Studies in thermal properties of knitted fleece fabrics

Abstract

This study investigates the thermal performance of threethread knitted fleece fabrics developed using different ground fibre compositions to evaluate their suitability for thermal comfort applications. Nine fleece fabric variants were produced on a special circular knitting machine using bamboo, modal, and cotton as ground yarns combined with polyester binder and loop yarns. The fabrics were characterized in terms of thickness, GSM, air permeability, thermal resistance, CLO value, and warmth retention using standard ASTM test methods. Statistical analysis, including regression modelling and 3D spatial visualization, was employed to examine the relationship between thermal resistance and key structural and comfort parameters. Results revealed significant variation in thermal behaviour depending on fibre composition. Bamboo-based fleece fabrics exhibited the highest thermal resistance (0.0182–0.0184 m²K/W), CLO value, and warmth retention, indicating superior insulation performance, while modal-based fabrics showed the lowest thermal resistance due to higher breathability and reduced heat retention. Cottonbased fabrics demonstrated intermediate behavior. Regression analysis confirmed that thermal resistance is governed by the combined influence of structural and comfort-related variables rather than individual parameters alone. The study highlights the critical role of fibre selection in designing knitted fleece fabrics with enhanced thermal comfort and provides practical insights for the development of winter and sportswear textiles.