U.S. patent application number 13/384782 was filed with the patent office on 2012-05-17 for method for forming an oxide layer on a brazed article.
This patent application is currently assigned to CARRIER CORPORATION. Invention is credited to Mark R. Jaworowski, Michael F. Taras.
Application Number | 20120118748 13/384782 |
Document ID | / |
Family ID | 43499601 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120118748 |
Kind Code |
A1 |
Jaworowski; Mark R. ; et
al. |
May 17, 2012 |
Method For Forming An Oxide Layer On A Brazed Article
Abstract
In a method for treating an aluminum article (10), flux is
applied to an outer surface of the aluminum article (10). The outer
surface of the aluminum article (10) is brazed. An oxide layer (36)
is formed on the outer surface of the aluminum article (10) by
anodizing the aluminum article (10), where a portion of the oxide
layer (36) is formed between the flux and the outer surface of the
aluminum article (10).
Inventors: |
Jaworowski; Mark R.;
(Glastonbury, CT) ; Taras; Michael F.;
(Fayetteville, NY) |
Assignee: |
CARRIER CORPORATION
Farmington
CT
|
Family ID: |
43499601 |
Appl. No.: |
13/384782 |
Filed: |
July 15, 2010 |
PCT Filed: |
July 15, 2010 |
PCT NO: |
PCT/US10/42059 |
371 Date: |
January 19, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61227983 |
Jul 23, 2009 |
|
|
|
Current U.S.
Class: |
205/50 ; 205/108;
205/188; 205/201; 205/324 |
Current CPC
Class: |
C25D 9/06 20130101; C25D
11/18 20130101; C25D 11/024 20130101; B23K 35/0244 20130101; B23K
35/286 20130101; C25D 11/026 20130101; C25D 11/06 20130101; C25D
11/04 20130101; B23K 35/025 20130101; B23K 35/36 20130101 |
Class at
Publication: |
205/50 ; 205/188;
205/108; 205/324; 205/201 |
International
Class: |
C25D 11/04 20060101
C25D011/04; C23C 28/04 20060101 C23C028/04; C25D 5/18 20060101
C25D005/18; C25D 11/10 20060101 C25D011/10; C25D 11/18 20060101
C25D011/18; C23C 28/00 20060101 C23C028/00; C25D 11/08 20060101
C25D011/08 |
Claims
1. A method comprising: applying flux to an outer surface of an
aluminum article; brazing the outer surface of the aluminum
article; forming an oxide layer on the outer surface of the
aluminum article by anodizing the aluminum article, wherein a
portion of the oxide layer is formed between a flux residue
produced by the brazing and the outer surface of the aluminum
article.
2. The method of claim 1, wherein forming an oxide layer comprises:
contacting a portion of the outer surface of the aluminum article
with an electrolyte solution; applying an electric current through
the electrolyte solution, wherein the outer surface of the aluminum
article serves as an anode.
3. The method of claim 2, wherein the electrolyte solution
comprises an acid selected from the group consisting of sulfuric
acid, oxalic acid, boric acid, phosphoric acid, chromic acid and
combinations thereof.
4. The method of claim 2, wherein the electric current is pulsed
direct current or alternating current.
5. The method of claim 2, wherein the electric current has a
current density between about 100 amperes per square meter and
about 300 amperes per square meter.
6. The method of claim 5, wherein the electric current forms an
electric field having an average voltage less than about 175
volts.
7. The method of claim 1, further comprising: removing the flux
from the outer surface of the aluminum article after forming the
oxide layer on the outer surface.
8. The method of claim 1, further comprising: applying a coating to
the aluminum article, wherein a portion of the coating is applied
over the oxide layer.
9. The method of claim 1, further comprising: sealing the outer
surface of the aluminum article.
10. The method of claim 1, wherein the oxide layer formed has a
thickness between about 1 micron and about 10 microns.
11. The method of claim 3, wherein the oxide layer is formed by
reacting aluminum on the outer surface of the aluminum article to
form aluminum oxide.
12. The method of claim 1, wherein the electrolyte solution
deposits silicate or phosphate compounds in the oxide layer to form
a ceramic oxide layer.
13. The method of claim 1, wherein the electrolyte solution
contains a titanium oxide, and wherein the titanium oxide deposits
metal ions to form the oxide layer.
14. An aluminum article produced by the process of claim 1.
15. An aluminum article produced by the process of claim 1, wherein
the aluminum article is a heat exchanger.
16. A method for treating an aluminum article having residual flux
on an outer surface, the method comprising: anodizing the aluminum
article to form an oxide layer between the residual flux and the
outer surface of the aluminum article; and removing the residual
flux from the aluminum article.
17. The method of claim 14, further comprising: applying a coating
to the aluminum article, wherein a portion of the coating is
applied over the oxide layer.
18. The method of claim 14, wherein the oxide layer formed has a
thickness between about 1 micron and about 10 microns.
19. The method of claim 14, wherein anodizing the aluminum article
comprises: contacting a portion of the outer surface of the
aluminum article with an electrolyte solution; applying an electric
current through the electrolyte solution, wherein the outer surface
of the aluminum article serves as an anode.
20. The method of claim 17, wherein the oxide layer forms by
reacting aluminum on the outer surface of the aluminum article to
form aluminum oxide.
21. The method of claim 17, wherein the electrolyte solution
deposits silicate or phosphate compounds to form a ceramic oxide
layer.
22. The method of claim 17, wherein the electrolyte solution
contains a titanium oxide, and wherein the titanium oxide deposits
metal ions to form the oxide layer.
Description
BACKGROUND
[0001] Aluminum and aluminum alloys are known and used in heat
exchangers for their relatively high strength, thermal conductivity
and formability. For instance, manifolds, fins, and/or tubes of
heat exchangers are commonly made from aluminum. However, aluminum
can corrode under normal atmospheric conditions. Therefore, a
protective coating or paint is often applied to the aluminum to
prevent corrosion of the underlying aluminum.
[0002] One drawback of using protective coatings and paints is that
manufacturing processes used to produce an aluminum component are
not always compatible with developing a strong bond between the
aluminum and the coatings. For instance, in the manufacture of heat
exchangers, a brazing process may be used to bond aluminum fins,
tubes and manifolds together using brazing and flux materials. Flux
materials are chemical cleaning agents which facilitate brazing and
welding by removing oxidation from the metals being joined.
Commonly used flux materials can leave a residual oxide glazing on
surfaces of the tubes and the fins, which may inhibit bonding
between a coating or paint and the aluminum.
[0003] One step in some protective treatment processes involves
anodizing aluminum surfaces of the heat exchangers. With regard to
anodized aluminum it is known to apply anodic coatings to aluminum
by making the metal anodic in a suitable solution and with a
suitable counter electrode (cathode). The application of an anodic
current converts the surface of aluminum to aluminum oxide, which
is characteristically hard and wear resistant. The anodic coatings
are usually microporous and can be sealed with dyes to obtain
desired colors or with other solutions to improve corrosion
resistance or to attain desired surface characteristics. Some of
the more commonly used solutions for applying anodic coatings on
aluminum include sulfuric acid, chromic acid, oxalic acid,
sulfophthalic acid, boric acid and their combinations.
SUMMARY
[0004] In a method for treating an aluminum article, flux is
applied to an outer surface of the aluminum article. The outer
surface of the aluminum article is brazed. An oxide layer is formed
on the outer surface of the aluminum article by anodizing the
aluminum article, where a portion of the oxide layer is formed
between a flux residue produced by the brazing and the outer
surface of the aluminum article.
[0005] In a method for treating an aluminum article having residual
flux on an outer surface, the aluminum article is anodized to form
an oxide layer between the residual flux and the outer surface of
the aluminum article. Residual flux is removed from the aluminum
article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a front view of an aluminum article.
[0007] FIG. 2 is an enlarged view of aluminum article components
prior to brazing.
[0008] FIG. 3 is an enlarged view of a brazed joint with flux
residue.
[0009] FIG. 4 is an enlarged view of the brazed joint of FIG. 3
after anodizing.
[0010] FIG. 5 is a flow diagram illustrating a method for anodizing
a brazed aluminum article.
[0011] FIG. 6 is a flow diagram illustrating another method for
anodizing a brazed aluminum article.
[0012] FIG. 7 is a flow diagram illustrating yet another method for
anodizing a brazed aluminum article.
DETAILED DESCRIPTION
[0013] FIG. 1 illustrates one embodiment of aluminum article 10.
Aluminum article 10 can be aluminum or an aluminum alloy. Within
this disclosure, "aluminum" shall refer to both aluminum and
aluminum alloys. In this example, aluminum article 10 is a heat
exchanger. However, it is to be understood that this disclosure is
also applicable to other types of aluminum articles and is not
limited to heat exchangers or the type of heat exchanger shown.
While FIG. 1 illustrates a straight (planar) heat exchanger, formed
heat exchangers and other parts can also benefit from the method of
the invention.
[0014] Aluminum article 10 includes first manifold 12 having inlet
14, outlet 16 and partition 26; tubes 18 and 22; second manifold
20, and fins 24. First manifold 12 includes inlet 14 for receiving
a working fluid, such as coolant, and outlet 16 for discharging the
working fluid. Each of a plurality of tubes 18 is fluidly connected
at a first end to first manifold 12 and at an opposite second end
to second manifold 20. Each of a plurality of tubes 22 is fluidly
connected at a first end to second manifold 20 and at an opposite
second end to first manifold 12 to return the working fluid to
first manifold 12 for discharge through outlet 16. Partition 26 is
located within first manifold 12 to separate inlet and outlet
sections of first manifold 12. Tubes 18 and 22 can include
channels, such as microchannels, for conveying the working fluid.
The two-pass working fluid flow configuration described above is
only one of many possible design arrangements. Single and other
multi-pass fluid flow configurations can be obtained by placing
partitions 26, inlet 14 and outlet 16 at specific locations within
first manifold 12 and second manifold 20. The method of the
invention is applicable to aluminum articles regardless of fluid
flow configuration.
[0015] Fins 24 extend between tubes 18 and the tubes 22 as shown in
FIG. 1. Fins 24 support tubes 18 and 22 and establish open flow
channels between the tubes 18 and 22 (e.g., for airflow) to provide
additional heat transfer surfaces. Fins 24 also provide support to
the heat exchanger structure. Fins 24 are bonded to tubes 18 and 22
at brazed joints 28. Fins 24 are not limited to the triangular
cross-sections shown in FIG. 1. Other fin configurations (e.g.,
rectangular, trapezoidal, oval, sinusoidal) are also suitable.
[0016] FIG. 2 illustrates one example of fin 24 and tube 18 prior
to brazing. Braze material 30 is positioned between fin 24 and tube
18. Braze material 30 is commonly supplied as an alloy cladding on
either fin 24 or tube 18. Flux 32 is applied over fin 24, tube 18
and braze material 30 to prevent oxide formation during brazing. In
one example, flux 32 includes at least potassium, aluminum and
fluorine. The fluorine can comprise a majority of flux 32 by
weight. One such flux 32 is Nocolok.RTM., available from Solvay
Fluor GmbH (Hannover, Germany). Flux 32 can be applied onto fin 24,
tube 18 and braze material 30 as a waterborne slurry or blown on as
an electrostatically-deposited powder. Alternatively, a brazing
paste containing braze material 30 and flux 32 can be applied
between fin 24 and tube 18 or a flux-coated brazing rod can be
positioned between fin 24 and tube 18.
[0017] Typically, heat is applied to melt braze material 30 and
form brazed joint 28 between fin 24 and tube 18. The braze process
can be a "controlled atmosphere braze" process conducted under a
substantially pure nitrogen atmosphere. At a predetermined brazing
temperature, flux 32 interacts with brazing material 30 to melt
brazing material 30. Melted brazing material 30 flows between fin
24 and tube 18 and forms a strong bond upon cooling and
solidification to form brazed joint 28.
[0018] FIG. 3 illustrates an enlarged view of one example of brazed
joint 28 of aluminum article 10. Flux 32 can leave a residual
fluoro-compound (flux residue 34) on portions of the surfaces of
fins 24 and tubes 18 and 22 following the brazing process. Flux
residue 34 can include fluorine from flux 32 in combination with
other elements from the atmosphere, brazing material 30 or from the
aluminum of tubes 18 and 22 or fins 24. For instance, flux residue
34 can include phases of fluoride and/or fluoro-oxy-compounds. The
composition of flux residue 34 can vary depending on the
composition of flux 32, brazing material 30 and aluminum; the
atmosphere, and the brazing process and conditions.
[0019] If flux residue 34 is not removed from the surfaces of fins
24 and tubes 18 and 22, flux residue 34 can inhibit strong bonding
between a later deposited protective coating or paint and the
underlying aluminum of fins 24 and tubes 18 and 22. Flux residue 34
can also contribute to formation of a powdery corrosion product on
surfaces of aluminum article 10 that can also inhibit bonding
between a later deposited protective coating or paint or produce an
undesired visual appearance.
[0020] To allow deposition of a subsequent protective coating, flux
residue 34 can be removed as described in International Application
No. PCT/US09/42552, filed May 1, 2009. Alternatively, anodizing
aluminum article 10 according to the present invention reduces
bonding between flux residue 34 and the surfaces of aluminum
article 10. Anodizing aluminum article 10 also conditions the
surfaces of aluminum article 10 to allow for improved adhesion with
subsequent coatings.
[0021] Anodizing aluminum surfaces is generally known to improve
wear resistance and surface hardness. Aluminum anodizing is
normally performed on an aluminum surface after the aluminum
surface is cleaned. However, Applicants discovered that when
aluminum article 10 was anodized before the removal of flux residue
34, an oxide layer formed between the surface of aluminum article
10 and flux residue 34. In order for an oxide layer to form between
flux residue 34 and the surface of aluminum article 10, flux
residue 34 must be at least somewhat permeable to ionic current.
Anodizing aluminum article 10 before removing flux residue 34
provides unexpected benefits.
[0022] First, the anodizing step reduces the bond strength between
aluminum article 10 and flux residue 34. Because the oxide layer
forms underneath flux residue 34 (i.e. between flux residue 34 and
the outer surface of aluminum article 10), flux residue 34 does not
adhere as strongly to aluminum article 10. Second, the anodizing
step improves adhesion between aluminum article 10 and a
subsequently applied coating without having to first remove flux
residue 34. Thus, not only can anodizing aluminum article 10 be
used as a flux residue removal process, but anodizing also improves
adhesion between the outer surface of aluminum article 10 and a
subsequently applied coating.
[0023] FIG. 4 illustrates an enlarged view of brazed joint 28 of
aluminum article 10 after it has been anodized according to the
present invention. During anodizing, oxide layer 36 forms along
outer surfaces of aluminum article 10 (fins 24, tubes 18 and 22,
manifolds 12 and 20) including underneath flux residue 34. Oxide
layer 36 forms a generally uniform layer on the outer surface of
aluminum article 10. Depending on anodizing conditions, oxide layer
36 has a thickness between about 1 micron and about 10 microns.
Most preferably, oxide layer 36 has a thickness of about 5
microns.
[0024] FIG. 5 illustrates one embodiment of a method for forming
oxide layer 36 on the outer surface of aluminum article 10. Method
40 includes applying brazing material 30 and flux 32 to aluminum
article 10 (step 42), brazing aluminum article 10 (step 44) and
anodizing aluminum article 10 (step 46). Method 40 also includes
the optional step of sealing aluminum article 10 (step 48). Steps
42 (applying flux) and 44 (brazing) are described above in
reference to FIG. 2.
[0025] Oxide layer 36 is formed on the outer surface of aluminum
article 10 and under flux residue 34 by anodizing aluminum article
10 in step 46. The anodizing process includes contacting or
immersing at least a portion of aluminum article 10 in an anodizing
(electrolyte) solution contained within a bath, tank or other
container. Aluminum article 10 functions as the anode in an
electrochemical cell. A second metal article functions as the
cathode in the cell. Direct or alternating current is passed
through the anodizing solution to anodize aluminum article 10 and
form oxide layer 36 under flux residue 34. Pulsed direct current or
alternating current is suitable for anodizing aluminum article 10
according to the present invention. When using pulsed current, the
average current is preferably not more than 250 volts, more
preferably not more than 200 volts, or most preferably not more
than 175 volts, depending on the composition of the chosen
anodizing solution. The current density is preferably between about
100 amps/m.sup.2 and about 300 amps/m.sup.2. The anodizing solution
is preferably maintained at a temperature between about 5.degree.
C. and about 90.degree. C. during anodizing step 46.
[0026] Oxide layer 36 can form on aluminum article 10 and under
flux residue 34 in different ways depending on the anodizing method
and solution chosen. First, aluminum oxide layer 36 can grow from
the base metal of aluminum article 10. Second, oxide layer 36 can
grow from the base metal of aluminum article 10 while silicate,
phosphate or other compounds are deposited from the anodizing
solution to form ceramic oxide layer 36. Third, oxide layer 36 can
be formed by deposition of metal ions from the anodizing solution
alone. The different ways of forming oxide layer 36 employ
different anodizing solutions and methods.
[0027] In applications where oxide layer 36 is an aluminum oxide
layer grown from the base metal of aluminum article 10 and under
flux residue 34, the anodizing solution typically contains an acid.
Suitable acids include sulfuric acid, oxalic acid, boric acid,
phosphoric acid, chromic acid, and combinations thereof. The acid
chosen for the anodizing solution affects the properties of oxide
layer 36 including corrosion resistance, hardness and adhesive bond
strength and can also affect cost, complexity and environmental
impact of the process. The anodizing solution can also contain
other compounds to adjust pH and other properties of the anodizing
solution and anodizing process. In one embodiment, an aqueous
anodizing solution containing sulfuric acid at a concentration of
about 165 grams per liter to about 200 grams per liter is used in
step 46. The aqueous anodizing solution contains a maximum of about
20 grams of dissolved aluminum ions per liter and a maximum of
about 0.2 grams of sodium chloride per liter. With this anodizing
solution, the current density is preferably between about 107
amps/m.sup.2 (10 amps per square foot) and about 162 amps/m.sup.2
(15 amps per square foot). Using an anodizing solution containing
sulfuric acid provides a relatively inexpensive method for forming
aluminum oxide layer 36 on aluminum article 10.
[0028] In applications where oxide layer 36 is a ceramic oxide
layer, step 46 can include anodizing solutions suitable for methods
such as the CeraFuse (Whyco Finishing Technologies, LLC, Thomaston,
Conn.) and Keronite (Keronite International Ltd., Cambridge, UK)
processes. In the CeraFuse process, a hard, dense ceramic layer of
alpha aluminum oxide is formed on aluminum article 10. In
Keronite's plasma electrolytic oxidation process, an electric
current is passed through a bath of the anodizing solution so that
a controlled plasma discharge is formed on the surface of aluminum
article 10, fusing oxides on aluminum article 10 into a harder
phase. The CeraFuse and Keronite processes both form ceramic oxide
layer 36 under flux residue 34 on aluminum article 10.
[0029] In applications where oxide layer 36 is formed by deposition
of metal ions from the anodizing solution, step 46 can include
anodizing solutions suitable for methods such as the Alodine.RTM.
EC.sup.2.TM. (Henkel Corporation, Madison Heights, Mich.) process.
In the Alodine.RTM. EC.sup.2.TM. process, oxide layer 36 is formed
through the electro deposition of titanium oxides. The anodizing
solution can contain compounds such as titanium dioxide. According
to this process, metal ions from the anodizing solution deposit on
aluminum article 10 to form oxide layer 36. Since oxide layer 36 is
formed only from the metal ions in the anodizing solution, the base
metal does not react to form an oxide layer. Oxide layer 36 formed
according to this process is dense and has a high adhesion
potential. Like the other anodizing steps 46, the Alodine.RTM.
EC.sup.2.TM. process forms oxide layer 36 under flux residue 34 on
aluminum article 10.
[0030] The embodiment of method 40 illustrated in FIG. 5 also
includes sealing the outer surface of aluminum article 10 (step 48)
following anodizing step 46. Sealing step 48 is typically performed
for aluminum article 10 in situations where a later paint coating
will not be applied. A later applied paint coating adheres better
to an unsealed outer surface of aluminum article 10 than to a
sealed outer surface. Sealing the outer surface of aluminum article
10 provides additional wear and corrosion resistance. Sealing step
48 can be performed by contacting or immersing the outer surface of
aluminum article 10 with nickel acetate or treating the outer
surface with boiling water or steam, chromic acid, or trivalent
chromium compounds.
[0031] FIG. 6 illustrates another embodiment of a method for
forming oxide layer 36 on the outer surface of aluminum article 10.
Method 40B includes applying brazing material 30 and flux 32 to
aluminum article 10 (step 42), brazing aluminum article 10 (step
44) and anodizing aluminum article 10 (step 46). Anodizing step 46
includes substeps for pretreating aluminum article 10 (substep 50)
and rinsing aluminum article 10 (substep 52). Method 40 also
includes the optional steps of removing residual flux (flux residue
34) from aluminum article 10 (step 54) and applying a coating to
aluminum article 10 (step 56).
[0032] Anodizing step 46 includes pretreatment substep 50.
Pretreatment substep 50 prepares aluminum article 10 for anodizing
and can include alkaline cleaning, alkaline etching, acid
desmutting, water rinsing or spraying and combinations of the
above. In one pretreatment substep 50, aluminum article 10 is
cleaned with a silicate-free alkaline solution at about 54.degree.
C. (130.degree. F.). Pretreatment substep 50 can also include water
rinsing or spraying using deionized water or tap water to prevent
entrapment of any acidic or alkaline solutions used during
pretreatment substep 50.
[0033] Anodizing step 46 also includes rinsing aluminum article 10
(substep 52). Once oxide layer 36 has formed on aluminum article
10, aluminum article 10 is rinsed with water to remove any residual
acids and other chemicals used in anodizing step 46. The water
rinse prevents residual acids or chemicals from corroding aluminum
article 10 and interfering with any subsequently applied
coatings.
[0034] The embodiment of method 40B illustrated in FIG. 6 also
includes removing residual flux from aluminum article 10 (step 54).
Once oxide layer 36 is formed on aluminum article 10 in step 46,
flux residue 34 can be removed more easily from aluminum article
10. Flux residue 34 can be removed by rinsing, water spraying or
hydrothermal treatment. By anodizing aluminum article 10 and
forming oxide layer 36 between the outer surface of aluminum
article 10 and flux residue 34 the bond between flux residue 34 and
aluminum article 10 weakens. Once the bond is weakened flux residue
34 is more easily removed. The parameters of anodizing step 46 and
characteristics of oxide layer 36 (e.g., thickness) can affect how
easily flux residue 34 is removed.
[0035] After some anodizing steps 46, flux residue 34 can be
removed simply by rinsing aluminum article 10. Rinsing can be
performed by immersion in water or flowing water over the outer
surface of aluminum article 10. Immersion in water can be
accompanied by agitation to speed up the removal of flux residue
34. In some situations, flux residue 34 is removed from aluminum
article 10 by spraying water at the outer surface of aluminum
article 10. The water can be sprayed at aluminum article 10 at
various temperatures and pressures to remove flux residue 34. In
cases where flux residue 34 resists removal during low pressure
spraying, the water pressure can be increased. In other situations,
hydrothermal treatment is used to remove flux residue 34. Suitable
hydrothermal treatments for removing flux residue 34 are described
in International Application No. PCT/US09/42552, filed May 1,
2009.
[0036] Method 40B also includes applying a coating to aluminum
article 10 (step 56) following anodizing step 46. Coating step 56
can be performed following residual flux removal step 54 or
immediately following rinsing step 52. FIG. 7 illustrates method
40C where coating step 56 is performed without an earlier flux
removal step. Various coatings, including paints or protective
coatings (e.g., UV protectant), can be applied to aluminum article
10 once oxide layer 36 has formed on its outer surface. Whether
coating step 56 is performed after flux removal step 54 or rinsing
step 52, at least a portion of the coating applied directly
contacts oxide layer 36. Coatings applied to aluminum article 10
typically offer wear and corrosion resistance to the outer surface
of aluminum article 10. Oxide layer 36 allows the coating applied
in step 56 to bond to the outer surface of aluminum article 10 with
more adhesion and bond strength than if the coating was applied to
the outer surface having flux residue 34 and no oxide layer 36.
[0037] The present invention provides a method for forming an oxide
layer on a brazed aluminum article. The oxide layer forms between
the outer surface of the aluminum article and residual flux
material applied for the brazing process. By forming the oxide
layer, the bond between the residual flux material and the outer
surface of the aluminum article is weakened. The residual flux
material can be removed from the aluminum article more easily. The
oxide layer also enhances the bonding capability of paint and other
coatings with the aluminum article.
[0038] While the invention has been described with reference to
exemplary embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiments disclosed, but that the invention will
include all embodiments falling within the scope of the appended
claims.
* * * * *