Coating process and apparatus

摘要

Specific surface areas of an article e.g. preheated electric motor stators 42, are coated by a stream of fluidized particles of fusible material, delivered from nozzle 48 within winding coil aperture 46 whilst adjacent interior pole faces 44 to be left uncoated are subjected to an exhaust stream which may be produced by a vacuum shoe 50 and/or air delivery nozzle 57 which divert material from these areas to be left uncoated. The coating may subsequently be levelled by post heating. The stream of fluidized particles preferably has laminar flow characteristics and the article to be coated may be pre-heated to a temperature not less than the melting point of the fusible material. The material drains off through vacuum shoes 50 or through an exhaust vent 32 in the coating chamber 18, is recirculated, and the process e.g. as applied to electric motor stators or rotors may be continous (Fig. 1 not shown) with the articles to be coated conveyed on an endless chain past or through loading, pre-heating, coating, post heating, coating, post heating, quenching and unloading stations or chambers. The technique may be applied to the coating of wire, pipe and metal containers with copper, lead, zincortin. The method may also be used in conjunction with electrostatic charges which are applied to create voltage differences between the delivery nozzles and surfaces to be coated.