A study of the electrostatic behavior of carpets containing conductive yarns

This paper describes experiments to characterize the role of triboelectric charging in developing static charge as people walk on carpets and further experiments to quantify the role of corona ionization to minimize static charge accumulation. The Modified Inclined Plane test, a test currently gaining acceptance in the electronics industry, was used to measure triboelectric charging effects. Results indicate that this test was not a good predictor of static charge accumulation as measured by the body voltage on a person after a standard walk test. A test was developed to measure the effectiveness of corona discharge ionization caused by conductive filaments in carpet for limiting static charge accumulation. Results of this test have shown that, for carpets with good static charge dissipation properties, charge reduction via corona occurs on a time scale of about 0.1 s and that conductive latex greatly enhances the corona effect. Another test was developed to investigate the corona discharge properties of the conductive yarns themselves, without being incorporated into the carpet. Results of this test have shown that the corona voltage to initiate corona discharge depends largely on conductive fiber geometry and, that the conductivity vs. applied across the series combination of conductive yarn and air gap deviates significantly from Ohm's law behavior. (C) 1997 Elsevier Science B.V.