Process For Flux Coating Braze Preforms And Discrete Parts
Systems and methods for evenly applying a flux coating to any number of different shaped parts with a single machine are described. The systems and methods provide advantages in that the flux coating may be applied accurately within 2% to 4% of desired thickness with 85% to 95% of the total yield of flux being applied, this minimizing waste. Thousands of parts may be batch treated with a single machine without operator input.
1 . A method of applying a flux coating on a plurality of parts for a brazing operation comprising:
tumbling the parts in a tumbling drum with a controlled atmosphere including a user definable temperature and humidity within the tumbling drum;
cycling the parts through a coating cycle comprising:
spraying a flux from at least one nozzle within the tumbling drum during the tumbling for a user defined period of time;
coating the parts with flux with a uniform thickness;
tumbling the parts following the user defined period of time to cure the flux to a desired hardness; and
repeating the coating cycle for a plurality of repetitions wherein the uniform thickness of coating on the parts is uniformly increased with each coating cycle.
2 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising providing an acrylic resin binder with an iso-butyl methacrylate polymer.
3 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 2 , further comprising mixing polyethylene carbonate with the binder.
4 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising coating the parts up to 0.015 in (3.81 mm) thick while maintaining the uniform thickness within 2% of the total weight of the part.
5 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising spraying the flux from a nozzle with an opening of 0.05 in (12.7 mm) to 0.08 in (20.32 mm).
6 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising circulating the atmosphere within the tumbling drum with exhaust ducts.
7 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising adhering 85% to 95% of the sprayed flux to the parts.
8 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising agitating the parts within the drum with at least one agitator during tumbling.
9 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising spraying a sealant over the parts and flux.
10 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising setting the parts on a conveyor that transports the parts into an enclosure with a plasma cleaning chamber, a heating chamber, and an ultrasonic flux spraying chamber.
11 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 10 , further comprising plasma cleaning the parts in the plasma cleaning chamber to remove contaminants allowing a proper adhesion of the flux coating to the parts.
12 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 11 , further comprising heating the parts after plasma cleaning in the heating chamber to a desired temperature.
13 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 12 , further comprising spraying the parts after heating in the ultrasonic spraying chamber with an ultrasonic sprayer configured to atomize a liquid flux solution and coat a single side of the parts with the flux coating and leaving an opposing side of the part free of the flux coating.
14 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 10 , further comprising adjusting a speed of the conveyor to dry the parts to a desired moisture content.
15 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , further comprising spraying one of a metal and an alloy on the flux coated parts, thus eliminating a need for a filler metal application during a brazing procedure.
16 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 1 , wherein the uniform thickness of the coating on the parts is within 2% of a desired thickness.
17 . A method of applying a flux coating on a plurality of parts for a brazing operation comprising:
spraying a flux from at least one nozzle within a tumbling drum during a tumbling operation for a user defined period of time;
coating the parts with the sprayed flux with a uniform thickness;
tumbling the parts following the user defined period of time; and
curing the flux to a desired hardness.
18 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 17 , further comprising:
coating the parts with the cured flux up to 0.015 in (3.81 mm) thick; and
maintaining the uniform thickness within at least one of 2% of the total weight of the part and 2% of a desired thickness.
19 . The method of applying a flux coating on a plurality of parts for a brazing operation of claim 17 , further comprising:
mixing an acrylic resin binder with an iso-butyl methacrylate polymer with the flux; and
mixing a polyethylene carbonate with the binder.
20 . A method of applying a flux coating on a plurality of parts comprising:
spraying a flux from at least one nozzle with an opening of 0.05 in (12.7 mm) to 0.08 in (20.32 mm);
tumbling the parts for a user defined period of time within a tumbling drum;
coating the parts with the sprayed flux to a uniform thickness;
curing the flux to a desired hardness by circulating an atmosphere within the tumbling drum with exhaust ducts;
maintaining the uniform thickness within at least one of 2% of the total weight of the part and 2% of a desired thickness; and
adhering 85% to 95% of the sprayed flux to the parts.