Correlation between the Ultraviolet Protection Factor and the weight and thickness of undyed cellulosic woven fabrics

The protection that a fabric offers against ultraviolet radiation can be quantified by the determination of the in vitro Ultraviolet Protection Factor (UPF). According to the literature, the factor that has a higher influence on the UPF of a fabric is its structure; it determines the aperture of a fabric, and thus the physical barrier that will oppose the passing of ultraviolet radiation. In the present paper, the UPF is correlated with the structural parameters of fabrics which are widely used in their technical description such as weight per surface unit and thickness. Models were defined for fabrics made with three different cellulosic fibres, cotton, Modal and Modal Sun.