U.S. patent application number 16/312991 was filed with the patent office on 2019-07-18 for a passive temperature control system for transport and storage containers.
The applicant listed for this patent is Softbox Systems Limited. Invention is credited to Timothy Astley-Cooper, Ross Malcolm Beech, Gavin Hill, James Nathan Jarvis, Arthur Smith-Fitchett, Richard Darren Wood.
Application Number | 20190219320 16/312991 |
Document ID | / |
Family ID | 56891717 |
Filed Date | 2019-07-18 |
United States Patent
Application |
20190219320 |
Kind Code |
A1 |
Wood; Richard Darren ; et
al. |
July 18, 2019 |
A PASSIVE TEMPERATURE CONTROL SYSTEM FOR TRANSPORT AND STORAGE
CONTAINERS
Abstract
The present invention relates to the field of the transportation
and storage of goods and to a passive temperature control system
for such a transport and storage containers. The present invention
seeks to provide a system that can enable goods to be securely and
reliably transported and stored for limited periods within
specified temperature ranges. Pharmaceuticals, proteins, biological
samples and other temperature sensitive products, including food
items, are regularly shipped in containers year round and are
subjected to a wide range of temperatures. Though they are shipped
in insulated containers and/or climate controlled environments, the
temperature stability of the shipping containers can be
significantly improved by utilising suitable phase change materials
in an ordered fashion. The present invention provides a simple
solution to the maintenance of temperature profiles for the
transport and storage of temperature sensitive products.
Inventors: |
Wood; Richard Darren;
(Bedfordshire, GB) ; Smith-Fitchett; Arthur;
(Oxon, GB) ; Beech; Ross Malcolm;
(Buckinghamshire, GB) ; Jarvis; James Nathan;
(Leighton Buzzard, GB) ; Hill; Gavin;
(Buckinghamshire, GB) ; Astley-Cooper; Timothy;
(Oxfordshire, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Softbox Systems Limited |
Long Crendon, Buckinghamshire |
|
GB |
|
|
Family ID: |
56891717 |
Appl. No.: |
16/312991 |
Filed: |
June 26, 2017 |
PCT Filed: |
June 26, 2017 |
PCT NO: |
PCT/GB2017/000096 |
371 Date: |
December 21, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 2303/08222
20130101; F25D 3/08 20130101; F25D 2331/804 20130101; F25D 2303/085
20130101; F25D 2201/1282 20130101; F25D 2500/04 20130101 |
International
Class: |
F25D 3/08 20060101
F25D003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2016 |
GB |
1611050.4 |
Claims
1. A temperature controlled transport/storage container for
transporting/storing temperature sensitive materials comprising: an
outer insulating container having a top inner wall, a bottom inner
wall and inner side walls; insulating means for insulating the
cavity comprised of a lining disposed adjacent to the inner walls
of the carton to define an insulated cavity; and a plurality of
first and second temperature control panels for placement within
the insulated cavity, adjacent to the means for lining the inner
walls to define a payload volume; wherein the first and second
temperature control panels include, respectively, first and second
phase change materials, wherein the first and second temperature
control panels have a major planar face, which major planar face is
directed toward the payload volume.
2. A temperature controlled transport/storage container according
to claim 1, wherein the temperature control panels are contained in
sealed containers, the sealed containers being defined by one of a
plastic bag, a blister pack, a sheet cellulose package, and a
sealed polymer enclosure.
3. A temperature controlled transport/storage container according
to claim 1, wherein the temperature control panels include at least
one further phase change material.
4. A packaging system according to claim 1-3, wherein the first
phase change material has a phase change temperature in the range
of +25.degree. C. to -20.degree. C.
5. A packaging system according to claim 1, wherein the phase
change materials are presented in the form of one or more of:
plastic bags; polymer bags; blister packs; putty; and foam
encapsulation particles.
6. A packaging system according to claim 1, wherein the phase
change materials are presented in a container such as a cardboard
box or a plastic pre-form.
7. A packaging system according to claim 6, wherein the phase
change materials are thermally connected via a thermally conductive
layer of material.
8. A packaging system according to claim 6, wherein for each side
of the container there is a single temperature control panel, which
retains a single phase change material.
9. A packaging system according to claim 6, wherein the phase
change materials are thermally connected with each other via a
thermally conductive layer of material applied to the
container.
10. A packaging system according to claim 9, wherein the thermally
conductive layer of material comprises a reflective coating.
11. A packaging system according to claim 1, wherein the container
is manufactured from one of: cardboard, plastic sheeting,
corrugated cardboard, and corrugated plastic.
12. A packaging system according to claim 1, wherein the means for
insulating the cavity comprises one of or more of: a plastic foam;
loose cellulose fiber; compressed cellulose fiber; multilayer
insulation; fiberglass woven cloth; and fiberglass woven cloth
impregnated with PTFE Teflon, PVF reinforced with Nomex bonded with
polyester adhesive, and FEP Teflon, Mylar that is aluminized on
both or one side.
13. A packaging system according to claim 1, wherein the means for
insulating the cavity further comprises a reflective coating.
14. A method of packing a container for shipment comprising the
steps of: a. obtaining a container; b. lining the entire interior
surface of the container with insulator material; c. selecting a
plurality of temperature control panels for placement within the
insulated cavity, wherein the temperature control panels include
generally planar packages one phase change materials arranged as,
each planar package having spaced apart first and second major
planes with edge faces connecting the first and second major
planes; wherein the phase change materials provide distinct thermal
characteristics; d. determining a temperature at which to condition
a temperature control panel means with regard to the size of the
container, the duration of transport/storage of the container, or
the expected ambient conditions; e. placing the temperature control
panel at the determined temperature in a temperature conditioning
apparatus, whereby to ensure the temperature control panel is
brought to the set temperature; f. placing the temperature control
panels having been brought to the set temperature in the container
whereby to define a payload volume wherein the at least two types
of phase change material packages are arranged such that the load
cavity is equidistantly separated with respect to each type of
temperature control panel; g. placing a payload within the payload
volume; h. placing a temperature control panel upon the payload and
other temperature control means; and i. closing and sealing the
container.
Description
FIELD OF INVENTION
[0001] The present invention relates to the field of the
transportation and storage of goods and to a passive temperature
control system for such a transport and storage containers.
BACKGROUND TO THE INVENTION
[0002] In the field of logistics, that is the field of movement and
supply of produce and materials, there is a substantial requirement
for the provision of a temperature control system to ensure that
certain types of produce and materials do not pass through
temperature thresholds. It is well known that, for example,
vegetables when subject to extremes of temperature that they become
flaccid, as the cell structure is broken down through the formation
of icicles or through dehydration. Similarly, in the transport of
drugs and vaccines and certain other chemicals, a solution may
separate or become solid. It will also be appreciated that even
relatively small amounts of pharmaceutical product can cost
thousands of pounds or more; temperature deviations from an allowed
temperature can become very expensive; such goods typically having
journey temperature plotting indicators, whereby any temperature
deviation means that product is discarded and destroyed,
irrespective of the cost of the product.
[0003] In essence, in any transport container with a thermally
sensitive load, the rate at which heat passes through the packaging
material of the transport container--the amount of heat that flows
per unit time through a unit area with a temperature gradient per
unit distance must not extend beyond a permitted temperature range
for the product. Temperature control of thermally sensitive goods
is particularly challenging when the thermally sensitive goods must
be maintained within a narrow temperature range.
[0004] Multilayer insulation (MLI) is the most common passive
thermal control element used in transport. MLI seeks to prevent
both heat losses to the environment and excessive heating from the
environment. Low cost temperature control in the transport industry
relies upon MLI to retain an inside temperature subject to the
thermal path to a transported product from an outside the outside
to maintain ideal operating temperature. MLI can simply comprise
layers of plastics foam; more complex MLI can consist of an outer
cover layer, an interior layer, and an inner cover layer. Some
common materials used to the outer layer are fiberglass woven cloth
impregnated with PTFE Teflon, PVF reinforced with Nomex bonded with
polyester adhesive, and FEP Teflon. The general requirement for
interior layer is that it needs to have a low emittance. The most
commonly used material for this layer is Mylar that is aluminized
on both or one side. The interiors layers can be thin compared to
the outer layer to save weight.
[0005] It has been known to store goods which are sensitive to
temperature in thermally insulated containers in which so-called
cooling blocks are housed. One simple example of such a container
is that used by homemakers to store food. In this case, the
interior of the thermal container need only be kept cool for a
relatively short period of time. Because of this, and because
direct contact of the food with the cooling block is not normally
harmful, it suffices to freeze the block to the necessary
temperature prior to using the same. In their simplest form, the
cooling blocks are filled solely with water, which when frozen has
a high heat of fusion and consequently is able to maintain the food
in a cool environment for a considerably period of time.
[0006] Such an apparatus is effective to keep food wholesome or to
keep beverages cool for a certain period of time at ambient
temperatures which lie above the desired storage temperatures. The
use of cooling blocks filled with water cannot be considered for
the storage of freeze-sensitive products, such as blood within
tolerable temperature ranges, particularly in the case when the
ambient temperature falls beneath a permitted storage temperature,
since the latent heat of fusion of water on the formation of ice is
not released until the temperature falls below 0.degree. C.,
meaning that a product could be cooled below an ideal
temperature.
[0007] Typical means for shipping temperature sensitive materials
involves the use of an insulated box, with the necessary shipping
and warning labels, along with some cooling agent. These cooling
agents have typically been, for example, a frozen gel, dry ice, or
wet ice, placed within an insulator packing agent, such as cotton
or, latterly, plastics materials such as expanded polystyrene foam,
wherein heat is absorbed by such cooling agents.
[0008] There are, however, several problems with the conventional
approach. First, the polystyrene foam used for insulation does not
degrade readily, leading to disposal problems. Second, the cooling
agents also present numerous practical problems in field use.
Specifically, gel systems are often too expensive for routine use
and disposal. As for dry ice, the carbon dioxide gas evolved during
shipment is so dangerous to shipping personnel that hazard warnings
must be posted and additional fees are required to be paid;
furthermore, outright bans on dry ice are pending in several areas.
Finally, wet ice poses handling problems in packing, as well as
leakage and product soaking problems.
[0009] Blood, meaning transfusion blood, must be maintained within
a close temperature range of between +1.degree. C. and +6.degree.
C. during its passage between donor and receiver. Various
biological products, such as platelets, whole blood, semen, organs
and tissue, must be maintained above a predetermined minimum
temperature and below a predetermined maximum temperature.
Pharmaceutical products are also commonly required to be kept
within a specified temperature range. Food products, flowers and
produce frequently have preferred storage temperature ranges as
well. Indeed, certain types of goods have stringent standards to be
adhered to. For example, as part of a World Health Organisation
(WHO) pre-qualification scheme, vaccine manufacturers are expected
to ensure their packaging complies with the criteria specified
below: Class A packaging: Vaccines must be packed to ensure that
the warmest temperature inside the insulated package does not rise
above +8.degree. C. in continuous external ambient temperatures of
+43.degree. C. for a period of at least 48 hours. Class B
packaging: Vaccines must be packed to ensure that the warmest
temperature inside the insulated package does not rise above
+30.degree. C. in continuous external ambient temperatures of
+43.degree. C. for a period of at least 48 hours. Class C
packaging: Vaccines must be packed to ensure that the warmest
temperature inside the insulated package does not rise above
+30.degree. C. in continuous external ambient temperatures of
+43.degree. C. for a period of at least 48 hours and the coolest
storage temperature of the vaccine does not fall below +2.degree.
C. in continuous external temperatures of -5.degree. C. for a
period of at least 48 hours. Many known methods and systems for
shipping such products are not able to keep temperatures within the
desired range.
[0010] Numerous insulated shipping containers have been developed
over the years, with those deploying a phase change material (PCM)
generally providing superior temperature control over extended
periods. Insulated shipping containers employing a PCM can be
deployed for a wide range of thermally sensitive goods over a wide
range of target temperatures by using different PCMs. For example,
D2O melts at +4.degree. C., H2O melts at 0.degree. C., a 20%
ethylene glycol solution melts at -8.degree. C., castor oil melts
at -10 .degree. C., neat ethylene glycol melts at -12.9.degree. C.,
mineral oil melts at -30.degree. C., and a 50% ethylene glycol
solution melts at -37.degree. C. This permits use of insulated
shipping containers for a broad range of thermally labile goods.
However, in order to accommodate the packaging of a wide variety of
thermally labile goods, the shipper needs to purchase and inventory
a sufficient number of PCM panels containing each of the different
PCMs to meet the highest possible demand for that type of PCM
panel. For example, assume that a shipper typically has between
about 800 and 1,200 passive thermally regulated shipping containers
in transport on any given day, each of which employ six PCM panels
and all of which could require one of two different PCM panels
containing different PCM. This shipper would need to purchase,
inventory, track and maintain 14,400 PCM panels ((1,200 containers)
(6 PCM panels/container) (2 PCM panel types)). The need to
purchase, track and maintain such a large number of PCM panels can
become cost prohibitive.
[0011] Current design practice in temperature controlled packaging
involves using a single temperature PCM conditioned in an `ideal`
state depending on the thermal challenge to be presented to the
temperature controlled packaging during shipment. However this is
troublesome on two counts. Firstly, the PCM packs must be warmed or
cooled to just above or just below their Phase Change Point, this
can be difficult to achieve in normal industrial warehousing
scenarios, as such ideal temperature ranges can be as narrow as
(for hot shipping conditions) +15.degree. C. to +19.degree. C. and
(for cold shipping conditions) +20.degree. C. to +24.degree. C.
Secondly, it is very hard to predict what conditions will be
experienced by the TCP during transit.
[0012] In order to maintain a stable temperature it is advantageous
to use a Phase Change Material (PCM) that has a Latent Heat of
Fusion both above and below the standard hold temperature of
+20.degree. C. (the mid-point of most pharmaceutical specification
warehouses), but this is difficult to achieve with the use of just
one PCM. Indeed, the use of two PCMs within a shipping container is
known. In U.S. Pat. No. 7,908,870 to Entropy Solutions and U.S.
Pat. No. 8,424,335 to Pelican, arrangements that utilise Dual PCM
embodiments are taught having a thermal insulation and a plurality
of different phase change materials within an interior volume.
Specifically, these documents relate to a container and a plurality
of different phase change materials within an interior volume, to
provide respectively--and with reference to FIGS. 1a and 1b, to a
container having exterior thermal insulation 1a1, a first phase
change material PCM1 (for example water), a further layer of
insulation 1a2, a second layer of phase change material PCM2, and
to a container having exterior thermal insulation 1b1, a first
phase change material PCM1 (for example water), a second layer of
phase change material PCM2 (for example paraffin wax), wherein at
least one of the PCMs acts as a thermal buffer to protect a
temperature sensitive payload against thermal damage from the other
PCM having a temperature outside of a predetermined temperature
range for payload protection. Each container will be adapted in
size/temperature combination to determine a thermally controlled
container in respect of a particular payload, target temperature,
guaranteed duration of thermal control, size of and weight of
container.
[0013] Whilst these systems are stated as working within limited
temperature ranges, for periods of time they can be difficult to
set up with different temperature profiles to be achieved.
Specifically, where two phase change materials are employed, these
materials have been selected, temperature conditioned, stored and
packed separately, in a correct, predetermined fashion to provide
the optimal thermal protection. It has been known that the phase
change materials have been confused and misplaced in a container
upon loading of the container, giving rise to an incorrect
temperature-time profile; equally, supervisory actions and checking
operations become necessary, leading to delay in often
time-critical situations and incur further processing costs.
OBJECT OF THE INVENTION
[0014] The present invention seeks to provide a solution to the
problems addressed above. The present invention seeks to provide a
simple system for the provision of a temperature controlled
transport/storage container that is easy to use and set-up using a
minimum of types of components. The present invention seeks to
provide a phase change material system that can enable goods to
reliably be maintained within a particular temperature range. The
present invention also seeks to provide a temperature controlled
transport/storage assembly for goods palletised or otherwise,
whereby goods can be maintained within an atmosphere having a
predefined temperature range.
STATEMENT OF INVENTION
[0015] In accordance with a general aspect of the invention, there
is provided a temperature controlled transport/storage container
for transporting/storing temperature sensitive materials
comprising: an outer insulating container having a top inner wall,
a bottom inner wall and inner sidewalls; insulating means for
insulating said cavity comprised of a lining disposed adjacent said
inner walls of said carton to define an insulated cavity; a
plurality of first and second temperature control panels for
placement within said insulated cavity, adjacent said means for
lining said inner walls to define a payload volume; wherein said
first and second temperature control panels include, respectively,
first and second phase change materials, wherein the first and
second temperature control panels have a major planar face are each
placed, which major planar face is directed toward the payload
volume. That is to say, the load cavity is equi-distantly separated
with respect to each type of temperature control panel, with the
panels not being stacked necessarily one with respect to each
other, whereby to increase usable load volume for a given
container. The major planes can be considered as being co-planar,
if first and second temperature control panels lie adjacent each
other on one side of a box container. The present invention
provides a packaging system, wherein the box has a number of sides
wherein there is a number of single phase change material
temperature control panel. Two or more single phase change material
temperature control panel may be employed per side of a carton. In
the packaging of a carton, for example, there may be provision for
a single temperature control panel of a first type on one face of a
rectangular container, with a single temperature control panel of a
second type on another or the same face of the rectangular
container. Industry standard shapes are generally rectangular
boxes, but it will be appreciated that circularly cylindrical
containers can also be employed without departing from the
inventive concept herein.
[0016] In use, the temperature control panels are configured for a
particular period of time, with reference to the type of load,
volume of load, and expected ambient temperatures likely to be
encountered. By configuring the different types of phase change
material in a co-planar rather than a stacked fashion, it will be
appreciated that an effective load volume for a given container can
be increased significantly, especially when one takes into account
the dimensions of any insulation also employed. This is because the
increase in effective transport volume is greater than a nominal
reduction in thickness per insulation layer and phase change
materials per given it may well be effective in three dimensions,
given that previous practice of providing such temperature control
elements in has been to provide such distinct phase control
elements in distinct layers. Conveniently, said temperature control
panels are contained within an envelope comprising a generally
rectangular box shape, made from an insulating sheet material such
as cardboard, or a plastics, in the form of a simple sheet or
corrugated, whereby to define a separation distance.
[0017] Conveniently, said temperature control panels--which include
one type of phase change materials--are contained in sealed
containers, said containers are arranged as a unitary element by
virtue of being associated with each other. For example, the panel
can be defined by one of a cardboard or plastics sheet box or
sleeve the sheet material being a plain sheet or optionally
corrugated, plastics bag, a blister pack, a sheet cellulose
package, a sealed polymer enclosure. Additional insulation could be
provided on an outside surface of the panel, although this could
have an effect in increasing a conditioning period of time in a
temperature controlled enclosure, before use, as is known. Ideally,
through the common use of a single size of panel, each panel having
a major face operably facing an interior load volume, inventory
levels can be simplified.
[0018] The temperature control panels can be configured to provide
a thermally stable atmosphere within the payload volume for a
number of days as is typical for international travel, for example.
The present invention can, by the use of specially adapted thermal
modelling software, be optimised for particular goods for specific
transport and storage time with respect to a specific payload
space. If the size and number of product cartons is known that need
to be shipped, an analysis can be simply be performed whereby to
provide users with graphical and statistical results to ensure cost
effective use of the present invention in a packaging system. By
maximising the available useful product volume, it will be
appreciated that the overall package employed will be smaller than
what otherwise have been used, with a concomitant benefit in a
reduction of transport and storage charges. This has the advantage
that a particular temperature sensitive consignment can be tailored
for a particular transport scenario.
[0019] The first phase change material could have a phase change
temperature in the range of +50.degree. C. to -80.degree. C.; the
second phase change material could have a phase change temperature
in the range of +50.degree. C. to -80.degree. C. It is possible
that the temperature control panels employed in a container include
at least one further phase change material. Such a range of phase
change materials can cater for most typical temperature controlled
storage and transport requirements. Typically, however the first
and second phase change materials which define the upper and lower
phase change temperatures have a difference of 6-10.degree. C. This
is such that in the case of vegetables, for example, transport
conditions are typically between 4.degree. C. and 12.degree. C.;
with reference to, say, lettuce, if the temperature goes below
freezing point, water within the cell structure present will become
ice and the ice crystals will destroy the leaf structure; equally,
having the products at extended periods above 12.degree. C. will
result in the water within the cell structure evaporating.
[0020] The phase change materials can be contained within each
panel in the form of one or more of flexible plastics bags;
flexible polymer bags; flexible blister packs; putty; foam
encapsulation. The phase change materials could also be presented
in a moulded plastics container, such as a blow-moulded enclosure
such as high density polyethylene plastics material or similar.
Conveniently, the packaging system, together with such phase change
materials, is presented in a container such as a cardboard box or
sleeve. The phase change materials can be thermally connected with
each other via a thermally conductive layer of material, which
could be applied to the container, and could comprise a reflective
coating such as an aluminised coating. Alternatively, the container
is manufactured from plastics sheeting, corrugated cardboard and
corrugated plastics. The insulating means for insulating said
cavity could comprise one of or more of: a plastics foam; cellulose
fibre (loose);
[0021] cellulose fibre (compressed); Multilayer insulation (MLI)
including plastics foam; fibreglass woven cloth; fibreglass woven
cloth impregnated with PTFE Teflon, PVF reinforced with Nomex
bonded with polyester adhesive, and FEP Teflon, Mylar that is
aluminised on both or one side. Given that certain packaging
systems comprise small cartons which such cartons are often
transported together, it has been found that when grouped, en
masse, this has had a negligible effect.
[0022] In a further aspect of the invention, the phase change
materials can be disposed in separate interlocking moulded
elements, whereby to provide a unitary temperature control element,
optionally provided with an insulation layer, whereby to be placed
adjacent product, without a further, separate layer of insulation,
to thereby still further maximise an internal volume but also
enabling a simplifying the associated packing process.
[0023] In accordance with another aspect of the invention, there is
provided a method of packing a container for shipment comprising
the steps of
a. obtaining a container; b. lining the entire interior surface of
the container with insulator material, c. selecting a plurality of
temperature control panels for placement within said insulated
cavity, wherein said temperature control panels include generally
planar packages one phase change materials arranged as, each planar
package having spaced apart first and second major planes with edge
faces connecting the first and second major planes; wherein the
phase change materials provides distinct thermal characteristics;
d. determining a temperature at which to condition each type of
temperature control panel with regard to the size of the container,
the duration of transport/storage of the container; expected
ambient conditions; e. placing the temperature control panel at the
determined temperature in a temperature conditioning apparatus,
whereby to ensure the temperature control panel is brought to said
set temperature; f. placing the temperature control panels having
been brought to said set temperature in the container whereby to
define a payload volume wherein the at least two types of phase
change material packages are arranged such that the load cavity is
equi-distantly separated with respect to each type of temperature
control panel; g. placing a payload within the payload volume; h.
placing a temperature control panel upon the payload and other
temperature control means; and, i. closing and sealing the
container. That is to say, the load cavity is equi-distantly
separated with respect to each type of temperature control panel,
with the panels not being stacked necessarily one with respect to
each other, whereby to increase usable load volume for a given
container. It will be appreciated that separate layers of
insulation may need to be provided. Equally, it may be such that
only two or four temperature control panels need be used, for a
particular set of volume/good/temperature range required/weather
conditions etc. Conveniently, both types of temperature control
panels are conditioned at the same temperature, whereby to simplify
the method.
[0024] The present invention can thus provide a simple to use
solution, conveniently using only two types of phase change panel
for a particular container system, which can be conditioned at the
same temperature thereby reducing the chance of failure through the
incorrect orientation/placement of one of two types of phase change
material. Additionally, the use of two phase change materials
arranged in co-planar fashion as opposed to being arranged in a
thicker, spaced apart in a parallel fashion--from an interior load
volume through to an external wall of a container perspective--can
reduce wastage within a container, meaning that more goods for a
given unit volume can be employed or a smaller box can be selected.
Additionally, a substantial benefit is that all the temperature
conditioning of the phase change materials occurs with respect to
one fridge/cool room prior to placement within a container for
transport/storage of temperature sensitive goods, where the sleeves
are either highly insulating in themselves or benefit from further
internal and or external thermally insulating media comprising
panels, sleeves or other insulating materials. Additionally, in one
embodiment, the invention also benefits from its ability to use the
same size temperature control panels to be utilised in different
containers; commonality of parts between ranges of product can
provide more cost-effective construction and/or different
functionality.
BRIEF DESCRIPTION OF THE FIGURES
[0025] For a better understanding of the present invention,
reference will now be made, by way of example only, to the Figures
as shown in the accompanying drawing sheets, wherein:
[0026] FIGS. 1a, 1b illustrate sections through two known
temperature control configurations from an inside wall of a
container through to a payload;
[0027] FIG. 2a, 2b illustrate first and second perspective views of
a "phase change panel";
[0028] FIG. 3 shows a view of a container in accordance with the
invention prior to placement of the insulating material cover and
panels of phase change material with respect to a load;
[0029] FIG. 4 shows a typical non-integrated pallet with a
load;
[0030] FIG. 5 shows the temperature--phase characteristic of two
types of phase change material;
[0031] FIG. 6 shows an exploded view of a container in accordance
with the invention indicating the placement of phase change panels
with respect to a load;
[0032] FIGS. 6a and 6b comprise graphs comparing temperature change
over time in packaging in accordance with the inventions at with
respect to typical external ambient temperatures, as encountered
during travel;
[0033] FIGS. 6c and 6d comprise graphs detailing the temperature
change over time in packaging in accordance with the inventions at
constant specific external ambient temperatures;
[0034] FIGS. 7 shows and example of a modular PCM strip;
[0035] FIGS. 8a-8c show the manufacturing steps in manufacturing
PCM modules; and,
[0036] FIGS. 9a-9f show the invention as a form of temp control
jacket.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] There will now be described, by way of example only, the
best mode contemplated by the inventor for carrying out the present
invention. In the following description, numerous specific details
are set out in order to provide a complete understanding to the
present invention. It will be apparent to those skilled in the art,
that the present invention may be put into practice with variations
of the specific.
[0038] With reference to FIG. 2, an aspect of one embodiment in
accordance with the present invention shall be described in a
simple to use assembly comprising a cardboard or panel (aka
"wallet"/"cassette"/"envelope"/"sleeve") 20 in which a number of
plastics bags are placed containing phase change materials (PCM)
are placed. Conveniently, there are four elements placed therein
or--alternatively--eight elements placed therein in two layers.
Other configurations are possible; simplicity is, nonetheless, of
benefit. This embodiment of the invention utilises plastic bags
filled with phase change materials, to maintain the internal
product temperature between +15.degree. to +25.degree., which
temperature is also known as the Control Room Temperature
(CRT).
[0039] Such panels are conveniently dimensioned to be placed with a
suitably tight fit within a container 30 as shown in FIG. 3 but a
typical panel will have dimensions of 450.times.285.times.40
mm--but the temperature control panel need not correspond exactly
with the inside dimensions of a load volume; there may even be some
overlap along edges. Equally, there may be one or more panels per
side of the container, given that large panels can become awkward
to handle by personnel, for example. An arrangement of phase change
materials as contained within plastics bags, as can conveniently be
simply manufactured using standard bag filling techniques, as
disclosed in a further contemporaneously filed patent application
by present application. The phase change materials can be contained
within plastics trays (as shall be discussed below), with the panel
being shown in cross-section vis-a-vis a load and panel 20. This
figure can be compared to the cross-sectional views shown in
relation to the prior art in FIGS. 1a and 1b. Whilst, the present
invention may well have a first and second insulation layers, it
can be readily understood, a layer of phase change material has
been removed from the container system relative to the prior art,
whereby to make the packing of shipping (or storage) containers
simpler and, importantly, less liable to incorrect packing, by for
example, a reversal of the order of the first and second coolant
panels 20, as could very be easily be performed by mistake in the
prior art systems. A significant effect is that the effective
payload area for a given volume is increased, given that the prior
art perception of a requirement of separation of distinct phase
control materials is not, in actual fact, required.
[0040] FIG. 3 provides a number of different phase change material
panels with the phase change material being selected in a simple
instance from one of two different phase change materials, PCM1
& PCM2, having phase change temperatures as indicated
(+17.degree. C. and +22.degree. C.). A main advantage of the
concept behind the present invention is that two or more
temperature control panels can be placed within a container having
been temperature conditioned at a single temperature, the types of
phase change materials, the respective amounts of the different
phase change materials and the conditioning temperature being
selected dependent upon the anticipated temperatures, the desired
internal temperature and the nature of the filling, taking into
account the nature of the packing container and associated
insulation surrounding the temperature control panels.
[0041] In a first variation, there can be further provided a layer
of material having a high thermal conductivity in contact with the
plastic bags containing the phase change material, to enable the
creation of a surface having a substantially homogenous temperature
within the panel, which material is preferably associated with the
face adjacent the payload space. In particular, the thermally
conductive layer can conveniently be positioned between the
plastics bags of phase change material and the face of the panel
that would face the payload area. Materials such as metallized film
adhered to a carrier paper or a metallized film applied to a rigid
plastics sheet and associated with corrugated board can be
conveniently provided. Such a material could also form part of the
panel body.
[0042] The present invention enables phase change materials about a
payload to absorb heat/release energy to resist cold by enabling a
phase change material to react with respect to changes in external
temperatures, where the phase change materials are selected to
define a selected permissible range of temperatures within a
payload area of the container. As will be appreciated, as the
container enters a reduced temperature zone, the phase change
materials will release energy due, at least in part, to a change in
phase of a lower temperature rated phase change material. Equally,
as the container enters an elevated temperature zone, the phase
change materials will absorb energy due, at least in part, to a
change in phase of a higher temperature rated phase change
material. That is to say, each phase change material will change
state from liquid to solid to release energy or will change state
from solid to liquid, to absorb energy. As will be appreciated, in
a change of phase state, a material will remain at substantially
the same temperature; i.e. the temperature of the material remains
stable, as can be seen in the graph shown in FIG. 4. It is
important to realise that in a freezing phase, energy is released
in an exothermic process; whilst in a melting phase, energy is
absorbed by the phase change material in an endothermic
reaction.
[0043] With reference to FIGS. 5, there is shown a graphical
comparison of the solid/liquid states of two types of phase change
material as an example of a temperature control containers having
panels in accordance with the present invention using two types of
phase change material. This dual PCM system, for example, allows
for the two phase change materials to be stored at +20.degree. C.
and achieve a composite of solid/liquid segments within respective
temperature control container. The overall thermal effectiveness of
the use of two panels permits protection of the temperature
sensitive goods to be achieved with a single conditioning
temperature of, for example +20.degree. C. Specifically, and as has
been tested in respect of the present invention, a combination of a
+17.degree. C. PCM and a +22.degree. C. PCM, when placed in a
container can be simply considered at 20.degree. C. as comprising a
first liquid phase change material (i.e. the +17.degree. C. PCM),
offering maximum thermal protection against cold thermal stress on
the system and a second solid phase change material (i.e. the
+22.degree. C. PCM), offering maximum thermal protection against
thermal stress on the system. It has been found that the provision
of a layer of material having a high thermal conductivity in
contact with the phase change materials plastics bags to allow a
homogenous temperature to be created on the contact face (lowermost
face) of the assembly--where it would contact the payload space in
the temperature controlled package.
[0044] Current design practice in temperature controlled package
involves:
i) in the case of the use of a single phase change material, then
this phase change materials is conditioned in an `ideal` state
depending on the likely thermal challenge to be presented to the
temperature controlled package during shipment. However this is
troublesome on two counts, namely that the phase change panels must
be warmed or cooled to just above or just below their determined
phase change temperature, which can be difficult to achieve in
normal industrial warehousing scenarios, as such ideal temperature
ranges can be as narrow as (for hot shipping conditions)
+15.degree. C. to +19.degree. C. and (for cold shipping conditions)
+20.degree. C. to +24.degree. C. and; it is very hard to predict
what conditions will be experienced by the temperature controlled
package during transit. ii) When two phase change materials are
employed, the distinct phase change materials are
contained/packaged/installed as two distinct components. It will be
noted that these distinct components need to be selected, labelled,
conditioned and placed in a distinct layer these components have to
be stored at the correct temperature and must be packed in the
correct manner to provide the optimal thermal protection.
[0045] The present invention thus allows for a simple, single
temperature preparation of the separate phase change
containers/panels at standard Control Room Temperature (CRT)
conditions. The design requires little training to facilitate use
which will safeguard quality of shipment. Importantly the margin
for error is significantly reduced. In use, the temperature of the
phase change materials is calculated to enable the temperature to
be centred about an ideal temperature depending on the thermal
challenge to be presented to the temperature controlled package
during shipment. However this is troublesome on two counts:
[0046] The phase change materials that are present in the
respective panels filled with two different PCMs that have
different Freeze/Thaw temperatures. With reference to the
embodiments in FIGS. 5-7c:
[0047] PCM1 has a Freeze/Thaw temperature at around +17.degree. C.,
that at +20.degree. C. would be in a liquid state and would
temperature stabilise at +17.degree. C. as it freezes if the TCP
was exposed to temperatures less than +17.degree. C. There is a
capability to tailor the amount of phase change material in the
cassettes whereby the overall thermal response characteristics can
be adjusted depending on the thermal challenge anticipated.
[0048] PCM2 has a Freeze/Thaw temperature at around +22.degree. C.,
that at +20.degree. C. would be in a solid state and would
temperature stabilise at +22.degree. C. as it thaws if the TCP was
exposed to temperatures greater than +22.degree. C.
[0049] To enable a simple appraisal of the thermal capability of
the present invention, extensive thermal testing has been
performed, with reference the results of which show a distinct
advantage of the Dual Adjacent PCM system of a system with only one
or the other PCM contained within. Specifically, with reference to
FIG. 6, which shows a container with external insulating panels
outside of the PCM panels, in first and second series of tests
under, respectively, summer and winter conditions, the three
systems being tested, as follows:
Si) The use of a single type of PCM material only--+17 PCM--which
provided poor HOT protection as no phase change occurs since such a
phase change material is liquid at +20.degree. C. Sii) The use of a
single type of PCM material only--+22 PCM--which provided good HOT
protection as phase change occurs at +22.degree. C. Siii) The use
of two types of phase change materials--+17 and +22 PCM
materials--which provided good HOT protection as phase change
occurs at +22.degree. C.--for the +22 PCM material. Wi) The use of
a single type of PCM material only--+17 PCM--which provided good
cold protection as phase change occurs since such a phase change
material has a phase transition temperature of +17.degree. C. Wii)
The use of a single type of phase change material only--+22
PCM--which provided poor cold protection as phase change occurs at
+22.degree. C. Wiii) The use of two types of phase change
materials--+17 and +22 PCM materials--which provided good cold
protection as phase change occurs at +17.degree. C.--for the +17
PCM material.
[0050] The results of the first and second tests are shown with
reference to FIGS. 6a and 6b and it is clear to see that the system
using two phase change material embodiment out performs the systems
that only utilise one phase change material type, which is common
in the TCP market place today.
[0051] In a further set of tests, a prototype system using the same
+17 and +22 PCM materials--changing phases, respectively at
+17.degree. C. and +22.degree. C. The system was prepared with all
the phase change materials conditioned at +20.degree. C. and then
tested at two ambient stresses, namely a constant +30.degree. C.
(equivalent to many ambient summer conditions) and a constant
+5.degree. C. (equivalent to many ambient winter conditions). The
results of these tests are graphically shown in FIGS. 6c and 6d,
respectively, where it is shown that: under summer conditions a
payload temperature was maintained payload between +15.degree. C.
to +25.degree. C. for 38 hrs; and under winter conditions a payload
temperature was maintained between +15.degree. C. to +25.degree. C.
for 68 hrs. It will be appreciated that the ratio of +17.degree. C.
to +22.degree. C. phase change materials can be altered to
`balance` the performance levels achieved against the hot and cold
stress test profiles. Equally different types of phase change
material could be employed. It is believed that by having the two
distinct phase change materials conditioned at the same
temperature, there is a beneficial synergistic effect in that a
different conditioned temperature of two separate phase change
materials do not counteract each other.
[0052] Applicants have also developed a process of manufacturing
phase change materials wherein phase change materials, in liquid
form, can be placed in trays defined in multi-layer thermo-formed
plastics films. Plastics such as Acrylonitrile-butadiene-styrene
(ABS) and acrylic can also be used to prove relatively rigid
assemblies, which can be of benefit. Pre-set phase change material
ratios can be adapted for particular circumstances and are placed
in respective trays, the material conveniently being placed whilst
in a liquid state under low atmospheric pressure and sealed with a
plastics film which is used to seal under the application of heat
and/or an adhesive. This plastics film could also be conductive, as
discussed above.
[0053] Further types of phase change materials are being
continuously developed and presently phase change materials are
being developed which have putty-like formable handling
characteristics at certain temperatures, whereby to enable
particular shapes to be created. Such shapes can be encased in
plastics films to provide phase change materials in something
analogous to blister pack pockets. Manufacturing methods for
producing blister packs are well-developed. The primary component
of a blister pack is a cavity or pocket made from a formable web,
usually a thermoformed plastic. This usually has a backing of
paperboard or a lidding seal of aluminium foil or plastic. Blister
packs are useful for protecting products against external factors,
such as humidity and contamination for extended periods of time.
Opaque blisters also protect light-sensitive products against UV
rays. In a further alternative of the present invention blister
packs can be produced with a shape arranged such that only a
percentage of cavities of a blister pack in a pattern being
employed, with apertures present where unfilled blisters are
present; by combining with another blister pack arrangement in
respect of a second phase change material, a two dimensional array
of two phase change materials could be prepared. Equally, not all
the "blister centres in a pattern need be occupied. A third or
further phase change material could be provided in the gaps that
have remained unfilled. Given that a range of phase change
materials exist, by the use of colour coding, visible, for example
through a small aperture in a cassette or wallet enclosure, a
make-up of a cassette can be determined and temperature conditioned
prior to use in a simple fashion.
[0054] It should also be noted that the presentation of phase
change material PCM materials is being continually developed. For
example, Microencapsulated phase change material sometimes referred
to as microPCM--products are now becoming commonplace.
Microencapsulated phase change material products comprise very
small dual-component entities consisting of a core material
comprised of a phase change material--and an outer shell or capsule
wall. The phase change material substance can conveniently be
provided as a wax--such as a paraffin-wax or a fatty acid ester
operable to absorb and release energy in the form of heat in order
to maintain a particular temperature. In use, in a warm environment
with an increasing temperature, the phase change material would
initially absorb the heat (the phase change material melts inside
the capsule wall) and store it until the temperature drops from the
outside environment; at which time, the heat is released (the phase
change material re-solidifying within the capsule wall) releasing
energy in the form of heat, which can assist in temperature
control. At all times, the capsule wall contains the phase change
material, so regardless of whether the actual phase change material
is in the liquid or solid state, the capsule itself remains as a
solid particle containing the phase change material. The capsule
wall can conveniently be provided as an inert, very stable polymer.
Such phase change materials can be provide in a manner of slurry,
where, for example a capsule size of 1-4 .mu.m is employed with
35-45% as solid in an aqueous slurry, a paste, where capsules of a
size between 10 and 30 .mu.m are present as 70% solids with water
or as a dry powder, the micro capsules of 10-30 .mu.m being
processed such that they can be provided with polyurethane foams
and the like. Larger beads or capsules, of the order of 2-5
mm--sometimes referred to as macroPCM capsules can also be
employed.
[0055] Thus, by the use of such micro/macroPCM particles, used with
PU foam, and other binders stable products of two or more phase
change materials can be reliably be produced. PU foam may be
considered as having too much insulator gas by volume; accordingly,
a binder may be employed such that the particles are compressed and
retained without too much dead space, which can also affect the
rate of change. By the use of organic-based phase change material,
the phase change properties are not been observed to lose their
efficacy over thousands of cycles.
[0056] With reference to FIGS. 8a-8c, an outline process shall now
be described: In FIG. 8a, a base multi-layer film is thermo-formed
into `trays`. Using foam technology, for example, a shape-stable
foam is placed into the tray cavities--per
[0057] FIG. 8b. Phase control materials are then introduced into
the stabilising foam, followed by sealing of the cavities by the
placement of a thermally conductive web used to seal the cavities
closed per FIG. 8c.
[0058] This method of manufacture can provide several benefits to
users, including the opportunity to Fine tune packaging performance
by adjusting a volume fill of each container unit of phase change
material. A specific panel could be provided for a particular
user/category of use. This benefit could be realised, for example
by having instantly available solutions for a particular user, who
may wish to have, for example winter and summer configurations,
selected on time of year/weather outlook. This would help ensure
`fit for purpose` package design and cost saving for the
customer.
[0059] If the packaging were to be only used in extremely cold
conditions, then the volume of PCM1 (+17.degree. C.) could be
increased, and the volume of PCM2 reduced. This could be achieved
by following methods:
1) Increase the Z dimension of the Shape Stable Foam. 2) Increase
either the X or Y dimension of the Shape Stable Foam. 3) Altering
the Volume of phase change material into each body, typical
percentage liquid saturation to shape stable foam volume are in the
order of 65% to 90%, therefore the foam volume could be dosed
according to the performance requirement without altering the
geometry.
[0060] This embodiment allows for simple, single temperature
preparation of the Dual phase change material panels at standard
Control Room Temperature (CRT) conditions. The design requires
little training to facilitate use which will safeguard quality of
shipment.
[0061] By changing the fill ratio between stabilising foam and
phase change materials, the thermal capabilities can be `tuned` to
cope with a specific transport/storage requirement. For example, a
customer with a travel requirement under very hot conditions could
opt to pack the shipper with more `Heat Protective` phase change
material than the `Cold Protective` phase change material for a
given number of phase change panels, thus enabling fine tuning of a
shipper's capabilities. This coupled with the use of thermal
simulation software could be a very useful and powerful combination
enabling the very best fit of a customer's needs to the
capabilities of the shipping system.
[0062] FIGS. 9a and 9b show an alternative form of the invention,
wherein there is provided four phase change coolant panels, in
alternate placement of first and second phase change material. The
separate phase change packages could be manufactured in a similar
fashion to those described with reference to the embodiments shown
in FIGS. 8a-8d, the difference residing in the fact that instead of
four--or another multiple--of phase change materials being present
there is only one phase change material per panel. The four phase
change packages, PCM1, PCM2 are enveloped by a plastics bag 91, the
bag is subsequently evacuated and heat treated such that the bag
adopts the outside shape of the four phase change packages and the
product of FIG. 9b is realised; the two edges of 93 & 93' then
being fused together to form a fold edge 94, which together with
fold edges 94', 94'' and 94''' provides a cylindrical arrangement
for the placement within a packing carton as shown in FIG. 9d, with
FIG. 9e showing the phase change package placed within a
temperature insulating material, such as, expanded polystyrene,
with the plastics material being moulded to fill the gaps between
the phase change elements, indicated generally by reference G. The
body of the shipper carton is designed to be a close fit with the
temperature insulating assembly. Equally, it will be appreciated,
that each PCM package contains first and second phase change
materials. FIG. 9f shows a six-sided linked PCM panel arrangement
95 prior to fastening into a cylindrical arrangement with base and
top covers.
[0063] Indeed, by the use of a configurable system as provided by
the present invention, a logistics company could fine tune the
exact performance level required for a logistics company to
overcome differing thermal challenges, coupled with the use of
thermal simulation software whereby to allow logistics companies to
make informed, safe and reliable decisions about how best to
configure their modular phase change material shippers. For
example, by the use of the micro/macro PCM particles, a `tuned`
performance of a particular package can be achieved by the simple
expedient of controlling the ratio of PCM1 to PCM2. In tests, it
has been found that this solution is appropriate for small express
parcel shippers (7- 60 litres in volume) used to distribute small
temperature sensitive products such as clinical trial supplies and
pharmaceuticals, or for small narrow body aircraft pallets employed
in cold chain shipping on regional (narrow body) aircraft. However,
the use of single PCM per face is more appropriate for the smaller
express parcel shippers (7-20 litres in volume). Given a payload
volume, then for an expected transport duration, it will be
appreciated that the appropriate PCM panels can be selected,
conditioned prior to use and positioned within a four or six
adjacent rectangular panel container. The benefits are reduced for
larger payloads, but then larger pallet shippers are typically
provided with distinct internal passive temperature control systems
and so this invention can be seen to provide a useful benefit to
the smaller parcel shippers.
[0064] Pharmaceuticals, proteins, biological samples and other
temperature sensitive products, including food items, are regularly
shipped in containers year round and are subjected to a wide range
of temperatures. Though they are shipped in insulated containers
and/or climate controlled environments, the temperature stability
of the shipping containers can be significantly improved by
applying the techniques of the present invention, whereby to
provide a simple solution to the maintenance of temperature
profiles for the transport and storage of temperature sensitive
products.
[0065] The advantages of using phase change materials for
temperature controlled packaging are numerous. Phase change
materials can easily replace dry ice or gel packs to reduce the
size of shipping containers; they can increase the duration of a
temperature control period during shipping. Phase change materials
are available to cover a wide range of temperatures. A reduction in
transportation costs can simply be realised since less space is
devoted to cooling systems, when phase change materials are
employed. Phase change materials are reusable. Phase change
materials assure predictable and stable temperature control and can
be effectively used in a passive temperature control system for
transport/storage containers.
* * * * *