Silver-filled electrically conductive epoxy and silver nitrate-plated textile composite materials for EMC

Abstract

A study on the effect of silver-filled electrical epoxy materials and the effect of electroless silver nitrate-plated woven fabrics on electromagnetic shielding effectiveness of various woven fabrics has been reported. Polyester, cotton, polyester/viscose blend, and polyester/cotton blend fabrics were treated with silver-filled electrical epoxy by pad-cure method. The polyester fabrics were treated with various levels of silver nitrate concentration, temperature, and time to analyze EMSE. The electromagnetic shielding effectiveness of these silver-filled electrical epoxy-coated fabrics and electroless silver nitrate-plated woven fabrics has been measured in the frequency range 20—18,000 MHz using network analyzer equipment with MIL-STD 285 and also the morphological structures of the silver-filled electrical epoxy-coated woven materials and electroless silver nitrate-plated woven fabrics were analyzed using scanning electron microscope. It is observed that the silver-filled electrical epoxy cotton fabric has better electromagnetic shielding effectiveness than the polyester/cotton blend, polyester/viscose blend, and polyester fabric in the frequency range 20—18,000 MHz. It is also observed that the silver-filled electrical epoxy-coated cotton fabric has maximum shielding effectiveness (50—69 dB) in the frequency range 60—15,000 MHz. It is observed that the silver nitrate concentration and temperature have a significant influence on electromagnetic shielding effectiveness of silver nitrate-plated fabrics. It is also observed that the maximum EMSE (45—55 dB) was obtained in the frequency range 180—8000 MHz.