Systems and methods for controlling phasing of advancing substrates in absorbent article converting lines
The present disclosure relates to systems and processes for controlling the relative positions or phasing of advancing substrates and/or components in absorbent article converting lines. The systems and methods may utilize feedback from technologies, such as vision systems, sensors, remote input and output stations, and controllers with synchronized embedded clocks to accurately correlate component placement detections and placement control on an absorbent article converting process. The systems and methods may accurately apply the use of precision clock synchronization for both instrumentation and control system devices on a non-deterministic communications network. In turn, the clock synchronized control and instrumentation network may be used to control the substrate position. As such, the controller may be programmed to the relative positions of substrates and components along the converting line without having to account for undeterminable delays.
1. A method for phasing absorbent products from a web converting manufacturing process, the method comprising the steps of:
providing a communication network;
connecting a sensor with the communication network, the sensor including a sensor clock;
connecting a controller with the communication network, the controller including a controller clock;
synchronizing the sensor clock with the controller clock such that the reported time of the controller clock and the sensor clock are correlated;
advancing a substrate in a machine direction through a converting process at a first speed;
virtually segmenting the substrate into a plurality of virtual segments;
advancing a series of component parts in the machine direction at a second speed, the component parts spaced from each other at a relatively constant distance;
sequentially adding component parts to the substrate;
inspecting the substrate and component parts with the sensor;
communicating inspection parameters from the sensor to the communication network;
assigning a timestamp to each inspection parameter, each timestamp based on the sensor clock;
receiving the inspection parameters and corresponding timestamps from the communication network into the controller;
correlating each inspection parameter with one virtual segment based on the timestamp of the inspection parameter;
identifying component positions in virtual segments based on the inspection parameters;
adjusting the placement of the component parts on the substrate; and
cutting the substrate with component parts added thereto into discrete absorbent articles.
2. The method of claim 1 , wherein the step of adjusting the placement further comprises changing the second speed of the component parts to a third speed and changing from the third speed back to the second speed.
3. The method of claim 2 , wherein the third speed is greater than the second speed.
4. The method of claim 2 , wherein the third speed is less than the second speed.
5. The method of claim 1 , further comprising the step of adjusting the timestamps associated with the inspection parameters based on a sensor time delay.
6. The method of claim 1 , wherein the component parts include parts added as a continuous web of material and parts added as a discontinuous web of material.
7. The method of claim 1 , wherein the communication network is non-deterministic.
8. The method of claim 1 , wherein the absorbent articles are diapers.
9. The method of claim 8 , wherein the substrate forms backsheets of the diapers.
10. The method of claim 8 , wherein the series of component parts are ears.