This invention relates to a novel apparatus and process for producing thermoplastic articles. For example, in accordance with various aspects of the present invention, the board may be provided with varying numbers of layers of material as well as include various edges and protective guards are placed on the board. Each VC range includes at least one VC for control and at least one VC for data transfer. The annular air casing is hollow and is mounted around the air holes in the constriction and has an air chamber, an annular surface and at least one air supply hole formed through the annular surface.