Feedforward control system for an elastic material
AssigneeKimberly-Clark Worldwide, Inc.
InventorsKent Allan Franklin, Aaron Dee Schilpp, Douglas N. Duehring
Life of this patent
Estimating the term…
Abstract
A process for providing feedforward control to control the feed rate of an elastic material. The process involves measuring the distance between registration marks on the elastic material prior to cut-off. These measurements are compared to a target cut length. The feed rate of a feed roll is adjusted, based on the target cut length and the distance between the registration marks, to maintain the cut length of the elastic material at the target cut length.
Claims55
A process for providing feedforward control to control a feeding of an elastic material to a target feed rate, comprising the steps of:
- determining a machine direction distance, L1, between a first registration mark and a second registration mark on an elastic material while the elastic material is under a first tension, T1;
- approximating a machine direction distance, L0, between the first registration mark and the second registration mark on the elastic material as if the elastic material were under zero tension, T0;
- feeding the elastic material at a second tension, T2;
- measuring a machine direction distance, L2, between the first registration mark and the second registration mark on the elastic material while the elastic material is under the second tension, T2;
- and
- adjusting a feed rate Ls, of the elastic material according to a given relation, to match a predetermined target feed rate.
A process for providing feedforward control to control cut length of an elastic material to a target cut length, Lc, comprising the steps of:
- using a feed roll to feel an elastic material at a converting tension, T2;
- measuring a machine direction distance, L2, between a first registration mark and a second registration mark on the elastic material while the elastic material is under the converting tension, T2;
- adjusting a feed rate of the elastic material according to a given relation utilizing the machine direction distance, L2, to match a predetermined target cut length, Lc;
- adjusting a speed of the feed roll to control the target cut length, Lc according to the relation:
- SPEEDfeed roll=LcL2/L0;
- wherein L0 is an approximated machine direction distance between the first registration mark and the second registration mark on the elastic material as if the elastic material were under zero tension;
- and
- cutting a length of the elastic material approximately equal to the target cut length, Lc, to form an elastic material segment.
A process for providing feedforward control to control cut length of an elastic material to a target cut length, comprising the steps of:
- transferring the elastic material to a feed roll;
- approximating a distance between a first registration mark and a second registration mark on the elastic material as if the elastic material were under zero tension;
- determining a distance between the first registration mark and the second registration mark on the elastic material while the elastic material is under tension;
- comparing a target ratio of the distance under tension to the distance under approximately zero tension to an actual ratio of the distance under tension to the distance under approximately zero tension;
- adjusting a speed of the feed roll in response to any difference between the target ratio and the actual ratio of the distance under tension to the distance under approximately zero tension;
- and
- cutting a length of the elastic material approximately equal to the target cut length, to form an elastic material segment.
A process for providing feedforward control to control a speed at which an elastic material is fed into a convening process, comprising the steps of:
- feeding the elastic material into a converting process at a first feed rate;
- determining a first distance between a first registration mark and a second registration mark on the elastic material while the elastic material is under a first tension;
- determining a second distance between the first registration mark and the second registration mark on the elastic material while the elastic material is under a second tension;
- determining a target feed rate for the elastic material based on a relationship between the first and second distances;
- and
- adjusting the first feed rate of the elastic material in response to any difference between the target feed rate and the first feed rate to make the first feed rate match the target feed rate.
Dependencies are inferred from the claim text.