The Problem

Mechanically-driven wrapping machines have
a number of limitations:
the machines need to be mechanically adjusted for product changeovers. This requires skill and takes time.
registration control requires the use of a variable ratio gearbox which is an expensive item and one that is also prone to wear.
the limp motion of the end crimps approximates to a constant velocity during sealing; its variation in speed is also restricted.
a no-product-no-bag feature is difficult to achieve mechanically.
registration is maintained by making coarse corrections.