Sport fabrics are not only used by athletics but also have gained extensive uses as leisure wears for body tuning and shaping. In such applications fabric must have special features one of which is comfort. The ability to transfer moisture is among many factors that affect fabric comfort. Sport fabrics can be found in great varieties. In this research thermal comfort properties of a novel fabric of comprise of blend of Estabragh fibers were investigated. Estabragh is a natural hallow fiber which grows widely in southern plains of Iran. The hallow structure of Estabragh makes it uniquely suitable for production of sport fabrics. Conversion of these crimpless fibers into carded layer demands special carding expertise. Therefore a novel Caustic soda treatment was employed to impart crimp to the fibers thus the facilitating the carding operation. Estabragh/cotton blended spun yarns in ratio of 1:1 were produced using short-staple spinning system. Two sets of weft knitted interlock fabrics using the blended Estabragh/cotton and 100% cotton yarns were produced on a flat knitting machine. Simulation of moisture and heat transfer through the samples was simultaneously performed. Fabric heat transfer ability, water vapour transmission, air permeability and capillary absorption were measured. Heat transfer ability and water vapour transmission were measured by hot plate and cup method respectively. Arrangement of fibers in the cross-section of the yarn samples was modeled. The results of simulation showed sweat transfer through Estabragh/cotton and 100% cotton samples were 66.4% and 60.22%, respectively. It was found that 100% cotton samples exhibited less moisture transfer rate than cotton/ Estabragh samples. As far as heat transfer is concerned, it was established that 100% cotton samples possess higher heat transfer ability than Estabragh/cotton. It was observed that the water vapour transmission rate of Estabragh/cotton samples is higher than those of 100% cotton samples. Results also showed the capillary absorption of Estabragh/cotton samples of in comparison to those of 100% cotton samples were higher. Air permeability of Estabragh/cotton was found to be higher than 100% cotton samples. It can be concluded that Estabragh/cotton knitted fabrics are more suitable for sport fabric than cotton knitted fabric. Key words: Sports clothing, thermal comfort, Estabragh, cotton, knitted fabric, heat, moisture and vapour transfer, air- permeability
