| 摘要 |
A process and apparatus are provided for making hollow macrospherical particles. The particles themselves are particularly adapted for use as anti-perspirants. The particles have a diameter between about 10 and 74 microns, preferably predominating between 15 and 44 microns, and a greater than unit density. As such, they are not subject to deep lung penetration. The process for producing the particles comprises providing a solution containing the materials from which the particles are made, diffusing the solution through small pores by centrifugal force such that the resulting hollow particles have a diameter greater than the pore diameter, and drying the solution droplets in a stream of heated air. The apparatus for producing the macrospherical particles comprises a centrifugal atomizer having a porous sintered metal filter ring which is rotated inside a spray drying chamber. The filter is treated to produce hollow macrospheres having substantially smooth outer walls of such thickness that they can withstand normal shipment and handling without significant fragmentation. |
