PlasmaGRAPH

PlasmaGRAPH is a machine designed to remove graphite lubricants from the wire surface. PlasmaGRAPH is a cost effective alternative to electro-polishing, used for the cleaning of Molybdenum wires contaminated with graphite (after hot drawing). Unlike electrochemical polishing, Plasma process results in no loss of base material. This makes PlasmaGRAPH more efficient compared to the traditional processes. PlasmaGRAPH is available as a Graphite De-Greasing machine or as a combined Annealer/Graphite De-Greaser.

Benefits of PlasmaGRAPH compared to electrochemical polishing

• Smooth and super clean wire surface with no traces of Graphite
• PlasmaGRAPH can be set up as annealer
• No loss of base material (unlike electrochemical polishing)

Traditional Molybdenum Drawing Process :

The traditional process of drawing Molybdenum wire is based on three main process steps: Drawing, Annealing and Electrochemical Polishing. Molybdenum is drawn at high temperatures with graphite lubricants. Electrochemical Polishing is used to remove Graphite lubricant from the wire surface after drawing. Electrochemical Polishing is a slow and inefficient process that can result in considerable loss of expensive base material - Molybdenum. Up to 10% of expensive Molybdenum can be lost during Electrochemical Polishing, which results in considerable cost to the manufacturer. The percentage of the lost material depends on wire diameter and required cleanliness. In a traditional process, Electrochemical Polishing and Annealing are performed separately (offline) due to different processing speeds. This results in unnecessary cost of wire manipulation.

PlasmaGraph Process :

To overcome the drawbacks of the traditional process Plasmait developed a new process that uses proven plasma technology to anneal and clean Graphite from the wire surface in a single step. The process was demonstrated with selected Molybdenum wire manufacturers. Drawn Molybdenum wire, contaminated with Graphite was annealed (PlasmaAnneal) and cleaned (PlasmaClean) on a Plasma machine. Plasma process was performed at the speed of 2m/s on wires with the diameter between 0.2mm and 0.8mm. The process resulted in smooth and super clean wire surface with no traces of Graphite whatsoever. There was no erosion of Molybdenum from the wire surface. The requirements for mechanical properties of the finished wire were met. Energy efficiency of the Graph was over 70% depending on diameter.