摘要 |
PROBLEM TO BE SOLVED: To provide a new method which enables a continuous application of no chromate coating on a tubular article. SOLUTION: In order to apply no chromate coating on the tubular article by fluidized bed dipping using a meltable powder polymer as a coating agent, this method is to clean the tubular article in a pretreatment device, to apply a primer on the tubular article, to bake the primer by a medium frequency induction coil, to use the medium frequency induction coil for preheating of the tubular article, to coat by applying the fluidized bed dip coating bath, to avoid a powder deposition by a device comprising an air shower on the upper part of the tubular article in the fluidized bed dip coating bath, to avoid the powder shortage by a guide plate comprising the air shower on the lower part of the tubular article in the fluidized bed dip coating, to make the incompletely molten coating flat by using the medium frequency induction coil, to completely and smoothly melt in the melting section, to cool down the surface of the tubular article by the air shower at first and further to cool down the coating again by water cooling. COPYRIGHT: (C)2004,JPO
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