Electromagnetic interference (EMI) is electromagnetic energy that adversely affects the performance of electrical/electronic equipment by creating undesirable responses or complete operational failure. To avoid the EMI, the shielding is required. Shielding is a very popular method of ensuring electromagnetic and it protects the electronic and electrical equipment and human beings against radiated electromagnetic energy. Shields are used either to isolate a space (a room, an apparatus, a circuit, etc.) from external sources of electromagnetic radiation or to prevent unwanted emission of electromagnetic energy radiated by internal sources. If an electromagnetic wave gets into an organism, it vibrates moleculesto give out heat. In the same way, when an electromagneticwave enters the human body, it will obstruct a cell’s regeneration of DNA and RNA. Furthermore, it brings on abnormal chemical activities to produce cancer cells, andincreases the possibility of leukemia and other cancers. In this research, the effect of various parameters which affect shielding against electromagnetic waves, have been investigated. Yarn and fabric structure, material type and finishing, can play an important role in the electromagnetic characteristics of fabrics. Also, textile conductivity is very important in shielding and protection. There are many methods of improving fabric conductivity, such as laminating the conductive layers of fabrics or adding the conductive fillers. Because copper has a high conductivity, copper wires with diameter 0.06, 0.08 and 0.1 mm were selected as conductive ?ller for producing copper core spun yarn. To investigate the effect of sheath material; cotton, viscose and polyester rovingswere used to produce different core spun yarn on a ring spinning frame. From the produced core yarn, fabrics were woven in three different pick densities; 12, 16 and 20 picks per cm were selected. Polyaniline was synthesized in two chemical polymerization methods to achieve different surface conductivity. Taguchi’s experimental design was used to estimate the optimum process conditionsand to examine the individual effects of each of thecontrollable factors on a particular response. The controllablefactors which were considered in this research are copper wire thickness, sheath material, fabric density and chemical polymerization method. There are four factors, andeach one has three levels with the exception of chemical polymerization method. The factor of chemical polymerization method varies at two levels.Therefore, the appropriate orthogonal array is L18 witheighteen runs. The response was the electromagnetic waves protectionat the frequency range of 1.7 to 2.7 GHz, which was measured by a waveguide.A level average analysis was adopted to interpret theresults. This analysis is based on combining the dataassociated with each level for each factor. The differencein the average results for the highest and lowestaverage response is the measure of the effect of thatfactor on electromagnetic waves protection. The greatest value of thisdifference is related to the strongest effects of thatparticular factor. According tothe level average analysis, factordensity fabric shows the strongest effect on electromagnetic waves protection. Factor thickness of copper wireis second and is followed by factor sheath materialand chemical polymerization method.The findings reveal that the samples at the frequency range 2.4-2.5 GHz show the highest protection. Keywords: absorbent materials, electromagnetic wave, electromagnetic protection, polyaniline, metalized core spun yarn, woven fabric
