Patent ID: 6284311
Filing Date: 2001-09-04
Classification: B05D

Abstract:
An improved process for coating a substrate with a polymer comprising heating said substrate, immersing said heated substrate into a fluidized bed of particles of the polymer, coating the substrate with the polymer and removing the coated substrate from the fluidized bed;wherein the improvement comprises:i) heating the substrate during said heating step to a temperature sufficient to tackify the polymer particles upon contact;ii) maintaining particle temperature in the fluidized bed below that at which the particles tackify;iii) covering substantially uniformly all surfaces of the heated substrate;iv) optionally heating the coated substrate to level the coating and to cure the polymer if it is thermosetting; andv) controlling the coating thickness, per unit time, to obtain thin coatings of up to 150 micrometers, by heating the substrate such that the coating temperature is within the tack temperature gradient but below Tm and maintaining particle sizes so that at least 80 weight percent are between 10 to 80 micrometers.