Dual Dancer Web Tension Control for Printing
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Solution Overview
Problem
Existing methods struggle to maintain a substantially constant web tension during the movement of a continuous material, particularly in processes requiring precise tension control, such as head printing, leading to potential deviations and quality issues in the final product.
Innovation Solution
A method involving two dancer mechanisms with actuators that generate forces to control rollers along intersecting paths, ensuring equal tension at specific locations, thereby maintaining constant tension over a web path section where image formation occurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single dancer mechanism is used to control web tension, then the structure remains simple, but the tension cannot be maintained substantially constant over a portion of the web path where manipulation is performed
Solution Approach 1:
The web path is divided into multiple sections, with the first dancer mechanism controlling tension at a first location and the second dancer mechanism controlling tension at a second location. This segmentation allows independent control of tension at different positions, enabling constant tension to be maintained over the manipulation portion where image formation occurs.
Solution Approach 2:
The patent introduces a control system as an intermediary that receives tension measurements from both dancer mechanisms and calculates the forces required to maintain constant tension. This mediator coordinates the two dancer mechanisms to work together, resolving the complexity of controlling multiple mechanisms while achieving precise tension control.
2Speed
If rollers advance the web along the path, then the web moves through the system, but the tension varies causing manipulation issues
Solution Approach 1:
The dancer mechanisms are equipped with tension sensors that continuously measure the web tension at their respective locations. This feedback is sent to the control system, which calculates the required forces to maintain constant tension and adjusts the dancer mechanism positions accordingly, compensating for tension variations caused by web advancement.
Solution Approach 2:
The dancer mechanisms are designed to be dynamically adjustable, with actuators that can change the position of rollers in real-time based on tension measurements. This dynamic adjustment allows the system to maintain constant tension even as the web moves and tension conditions change.
Data Source
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AI summary
A method for controlling a tension of a continuous web (W) comprises: moving said web along a web path; controlling a first actuator of a first dancer mechanism (100) to generate a first force to move first rollers (110) of said first dancer mechanism (100) along a respective first path on a respective first surface, said first rollers contacting said web at a first portion of said web path; and controlling a second actuator of a second dancer mechanism (200) to generate a second force to move second rollers of said second dancer mechanism along a respective second path on a respective second surface, said second rollers (120) contacting said web at a second portion of said web path, said second portion being separate from said first portion. Said first force and second force are determined so that the tension of said web is substantially equal near said first portion and near said second portion.