Polyamide fluidized-bed-coating powder for thin-layer fluidized-bed coating

摘要

A polyamide powder for coating metal surfaces by the fluidized-bed coating process, wherein (a) the powder has a median grain size (d 50) of from 20 to 90mu m; (b) the content of fines < 5mu m is below 1%; and (c) the powder has at least 75% of spherical particles in which all three spatial axes (x, y and z) of the grain have the same dimension to within ± 10%; and a method for the external coating of pipes by fluidized-bed coating based on a the polyamide powder including the step of applying a primer to the surface of a pipe, baking the primer, preheating the pipe and applying the fluidized-bed coating thereto.