Vac-Forming or Thermo-forming is a process where the component is made from a flat plastic sheet which is heated until soft. It is then stretched over a mould or pattern, then sucked down tightly with a vacuum.
The plastic cools very quickly and retains that shape. Vacuum forming is ideal whenever a “shell” type plastic part with uniform wall thickness is required.
Many illuminated signs are manufactured in this way.
Firstly the required material is clamped on a frame. The frame is then closed to prevent the sheet from moving during the operation. A heater is then located above