A substance capable of being melted by means of heat repeatedly.
A plastic that repeatedly can be softened by heating and hardened by cooling through a temperature range characteristic of the plastic, and when in the softened stage, can be shaped by flow into articles by molding or extrusion.
Thermoplastic materials can be melted again and again. They will melt when heated to a certain temperature, but harden again as they cool. Widely used thermoplastics include ABS, Acrylic, polycarbonates and Polyvinyl Chloride (PVC).