Sandwich Puff Sheet Manufacturing Process : The top and bottom coil (sheet metal) are clamped onto the plants unwinding unit and fed into the machine. In the first step, "corona system" cleans both reverse sides of the sheet metal using high frequency to remove greases and dirt and to guarantee the best possible subsequent full spread adhesion between foam and sheet metal. Thereafter the protective films are rolled onto outside of both metal sheets. The sheets are then brought together, the bottom sheet is foamed by the swinging foam head and the top sheet is mechanically steadied. Immediately after that, the panel is fed into the heated drying tunnel where the foam expands to its full volume, binds to the sheets and transforms both sheets to one robust, shear resistant composite structural panel. After leaving the tunnel the panels are cut according to your specification using flying saw/cutter.