Graphite de-lubrication made easy Hot drawing processes depend on Graphite as a lubricant but this poses some difficulties as it is hard to remove it effectively from the wire surface afterwards. This is particularly the case with Molybdenum wire used for lighting applications, where complete removal of graphite is critical to the quality of the end product. Until now, graphite could only be completely removed with an aggressive electro-polishing process that results in considerable waste of the base material. The loss of expensive Molybdenum can be very costly especially for small diameter wires. This problem has now been solved with the Plasma-Graph process developed by Plasmait. PlasmaGraph is based on Plasmait-patented technology and is used for a range of metals that use graphite lubricants as part of the hot drawing process. The surface cleanliness of the finished wire matches that achieved by electrochemical polishing but, un-like the latter, use of PlasmaGraph results in no loss of base material. Up to 10% of expensive Molybdenum can be lost during electrochemical polishing, which results in a consider- able cost to the manufacturer. The percentage of the lost material depends on wire diameter and required cleanliness. In the traditional process, electrochemical polishing and annealing are performed separately (offline) due to different processing speeds. This results in unnecessary wire manipulation. To overcome the drawbacks of the traditional process Plasmait developed its new process based on proven plasma technology to anneal and clean graphite from the wire surface in a single step. The company demonstrated its new process to several selected Molybdenum wire manufacturers with impressive results. Drawn Molybdenum wire, contami-nated with graphite was annealed (PlasmaAnneal) and cleaned (Plasma-Clean) on a PlasmaGraph machine. The process performed at a speed of 2m/s on wires with diameters between 0.2mm and 0.8mm. The process resulted in a smooth and super clean wire surface with no traces of graphite. Additionally there was no erosion of Molybdenum from the wire surface and the requirements for the mechanical properties of the finished wire were met. Publish:admin