| 摘要 |
PURPOSE:To obtain an epoxy multi-layered coated metallic body having a coating film which has an excellent impact resistance and bending resistance, and is not likely to generate any defects during coating, and further not necessary to be covered with a heat insulating material by providing a compact epoxy resin layer, furthermore, a porous epoxy resin layer containing foams thereon. CONSTITUTION:A steel pipe 4 to be coated is at first heated by a heating furnace 2 up to the temperature necessary to performs a powder epoxy coating. Next, the steel pipe is forwarded into a powder coating booth 1 and coated with a powder epoxy coating material having no foaming property used in prior art by means of a coating gun 7 at the front stage in the booth. Afterwards, during the period when the coating material applied at the front stage melts and forms a film, and immediately before the melted film is completely cured, namely, gelled, the pipe is coated with a powder epoxy coating material having foaming property by means of a coating gun 8. After the steel pipe applied with the powder epoxy coating material in different two layers in this manner is held at a high temperature for sufficiently foaming it as an epoxy film, it is cooled by means of a water cooling booth 6 up to the temperature for increasing the hardness as an epoxy resin. |
