Multilayer cotton fabric porosity and its infl uence on permeability properties

Abstract

Apart from their soft feel and good water absorbency, cotton fabrics are also characterised by good heat conductivity, air permeability and breathing. By increasing the open surface of one-layer fabrics, their air and water vapour permeability, and heat conductivity should increase as well, whereas the protection against UV rays, on the other hand, which is especially important for summer clothes, decreases. The aim of the research was to establish the influence of multilayer cotton fabric constructions on the properties connected with porosity, i.e. thermal resistance, water vapour resistance, UV-light permeability and air permeability. One-layer, two-weft and double cotton fabric constructions were woven from white, blue and black yarn with fineness 8 × 2 tex, warp density 40 ends/cm and weft density 60 picks/cm, taking into consideration the colour distribution of yarns in the fabrics as well. The research results showed that the most optimal construction characterises multilayer two-weft and double fabrics. Among the studied fabrics, a positive correlation was established between the porosity of fabrics and their air permeability or ultraviolet protection factor (UPF), respectively, and a negative correlation between the porosity of fabrics and their heat or water vapour permeability, respectively. The correlation between the calculated number of pores of individual samples, as an important factor in porosity, and the studied permeability resistance properties (i.e. heat resistance, water vapour resistance, UV-light permeability and air permeability resistance) was higher than the correlation between the porosity of samples and the abovementioned permeability properties.

Keywords

• multilayer fabrics
• textile construction
• air permeability
• water vapour permeability
• thermal resistance
• UV-light permeability