Thermal comfort properties of Viloft/cotton and Viloft/polyester blended knitted fabrics

Viloft is a special regenerated cellulosic fiber with a flat cross-section and crenulated surface that maintains air gaps in the yarns that help to improve the thermal properties of the fabrics. This fiber is mainly used for underwear, socks and sportswear fabrics and blends of Viloft with polyester or cotton are commonly preferred in the market. In this study, thermal-related characteristics, such as the thermal conductivity, thermal diffusivity, thermal absorptivity, thermal resistance, moisture and air permeability, of Viloft/cotton and Viloft/polyester blended knitted fabrics were investigated. For this purpose, 100%–0%, 67%–33%, 50%–50%, 33%–67% and 0%–100% blends of Viloft/cotton and Viloft/polyester slivers were produced and spun as 19.7 tex on a ring spinning system. In addition, single-jersey and 1 × 1 rib fabrics were produced and the comfort properties of these fabrics were measured using the Alambeta, sweating guarded hotplate, Permetest and air permeability testing devices. A simplex lattice design for the blended fabric properties was also developed and statistical analyses were carried out. According to the results, Viloft-rich blends, in general, improved the thermal properties of the fabrics. However, the relative water vapor permeability of Viloft/polyester blended fabrics was found not to be significant and only small significances were present for cotton blended ones, statistically.