop rapidly at low temperatures. Even at -40 degrees, it has a very good toughness. The biggest use ABS is as pipelines to transport gasoline, crude oil and water.
2. PA: The biggest feature is low friction coefficient, good wear resistance and self-lubricating.
3. PC: The most prominent feature is toughness and rigidity. Its unnotched impact strength is the highest among the commonly used plastics. The molded parts can reach high precision tolerances and maintain dimensional stability. Therefore, PC is also called plastic metal.

4. POM: The most fatigue-resistant, can be used to make bearings, gears, especially for occasions where lubricants cannot be added.
Since the thermosetting plastic burns slowly only under the flame, it does not soften the flow, and the solvent can't do anything about it. Therefore, it is especially necessary to prevent the heat-cured thermosetting plastic from being mixed into the thermoplastic during molding or pelletizing.