This paper describes a study on the development of novel lightweight and highly flexible composites for electromagnetic interference (EMI) shielding applications. The weft-knitted fabrics produced by using polyester/cotton, polyester/cotton-copper, and polyester/cotton-stainless steel composite yarns with metal deposition and without metal deposition were tested to determine the EMI shielding effectiveness (SE). The surface structures of all composite fabric samples were observed by stereomicroscope. The state of the presence of metal particles on the metal deposited composite fabric was studied by field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) analyzer. The EDX analyses confirmed the presence of metal particles, and the FESEM analyses revealed uniformly deposited metal particles on the surface of composite fabrics. The EMI shielding was also evaluated using vector network analyzers in the frequency range of 8-12 GHz for all samples. The highest value of EMI SE in this research for the composite fabric with the metal deposited sample was achieved to 19.53-23.95 dB. Moreover, the breathability and the durability of produced fabrics were characterized by air permeability, moisture regains, abrasion resistance, and washing fastness. The results of EMI shielding, durability, and breathability tests confirmed their potential for use as an excellent material for EMI shielding in wearable textiles for commercial applications.
