Influence of washing/drying cycles on fundamental properties of metal fiber-containing fabrics designed for electromagnetic shielding purposes

The development of lightweight flexible materials for electromagnetic interference shielding has received increased attention in recent years, particularly for clothing or technical applications and especially in areas of aircraft, aerospace, automobiles and flexible electronics, such as portable electronics and wearable devices. There are many references in the literature concerning the development and investigation of electromagnetic shielding lightweight flexible materials, especially those that are textile based with different electrically conductive additives. However, little attention has been paid to the problems related to the performance of developed electromagnetic shielding materials for clothing in use, above all wet processing (washing and drying). The main aim of this paper is a description of the influence of washing/drying cycles on the fundamental properties of metal fiber-containing fabrics. Changes in electromagnetic shielding ability and electric conductivity after washing/drying cycles were studied and also other characteristics, such as pilling, changes in mass per unit area and thickness of conductive fabrics, were evaluated. For the purpose of this study, fabrics with different structures (knitted, woven) containing extremely thin stainless steel staple fibers incorporated to the yarn structure as the conductive filler were chosen. For quantification of the influence of the washing/drying cycles on the above-mentioned characteristics, regression methods and simple t-tests were used. Both knitted and woven fabrics withstood satisfactory repeated application of wet processing with respect to the main requirement – electromagnetic shielding ability; in addition, woven fabrics exceeded in higher electrical conductivity, higher shielding effectiveness and lower inclination to pilling and therefore can be used for the production of protective cloth.