Companies melting high quality glassware often require stirrers that are capable of operating reliably for long periods in the 1000-1300 deg C temperature range. Many technical solutions have limitations, however, Johnson Matthey has designed a "diffusion choke" as an alternative to molybdenum technology. A trial was recently conducted in CRT glass using a PM2000 stirrer shaft and a 20% Rh-Pt sheet metal cladding. A mesh of finely knitted 10% Rh-Pt alloy, the "diffusion choke", was placed between the two. After production trials of 20 months, the removed stirrer was returned to Johnson Matthey for investigation. Visual examinations and destructive analysis showed no sign of degradation of the surface at any point along its length. For more information please email Johnson Matthey on: nobleuk@matthey.com or see website: www.noble.matthey.com
