Coating processes – Interior of hollow article coating
Reexamination Certificate
1999-07-21
2001-03-13
Beck, Shrive (Department: 1762)
Coating processes
Interior of hollow article coating
C427S388100, C427S385500, C427S239000
Reexamination Certificate
active
06200632
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention concerns novel methods for applying and using liquid fluoropolymer containing solutions. More specifically, this invention concerns methods for applying a fluoropolymer solution to a substrate and thereafter removing the liquid carrier from the solution to give substrates coated with a durable fluoropolymer film. The thin, durable fluoropolymer film is useful as a corrosion inhibiting agent, as a heat transfer promoter, and as an adhesion barrier. In addition, this invention is an apparatus that is useful for applying a thin coating of fluoropolymer to the internal surfaces of a heat exchanger.
(2) Prior Art
The prior art discloses soluble fluoropolymer solutions. For example, U.S. Pat. No. 5,459,191 discloses solvents that are useful for manufacturing perfluorinated fluoropolymer solutions. The '
191
patent further discloses that such perfluorinated fluoropolymer solutions are useful to coat electronic components.
U.S. Pat. No. 4,446,269 discloses solutions of fluoropolymers. The solutions are disclosed as being useful in the manufacture of liquid permeation membranes.
While solutions of fluoropolymers are known in the art, there remains a need to find new uses for the solutions. In addition, there is a need for improving the heat transfer capabilities of substrates.
SUMMARY OF THE INVENTION
This invention is a new method for using a fluoropolymer solution to form a corrosion barrier/heat transfer promoting film on a substrate. In addition, this invention is a new method for using a fluoropolymer solution to form an adhesion barrier film on metal and non-metal substrates.
This invention is also a heat transfer surface coated with a thin durable fluoropolymer film that is prepared by applying a fluoropolymer solution to a metal or non-metal substrate to give a substrate coated with a very thin layer of fluoropolymer.
In addition, this invention is a substrate coated with a fluoropolymer film having a thickness of from about 0.1 microns to about 10.0 microns or more.
This invention is also a method for applying a thin layer of fluoropolymer to the internal and/or external surfaces of a heat exchanger such as, but not limited to, radiators, air liquid heat exchangers, liquid coolers, liquid heaters and coolers, gas heaters and coolers, and any other existing heat exchangers as well as heat exchangers developed in the future.
In another aspect, this invention is an antifreeze solution including a soluble fluoropolymer dispersion that protects the internal radiator heat transfer surfaces from corrosion and scum accumulation.
Yet another object of this invention is an apparatus that is useful for coating the internal surface of a heat exchanger with a fluoropolymer coating.
Still another object of this invention is a method for coating the internal surface of a heat exchanger with a fluoropolymer.
In one embodiment, this invention is a method for applying a fluoropolymer coating to a substrate. The method is accomplished by preparing a fluoropolymer solution comprising from about 0.1 to about 20.0 weight percent fluoropolymer. The fluoropolymer solution is then applied to a substrate to give a fluoropolymer coated substrate. Finally, the fluoropolymer coated substrate is cured to give a fluoropolymer film coated substrate.
In another embodiment, this invention is a method for applying a fluoropolymer coating to the internal surfaces of a heat exchanger having a hollow interior, a fluid inlet, and a fluid outlet. The hollow heat exchanger is coated by directing a flushing solution into the heat exchanger inlet, through the hollow interior of the heat exchanger and out of the heat exchanger outlet to give a flushed heat exchanger. The flushing solution is then removed from the flushed hollow heat exchanger and air is introduced into the cleaned hollow heat exchanger to give an essentially dry hollow heat exchanger. A fluoropolymer solution is introduced into the essentially dry hollow heat exchanger and the fluoropolymer solution is circulated through the heat exchanger for a period of time sufficient to give a fluoropolymer coated heat exchanger. The fluoropolymer solution is withdrawn from the fluoropolymer coated heat exchanger, and air is introduced into the fluoropolymer coated radiator for a period of time sufficient to give a fluoropolymer film coated heat exchanger.
In yet another embodiment, this invention is a fluoropolymer film coated heat exchanger whereby the fluoropolymer film is applied by methods of this invention.
In still another embodiment, this invention is an apparatus useful for applying a thin fluoropolymer film coating onto the inner hollow surface of a heat exchanger. The apparatus includes a first storage tank for containing a flushing solution; a first pump having an inlet associated with the first storage tank and an outlet associated with a first flexible hose inlet, the flexible hose including an outlet for association with a hollow heat exchanger inlet; a blower associated with the first flexible hose; a second storage tank for containing a fluoropolymer solution including an outlet; a second pump including an inlet associated with the second storage tank outlet and an outlet associated with the first conduit; a second flexible hose including an inlet associated with a hollow heat exchanger outlet, and an outlet associated with a piping manifold; and a piping manifold for uniting first storage tank, second storage tank, first pump, second pump, and blower with first flexible hose and with second flexible hose.
REFERENCES:
patent: 5478905 (1995-12-01), Anolick et al.
patent: 5637663 (1997-06-01), Anolick et al.
Beck Shrive
Cleveland Michael
McDonnell Boehnan Hulbert & Berghoff
LandOfFree
Methods and apparatus for applying liquid fluoropolymer... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods and apparatus for applying liquid fluoropolymer..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods and apparatus for applying liquid fluoropolymer... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2526707