Vacuum Forming

In simple terms a vacuum former consists of a vacuum box with an air outlet, a clamping frame to hold material in place, a heating element, a vacuum pump and a mould.

The operator first clamps the slightly oversized material in place. If clamped properly this creates an air tight lid. Once this operation is successful a heating panel is placed above the plastic sheet, generally about 6 inches above. The heating elements can vary with a number of heating elements in place to allow some to be turned off or others in place to allow generation of more heat in some areas. This allows for better definition in the forming process.  Once the material has been heated efficiently it reaches its forming temperature.

When the plastic material starts to sag the heater is removed and the vacuum pump switched on.  This sucks out all the air within the vacuum box through fine holes in the mould. Pressure forces the softened material onto and into the mould, following the contours of the defined mould.

Once the material has been allowed to cooled down it will hold its formed plastic shape. Sometimes this is allowed to happen naturally or the cooling process can be encouraged and speeded up with the use of cool blown air or even with cold spray.  The vacuum pump switch off and material removed from the clamp.  The final step is to trim off the excess material