“This procedure will help you construct a simple vacuforming device. With it, you’ll be able to fabricate plastic parts or make copies of of objects in plastic. Vacuum forming is a popular industrial process for manufacturing hollow, thin walled, plastic parts. In industrial units, a sheet of plastic is heated, usually by infrared lamps. This homemade vacuformer is made by using a piece of perforated circuit board as the platform, and a project box as the vacuum chamber. A heat gun is enough to melt most thing plastics, and a shop vac provides plenty of ‘suck’.” Thanks Jason! Link.
HOW TO – Make a DIY Vacuformer