Assessing powder coatings

摘要

PCT No. PCT/GB85/00193 Sec. 371 Date Dec. 31, 1985 Sec. 102(e) Date Dec. 31, 1985 PCT Filed May 8, 1985 PCT Pub. No. WO85/05182 PCT Pub. Date Nov. 21, 1985.A technique for assessing electrostatically deposited coatings of powder to be later fused into a surface finish. Powder deposited by the coating process onto a test piece or an unimportant part of an actual article is disturbed by, for example, a series of puffs of compressed air. The removal of the powder by the disturbance is monitored. In one arrangement infra-red light is shone through the coating and the change in transmissivity with each puff of air is measured to give an indication of the quality of the powder deposit.