Patent ID: 6738684
Filing Date: 2004-05-18
Classification: B65H

Abstract:
In a production operation for producing rolls of tissue or towel from a parent roll or rolls including a converting line provided with a rewinder, an accumulator and downstream processing equipment, a method of controlling said converting line comprising:(a) providing an upper target limit for an inventory level of said accumulator; (b) providing a lower target limit for the inventory level of said accumulator; (c) determining the slowest maximum speed of said downstream equipment; (d) determining the fastest minimum speed of said downstream equipment; (e) monitoring average production speed of said rewinder; (f) monitoring the actual inventory level of said accumulator; (g) generating a master speed reference value which: (i) corresponds to said slowest maximum speed of said downstream equipment if said actual inventory level of said accumulator is greater than about said upper target limit for the inventory level of said accumulator; or (ii) corresponds to said fastest minimum speed of said downstream equipment if said actual inventory level of said accumulator is less than about said lower target limit for the inventory level of said accumulator; or (iii) is based on actual production speed of said rewinder if the actual level of inventory in said accumulator is less than about said upper target limit for the inventory level of said accumulator and greater than about said lower target limit for the inventory level of said accumulator; and (h) controlling the production speed of said downstream equipment based on said master speed reference value.