Moni Sankar Mondal

Deakin Institute for Frontier Materials, Deakin University, Australia

Title: A Rapid Integrated ATR–FTIR and DSC Approach for Fibre Sorting in Textile Waste Recycling

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Biography

Moni Sankar Mondal is a PhD candidate at the Institute for Frontier Materials, Deakin University, Australia. He holds a BSc in Textile Technology and an MSc in Textile Engineering. His doctoral research focuses on developing rapid and reliable analytical methods for identifying and quantifying fibres in post-consumer textile waste and environmental microfibre samples. His expertise includes ATR-FTIR spectroscopy, TGA/DTG, DSC, STA, UV–Vis–NIR spectroscopy, microscopy, calibration modeling and method validation. He has authored or co-authored 16 peer-reviewed research papers published in recognised international journals. Before commencing his PhD, he worked for approximately ten years as a university lecturer and two years in the textile dyeing and finishing industry. His research interests include textile recycling, fibre characterisation, microfibre pollution, sustainable textile processing and the application of advanced analytical techniques to support circularity in the textile industry.

Abstract

Post-consumer textile waste poses a major constraint to circularity because conventional garment-sorting methods are often challenging and time-consuming. This issue has also been encountered in an ongoing mechanical textile-recycling project at the Institute for Frontier Materials (IFM), Deakin University, where reliable fibre identification is essential for sorting waste and producing consistent recycled feedstock. Although near-infrared spectroscopy enables rapid, non-destructive analysis, its accuracy can be affected by garment colour, structure, finishes, moisture, and aging. Existing ATR-FTIR models also rely mainly on pure-fibre spectra and often inadequately address overlapping or shifting characteristic bands in blended textiles.

This study developed a multi-instrument analytical approach for identifying and quantifying fibres in post-consumer garments collected from second-hand retail stores. Reference cotton, viscose, polyester, polyamide and Lycra fibres and their blends were analysed using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). Calibration models were constructed using characteristic ATR-FTIR bands, while DSC melting enthalpies confirmed polymer identities based on their thermal degradation profiles. Characteristic bands for cotton (1029, 892, 663 and 557 cm?¹), polyester (1712, 1243, 871 and 723 cm?¹) and nylon (1635, 1537 and 3296 cm?¹) enabled fibre identification and quantification in selected post-consumer blends. 

The fibre-specific models successfully quantified the major fibre components in binary and tertiary blends, including 68.7% polyester in a 65/35 polyester–cotton, 31% polyester in a 70/30 viscose–polyester, and 18% nylon in an 80/20 cotton–nylon garment, with absolute errors of 1-7%. Minor Lycra contents of 0–5% were difficult to detect by ATR-FTIR in both intact fabrics and milled fibres, likely because of their distribution within the fabric. However, Lycra was distinguishable and quantified through its DSC melting endotherm and subsequent degradation profile.