Raman Spectroscopy Crystallinity Measurement for Mixed Resins
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Solution Overview
Problem
Existing methods for measuring the crystallinity of crystalline thermoplastic resin, such as those using Fourier transform infrared spectrometry or thermal melting methods, face challenges in accuracy and non-destructive inspection, especially when materials other than crystalline thermoplastic resin are present.
Innovation Solution
A crystallinity measurement device utilizing Raman spectroscopy to acquire a Raman spectrum of resin-containing materials, calculating crystallinity based on the intensity of a low-wavenumber spectrum less than 600 cm−1, which is not affected by molecular oscillations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Fourier transform infrared spectrometry is used to measure crystallinity, then measurement can be performed on crystalline thermoplastic resin, but measurement accuracy deteriorates when materials other than crystalline thermoplastic resin (such as thermosetting resin, amorphous thermoplastic resin, and reinforced fibers) are included
Solution Approach 1:
The patent segments the infrared spectrum into two distinct regions: a first wavenumber region (4000-2000 cm⁻¹) used for acquiring the infrared absorption spectrum, and a second wavenumber region (650-400 cm⁻¹) used for selecting reference spectra. This segmentation allows the measurement system to separate the analytical function from the reference function, enabling accurate crystallinity measurement even in mixed materials by using the first region for sample analysis and the second region for finding comparable reference standards.
Solution Approach 2:
The patent makes the reference spectrum selection process universal by searching through a database of reference spectra covering multiple material types (crystalline thermoplastic resin, amorphous thermoplastic resin, thermosetting resin, and reinforced fibers) in the second wavenumber region. This universal reference database allows the system to adapt to any combination of materials in the sample, not just pure crystalline thermoplastic resin, thereby achieving both accuracy and versatility.
2Measurement precision
If thermal melting method (DSC) is used to measure crystallinity, then measurement can be performed, but the method is destructive and cannot be used for quality guarantee inspection
Solution Approach 1:
The patent replaces the thermal melting method (DSC) which requires heating and melting the resin, with an infrared absorption spectrum-based measurement method. This substitution uses optical measurement instead of thermal processing, allowing crystallinity to be determined without destroying the sample, thus enabling non-destructive quality inspection while maintaining measurement capability.
3Measurement precision
If X-ray diffraction method is used to measure crystallinity, then measurement can be performed, but facility protection against radiation is required making it unsuitable for manufacturing sites
Solution Approach 1:
The patent replaces the X-ray diffraction method which requires complex radiation protection facilities with an infrared absorption spectrum-based measurement method. This substitution uses infrared radiation that does not require shielding, eliminating the need for complex safety facilities while maintaining crystallinity measurement capability, thus making the system suitable for manufacturing site deployment.
4Measurement precision
If reference sample with controlled thickness and crystallinity is used in infrared measurement, then crystallinity calculation can be performed, but the method becomes complex and requires precise control of reference parameters
Solution Approach 1:
The patent adds a dimensional aspect to the reference spectrum selection by introducing a second wavenumber region (650-400 cm⁻¹) that is separate from the measurement region. Instead of controlling physical parameters like thickness and crystallinity of reference samples, the system searches through a database of reference spectra in this additional spectral dimension, automatically selecting the most appropriate reference based on spectral similarity. This reduces physical preparation complexity while maintaining calculation accuracy.
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 easy and accurate calculation of crystallinity even in the presence of non-crystalline materials, allowing for real-time measurement during manufacturing processes and adjustment of heating treatments to achieve desired crystallinity.
Implementation Method 1
a Raman spectroscopy unit (11) configured to acquire a Raman spectrum of resin-containing material (1) including crystalline thermoplastic resin
Data Source
AI summary
A crystallinity measurement device includes a Raman spectroscopy unit configured to acquire a Raman spectrum of resin-containing material including crystalline thermoplastic resin; and an analysis unit configured to calculate crystallinity of the crystalline thermoplastic resin based on an intensity of a low-wavenumber spectrum that is a spectrum in a region of less than 600 cm−1, in the Raman spectrum.