On the Characteristics of Discharges from Electrostatically Charged Cloths

Abstract

ABSTRACT:Generation of static charge by friction, discharges in the course of separation from a backing metallic plate, and discharges to an approaching sphere or wire electrodes after such a separation were investigated for various cloths. In the separation procedure, a large proportion of charge was lost through discharges to the backing plate, giving a maximum charge density of about 15 pCfm2 after separation. Oscilloscopic observations of discharges in the approaching procedure revealed that charge is lost through a large number of regular Triche! pulses in the negative corona, while in the positive corona, charge is lost through pulseless glow when fine electrodes are applied; the glow gives way to large pulses as the diameter of the electrode increases. While the amount of lost charge agreed well with the total charge of the pulses and pulseless glow observed by oscilloscope in the approaching procedure, these charges did not agree in the separation procedure. This disagreement was ascribed to the small ratio of the stray capacity to the capacity between the cloth and the backing plate. However, discharges in the separation procedure were found to be similar to those in the approaching procedure by analysing the charge distribution patterns.KEY WORDS Static Electricity 1 Cloth 1 Charge Density 1 Corona Discharge I Pulse I Glow I

Measurement Of Cleanroom Fabric Surface Resistivities

“…Hirakawa [ 3 ] reported electrostatic discharges from woven cloths of polyesterhayon, poly(viny1 alcohol), poly(viny1 alcohol)/cotton, polyester/cotton, and polyacrylonitrile when rubbed against knitted cloths of wool, cotton, polyacrylonitrile or poly(viny1 chloride). Wilson 141 explorcd various approaches to characterizing some woven fabrics; surface resistivity, charge decay, spark discharge; he found some arcing to grounded conductive spheres for each of these: polyester, polyester surrounding a conductive core, polyester with a conductive material sandwiched across the diameter, Nylon with a conductive coating.…”