Thermoforming is the process of heating a thermoplastic sheet to its softening point which is then held horizontally over a mold and pressed into or stretched over the mold using vacuum pressure, air pressure, or mechanical force. The softened sheet conforms to the shape of the mold and is held in place until it cools. By using the thermoforming technique, elaborate and complex moldings are able to be produced.
Vacuum forming is a process in which a thermoplastic sheet is heated, stretched around a mold or into a pattern, and then conformed to the mold by applying vacuum pressure between the mold surface and the plastic sheet. Because heating is involved in the vacuum forming process it is considered a form of thermoforming.
