Metal deposition by spark ignition - adjusting spark voltage and current to compensate for wear of rollers without stopping them

摘要

The coating system has an electrode opposite the roller's working surface and connected to one pole of a voltage source to produce sparks. The metal coating is applied to the roller whilst the roller is in use. The current and voltage employed are chosen such that the metal deposited counteracts the metal worn away. The metal coating therefore has a constant thickness. The rate of wear of metal from the roller's surface is measured over a given time and the current and voltage set accordingly. The voltage source's second pole is connected to the roller via a sliding contact touching the roller at an appropriate place.