In the SA (semi automatic) versions only the processing cycle is automatic, while in the SM (semi manual) series only the crucial heating cycle is automated.

Blister forming operation involves the drawing of plastic film (usually from reel stock) under the clamp frame and heating the plastic until softened. The mould is then raised and vacuum applied to draw the softened plastic onto the mould. The formed sheet is then cooled; the material is indexed a pitch and finally, the formed sheet is separated from the web by guillotine. The sequence is automatically repeated and controlled by a microprocessor. This model is referred to as the Auto (or Midmatic) series.