Electromagnetic interference shielding effectiveness of electroless Cu-plated PET fabrics

In order to develop the high quality electromagnetic interference (EMI) shi elding textiles for protective clothing, polyester fabrics were electroless copper-plated. Effects of pretreatment conditions such as scouring, etchin g, and catalyzation on electromagnetic interference shielding effectiveness (EMISE) and physical properties of treated fabrics were investigated. High EMISE of fabrics over the wide range of frequency level were obtained when fabrics were scoured with 0.3% NaOH and 1.0% Triton X-100, and etched with the mixture of HCl/HNO3, at 25 degreesC for 30 min before activation. We found that KCl was the better catalyst activator than commonly used SnCl 2. EMISE of copper-plated fabrics increased as the concentration of KCl inc reased up to 1:8 molar ratio of PdCl2:KCl then decreased with further addit ion. As the catalyzation temperature increased from 25 to 40 degreesC, the EMISE of copper-plated fabrics increased, whereas their EMISE reduced to ab out zero when the activation temperature exceeded over 40 degreesC. Physica l proper-ties including tensile extension and drape stiffness of copper-pla ted fabrics are higher than those of the untreated PET. but tensile strengt h was slightly decreased. By scanning electron microscope (SEM), we found s pecial fracturing behavior of the copper-coated PET fabrics due to the duct ility and brittleness of copper film on the PET fabric. (C) 2001 Elsevier S cience B.V. All rights reserved.