The plug cutting system is fed slabs of rockwool from an automated magazine, while the empty plastic plug trays are hand fed by an operator.  With slab and tray in position, a cutter head descends into the slab, cutting 50 plugs simultaneously and inserts them into the waiting tray, with optional seed holes and opening slots in each plug.  The automated sequence has a cycle time of 3 seconds and occurs inside a vacuum chamber.