Coating apparatus for an aluminum alloy heat exchanger member, method of producing a heat exchanger member, and aluminum alloy heat exchanger member
An coating apparatus, wherein the apparatus applies a coating, onto a surface of an aluminum alloy member for a heat exchanger to be assembled by brazing, with a top-feed-type roll transfer system having at least three rolls, the coating being obtained by mixing into an organic binder a metal powder, a flux powder, a powder mixture thereof, or a compound containing a metal component and a flux component, wherein rotation directions of transfer rolls of the apparatus arranged above a surface to be coated of an aluminum alloy extruded member that moves in a horizontal direction, satisfy a relationship in which a rotation direction of a coated-metal roll for coating, which rotates in a direction opposite to a moving direction of the extruded member, and a rotation direction of a metal roll for adjusting an adhesion amount of the coating by contacting with the above roll, are opposite to each other; and a method of producing an aluminum alloy heat exchanger member using the apparatus; and an aluminum alloy heat exchanger member.
1. A method of producing a resin-coated aluminum alloy flat multi-cavity tube for a heat exchanger comprising:
adjusting the surface roughness of an aluminum alloy flat multi-cavity tube so that at least one flat surface of the aluminum alloy flat multi-cavity tube has a surface roughness of a center line average roughness (Ra) of 0.4 μm or more, and a ten-point height of irregularities (Rz) of 3 μm or more,
supplying, by a top-feed system, a resin coating containing a metal powder for brazing, the metal powder containing a brazing flux, an acrylic resin, and a cross-linking agent with a metal powder volume content in solid content of 50% to 90%, and prepared together with water and an organic solvent;
applying said resin coating by a reverse system to said roughened surface of said aluminium alloy flat multi-cavity tube; and drying.
2. The method of producing the resin-coated aluminum alloy flat multi-cavity tube for a heat exchanger as claimed in claim 1 , wherein the metal powder has an average particle diameter of 30 μm or less and a density of 4.0 Mg/m 3 or less.