MEJORAS EN APARATO PARA RECUBRIR EXTERNAMENTE TUBERIA DE METAL CONTINUA CON MATERIAL PLASTICO

摘要

An apparatus for externally coating elongated metal members and, particularly, endless metal tubing with synthetic-resin using a powder-melt process in which the powder is initially fused to the surface of the metal member and concurrently or subsequently caused to coalesce into a coating film. The metal member is passed through a fluidized bed of the synthetic-resin powder after being preheated and the powder is induced to flow along the metal member through an annular nozzle formed on a coating head within the fluidized bed. The powder is advantageously sucked through the coating head and is drawn via the annular nozzle into contact with the metal member.