The clamp frame ensures the plastic sheet is held firmly in place during the vacuum forming process.
Radiant heaters are used to heat the sheet which has been positioned over the aperture of the vacuum forming machine. Thicker sheets may require both surfaces be be heated by moving heaters into position both above and below the sheet.
Is used to achieve "even" wall thickness. Air is introduced to blow a small "bubble" and the mold is then raised into the pre-stretched sheet.
A vacuum is applied, the sheet is drawn into tight contact with the mold and the mold detail is picked up.
Where a deep draw is required, a top "plug" may be used to push material into the mold during the vacuum forming process retaining even wall thickness.
Cooling and Release
The material is allowed to cool. The cooling process may be shortened with blown air and the molding is then released from the mold by introducing air pressure.