Patent ID: 7568412
Filing Date: 2009-08-04
Classification: B26D,Y10T

Abstract:
1. A method for minimizing scrap in a gapless order change for a corrugator, said corrugator including a plunge slitter having multiple slitting tools, including interior slitting tools and edge trim slit tools, each operable to be moved vertically into slitting engagement with a continuous corrugated paperboard web at the start of a new order to provide longitudinal slit lines in the web, the slit lines dividing the web into a plurality of output webs of selected widths, said slitting tools operable to be moved vertically out of slitting engagement with the web at the end of a running order, a pair of vertically separated cut-off knives downstream of the slitter for receiving and cutting the output webs into selected sheet lengths, said knives including an upper knife and a lower knife, and a web selector device between the slitter and the cut-off knives for selectively separating the output webs along a common innermost slit line into an upper output web portion and a lower output web portion for said respective upper knife and lower knife, said method comprising the steps of: (1) operating the slitter to start a new order while continuing to slit the running order to create an overlap region in the web where all running order and new order slits overlap; (2) maintaining the slitting tool for the common innermost slit line of the running order in slitting engagement with the web for a selected distance beyond the overlap region to define with the new order slit lines an order change region upstream of and outside the overlap region; (3) maintaining the edge trim slit tools of the running order in slitting engagement with the web for a selected distance beyond the overlap region and into the order change region; (4) partially severing the web upstream of the web selector device to provide a generally transverse slit in the order change region to connect the common innermost slit line of the running order web portions and the common innermost slit line of the new order output web portions; and, (5) severing the web upstream of the web selector device from the innermost edge trim slit line of the running and new orders laterally to the edge of the web on both sides.