| 摘要 |
Machinery for cutting back part of the mouth of each of a series of plastics bags comprises a pair of rails to guide the flattened bags through a position where they stop and overlap the track of a moving belt which cutting blade and follows the profile required for the cut in the bag. The knife carrier belt is supported on a chassis which can retract to allow a cut bag to proceed further along the guide rails, and rise to intercept the next bag. Pref. the cutter cycles at a higher frequency than the bag movements and the oscillation of the cutter chassis relative to the level of the bag rack is provided by a rotary cam jack with opt. two or more nodal positions. The bag is clamped during cutting by suction vents in the guide rails and opt. an elastomeric clamping pad having a slot to accommodate the recirculating knife. The system can be integrated with and match the throughput of machinery producing bags from tubular film, to provide a pair of projecting webs for handles. |
