Fosber's patented CONSTANT SYSTEM order change allows a true gapless order change on two knife levels through the cut-off knife. The problems of conventional order changes are eliminated by removing the need to sever the web at the rotary shear. This unique order change sequence requires the installation of the CONSTANT SYSTEM Rotary Shear with the Fosber TWIN automatic slitter scorer.

The CONSTANT SYSTEM Rotary Shear operates as a standard blade to soft anvil rotary shear in all respects except that the knife shaft has a series of 26 segmented blades which can be independently activated into cut mode. The lower anvil shaft is covered with sectioned polyurethane sleeves with a male to female locking design, for easy removal and replacement. The waste expulsion section is identical to a standard rotary shear, consisting of a pneumatically indexed diverter plate, an expulsion nip roll and a high-grip expulsion belt as well as an upper no-crush roller which applies positive pressure on the board at waste discharge.

The CONSTANT SYSTEM Rotary shear can operate as a conventional shear, chopping out waste or making a full width single cut to initiate a conventional order change, as well as gapless order change mode. In CONSTANT SYSTEM order change mode, individual blades are engaged to cut selected areas across the web. At order change, the required blades are indexed and the knife bar makes a single turn, cutting the web at only the side trim locations and the central area between the upper knife and lower knife web-divided points for the old and new order. When the order change area of the web reaches the Fosber TWIN slitter, the trim and dividing slitting heads are activated to create an overlap of the old order and new order divide slits while all other scores and slit heads are lifted out of the board line.

Fosber's CONSTANT SYSTEM Order change simply and effectively unifies the old and new orders so that a continuous flow of board runs through the web at all times – including order change. This eliminates problems associated with other order change methods such as: Reduced speed for order change, High acceleration of the old order, Jam ups due to leading edge at the slitter or knife, web weave, sheet variation at order change, and switching of measuring devices. The risk of Jam-ups is eliminated.