Corner dubbing, or aka nubbing, is the process of grinding off the sharp corner which remains after edge grinding all four sides. This corner can be sharp and some Customers desire that this be removed, for safety reasons. This corner cannot simply be knocked off, as it will leave a chip. It must be ground off.
Old style corner dubbing heads included a set of idler wheels around the grinding wheel. These wheels would limit the corner a certain amount of travel into the grinding wheel. Therefore these wheels had to be changed for different production needs, and they were also often wearing considerably. The other complication from the old style was a speed limitation, as the back corner had to be ‘caught’ as it was running past.
GLASSLINE’s concept is to provide a servo linear-actuated grinding spindle, as well as part edge tracking, to have a programmable corner dub. This provides flexibility in the corner desired, and there are no extra idler wheels to wear. The use of the servo provides for a nominal speed capability of 12m/min flow rates. Optionally, dual heads can be provided, which raises the processing speed to 18m/min or more.