Prodn. of porous coatings on thermoplastic mouldings - by drawing aerial suspension of particles onto and through sintered mouldings, using e.g. similar types of polymer for both materials

摘要

Open-pore sintered thermoplastic mouldings are given a porous surface coating. The particles of the coating material are fed into an air current, the aerial suspension is fed to and drawn through the sintered moulding, the particles remain on the surface, partly entering the outer pores. When the required thickness of coating is reached, as measured, e.g. by loss of pressure, the feed of particles is stopped by cutting off the air current and the particles on the moulding are bonded together by sintering, by adhesive or by welding, etc. and are bonded to points on the moulding. ADVANTAGE - The method is flexible and can suit various different conditions, e.g. by adjusting the fineness of the particles or the e.g. flow speed of the current.