METHOD AND MACHINE FOR PREPARING POROUS HOLLOW GLASS BEAD

摘要

Porous hollow glass beads(11) of 30-100 microns diam. are produced by forming drops(7) from a concentric dual nozzle unit which contains a soln. of bead forming material(6) of 100-150 cps. viscosity and blowing inert gas(5) through its inner nozzle(1). The flowing rate of the bead forming material is 12-22ml/min, and that of the blowing gas is 5-14ml/min. The drops(7) pass through the atmospheric gas mixture(10) of NH3 and N2 (ammonia gas and nitrogen gas) for 5-15sec. cured in ethanol solution, dried by a super critical drying method of liquid CO2 and finally heat-treated under 1000-1200 degrees centigrade.