Infrared Camera Paper Quality Measurement

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Solution Overview

Problem

Current quality control systems for paper machines using scanning sensors face delays in measurement and control due to filtering requirements, leading to inefficiencies and inaccuracies in measuring paper quality parameters, especially in high-speed environments, and require radioactive sources which are burdensome and not suitable for small machines.

Innovation Solution

A non-scanning quality parameter measurement method using an infrared camera with an InGaAs area sensor and LED light sources that measure paper quality parameters without radioactive rays, allowing for simultaneous whole-width measurement and online calibration and standardization, enabling quick and accurate determination of quality parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If scanning sensors are used to measure paper quality parameters, then measurement coverage of the entire paper width is achieved, but measurement speed decreases and filtering is required causing delays

Engineering Contradiction:
Improvemeasurement coverage areaVSAvoidmeasurement speed
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent replaces the mechanical scanning system with a fixed sensor array that captures the entire paper width simultaneously. Instead of moving a single sensor point-by-point across the paper width, multiple sensors are arranged in a two-dimensional array to capture all measurement points at once, eliminating the mechanical scanning motion and enabling simultaneous whole-width measurement without filtering delays

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent divides the measurement system into multiple independent sensor elements arranged in an array, where each sensor measures a specific point on the paper web. This segmentation allows parallel measurement of multiple points simultaneously, achieving both complete width coverage and high measurement speed without the need for sequential scanning

Inventive Principle:
Principle #1Segmentation

2Reliability

If scanning sensors with filtering are used, then noise from high-speed machine fluctuations is reduced, but measurement accuracy for rapid quality changes decreases

Engineering Contradiction:
Improvenoise reductionVSAvoidaccuracy of rapid quality changes
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs measurement before the paper web reaches the winder, capturing quality parameters at the exact location where they are most relevant for control. By measuring at this upstream position with simultaneous whole-width capture, the system obtains accurate data on rapid quality changes before they are mixed or diluted by subsequent processing, eliminating the need for filtering that would delay detection

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If radioactive sources are used for quality measurement, then measurement capability is improved, but device complexity and safety requirements increase

Engineering Contradiction:
Improvequality measurement capabilityVSAvoidsafety and regulatory complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces expensive, regulated radioactive sources with inexpensive, non-radioactive optical sensors that use LED or laser light sources. These optical measurement systems achieve sufficient measurement precision for paper quality control without requiring special safety licenses, shielding, or regulatory compliance, dramatically simplifying device complexity and operational requirements

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the measurement parameter from radioactive radiation detection to optical property detection. By measuring optical properties such as light transmission, reflection, or absorption characteristics of the paper web, the system achieves quality measurement capability without using ionizing radiation, thereby eliminating safety and regulatory complexities associated with radioactive sources

Inventive Principle:
Principle #35Parameter changes

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 improves measurement accuracy and speed, reduces the need for radioactive sources, and is applicable to small paper machines, enhancing productivity and quality control without the need for scanning or filtering, thus offering economic benefits and improved paper quality.

Implementation Method 1

an infrared LED light source and an infrared camera configured to receive infrared traveling via the long sheet material

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

measuring, by using an infrared light source and an infrared camera configured to receive infrared, a quality parameter of the long sheet material moving toward a winder

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP3805733B1Quality measuring method and quality measuring device for long sheet material
Publication Date: 2023.10.25 PSM INT INC
  • EP3805733B1 patent drawingFigure 1
  • EP3805733B1 patent drawingFigure 2
  • EP3805733B1 patent drawingFigure 3

AI summary

The quality measurement method for a long sheet material W includes measuring cellulose fibers, %moisture, and %ash of the paper web W by using area cameras 1102 to 1106 having an infrared light receiving element and a light source 1100 having an infrared light emitting LED element. Performance check for the infrared cameras 1102 to 1106 over the entire width and correction of measured values are performed by using consistency between measured values for the same point in an overlap area measured by adjacent cameras and reference samples 1107 at the off-sheet positions provided at both sides.