Vertical line production of low-mercury content fluorescent tubes

Abstract

Liquid mercury is eliminated from a fluorescent lamp production machine, on which lamps are processed while in a vertical position, and replaced by a cathode shield coated with a highly stable mercury alloy and a non-evaporable getter. The modifications lead to an 18 per cent increase in production speed, more uniform lamp quality and superior performance throughout life. Reduced machine maintenance also contributes to process economy. Ecological benefits are considerable as much less mercury per lamp is utilised. Mercury levels in the factory air have been substantially reduced and the abnormally high values of urine mercury found in operators working in or near previously contaminated zones are now falling towards the normal biological background limits.