Abstract: Fluoride-based flux is uniformly dispersed in and mixed with synthetic resin, which has fluidity at room temperature and sublimes at a temperature lower than a brazing temperature, so as to constitute 40 to 70 wt. % of the mixture, thereby producing coating material. This coating material is applied to coating belts which undergo rotation and is transferred from the coating belts to the surface of the aluminum material. The coating material has high viscosity and stably adheres to the transferred areas.

Abstract: During the course of bending and deforming a strip-shaped metal plate in multiple stages through use of a press roller, to thereby constitute a tube base having a closed cross section, slime-like flux is applied to solely the portions of the metal plate to be brazed, and the tube base is heated in a heating furnace, to thereby braze the portions to be brazed. Accordingly, waste of the flux is eliminated. Further, flux coating can be performed on a tube forming line, thus simplifying facilities.

Abstract: Fluoride-based flux is uniformly dispersed in and mixed with synthetic resin, which has fluidity at room temperature and sublimes at a temperature lower than a brazing temperature, so as to constitute 40 to 70 wt. % of the mixture, thereby producing coating material. This coating material is applied to coating belts which undergo rotation and is transferred from the coating belts to the surface of the aluminum material. The coating material has high viscosity and stably adheres to the transferred areas.

Abstract: Fluoride-based flux is uniformly dispersed in and mixed with synthetic resin, which has fluidity at room temperature and sublimes at a temperature lower than a brazing temperature, so as to constitute 40 to 70 wt. % of the mixture, thereby producing coating material. This coating material is applied to coating belts which undergo rotation and is transferred from the coating belts to the surface of the aluminum material. The coating material has high viscosity and stably adheres to the transferred areas.

Abstract: The top peaks of the outer fin are coated with slime-like flux. A sandwich unit is assembled from the outer fin and the tube plates by attaching the tube plates to the respective sides of the outer fin such that the surfaces of the tube plates having the butt bead faces formed thereon face inward. The butt bead faces on the respective tube plates on either side of the sandwich unit are coated with the slime-like flux. A plurality of sandwich units whose tube plates are coated with the flux are laminated and brazed, and the thus-formed assembly is heated in a heating furnace, to thereby braze together the tube plate pairs and the tube plates connected to the outer fin.

Abstract: A method for the production of a heat exchanger having a core part thereof formed by joining a tube of aluminum material and heat-transfer fins of aluminum material with a brazing material, which method is characterized by effecting said brazing by the use of a flux obtained by suspending a potassium fluoroaluminate complex in an aqueous solution of a pigment-forming water-soluble compound.