Transitional product flow and adaptive control

PCT No. PCT/US96/10946 Sec. 371 Date Dec. 23, 1997 Sec. 102(e) Date Dec. 23, 1997 PCT Filed Jun. 26, 1996 PCT Pub. No. WO97/02179 PCT Pub. Date Jan. 23, 1997A method and apparatus for feeding substantially free flowing solid product charges (P''') in a continuous vertical form, fill and seal packaging machine (10) is disclosed. Improved transitional product flow from the computerized weigher (W) to the bag former and closer is obtained by tracking and sampling the charges along the flow path. In the method, the steps include sensing the presence of the charges along the flow path at two locations, comparing each sensed charge presence to a defined time target that has previously been determined and adjusting at least one operating step in accordance with any deviation found to cause the charge or charges to approach the defined time target for optimum operation. Either a predictive time adaptive control (77) requiring operator input, or computer control (76) can be incorporated into the method. A series of product charge flow enhancers (102, 103; 131; 121) are provided along the flow path to assist in maintaining the charges within the time target.