The Change of Air Permeability and Structure of Breathable-Coated Textile Materials after Cyclic Stretching

Abstract

In this article, the change of air permeability and structure of breathable-coated textile materials after cyclic stretching is discussed. The cyclic stretching test of woven cotton/polyester (PES) fabric with microporous polyurethane coating was done on the tensile testing machine Z005 (Zwick, Germany) by varying number of extension cycles and size of fixed elongation. The maximum number of stretching cycles was 420, and elongation varied in the range of 5 % – 25 %. The investigation of fabric was done both before mechanical treatment and fully relaxed (not less than 24 hours) after the cyclic stretching. Linear and logarithmic correlation analysis results, when researching the intensity of relationship between the parameters of cyclic stretching and air permeability, showed the sufficiently large values of coefficient of determination. It has been shown that an air permeability value after cyclic stretching increases depending on the increased number of stretching cycles and elongation. Comparison between the predictive and experimental values of air permeability has been carried out. The intensity of relationship between extension factors and the surface cover factor and this factor relationship with the air permeability of the fabric, are analyzed too. It has been concluded that the air permeability of the breathable-coated fabric is under the influence of the enlarged micropores in the coating structure.