Thermoforming is a manufacturing process where a plastic sheet is heated to forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and certain material types, is heated in an oven to a high-enough temperature that it can be stretched into or onto a mold using vacuum and cooled to a finished shape.
After a short form cycle, a burst of reverse air pressure is actuated from the vacuum side of the mold as the form tooling opens, commonly referred to as air-eject, to break the vacuum and assist the formed parts off the mold. The sheet containing the formed parts then indexes into a trim station, where cuts the parts from the remaining sheet web. After that parts are trimmed on 5 axis routers using vacuum fixtures. The sheet web remaining after the formed parts are trimmed is collected and sent for recycling.
An integral part of the thermoforming process is the tooling which is specific to each part that is to be produced.