Cellulose Composite Determination via Infrared Spectral Normalization

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Solution Overview

Problem

Existing methods struggle to accurately determine the composite ratio of cellulose in composite resins due to overlapping peaks from resin, cellulose, and antioxidants, making it difficult to distinguish between composite resin spectra and resin-only spectra, especially at low cellulose concentrations.

Innovation Solution

A method using infrared spectroscopy that normalizes spectral intensity ratios at specific wave numbers different from resin-derived peaks, allowing for accurate determination of cellulose content by comparing normalized values from composite resin spectra to those of single resin samples, focusing on background intensities rather than peak intensities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional infrared spectroscopy is used to determine cellulose content in composite resin, then the measurement can be performed non-destructively, but the peaks from resin, cellulose, and antioxidants overlap making accurate determination difficult

Engineering Contradiction:
Improvenon-destructive measurement capabilityVSAvoidcellulose content determination accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent divides the spectral analysis into two distinct parts: using peak intensity ratios (around 1000 cm⁻¹) to identify resin type and background intensity ratios (around 500 cm⁻¹) to determine cellulose content. This segmentation allows each measurement aspect to be optimized independently, resolving the overlap problem while maintaining non-destructive measurement capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces background intensity at 500 cm⁻¹ as an intermediary parameter that is not affected by the overlapping peaks of resin, cellulose, and antioxidants. This intermediary measurement point serves as a reliable indicator for cellulose content determination without being contaminated by the spectral interference that plagues traditional peak-based methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If peak intensity ratios are used for determination, then resin type can be identified, but cellulose content cannot be accurately distinguished due to peak overlapping

Engineering Contradiction:
Improveresin type identificationVSAvoidcellulose content differentiation
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent segments the spectral information usage: peak intensity ratios (1000 cm⁻¹ region) are dedicated to resin type identification, while background intensity ratios (500 cm⁻¹ region) are exclusively used for cellulose content determination. This clear segmentation eliminates the conflict between these two determination goals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different analytical approaches to different regions of the spectrum: peak-based analysis for resin identification and background-based analysis for cellulose quantification. This local quality approach optimizes each region for its specific purpose, with the 500 cm⁻¹ background region providing pure cellulose signal free from overlapping interference.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If traditional spectrum matching is used, then resin type determination is straightforward, but composite resin with low cellulose concentration cannot be distinguished from resin-only spectra

Engineering Contradiction:
Improvespectrum matching simplicityVSAvoidlow concentration cellulose detection
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses background intensity at 500 cm⁻¹ as an intermediary parameter that provides a clear signal for cellulose content even at low concentrations. This background measurement acts as a sensitive indicator that can detect small amounts of cellulose without being masked by the dominant resin spectrum, enabling distinction between composite and pure resin samples.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the measurement parameter from peak intensity (which is dominated by resin) to background intensity ratio (which is sensitive to cellulose content). This parameter change transforms the measurement from being resin-dominated to being cellulose-sensitive, enabling detection of low concentration cellulose while maintaining ease of operation through ratio-based analysis.

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

Enables precise determination of cellulose content in composite resins, even at low concentrations, by utilizing normalized spectral intensity ratios, thereby improving the accuracy of composite resin analysis and differentiation from resin-only spectra.

Implementation Method 1

irradiating composite resin containing cellulose with infrared light; receiving reflected light from the composite resin irradiated with the infrared light

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 2

obtaining a reflection or absorption spectrum by using the reflected light

Methodology Applied
Scientific EffectVibrational spectroscopy: Absorption Spectroscopy

Data Source

PatentEP4019945B1Cellulose composite determination method and apparatus therefor
Publication Date: 2024.09.11 PANASONIC HOLDINGS CORP
  • EP4019945B1 patent drawingFigure 1
  • EP4019945B1 patent drawingFigure 2
  • EP4019945B1 patent drawingFigure 3

AI summary

Composite resin containing cellulose is irradiated with infrared light, reflected light from the composite resin irradiated with the light is received, normalization is performed at a peak position maximized in a peak at 2800 cm-1 or more and 3000 cm-1 or less, which is a C-H stretching peak caused by the composite resin, in a reflection or absorption spectrum obtained by the reflected light, and a reflection or absorption spectrum for determination is obtained. The spectrum is used to acquire a ratio value of a spectral intensity (background intensity) at a position of 1000 cm-1 or less according to a determined resin type and different from a wave number at which a peak derived from resin of the determined resin type is expressed, and a ratio of the spectral intensity (background intensity) is used so that a composite of cellulose combined in composite resin can be determined with high accuracy.