Roll-to-Roll Web Tension Mapping with Non-Contact Resonance
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Solution Overview
Problem
Existing methods for measuring web tension distribution in roll-to-roll processes are inadequate for achieving comprehensive, accurate, and reliable results, particularly in flexible printed electronics manufacturing, leading to nonuniform device performance and reduced yield due to nonuniform tension distribution.
Innovation Solution
The system and method utilize a non-contact resonance (NCR) and gentle contact stiffness mapping (GCSM) techniques to measure web tension distribution across the width of a web, employing resonance frequencies and contact stiffness mapping based on first principles mechanics models, without the need for instrumented rollers, to determine average tension and linear variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If instrumented rollers with tension sensors are used to measure web tension, then web tension can be measured and controlled, but the system requires customized rollers, recalibration when web path changes, and sensors are prone to drifting and environmental sensitivity
Solution Approach 1:
The patent replaces mechanical tension sensors mounted on rollers with an optical measurement system. A laser source projects a laser line onto the web, and a camera captures the deformation of this laser line. The web tension is calculated by analyzing the deformation pattern of the laser line, substituting mechanical contact-based measurement with non-contact optical measurement. This eliminates the need for customized instrumented rollers and their associated complexity.
Solution Approach 2:
The patent introduces a laser line as an intermediary element between the measurement system and the web. Instead of directly measuring web tension with sensors, the system projects a laser line onto the web and uses the deformation of this laser line as a mediator to infer tension. The camera captures the laser line deformation, and computational algorithms convert this visual information into tension measurements, creating an indirect but accurate measurement pathway.
2Measurement precision
If conventional tension measurement methods are used, then average tension can be measured, but nonuniform tension distribution across the web width cannot be detected
Solution Approach 1:
The patent segments the web width into multiple measurement zones by projecting a laser line that spans across the entire web width. The camera captures the deformation of the laser line at different横向 positions simultaneously. By analyzing the deformation pattern across the entire laser line, the system obtains tension information for multiple segments of the web width, enabling detection of nonuniform tension distribution that conventional single-point sensors cannot detect.
3Ease of manufacture
If friction between web and rollers is assumed uniform, then tension measurement is simplified, but nonuniform friction causes nonuniform stress induction in the web
Solution Approach 1:
The patent replaces mechanical contact-based tension measurement with non-contact optical measurement. By using a laser line projection and camera capture system, the measurement process does not involve physical contact between sensors and the web, thereby eliminating friction-induced stress. The laser line deformation captures the actual stress state in the web without introducing additional frictional effects that would alter the stress distribution.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Accurately measures web tension distribution, improving quality control and increasing device yield by reducing nonuniform tension variations, applicable to a wide range of web properties and environmental conditions.
Implementation Method 1
employing resonance frequencies and contact stiffness mapping based on first principles mechanics models
Implementation Method 2
means for inducing deflection in the web between the first and second rollers
Data Source
AI summary
Systems and methods for measuring web tension distribution in roll-to-roll processes, for example, such as R2R processes employed in the fabrication of printed devices. Such systems and methods entail a web that travels between first and second rollers in a longitudinal direction of the web, inducing tension in the web in the longitudinal direction thereof such that tension is present in a flexible substrate of the web between the first and second rollers, and operating the system to determine an average tension and linear variation of tension present in the flexible substrate resulting from the tension induced in the web inducing a nonuniform tension distribution in the flexible substrate between the first and second rollers. The systems and methods utilize one or more devices that induce deflection in the web between the first and second rollers.