Vacuum forming is used on thermoplastics.

• A. True
• B. False
• C. Not sure
• D. Sometimes

Answer: (A)

Vacuum forming relies on heating a plastic sheet until it becomes pliable and then pulling it over a mold with vacuum. This works because thermoplastics soften when heated and can be reshaped and then harden again as they cool. That reworkability is the key feature that makes vacuum forming possible. Thermosetting plastics, once cured, don’t soften with heat, so they aren’t suitable for this process. So vacuum forming is used on thermoplastics, with common materials like polystyrene, ABS, PETG, and polycarbonate.