Spectral Interference Measurement for Liquid Film Thickness Control
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Solution Overview
Problem
Existing methods for measuring liquid layer thickness are limited in accuracy and applicability, particularly for non-spherical member shapes and surfaces with roughness above 1.0 µm, leading to inefficiencies in abrasion reduction and product quality in tenter apparatuses.
Innovation Solution
A spectral interference method using curve fitting techniques with a portable sensor to measure liquid layer thickness on members of various shapes, including those with rough surfaces, by analyzing reflected light and controlling the liquid layer thickness on clip rails in tenter apparatuses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement methods (glass ball and race groove, or simple reflected light brightness) are used, then the measurement process is simple, but the measurement precision is insufficient for rough surfaces and non-spherical members
Solution Approach 1:
The measurement system is designed to be movable and adaptable, allowing the sensor to contact the liquid layer at different positions and angles. The system can dynamically adjust to measure various member shapes and surface conditions, rather than being fixed for单一 geometry
Solution Approach 2:
The system measures multiple parameters including reflectance at different wavelengths, incident angles, and polarization states. By changing these measurement parameters and analyzing the spectral characteristics, the system achieves high precision measurement on rough surfaces where conventional single-parameter methods fail
2Reliability
If a liquid layer is formed between members to reduce abrasion, then member durability is improved, but oil dissipation and foreign object generation occur
Solution Approach 1:
The measurement system provides real-time feedback on liquid layer thickness during operation. This feedback enables dynamic adjustment of liquid supply to maintain optimal thickness, preventing both insufficient lubrication and excessive liquid that causes dissipation and contamination
Solution Approach 2:
The system measures and controls liquid layer thickness before critical wear or dissipation problems occur. By maintaining proper thickness in advance, the system prevents abrasion acceleration and reduces oil loss before it becomes a problem
3Reliability
If the liquid layer thickness is increased to ensure adequate lubrication, then abrasion reduction is improved, but liquid flies around and adheres to products deteriorating quality
Solution Approach 1:
The system precisely controls liquid layer thickness as a critical parameter, maintaining it within an optimal range that provides sufficient lubrication without excess liquid that would fly off and contaminate products
Solution Approach 2:
The system replaces mechanical estimation of liquid layer adequacy with optical measurement and spectral analysis, enabling precise non-contact measurement and control of liquid thickness to prevent both wear and contamination
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
This method provides accurate and quantitative measurement of liquid layer thickness, reducing abrasion and dissipation of oil and metal powder, thereby enhancing film quality and reducing defective generation in tenter apparatuses.
Implementation Method 1
applying a light beam to a liquid layer disposed on a surface of a member, detecting the reflected light by a sensor
Implementation Method 2
analyzing the reflected light according to a spectral interference method
Data Source
Figure 1~2
Figure 3
AI summary
The invention provides a measuring method and a measuring apparatus characterized by applying a light beam to a liquid layer disposed on the surface of a member, detecting the reflected light by a sensor, and analyzing the reflected light according to a spectral interference method using the curve fitting technique to determine the thickness of the liquid layer. They can measure quantitatively and very accurately the thickness of a liquid layer formed on members of various shapes. In addition, generation of defectives due to dissipation of oil and metal powder can be reduced if film production is performed while controlling the thickness of the liquid layer on the clip rails in the tenter apparatus on the basis of measurements taken by using the measuring method and the measuring apparatus according to the present invention control.