[0001] This invention relates to the transport of temperature-sensitive products, such as
vaccines where it is desirable or even essential for the product to arrive at its
destination without having experienced extremes of temperature.
[0002] It is well known that sheep's wool is a useful hygroscopic material that can be used
within packaging such as corrugated cardboard boxes to provide a local temperature
climate within the box by which products being transported, such as heat sensitive
vaccines, can be kept within a required temperature range, such as between 2°c and
8°c, without any artificial means for controlling temperature within the box. This
is particularly useful in circumstances whereby power is unavailable for artificially
controlling the temperature of the box and it is now even possible to transport fragile
items such as vaccines and donor organs to remote places over a period of at least
72 hours without any substantial degradation in the required temperature range. This
concept can be assisted by the use of phase change materials (PCMs) such as ice, which
gradually melt or otherwise change phase during transport, thereby absorbing heat
without unduly increasing the temperature of the immediately surrounding environment.
However, it is also known that live vaccines and living organs can be killed or irreparably
damaged by the presence of PCMs in such containers and the present invention is derived
from the realisation that there is a need to resolve this problem in a user-friendly
manner without resorting to powered refrigeration techniques.
[0003] According to a first aspect of the invention there is provided a thermally insulated
product delivery container (PDC), including therewithin a rigid shell defining a hollow
tube containing wool, first and second tube-end closure boxes containing wool to thereby
collectively define an inner void for receiving at least one phase change material
container for providing a temperature controlled condition within the void in the
presence of a phase change material (PCM), and at least one thermal baffle positionable
between the or each phase change material container and a product to be carried within
the compartment.
[0004] With this arrangement, the PDC may take the form of a corrugated cardboard container
within which may be inserted a foldable corrugated tubular cardboard shell containing
wool between its inner and outer walls, and a pair of tube closure boxes, one for
each end of the tube, each also containing wool to therefore collectively define a
product receiving void which acts to hygroscopically control the temperature gradient
between the outside of the container and the inside of the container. One or more
PCM containers may therefore be introduced into the interior of the container as a
means of establishing a desired temperature range for the atmosphere within the container
and, in order to ensure that a product to be transported within the container does
not become too cold or too hot during transport a thermal baffle is provided between
the product and the or each PCM container.
[0005] Conveniently, the thermal baffle comprises one or more layers of corrugated cardboard
serving to control the flow of heat to or from the product, thereby to prevent or
inhibit thermal shock to the product.
[0006] Preferably, the PDC is modular, being cuboid or cylindrical, in which the hollow
wool-containing shell is a sliding fit within the container, the or each PCM container
is a sliding fit within the wool-containing shell, a thermal baffle is a sliding fit
over the or each PCM container e.g. a medical product in its original primary packaging
fitted over or between the or each thermal baffle so that when the container is closed
it assumes a generally rigid structure whereby to minimise mechanical damage to the
contents during transport. Conveniently, the or each PCM container includes apertures
with which to exchange temperature differences within the PDC.
[0007] Conveniently, the first and second tube closure boxes are each separated into two
compartments one for receiving wool and the other for receiving a PCM for controlling
the temperature within the interior of the PCD.
[0008] The invention in a second aspect also provides a method of transporting temperature-sensitive
products by the use of a container in accordance with the first aspect of the invention,
the method including the steps of identifying for the product to be delivered a required
minimum and maximum temperature range for the duration of transport, identifying a
suitable PCM and identifying a suitable thickness or composition of thermal baffle
acting between the PCM and the product being transported so as to prevent or inhibit
thermal damage thereto.
[0009] The invention will now be described, by way of example only, with reference to the
accompanying drawing which shows an exploded view of a product delivery container
(PDC) 1 according to the first aspect of the invention. The PDC 1 comprises a cuboid
corrugated cardboard box 2 insertable within which is a correspondingly shaped and
sized hollow tubular shell 3 having therewithin a continuous batt of wool to, in use,
act as a hygroscopic thermal insulant. The inner wall 4 of the hollow shell 3 is of
shape and size corresponding to the external dimensions of, respectively, a first
tube closure box 5 having a lower chamber 5a containing wool (not shown) and an upper
chamber 5b into which may be placed a PCM such as plastics-covered ice cubes which
may thermally interact with the area of the interior of the PCD via a series of ventilation
apertures 6. Above the apertures are a pair of thermal baffles 7, 8 between which
may be placed a product to be transported (not shown) such as a pre-packaged temperature
sensitive vaccine. Above the thermal baffle 8 is a dedicated PCM container 9 having
various apertures (not shown) for permitting thermal interaction with a PCM and the
inside of the container 1, above which is a second tube closure box 10 which, as with
the first tube closure box 5 includes an outer compartment 10a containing wool and
an inner compartment 10b for containing further PCM.
[0010] In use, the hollow wool-insulated tube 3 is placed within the cardboard box 2 and
the first tube closure box 5 is pushed down to the lower end of tube 3 after a PCM
has been inserted within the upper compartment 5b. The thermal baffle 7 is then placed
on top immediately below a product to be carried (not shown) whereafter the second
baffle 8 is placed thereover followed by PCM container 9 and finally the second tube
closure box 10 after the PCM container 10b has been filled with a PCM.
[0011] As will be apparent, the size and shape of the PDC may vary to suit the type of product
being transported but in each case the general principle in accordance with the invention
is that the product is surrounded by an outer layer of hygroscopic thermal insulation
in the form of wool and the product itself is protected from any adverse thermal shock
from the PCM by the presence of thermal baffles 7, 8, the thickness of which may be
adjusted to suit the requirements of the product being transported. Thus, it has been
found through trial and error that a thermal barrier containing folded layers of corrugated
cardboard is sufficient to protect live and other vaccines from cold damage by the
PCM.
[0012] A further feature of the invention is that all of the components (other than the
thermal insulation and PCM) can be made from sheet material such as corrugated cardboard,
which lends itself to recycling along with the wool or even re-use of the product
delivery container in the event that there has been little or no damage to it during
transport. This has the added benefit in permitting PDC to be flat-packed for storage
and transport to end-users for subsequent self-assembly.
1. A thermally insulated product delivery container (PDC), including therewithin a rigid
shell defining a hollow tube containing wool, first and second tube-end closure boxes
containing wool to thereby collectively define an inner void for receiving at least
one phase change material container for providing a temperature controlled condition
within the void in the presence of a phase change material (PCM), and at least one
thermal baffle positionable between the or each phase change material container and
a product to be carried within the compartment.
2. The PDC of Claim 1 further including a corrugated cardboard container within which
may be inserted a foldable corrugated tubular cardboard shell containing wool between
its inner and outer walls, and a pair of tube closure boxes, one for each end of the
tube, each also containing wool to therefore collectively define a product receiving
void which acts to hygroscopically control the temperature gradient between the outside
of the container and the inside of the container.
3. The PDC of Claim 1 or Claim 2 in which one or more PCM containers may therefore be
introduced into the interior of the container as a means of establishing a desired
temperature range for the atmosphere within the container
4. A PDC according to any preceding Claim further including a thermal baffle between
the product and the or each PCM container in order to ensure that a product to be
transported within the container does not become too cold or too hot during transport.
5. The PDC of Claim 4 in which the thermal baffle comprises one or more layers of corrugated
cardboard serving to control the flow of heat to or from the product, thereby to prevent
or inhibit thermal shock to the product.
6. A PDC according to any preceding Claim of modular form, being cuboid or cylindrical,
in which the hollow wool-containing shell is a sliding fit within the container, the
or each PCM container is a sliding fit within the wool-containing shell, a thermal
baffle is a sliding fit over the or each PCM container e.g. a medical product in its
original primary packaging fitted over or between the or each thermal baffle so that
when the container is closed it assumes a generally rigid structure whereby to minimise
mechanical damage to the contents during transport.
7. A PDC according to any preceding Claim in which the or each PCM container includes
apertures with which to exchange temperature differences within the PDC.
8. A PDC according to any preceding Claim in which the first and second tube closure
boxes are each separated into two compartments one for receiving wool and the other
for receiving a PCM for controlling the temperature within the interior of the PCD.
9. A method of transporting temperature-sensitive products by the use of a container
in accordance with the first aspect of the invention, the method including the steps
of identifying for the product to be delivered a required minimum and maximum temperature
range for the duration of transport, identifying a suitable PCM and identifying a
suitable thickness or composition of thermal baffle acting between the PCM and the
product being transported so as to prevent or inhibit thermal damage thereto.