Fluid jet polishing of planar flat glass surfaces and within holes

Planar ground float glass surfaces and the surfaces within holes are polished using fluid jet polishing (FJP) in order to improve their visual appearance or material strength. The large flexibility of FJP makes it suitable for polishing holes and other complex geometries. The influence of polishing speed, incident angle, distance, pressure, abrasive concentration, and nozzle diameter are investigated. Al₂O₃ is the abrasive used. The surface quality is evaluated visually and also measured with an optical profiler. The mechanical strength of the polished holes are evaluated with an MTS testing machine. Planar surfaces, and the surfaces of drilled and water cut holes are greatly improved by polishing. For a planar surface the lowest root mean square surface slope, S_dq, value achieved is 0·5 deg using 50% abrasive and 1000 mesh grains. The failure load of the glass with drilled holes increased 20% with FJP.