Electrostatic protective garments are used to prevent ignition accidents caused by electrostatic discharges, and their performance has been evaluated using the frictional charging test specified in JIS T 8118:2001. However, it has become difficult to obtain conventional reference fabrics. In this study, new acrylic and nylon fabrics were compared with conventional fabrics through resistivity measurements, SEM observations, and frictional charging tests. The results showed no significant differences in performance between the conventional and new fabrics. In particular, the frictional tests demonstrated that fabrics containing conductive yarns suppressed charging and did not exceed the threshold, whereas fabrics without conductive yarns̶especially nylon̶exceeded the threshold, with both conventional and new fabrics showing the same result. Key words : Antistatic Clothing, Triboelectrostatic Alternative Reference Fabric, Electrostatics, Charge Density

In this study, an apparatus capable of generating spark discharges with positive and negative polarities, anticipated in the dust explosion accidents, was developed to contribute to the mitigation of accidents. The voltage and current waveforms measured in the discharges with the polarity reversal induced by the developed apparatus indicated that the transition from streamer to spark discharge and the increase of current-rise rate with increasing capacitor charging energy. Since these results corresponded to the characteristics of spark discharge generation, the capability of the developed apparatus to generate polarity-reversal spark discharges was experimentally verified. The voltage and current waveforms of positive- and negative- polarity spark discharges were found to exhibit polarity-reversed characteristics, and the effective spark discharge energy increased with increasing capacitor charging energy. Waveform analysis further confirmed that the effective energy for spark discharges with both polarities corresponded to the portion of the capacitor charging energy distributed to the resistance of spark discharge.