U.S. patent application number 13/952065 was filed with the patent office on 2014-01-30 for surface treatment of beverage containers to keep the beverage cool.
The applicant listed for this patent is Barbara Hildegard Pause. Invention is credited to Barbara Hildegard Pause.
Application Number | 20140026595 13/952065 |
Document ID | / |
Family ID | 49993536 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140026595 |
Kind Code |
A1 |
Pause; Barbara Hildegard |
January 30, 2014 |
Surface treatment of beverage containers to keep the beverage
cool
Abstract
The invention pertains to a method suitable to reduce the heat
transfer into a beverage container in order to keep the beverage
cool over an extended period of time after taken from the
refrigerator. The method is based on a surface treatment of the
beverage container which comprises a binder in which phase change
material is incorporated. By absorbing latent heat without a
temperature increase, the phase change material creates a thermal
barrier against heat penetration. The binder with the phase change
material contained wherein is applied to the surface of the
beverage container, for instance, by spray coating. The coating
layer covers most of the container's surface. A second coating
layer which does not contain phase change material is applied on
top of the first coating layer in order to provide protection
against mechanical stress during high speed filling and
packaging.
Inventors: |
Pause; Barbara Hildegard;
(Longmont, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pause; Barbara Hildegard |
Longmont |
CO |
US |
|
|
Family ID: |
49993536 |
Appl. No.: |
13/952065 |
Filed: |
July 26, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61741826 |
Jul 27, 2012 |
|
|
|
Current U.S.
Class: |
62/4 |
Current CPC
Class: |
F25D 3/08 20130101; C09K
5/063 20130101; F25D 5/02 20130101; F25D 2331/803 20130101; F25D
2303/085 20130101; Y02E 60/147 20130101; F25D 2303/0841 20130101;
F28D 20/02 20130101; F25D 2303/0843 20130101; Y02E 60/14
20130101 |
Class at
Publication: |
62/4 |
International
Class: |
F25D 5/02 20060101
F25D005/02 |
Claims
1. A method to keep a beverage cool over an extended period after
the beverage container is taken from the refrigerator realized by a
surface treatment of the container comprising: a first layer made
of a polymeric compound which contains non-microencapsulated phase
change material cross-linked wherein applied to the surface of the
container by a coating technique in a first step, and a second
layer made of a polymeric compound which does not contain phase
change material and which is topically applied to the first layer
as a protective coating by a coating technique in a second step,
and where the phase change material is used to limit the heat
transfer into the beverage container by absorbing latent heat
generated from an external heat source such as the consumer's hand
and where a visible change in the appearance of the container's
surface from icy-white during refrigeration to transparent during
room temperature conditions occurs due to the change in the
appearance of the phase change material from opaque to transparent
during the latent heat absorption.
2. The method according to claim 1, where the phase change material
used to reduce the heat transfer into the beverage container is a
mixture of crystalline alkyl hydrocarbons which absorbs latent heat
in a temperature range between 5.degree. C. and 15.degree. C.
3. The method according to claim 1, where the phase change material
mixture used to reduce the heat transfer into the beverage
container consists of about 10 wt. % to 15 wt. % Tetradecane and 85
wt. % to 90 wt. % Hexadecane.
4. The method according to claim 1, where the phase change material
mixture used to reduces the heat transfer into the beverage
container possesses a latent heat storage capacity of about 200
J/g.
5. The method according to claim 1, where the phase change material
mixture used to reduce the heat transfer into the beverage
container is integrated in a polymeric compound in a quantity of up
to 60 wt. %.
6. The method according to claim 1, where the phase change material
mixture used to reduce the heat transfer into the beverage
container is integrated into a polymeric compound which is applied
to the surface of the beverage container by spray coating, or
dip-coating, or belt or roller coating, or screen printing in a
first step.
7. The method according to claim 1, where a protective layer of a
polymeric compound which does not contain phase change material
which is applied to the surface of the beverage container on top of
the first layer by spray coating, or dip-coating, or belt or roller
coating in a second step.
8. The method according to claim 1, where the surface treatment
covers the main body of the beverage container.
9. The method according to claim 1, where the surface treatment
covers the main body and the bottom of the beverage container.
10. The method according to claim 1, where the beverage containers
surface appearance changes from icy-white under low refrigerator
temperatures to transparent under room temperature conditions.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The application claims priority of the U.S. Provisional
Patent Application Ser. No. 61/741,826 filed Jul. 27, 2012 entitled
"Surface treatment of beverage containers to keep the beverage
cool".
FIELD OF THE INVENTION
[0002] The present invention pertains to a method suitable to keep
the beverage in the container cool after it is taken from the
refrigerator. The method is based on a surface treatment of the
beverage container. The surface treatment comprises a binder
equipped with phase change material as heat storage mean.
BACKGROUND OF THE INVENTION
[0003] Consumer's satisfaction with cold beverages depends often on
the initial sensation of coldness and the beverage staying cold
while the content is being consumed. However, the beverage in the
container warms up quickly after it has been removed from the
refrigerator. The heat transfer from the environment into the
beverage container occurs many by conduction. The major heat source
is the consumer's hand when it holds the container such as a
bottle. Another heat source could be the surface of a table where
the container is put down between sips. In addition, there could be
a convective heat transfer into the container initiated from
surrounding air as well as radiant heat transfer when the container
is exposed to sunlight.
[0004] Insulated holders of the beverage containers used to keep
the beverage cool are disclosed, for instance, in U.S. Pat. No.
7,784,759. These holders made, for instance, of neoprene closed
cell foam or another insulating material, have not provided the
desired solution because they are often perceived as interfering
with the experience of holding a cold drink.
[0005] Insulative labels attached to beverage containers especially
bottles have been disclosed in U.S. Patent Application no.
20080113127 as another solution to keep beverages in containers,
such as glass bottles cool. The insulation effect is provided by
air gaps between two film layers the labels consist of. However, as
disclosed in the said Patent Application, the air layer between the
two film layer are only about 2-4 thousands of an inch thick.
Therefore, the insulation effect is expected to be only very
small.
[0006] A new approach to this problem is the surface treatment of
the beverage container with phase change material incorporated into
a binder.
[0007] Phase change material possesses the ability to change its
physical state within a certain temperature range. When the melting
temperature is obtained in a heating process, the phase change from
the solid to the liquid state occurs. During this melting process
the phase change material absorbs and stores a large amount of
latent heat. In a cooling process of the phase change material, the
stored heat is released into the environment in a certain
temperature range; and a reverse phase change from the liquid to
the solid state takes place.
[0008] During the entire melting process, the temperature of the
phase change material as well as its surrounding area remains
constant. The undesired temperature increase, concomitant during
the normal heating process, does not occur. The same is true for
the crystallization process. During the entire crystallization
process, the temperature of the phase change material also does not
change. The high latent heat absorption or latent heat release
without any temperature change, is responsible for the phase change
materials appeal as a source of heat storage.
[0009] In order to contrast the amount of latent heat absorbed by a
phase change material during the actual phase change with the
amount of sensible heat absorbed in an ordinary heating process,
the ice-water phase change process will be used for comparison.
When ice melts, it absorbs an amount of latent heat of about 335
J/g. When the water is further heated, it absorbs a sensible heat
of only 4 J/g while its temperature rises by one degree C.
Therefore, the latent heat absorption during the phase change from
ice into water is nearly 100 times higher than the sensible heat
absorption during the heating process of water outside the phase
change temperature range.
[0010] In addition to ice (water), more than 500 natural and
synthetic phase change materials are known. These materials differ
from one another in their phase change temperature ranges and their
latent heat storage capacities.
[0011] Applied to a carrier material, the phase change material
limits the heat flux through this material as long as the phase
change takes place and, therefore, creates a kind of thermal
barrier.
[0012] The efficiency of this thermal barrier and the duration of
the thermal effect depend mainly on the thermal storage capacity of
the applied phase change material and its quantity. In addition,
the heat transfer characteristics of the carrier material and
adjacently arranged materials have an influence on the efficiency
of the thermal barrier function.
SUMMARY OF THE INVENTION
[0013] The invention pertains to a method to keep a beverage cool
over an extended period after the beverage container is taken from
the refrigerator. The method is based on a surface treatment of
beverage containers such as glass or plastic bottles, and aluminium
cans with phase change material. Phase change material is a
highly-efficient thermal storage means. It absorbs a large amount
of latent heat when its physical state changes from solid to
liquid. During the latent heat absorption, the temperature of the
phase change material remains constant. By absorbing heat without a
temperature increase, the phase change material creates a barrier
against heat penetration and, therefore, prevents the transfer of
ambient heat into the container. As a result, the temperature of
the beverage enclosed in the container does not rise for an
extended period of time. Under the scope of the invention, a phase
change material mixture has been developed which possesses an
appropriate melting point and a high latent heat storage capacity
in order to provide a long-lasting thermal effect. The phase change
material mixture is incorporated into a binder. The binder with the
phase change material is spray-coated or applied otherwise onto the
exterior surface of the beverage container, creating a film-like
structure. The coating covers most of the container's surface and
sticks to it. In a preferred embodiment of the invention, the
film-layer containing the phase change material is covered by a
protective coating layer in order to withstand mechanical stress
during high-speed filling and packaging.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a sectional view of a bottle as one embodiment of
a beverage container with the surface treatment containing phase
change material applied to its main body.
[0015] FIG. 2 is a sectional view of a bottle as one embodiment of
a beverage container with the surface treatment containing phase
change material applied to its main body and its bottom.
[0016] FIG. 3 is a graphical representation of the development of
the temperature of the beverage inside containers with and without
phase change material surface treatment of the container.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In the method of the present invention, a beverage enclosed
in a container is kept cool for an extended period of time by the
surface treatment of the container with a binder where phase change
material is integrated as a thermal storage means.
[0018] The binder may comprise, by way of example and not by
limitation an acrylic copolymer, an acrylic latex copolymer, a
polyurethane copolymer as well as a phenolic resin, a polyester
resin, a polyethylene-based resin, a polyvinyl-based resin or an
amino-based resin. In the preferred embodiment of the invention a
transparent acrylic latex copolymer binder has been used.
[0019] Phase change materials comprise, by way of example and not
by limitation crystalline alkyl hydrocarbons, salt hydrates,
organics such as fatty acids and eutectics. In order to comply with
food safety standards, crystalline alkyl hydrocarbons are most
suitable for the application in the present invention. Crystalline
alkyl hydrocarbons are byproducts of petroleum refining and
therefore, relatively inexpensive. They can be mixed to each other
in order to realize desired temperature ranges in which the phase
change takes place. The thermal behavior of the crystalline alkyl
hydrocarbons remains stable also under permanent use.
[0020] Based on a variety of preliminary tests, it was figured out
that the beverage containers surface must remain at a temperature
between 5.degree. C. and 15.degree. C. in order to keep the
beverage temperature below a desirable value of 10.degree. C. The
beverage temperature has been about 5.degree. C. on average when
taken from the refrigerator. Therefore, in the preferred embodiment
of the present invention, a mixture of the crystalline alkyl
hydrocarbons hexadecane and tetradecane is used. Preferably, the
mixture consists of about 10 wt. % to 15 wt. % tetradecane and
about 85 wt. % to 90 wt. % hexadecane. By applying this crystalline
alkyl hydrocarbon mixture to the binder the latent heat absorption
takes place in a temperature range between 5.degree. C. and
15.degree. C. The developed crystalline alkyl hydrocarbon mixture
possesses a latent heat storage capacity of about 200 J/g. The
selected temperature range as well as the high latent heat storage
capacity ensures a sufficient heat absorption effect which limits
the heat flux into the beverage container and, therefore, keeps the
beverage cool over an extended period of time.
[0021] On the other hand, the crystallization of the phase change
material mixture takes place in a temperature range between
4.degree. C. and 11.degree. C. This ensures that the phase change
material is fully charged under a usual refrigerator temperature
between 3.degree. C. and 5.degree. C. within about 30 minutes.
[0022] In the preferred embodiment of the present invention, the
phase change material mixture has been applied to the selected
acrylic latex copolymer binder in a quantity of about 30 wt. % or
about 50 vol. %. Incorporated into other binders, the phase change
material mixture might be applicable in a quantity of up to 60 wt.
%.
[0023] After mixing the phase change material mixture which is in a
liquid stage at room temperature into the liquid acrylic latex
binder, the compound is applied to the exterior surfaces of the
various beverage containers, for instance, by spray-coating and
sticks to them. In order to accelerate the curing process, the
coated containers are placed in a warm environment at a temperature
of about 40.degree. C. In this environment, the curing process
lasts less than five minutes. The compound could also be applied to
the beverage containers by other coating methods, such as
dip-coating, belt or roller coating, or screen printing.
[0024] The coated layer (2) is preferable applied to the main body,
but not the neck of glass bottles or plastic bottles (1) as it is
shown in FIG. 1. The content of the bottle neck is usually emptied
with the first sip. Therefore, the bottle neck does not need to be
cooled. In another embodiment of the invention, shown in FIG. 2,
the bottom of bottles is also coated with the binder containing the
phase change material, because of a possible contact with a warm
table surface. Aluminum cans should be coated on all sides with
exception of the lid.
[0025] The film-like structure of the coated layer is preferably
less than one millimeter thick. The liquid phase change material
mixture is cross-linked into the acrylic latex copolymer binder
and, therefore, does not leak out while in its liquid stage. In a
preferred embodiment of the invention, the film-layer containing
the phase change material is covered by a protective layer (3) of a
clear coating compound in order to withstand mechanical stress
during high-speed filling and packaging. For instance, the same
acrylic latex binder without the phase change material could be
used for the protective coating. The protective coating layer could
also be applied by spray-coating, dip coating, belt or roller
coating. Labels as well as external temperature measuring devices
can be easily applied to the protective coating layer by a common
pressure sensitive adhesive. The protective coating layer is
printable. All the materials selected for the surface treatment of
the beverage containers are non-toxic and safe in terms of direct
food contact.
[0026] When placed in the cold environment of a refrigerator, the
phase change material included in the coating layer of the beverage
container crystallizes. During the crystallization process, the
appearance of the phase change material changes from transparent to
opaque. Due to the even dispersion of the phase change material
throughout the binder, the appearance of the coated film layer
changes from transparent to opaque. This, leads to an impression of
an icy-touch on the container's surface after the container has
been placed in the refrigerator for at least one hour. This feature
also serves as an indicator that the beverage has obtained its
desired temperature.
[0027] On the other hand, when the beverage container is taken from
the refrigerator the phase change material absorbs the heat release
from the consumer's hand as well as from the environment, the phase
change material changes its appearance from opaque to transparent
and the icy-touch of the container's surface goes away again.
[0028] In order to determine the improvement in cold sensation of
the beverage due to the phase change material treatment of the
beverage container, a test has been performed. In order to carry
out the test, the beverage containers with and without the phase
change material treatment were pre-conditioned for 24 hours at
5.degree. C. in a climatic chamber. The prevailing test container
were removed from the chamber, were opened and about 40 ml of the
beverage was taken out of the test container at the beginning of
the test. The temperature of the beverage was measured with a
temperature sensor which was dipped into the beverage. The same
amount of the beverage was taken from the test container every two
minutes and the beverage temperature was then measured. During the
test, each test container was held in the hand of the person which
conducted the test. The tests were carried out at an ambient
temperature of 23.degree. C. and a relative humidity of 50%.
[0029] FIG. 3 shows the development of the beverage temperature
during the test. The test results shown in FIG. 3 indicate that the
beverage inside the beverage container are kept cool over an
extended period of time (about twice as long) with the phase change
material treatment of the container's exterior surface.
* * * * *