Research on the influence of yarn parameters on the ultraviolet protection of yarns

Considering both the yarn parameters and the light interaction (reflectance and transmittance) between two adjacent yarns, an optical model was presented to understand the ultraviolet (UV) light penetrating a single undyed yarn and a lot of yarns. The optical model was verified with results of diffuse reflectance spectra measurement on wool yarn samples. This optical model was used to predict the factors influencing UV protection, including fibre diameter, yarn linear density, yarn twist, transmittance index and refractive index. The statistical predictive model was also set up to show the relationship between the yarn parameters and the UV protection (UPF values) of the yarns. Yarns with the fine diameter, large yarn linear density and low yarn twist had the high UV protection.