| 摘要 |
A vented food casing (41) having a plurality of die cut vent openings which are uniform and free-draining so as to provide the casing with a vent rate for air and liquids such as meat juices which is substantially constant around the periphery of the casing. The vent openings are formed by a die cutting operation by drawing flattened casing between first and second rollers, the first of which has female die openings (48) which mate with male punches (34) in the second roller(30). The slugs (50) which are cut out of the food casing by the punches of the first roller are removed from the hollow interior of the second roller. The punches and die openings are arranged such that progressive engagement of the punches in the die openings across the width of the rollers (30, 36) is scattered between different columns of openings extending around the periphery of the second roller (36). The rollers (30, 36) are caused to rotate by the flattened casing being drawn through the gaps between the rollers. <IMAGE> |
