Gravimetric and Optical Quantification Protocols for Bast Defect Content
Gravimetric digestion provides absolute mass baseline proof for bast defects, while optical scanning provides fast surface area sorting requiring lot calibration.
Multispectral Reflectance Ratio
Spectral Evaluation
A calculated numerical value derived from the intensity of light reflected at specific wavelengths provides a non-destructive measure of material composition. The multispectral reflectance ratio is utilized to determine the residual lignin content in processed flax fibers and linen yarns. This measurement identifies how much non-cellulosic material remains after retting and boiling-off processes.
It offers a fast, chemical-free alternative to traditional acid extraction methods for assessing fiber purity.
Band Selection
Sensor systems capture the reflected energy across multiple distinct bands of the electromagnetic spectrum, focusing on the visible and near-infrared regions. By calculating the multispectral reflectance ratio between the absorption band of lignin and the high-reflectance band of pure cellulose, the system calculates a localized index. This index shifts predictably as the flax undergoes chemical scouring and bleaching, showing when the target purity has been achieved.
The method allows immediate adjustment of the chemical baths to prevent over-processing and fiber degradation.
Maturity Grading
Analyzing raw fiber batches with this spectral approach helps spinners group incoming shipments by their natural color and retting uniformity. The ratio flags lots that might absorb dyes inconsistently, preventing striping defects in the finished woven linen. This automated grading ensures consistent dye uptake across different production runs.