Thermoforming - also recognised as vacuum forming - is a manufacturing process whereby plastic sheets are preheated in automated pressure & vacuum forming equipment until soft and malleable.  The preheated sheet then makes contact with a mould or form and a vacuum source is turned on that sucks the sheet to the mould.  When cool, the sheet takes the shape of the mould. Should additional detail be required, a technique generally known in the industry as pressure forming can be used.

Thermoforming moulds can be either male or female depending on the geometry of the parts and where the weakest areas need more material thickness.  Moulds can be surfaced to convey different finishes using a female mould and positive air pressure.