Method and apparatus for synchronizing end of order cutoff for a plunge slit order change on a corrugator
First Claim
1. A method for minimizing scrap in a gapless order change for a corrugator, said corrugator including a slitter-scorer operable to provide longitudinal slit lines and score lines in a continuous corrugated paperboard web passing through the slitter-scorer, the slit lines dividing the web into a plurality of output webs of selected widths, a pair of vertically separated cut-off knives downstream of the slitter-scorer 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-scorer 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) determining an order change location in the web defining the transition from a running order to a new order of a selected one of the upper and lower output web portions;
(2) partially severing the web upstream of the web selector device to provide a generally transverse slit at the order change location to subsequently 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;
(3) adjusting the slitter-scorer in an order change region of the web that includes the order change location to terminate the running order slit and score lines and to begin the new order slit and score lines;
(4) after separating the output web portions, sensing a transverse edge of a web portion defined by said transverse slit and generating an edge location signal; and
, (5) operating one of the cut-off knives in response to said transverse edge location signal to cut one of the web portions on the line of said transverse slit.
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Accused Products
Abstract
A system is provided for synchronizing the end of order cutoff for a plunge slit order change on a corrugator that minimizes scrap and cuts the end order sheets to a length and width such that jam-ups at order change are eliminated. The system detects a transverse edge discontinuity immediately prior to end of order cutoff and, in conjunction with a prior calculation comparing sheet lengths and order end positions between upper and lower webs, positions an upstream transverse partial web slit at an optimum order end position such that the entire web is ultimately cut on the partial sever at an optimum position for scrap minimization and scrap sheet size and shape.
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Citations
16 Claims
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1. A method for minimizing scrap in a gapless order change for a corrugator, said corrugator including a slitter-scorer operable to provide longitudinal slit lines and score lines in a continuous corrugated paperboard web passing through the slitter-scorer, the slit lines dividing the web into a plurality of output webs of selected widths, a pair of vertically separated cut-off knives downstream of the slitter-scorer 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-scorer 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:
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(1) determining an order change location in the web defining the transition from a running order to a new order of a selected one of the upper and lower output web portions;
(2) partially severing the web upstream of the web selector device to provide a generally transverse slit at the order change location to subsequently 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;
(3) adjusting the slitter-scorer in an order change region of the web that includes the order change location to terminate the running order slit and score lines and to begin the new order slit and score lines;
(4) after separating the output web portions, sensing a transverse edge of a web portion defined by said transverse slit and generating an edge location signal; and
,(5) operating one of the cut-off knives in response to said transverse edge location signal to cut one of the web portions on the line of said transverse slit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for minimizing scrap in a gapless order change for a corrugator, said corrugator including a slitter-scorer operable to provide longitudinal slit lines and score lines in a continuous corrugated paperboard web passing through the slitter-scorer, the slit lines dividing the web into a plurality of output webs of selected widths, a pair of vertically separated cut-off knives downstream of the slitter-scorer for receiving and cutting the output webs into selected sheet lengths, said knives including an upper knife and a lower knife each having a minimum sheet length cut capability, and a web selector device between the slitter-scorer 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:
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(1) determining an order change region in the web defining the transition from a running order to a new order in which the common slit line separating the running order upper and lower output web portions is offset laterally from the common slit line separating the new order upper and lower output web portions;
(2) determining an order change location in said order change region for the last knife cut for each of the running order upper and lower output web portions;
(3) partially severing the web upstream of the web selector device to provide a generally transverse slit in the order change region and at the order change location or upstream of the order change location by a distance at least equal to said minimum sheet length to subsequently connect the common slit line of the running order web portions and the common slit line of the new order output web portions;
(4) adjusting the slitter-scorer in the order change region of the web to terminate the running order slit and score lines and to begin the new order slit and score lines;
(5) after separating the output web portions, sensing a transverse edge of one of the output web portions defined by said transverse slit and generating an edge location signal; and
,(6) operating one of the cut-off knives in response to said edge location signal to cut an output web portion on the line of said transverse slit. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification