Method for manufacturing a punching unit

摘要

A cutting die assembly for cigar wrappers is manufactured by rigidly interconnecting a knife blade unit and a die assembly on a common carrier. The die assembly has an opening of particular shape bounded by a generally planar margin over which tobacco leaf may be draped. The knife unit is formed by shaping knife blade strip into a closed form to fit just inside the shaped margin of the die assembly with the knife edge just above same. The shaped knife blade strip is filled with a filling body interiorally to a height substantially below the cutting edge and is internally rigidified thereby. A suction air chamber is defined by the rigidly interconnected units and is bounded by the common carrier, the die assembly and the outer surface of the knife blade strip. Openings are provided through the margin of the die assembly to the suction air chamber to hold the draped tobacco leaf and stretch it over the knife edge. An expelling plunger is provided within the shaped knife blade strip and suction air passages are formed through the filling body and the plunger to hold tobacco leaf firmly against the cutting edge. The knife blade strip may take the form of plural strips interconnected to form adjacent die cavities.