THERMAL TOUGHENING OF GLASS

摘要

Glass is heated to a temperature above its strain point and is thermally toughened by chilling with a quiescent gas-fluidised particulate material which has gas-generating properties and a mean particle size in the range 30 .mu.m to 120 .mu.m, a particle size distribution in the range 1.15 to 2.78, a flowability in the range 69.5 to 92, and a thermal capacity per unit volume at minimum fluidisation in the range 0.7 to 1.59 MJ/m3K. The invention is particularly suitable for thermally toughening glass sheets for vehicle windscreens.