Forensic Discrimination of Various Subtypes of Regenerated Cellulose Fibers in Clothing Available on the Consumer Market

The discrimination of five subtypes of regenerated cellulose fibers, i.e., viscose, bamboo, lyocell, modal, and cupro, from both men’s and women’s clothing available on the prevalent apparel market was described. The examinations were conducted using optical microscopy (in transmitted white light and polarized light), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM–EDX), and Fourier Transform Infrared Spectroscopy (FTIR). The microscopic methods revealed characteristic features of the morphological structure of the examined fibers, enabling the identification of differences between the subtypes. As a result, the microscopic methods were found to be the most effective for identifying and distinguishing between the types of examined fibers. Although the FTIR technique did not allow for distinguishing between the fiber subcategories, it contributed to the enlargement of the IR spectra databases for regenerated cellulose fibers. Based on the findings, a general scheme of the procedure for identifying the tested fibers was proposed.