Electromagnetic shielding effectiveness of copper/glass fiber knitted fabric reinforced polypropylene composites

The main objectives of this research work are to develop conductive knitted fabric composite materials and to determine their electromagnetic shielding effectiveness (EMSE). Polypropylene is the matrix phase and glass fibers are the reinforcement phase of the composite material. Copper wires are incorporated as conductive fillers to provide the electromagnetic shielding properties of the composite material. The amount of copper in the composite material is varied by changing the yam composition, fabric knit structure and stitch density. The EMSE of various knitted fabric composites is measured in the frequency range of 300 kHz to 3 GHz. The variations of EMSE of knitted fabric composites with fabric structure, stitch density and yam compositions are described. Suitability of conductive knitted fabric composites for electromagnetic shielding applications is also discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.