Integral Assessment of Antistatic Properties of Materials Used in Individual Safety Gear

Abstract

The buildup of static electricity on materials is a big problem for many industrial sectors especially in situations when uncontrolled changes occur near flammable materials and liquids. Yet the combustion risks associated with static electricity, as well as the sources of fires and explosions can be controlled through the provision of proper electrostatic protection to the entire production process. Antistatic footwear is one of the elements of safety gear that protects people from static electricity at the workplace. There are three types of antistatic footwear: antistatic conductive shoes with the electric impedance of <1•105 Ohms, antistatic scattering shoes with the electric impedance of 1•105-1•108 Ohms; and antistatic insulating shoes with the electric impedance of >1•108 Ohms. The properties of antistatic shoes directly depend on the materials that they are made of. Thus, it is necessary to study the antistatic properties of materials to design antistatic footwear. This article aims to identify the relaxation time constant for the electric charges on the exterior, interior, and intermediate layers of shoe top materials using the integral method. The authors demonstrate that the relaxation time constant of shoe materials can vary between 4 and 40 seconds. The measured values help rationalize the selection of materials to produce antistatic footwear, the materials that can carry the charge into the ground and prevent its accumulation.