Patent ID: 6316047
Filing Date: 2001-11-13
Classification: C23C

Abstract:
A method of applying refractory particle coating to densified foundry sand cores having micropores between sand grains, thereby comprising:(a) mixing a dry powder refractory material with a dry powder impacting media, the refractry material having a particle size in the range of 5-40 microns and the weight ratio between said refractory material and impacting media being 1:13 to 1:22;(b) fluidizing said mixture in a contained zone by introducing positive air pressure at one end of such zone and applying a negative pressure at the other end of such zone; and(c) entirely immersing said sand cores into said zone containing such fluidized mixture and substantially immediately thereafter withdrawing such sand cores without need for added reciprocal motion to be coated with essentially only the refractory material as impacted by said impacting media.