SMART& BIGGAR

                            BARRISTERS & SOLICITORS
                            P.O. BOX 2999, STATION 0
                         55 METCALFE STREET, SUITE 900
                             OTTAWA, CANADA KIP 5Y6
                           TELEPHONE: (613) 232-2486
                                TELEX: 053-3731
                           FACSIMILE: (613) 232-8440

OUR FILE No. 74018-1                                            November13, 1991

                                 LETTERS PATENT
                                 --------------

                         COUNTRY:                 CANADA

                         NUMBER:                  1,291,073

                         DATE:                    OCTOBER 22, 1991

                         TERM:                    SEVENTEEN YEARS EXPIRES
                                                  OCTOBER 22, 2008

                         PATENTEE:                D. LINDLEY HENRY

                         INVENTION:               THERMAL PACKAGING ASSEMBLY

                         TAXES DUE:               OCTOBER 22, 1993 AND YEARLY
                                                  THEREAFTER

                         WORKING:                 NOT NECESSARY


<PAGE>

Consumer and
Corporate Affairs Canada

Patent Office
--------------------------------------------------------------------------------

Canadian Patent
N0.1291073

To all to whom these presents shall come:

Whereas a petition has been presented to the Commissioner of Patents praying for
the grant of a patent for a new and useful invention,  the title and description
of which are contained in the specification of which a copy is hereunto attached
and made an essential part hereof, and the requirements of the Patent Act having
been complied with.

Now therefore the present  patent grants to the  appli-cant  whose title thereto
appears from the records of the Patent  Office and as indicated in the said copy
of the specification  attached hereto, and to the legal  representatives of said
applicant  for a period of seventeen  years from the date of these  presents the
exclusive  right,  privilege  and  liberty  of making,  constructing,  using and
vending to the  others in Canada  the  invention,  subject  to  adjudication  in
respect thereof before any court of competent jurisdiction.

Provided  that the grant hereby made is subject to the  conditions  contained in
1he Act aforesaid.

All patents are subject to annual  maintenance  fees  subsequent to the modified
Patent Act.

In  testimony   whereof,   these  letters  patent  bear  the  signature  of  the
Commissioner and the seal of the Patent Office hereunto affixed at Hull, Canada.

This Patent was issued on:

[SEAL]

                                             Date OCT 22 1991
                                                  -----------

                                             /s/
                                             -----------------------------------
                                             Commissioner of Patents

                                             /s/ D. Headrick
                                             -----------------------------------
                                             Attesting Officer

<PAGE>


Consommation                                            Consumer and
et Corporations Canada                                  Corporate Affairs Canada

Bureau des brevets                                      Patent Office

Ottawa, Canada                               (11) (c)       1,291,073
K1A OC9
                                             (21)           544,403
                                             (22)           1987/08/13
                                             (45)           1991/10/22
                                             (52)           217-6

        5
(51) INTL.CL. B65D-81/18

(19) (CA) CANADIAN PATENT (12)

(54) Thermal Packaging Assembly

(72) Henry, D. Lindley U.S.A.

(73) Same as inventor

(57) 11 Claims

<PAGE>

                           THERMAL PACKAGING ASSEMBLY

BACKGROUND OF THE INVENTION

     The,  present  invention  relates to thermal  packaging  assemblies for any
items which are to be packed ina thermally  controlled  environment for extended
periods of time,  such. as  foodstuffs,  beverages,  plants,  other  biological.
materials,  medicines  or  other  chemicals,  temperature  sensitive  electronic
equipment, tissue specimens, and so on.

     The use of  refrigerants  to keep  items or  products  cool  over  extended
periods of time is widespread, both for transportation of heat sensitive or heat
damageable  products and for long term storage of such  products.  Refrigerators
and  refrigerated  transport  systems can be used on the large scale for storage
and transportation,  but less massive and expensive coolant systems are required
for smaller scale  purposes,  for example short haul delivery  systems,  airline
transportation,  and home and recreational  cooling of foods,  beverages and the
like.

     The  packing  of  temperature   sensitive   products  such  as  foodstuffs,
pharmaceuticals,  plants, biological materials and the like in ice or dry ice to
maintain their temperature over a prolonged period of time is well known and has
been used  extensively  for many years.  For example,  the general public widely
uses insulated  containers or cool boxes packed with ice to maintain  foodstuffs
and  beverages  cool  when  camping,  travelling  or on  picnics  and the  like.
Commercially,  ice is used in packing foodstuffs,  flowers,  plants and the like
for  transportation  and storage until sold or until placed in a  refrigerator
in, a store, for example.

<PAGE>

In the medical field,  ice is used to reduce  trauma,  swelling and pain from
injuries  of all kinds,  and is also used in  transportation  and storage of
blood,  tissue  organs,  pharmaceuticals and the like. Ice or dry ice is also
used in transport and use of heat  sensitive  equipment or instruments, and
ice  baths and  controlled  chemical  reactions.

     The use of ice or dry ice as a coolant  material  serves a preservative  in
many cases and  inhibits  the growth of many  harmful  micro-organisms.  Another
coolant  in  common  use,  particularly  in cool  boxes  used  for  recreational
purposes,  is the  so-called  "blue  ice",  which is a block  or bag of  coolant
material which is frozen solid before being placed in a container such as a cool
box to maintain  foodstuffs or drinks in the container cool for extended periods
of time.

The major drawback to the use of ice as a coolant material is that it melts. The
space taken up by the ice when  melted  will be less than when it is frozen,  so
that it will no longer be an  effective  packing  material.  The  melted  ice is
easily  contaminated by microorganisms and, since it will be in intimate contact
with  the  products  it  is   protecting,   these  are  also  liable  to  become
contaminated.  They may also be damaged by getting  wet.  If the  products to be
protected  cannot  tolerate  wetness,  they must be protected from melted ice in
some way,  for  example by the use of raised  shelves in cool boxes for  placing
foodstuffs  above the level of the ice or by some sort of  waterproof  packaging
before they are packed in the ice.

<PAGE>

The  melted  ice will also  allow the  products  to move or slosh  around in the
container,  risking  damage  by  impact  with the  walls of the  container.  The
container itself must also be waterproof.

     Dry ice has similar  problems,  in that it is converted into CO 2 with time
and thus the gas must be  dissipated  and the  product  will no longer be packed
against movement in its container. Both water and dry ice can be used only once,
adding to the expense of thermal storage.

     In contrast,  blue ice can be used repeatedly by refreezing the contents of
the bag or block, but is brick hard when frozen into a solid block and is unable
to conform to the shape of products to be kept cool in this state.  Thus it does
not maintain good contact with unevenly  shaped products over a large portion of
their surface area. It will become soft and pliable as the material melts within
the bag.

     Neither ice nor "blue ice" is shock  absorbent when activated or frozen and
they are therefore not ideal  packaging  materials,  particularly  of relatively
fragile items or articles of complex and non-uniform shapes.

SUMMARY OF THE INVENTION

     According to the present  invention  there is provided a thermal  packaging
assembly,  comprising

     an outer  container;

     a plurality  of separate  reusable  capsules  in said each  container  each
capsule  comprising a continuous outer skin of flexible  plastics material and a
thermal  controlling  agent  completely  filling the capsule,  the agent being a
liquid in a predetermined  temperature  range,  and freezable into a solid phase
prior  to use  in the  packaging  assembly;

<PAGE>

     said outer container  comprising  means for packing the capsules around one
or more items to be packed,  the  container  having an opening for receiving the
capsules and items to be packed;

     the capsules each being of identical  shape and  dimensions and each having
opposed  sloping,  curved outer  surfaces for resisting  close  packing  against
adjacent  capsules in the  packaging  assembly  and for forming air gaps between
each capsule and.the next adjacent capsules;

     the capsules  comprising means for cushioning an item or items around which
they are packed,  means for absorbing  shocks by moving  freely  relative to one
another  and means for  maintaining  a  predetermined  temperature  range for an
extended period of time.

     The invention  further provides a thermal  packaging  material for wrapping
around an item or items,  comprising:

     a continuous  sheet  containing  a plurality  of rows of adjacent  reusable
capsules, each containing a thermal controlling agent which completely fills the
capsules,  each row being  separate from the next adjacent row by a first set of
spaced seal lines and the capsules in each row being  separate  from one another
by a second  set of spaced  seal  lines  perpendicular  to the first  set;

     each capsule having a generally  rectangular  outer  periphery and opposing
curved  outer  surfaces  on the upper and lower face of the sheet;

     the thermal controlling agent being a liquid in a predetermined temperature
range and frozen into a solid phase having  malleable  characteristics  prior to
use in the packaging assembly; and

<PAGE>

     the sheet being  selectively  bendable when the agent is  solidified  along
both sets of  perpendicular  seal lines to completely  wrap around an item to be
packed and an outer  enclosure  releasably  enclosing said sheet.

     The  invention   additionally   provides  a  thermal  packaging   assembly,
comprising:

     a plurality of pillow-shaped  hollow capsules of flexible plastics material
each containing a reusable  thermal  controlling 10 agent elected from the group
consisting of an aqueous solution of 3% by weight  polyethylene  glycol having a
molecular  weight in the range from 7,000 to 9,000  which  completely  fills the
capsule  leaving no air gaps, and a eutectic  solution having a liquid phase and
at least  two solid  phases,  the agent  being a liquid  within a  predetermined
temperature range;

     enclosing  means for  packing the  capsules  around at least one item to be
packed so that the item is enclosed by and in direct  contact  with the capsules
the capsule  being within said  enclosing  means;

     the opposed  sloping outer  surfaces of the capsules  comprising  means for
resisting close packing and for leaving air gaps between  adjacent  capsules and
between the innermost  capsules and the item to be packed.

     According to another aspect of the invention  there is provided a method of
packing one or more items to maintain a predetermined  temperature  range for an
extended  period  of time  and to  cushion  the item or  items  against  shocks,
comprising  the steps of:

<PAGE>

     taking  a  plurality  of  reusable   capsules  each  containing  a  thermal
controlling  agent which  completely  fills the  capsules  and which is a liquid
within a predetermined  temperature range and has a solid phase and freezing the
capsules until the liquid in the capsules  solidifies;  and

     packing the  capsules in a container  around at least one item to be packed
so gaps between the opposed,  curved outer surfaces of each capsule and the next
adjacent  capsules and the capsules are free to move  relative to one another to
absorb shocks,  the capsules  maintaining  the packed item in a predetermined
temperature range for an extended period of time and cushioning the item against
shocks during and beyond the extended period of time; and

     subsequently  reusing the capsules by refreezing them prior to packing them
around other items to be packed.

     Useful thermal controlling agents include:

               (a) an  aqueous  solution  of 3% by weight of  polyethyleneglycol
          having a molecular weight in the range of 7,000 to 9,000; 20

               (b) 40%  propylene  glycol,  50%  isopropanol  and 10%  deionized
          water; and

               (c) an aqueous  solution of 30% by weight of polyethylene  glycol
          having a molecular weight in the range of 7,000 to 9,000.

     According to the present invention a thermal packaging assembly is provided
which comprises a plurality of capsules of non-rigid  material each containing a
thermal controlling agent for maintaining a predetermined  temperature range for
an extended  period of time,  and a means for containing or packing the capsules
around one or more items to be maintained in the predetermined temperature range
for a certain time period.  The  individual  capsules  are of  relatively  small
dimensions as compared to the item or total volume of items to be packaged,  and
since  they are  packed  relatively  loosely  around the item they will be shock
absorbing to a certain extent to cushion the packed item against  damage,  while
at the same time protecting  against change in temperature for extended  periods
of time.

<PAGE>

     The capsules may be packed in a suitable  insulating outer  container,  and
they may be  separate  or  connected  together in the form of a sheet of bubbles
with an  interconnecting  web.  They may be of any  suitable  shape,  the  shape
preferably being chosen so that the capsules resist  compaction and will be free
to move  relative to one another  when packed  around one or more items so as to
provide a relatively  good  cushioning  effect.  They may, for example,  be of a
shape similar to the known poly foam pellets use for  packaging,  or of arcuate,
ovoid,  tubular or other shapes which will resist close  packing,  i.e.  tend to
pack  together  loosely  with gaps  between  adjacent  capsules.  In a preferred
embodiment they are pillow shaped.

     The packaging  assembly of this invention is therefore an improvement  both
over known  coolants such as ice, dry ice or blue ice, and over known  packaging
materials which have no thermal controlling properties.

     The thermal  controlling  agent  contained in the capsules is  preferably a
refrigerant although it may be designed to hold items at any chosen temperature,
i.e. even at  temperatures  above the ambient or surrounding  temperature.  In a
preferred embodiment of the invention the agent is a eutectic solution which has
the capacity to absorb or release  heat with little or no change in  temperature
while in the process of changing from one physical state to another,  e.g. solid
to liquid or vice versa.

<PAGE>

The capsules must first be charged or frozen to the phase change  temperature or
lower.  They  will  then  maintain  items  around  which  they are  packed  in a
temperature  controlled  environment for a time interval dependent on the number
of capsules used,  the insulating  properties of any container in which they are
packed, and the surrounding ambient temperature.

     Water is one example of such an agent where it will phange  from,  a liquid
to a  solid  state  at  the  precise  temperature  of 320 F  (the  phase  change
temperature).  In the preferred embodiment of the invention the agent comprise a
mixture of two or more substances which are miscible as liquids but which have a
lower freezing point when combined than either of the two substances separately.
The point at 15 whicb both substances solidify is known as the eutectic point.

     In one example of the  invention  the eutectic  solution is a solution of a
eutectic salt or compound  which is  formulated  to provide good energy  storage
capability at a given  operating  temperature.  Such compounds may be formulated
for storage capabilities at a wide variety of different  temperature ranges, and
may be used for hotor cold storage according to the eutectic point of the chosen
eutectic compound or compounds in the capsules.

     The  individual  capsules  or sheet  of  capsules  may be used  alone or in
combination with dry ice, for example. This avoids the problems of using dry ice
alone while allowing its effective cooling period to be prolonged.  The capsules
may be designed for any specific  operating  temperatures  by suitable choice of
the eutectic compound or compounds.

<PAGE>

     In one particular embodiment the capsules.are designed to exhibit a similar
cooling  temperature range to ice. In this example the~ thermal storage material
in each capsule is a. solu.tion of ammonium sulfate,  calcium chloride, or other
inorganic salt, with the temperature at the eutectic point of the material, i.e.
the point at which the solution changes phase, being dependent on the particular
salt used in the  material.  The capsules may also be designed to hold  products
higher temperatures with suitable choice of the thermal storage material.

BRIEF DESCRIPTION OF THE DRAWINGS

     The  present  invention  will be  better  understood  from the taken in
conjunction with the accompanying  drawings in which, like reference numerals
refer to like  parts and in  which:

     Figure  1  shows  a side  elevation  view  of a  thermal  packing  assembly
according to a first  embodiment  of the present  invention,  partly cut away to
show a suitable  item to be packed and  thermally  protected  embedded in the
packing material.

     Figure 2 is a top plan  view of a  particular  configuration  of one of the
capsules of the packing  assembly;

     Figure 3 is a-side  elevation  view of the capsule of Figure 3.

     Figure 4 is an enlarged  sectional view taken on the lines 4-4 of Figure 3;

     Figures 5 to 9 are  perspective  views of various other 30 possible  shapes
for the capsules; and

<PAGE>

     Figure 10 shows -an alternative embodiment of the thermal.packing  assembly
according to the present invention.

DESCRIPTION OF THE PREFERRED  EMBODIMENTS

     Figure 1 shows a first embodiment of a thermal packing  assembly  according
to the present  invention,  in which a plurality  of  capsules 10  containing  a
thermal  controlling agent or refrigerant are packed in a container 14 around an
item 16 to be thermally protected.

     The item 16 may be  anything of a  perishable  or  temperatured  damageable
nature, for example, or anything which is to be kept at a controlled temperature
for any reason,  and more than one item may be packaged  in the  capsule's.  The
item or items 16 may, for example, be foodstuffs,  beverages, plants, biological
materials, tissue sampies, chemicals,  medicines, or live creatures sucb as bait
for fishing. The container may be of any suitable shape and dimensions according
to the item or items to be packed, and is preferably insulated.

     As shown, the individual  capsules are each of dimensions much smaller than
those of the item or total  volume of items to be packed,  so that the  capsules
packed  around the item will have some  cushioning  effect to  protect  the item
against  shocks and can also contact most of the outer  surface of the item even
if it is of a non-uniform or irregular  outer shape.  The capsules may be shaped
so that they resist compaction when packed, i.e. so that they will tend to leave
gaps 18 between adjacent capsules. This will enhance the cushioning effect since
capsules  will be able to move  relative  to one  another  to  resist  or absorb
shocks.

<PAGE>

     The capsule  dimensions  are  preferably of the order of one square inch or
less but may be larger  (e.g.  3 square  inches)  for larger  scale  packing and
further may have dimensions of up to 3"x3"x1/4",  for example. The smaller scale
capsules will be filled with 0.5 ml to 2 ml of refrigerant  liquid,  with larger
scale capsules containing up to 20 ml of refrigerant.

     Figures 2 to 9 show some of the many possible capsule shapes.  Figures 2 to
4 show a first possible  configuration  in which each capsule 20 is tubular with
its opposite  ends sealed.  Such  capsules may be  manufactured  from lengths of
tubing filled with a suitable refrigerant 12 (See Figure 4), which are sealed at
suitable  spaced  intervals,  and then cut to form individual  capsules.  In one
specific  example  of this  type of  capsule  the  capsules  were made of 1 inch
segments of  polyethylene  tubing having an outside  diameter of 1/4" and a wall
thickness of 1/16",  filled with  approximately 0.5 ml of refrigerant  solution.
However these  specific  dimensions  may be changed  according to the particular
applications for which the capsules are to be used,

     Figures 5 to 9 show some of the many  possible  alternative  configurations
for the  capsules.  In  Figure  5, the  capsule  30 is of  generally  square  or
rectangular outline and of pillow-like form.

     In Figure 6 the  capsule  40 is of curved of S-like  shape,  similar to the
shape of foam  pellets  commonly  used  for  packaging.  Figure 7 shows  another
alternative  capsule  shape 50 which is of a  tubular  form  with  enlarged  end
portions.  Figure 8 shows a capsule shape 60 of curved,  C-shaped  form,  and in
Figure 9 the  capsule  70 is of a star or  flower-like  form.  In each  case the
capsules may be formed, for example,  by moulding the individual capsules from a
suitable material and then filling with the refrigerant 12.

<PAGE>

     The capsules may be  manufactured  in any suitable  manner,  including blow
mouldingo,  vacuum  moulding,  machine 5 forming or  extruding  tubing  which is
suitably  sealed and cut,  forming  tubing from a  continuous  film and suitably
sealing, filling with refrigerant, and cutting into individual capsules, and die
moulding of individual capsulesand filling with refrigerant.

     The  individual  capsules  are  formed  with an  outer  skin of a  suitable
non-rigid  or  flexible  material  which is chosen  according  to the  operating
temperature  of the  assembly  in  which  the  capsules  are to be used  and the
refrigerant which the capsules are to contain. The capsules are preferably of 15
a suitable plastics material such as low temperature melting polyethylene,  PVC,
Teflon  (Registered  Trademark),  polypropylene,  polycarbonates,  nylon and the
like.

     Each capsule is filled with a refrigerant  12 which is chosen  according to
the desired operating  temperature.  Although the assembly will normally be used
to maintain a temperature  controlled  environment  below ambient  temperatures,
i.e.  as a cooling  assembly,  it may also be designed  for use at  temperatures
higher  than  ambient,  i.e.  for  heating  or  maintaining  items  at a  raised
temperature,  with  suitable  use of the  agent  12  within  the  capsules.  The
refrigerant  12 is  preferably  a material  which will change from one  physical
state  to  another,  i.e.  liquid  to solid or vice  versa,  at a  predetermined
temperature,  called the phase-change temperature. The capsules must first be 30
charged,  or cooled to a temperature at or below the predetermined  temperature.
They  must  normally  be  charged  at a  temp~qrature  20 C  below  the  holding
temperature for periods of between 16 and 20 hours depending on the total volume
of capsules to be charged and their phase change temperature.  The capsules will
then stay in a certain  temperature range for an extended period.of time to hold
the  temperature  of an item or items  around  which  they are  packed f or time
dependent on the insulating  properties of any outer  container,  the number and
weight of the capsules used, and the surrounding ambient temperature.

<PAGE>

     According to the choice of  refrigerant  material the  thermal  packing
assembly can hold products at various preselected  temperatures from -13 C (9 F)
to 25 C (77 F) for periods ranging from a few hours up to nearly 500 hours,
according  to  the  number  of  capsules  used  and  the  properties  of the
surrounding  insulated container.  With suitable choice of the controlling agent
it  may  even  be  possible  to  provide  temperature  control  at  any  desired
temperature in a range from -60 C to 66C. The capsules are most efficient when
used  with a well  insulated  container.  The  thermal  controlling  agent or
refrigerant  has the capacity to absorb or release heat with little or no change
in  temperature  while in the process of  changing  from one  physical  state to
another,  i.e. liquid to solid or solid to liquid.  it is this property which
makes ice such a good  refrigerant.  Where  the  refrigerant  12 is  water,  the
capsules  will first be frozen at 32 F. The ice must then  absorb 144 BTU's of
heat  energy  before it  becomes  liquid  again.

     Although water is a possible refrigerant for the capsules, in one preferred
embodiment the refrigerant is a eutectic  solution,  or a mixture of two or more
substances  which has a lower freezing  point,  known as the eutectic point than
either of the two substances  taken  individually.  The solution on cooling will
transform from a single liquid phase to two or more solid phases at the eutectic
point. This is known as a eutectic reaction and may be used to maintain a chosen
temperature  range in a manner  similar to, or even more efficient than ice. The
solution may, for example,  comprise a mixture or solution of an inorganic  salt
in water.  The salt  may,  for  example,  be chosen  from the  fol1owing  class:
Sodium,calcium,ammonium,or  potasslum  chloride;  ammonium,magnesium,  or sodium
sulfate; potassium or sodium nitrate, among others.

     The  refrigerant  or  cooling  agent is  formulated  to  maintain  specific
temperature  ranges  under  controlled  conditions,  and a  range  of  different
capsules  containing  different  agents may be provided  for  various  different
applications.

     Some specific examples of eutectic and other  refrigerants are given below,
although other  refrigerants  or temperature  controlling  agents can clearly be
designed  for  operation  at various  temperatures.  The  refrigerants  used are
non-toxic and non-corrosive  materials,  and preferably have high boiling points
and  low  expansion  coefficients  in both  the  solid  and  liquid  phase.  The
refrige.rants  are  preferably  of  high  density  with a heat of  fusion  (heat
required for change of state at phase change  temperature) of over 100 BTU's per
pound.


<PAGE>

Example 1
---------

     The capsules are filled with an 11% by weight aqueous  solution of ammonium
sulfate.  The capsules are charged by storing for 10 to 16 hours  (depending  on
their  total  mass)  at a  temperature  of -4 F for  example,  in  any  suitable
refrigerator or cooling assembly. The eutectic or freezing point of the solution
is -3.18 C. The  ammonium  sulfate may be replaced  with calcium  chloride,  for
example,  or other  suitable  inorganic  salts.  The  capsules  will  maintain a
constant  temperature over a similar period to an equivalent volume of ice. With
a  surrounding  ambient  temperature  of 21 C a weigbt of 5 lbs of the  capsules
contained in a volume of 432 cu. inches  within a container  having 3 inch thick
urethane walls can hold or maintain refrigerator  temperatures in the range from
2 to 8 C for up to 103 hours,  which is equivalent to a similar volume of ice or
blue ice while  not  having  the  disadvantages  of such  cooling  agents,  i.e.
melting, non-cushioning, and so on.

Example 2
---------

     In  this  example  the  refrigerant  is  the  following  mixture:

          200 gm polyethylene  glycol (PEG) 20% wt. over volume 28.392 gm sodium
          phosphate diabasic 0.15 molar with pH adjusted to 7.2(Na2HP04.7H2O)

          19.8 gm ammonium  sulfate 0.15 molar in distilled  water.

The  eutectic  point of this mixture is -2 0 C. The holding  temperature  may be
increased or decreased by decreasing or increasing,  respectively, the amount of
ammonium sulfate or PEG.

<PAGE>

     Capsules containing this refrigerant contained under the same conditions as
the  capsules  in Example 1 can  maintain  refrigerator  like  temperatures  for
equivalent periods of time and have the additional  advantage that the added PEG
will prevent the mixture from completely  solidyfying even when frozen. Thus the
capsules will still be malleable, or semi-hard,  when charged and will therefore
have improved cushioning characteristics.

Example 3
---------

     The frigerant in this example comprises N-Tetradecane (CH3(CH2)12CH3). This
has a phase change  temperature  of 4.4 C and under  similar  conditions  to the
capsules  in  example 1  capsules  containing  this  refrigerant  can hold their
temperature for about 76 hours and thus have thermal  insulating  properties for
equivalent periods of time.

Example 4
---------

     In this example the capsules contain ethylene glycol 400, which has a phase
change temperature of -12.7 C. This material will still be malleable when frozen
and thus  the  capsules  will  have  improved  cushioning  characteristics.  The
capsules must be charged at lower temperatures than the previous  examples,  for
example at -20 C for up to 16 hours  depending  on the total mass to be charged.
Under equivalent  conditions to the previous examples  capsules  containing this
refrigerant  will stay  frozen  for up to 49  hours,  and can  maintain  a lower
temperature  environment than the previous examples which maintain  refrigerator
like temperatures.

<PAGE>

Example 5
---------

     In this example the capsules contain N-Hexadecane, which has a phase change
temperature  of 25 C. This may be used,  for example,  to maintain  temperatures
higher than the surrounding ambient temperature over extended periods of time.

     The above five examples are compared in the following  table over different
ambient temperatures,  with the capsules in each case being pre-charged to at or
below the phase change temperature for a predetermined  period of time and being
contained as described  above in connection  with Example 1. The table shows the
theoretical  holding  time in  hours  which  may be  achieved  by the  different
controlling agents in each example.

<TABLE>

 TABLE  Average  Ambient
Temperature*(O q
<CAPTION>

CAPSULE                  -18    -6      4      21    32     38      43
OPERATING
TEMP (0 C)                HOLDING TIME IN  HOURS
<S>                      <C>    <C>    <C>    <C>    <C>    <C>     <C>
-13 (Ex.4)               393    311    125    62     46     41      37
-3  (Ex.1)               165    621    340    103    70     61      53
0   (Ex.2)               120    319    478    101    66     56      49
4   (Ex.3)               64     129     -     86     51     43      37
25  (Ex.5)               38     53     78     412     -      -       -

</TABLE>

     The average holding time for any thermal packing  assembly can be estimated
in advance given the surrounding ambient temperature and the mass of capsules to
be used,  together with the thermal  conductivity of any surrounding  insulating
container.  The holding time will be equal to the beat available  divided by the
beat  loss,  which  will be  dependent  on the  total  volume  and  the  thermal
conductivity properties of the container.  Thus anyone with a specific packaging
and thermal  control  problem will be able to estimate in.  advance the probable
amount  of  capsules  needed  for a  pariticular  length  of time,  and the most
desirable thermal cohtrolling agent to use in the capsules.  Capsules containing
different thermal  controlling  agents may be mixed together in certain cases to
prolong the cooling periods, for example.

<PAGE>

     Thus  the  packing  assembly  described  above  has the  advantage  of both
cushioning iiems packed against shocks or 15 damage while  maintaining them in a
predetermined  temperature  range over extended  periods of time.  The amount of
capsules  needed and the type of  refrigerant  to be used can be  calculated  in
advance according to the items to be packaged, the expected ambient temperature,
and  the  length  of  time  they  are  to be  maintained  in  the  predetermined
temperature  range,  which will typically be refrigerator  temperature or lower.
Even when the capsules  reach  ambient  temperatures,  they will still have some
insulating  properties  to continue to  insulate  the packed  items to a certain
extent,  and will still be a good packaging  material since there will be little
or no change in the volume  they  displace  when the  material  in the  capsules
changes phase.

     The  capsules  may be used  alone or mixed  with  anothr  refrigerant.  For
example,  in cases  where dry ice (C02) would 30  otherwise  be  specified  as a
coolant, a mixture of dry ice with the capsules may be packed around the item or
items to be refrigerated. This would act both to prolong the cold generated' by'
the dry ice and keep it away from direct contact with the item or items. Some of
the  capsules  themselves  may  also  be  filled  with  dry  ice as the  thermal
controlling agent.

<PAGE>

     The  material of the  capsules is chosen  such that the  capsules  will not
stick or adhere to each other or adjacent  surfaces  which is a problem with ice
and similar coolant materials.  The capsules have a non-wetting and non-wettable
surface so that  condensation will be minimal and growth of  micro-organisms  on
the surface will normally not be supported.

     As  described  above the shape of the  capsules  can be chosen so that they
resist  compaction.  Typically the percentage of compaction  should be less than
one fifth of the total volume in which the capsules are contained.  The capsules
can be re-used  any number of times  simply by  re-charging  them once they have
reached ambient temperature.  The outer skin is flexible but fairly resistant to
tearing.  The capsules will  therefore be relatively  inexpensive,  particularly
when  compared  to ice and  other  single  use  coolant  materials,  and  have a
relatively long life.

     If the  capsules  should by some chance be  ruptured,  the agent  inside is
chosen to be non-toxic,  non-corrosive, and washable with water. The material of
the capsules themselves is also non-reactive,  non-toxic, non-corrosive, and non
digestible.

<PAGE>

     The capsules may be used as described above in a thermal  packing  assembly
to transport or store any delicate and/or  temperature  sensitive items, such as
perishable  foodstuffs,  plants,  pharmaceuticals and so on. They may be used to
store and/or transport frozen foods,  biologicals and other frozen materials for
20 to 60  hours  at  temperatures  of  -20 C to -4 C  with  suitable  choice  of
refrigerant  in the  capsules.  They may be used in place of ice or blue ice for
recreational  purposes to keep foods and drinks cool on picnics while camping or
on other outings,  for example.  Another  possible use is to keep bait cool when
fishing.

     The capsules of this invention may also be used, for example,  in ice baths
for  temperature  control  of  laboratory  chemical  reactions,  for  protecting
temperature  sensitive  film, or for treating  swelling or other injuries in the
form of ice packs.  Another  possible use is in ice dispenser or storage systems
where  packs of ice for use in drinks and the like are  stored  prior to sale or
use.  it can  therefore  be seen  that the  capsules  of this  invention  are an
extremely  versatile,  economical and efficient thermal  controlling and packing
material,  which can be designed  for packing any number of  different  types of
items and for  operating  temperatures  over a wide range,  both below and above
ambient.

     The capsules need not be contained in a rigid outer  container,  but may be
enclosed around an item or items to be packed by any suitable means, for example
as a flexible wrapping.


<PAGE>

     Figure  8 shows  an  alternative  example  of a  thermal  packing  assembly
according  to the  invention.  In  this  example  a  plurality  of  capsules  80
containing  a suitable  refrigerant  82,whicb  may be any  suitable  material as
described above in connection with the previous embodiments,  are interconnected
in the form of a sheet 84 of bubble  pack,  type  material.  The sheet 84 may be
manufactured  in a similar manner to standard  bubble pack  material,  with each
bubble or capsule 80 being filled with the  refrigerant  82 in its liquid state.
The  capsules  in the  sheet may be of any  suitable  shape.  The sheet  will be
pre-charged in the same manner as the individual.  capsules as described  above,
and then wrapped around an item or items to be packed.  The wrapped sheet may be
6nclosed in an outer container if 'desired,  for added insulation,  or it may be
secured around the item to comprise the bntire packing assembly.

     Although some  preferred  embod iments of the present  invention  have been
described above by way of example, it will be understood by those skilled in the
field that  modifications  may be made which are within the scope of the present
invention, which is defined by the appended claims.

<PAGE>

                  THE EMBODIMENTS OF THE INVENTION IN WHICH AN
                       EXCLUSIVE PROPERTY OR PRIVILEGE IS
                         CLAIMED ARE DEFINED AS FOLLOWS:

1. A thermal packaging assembly,  comprising an outer container;

     a plurality  of separate  reusable  capsules  in said each  container  each
capsule  comprising a continuous outer skin of flexible  plastics material and a
thermal  controlling  agent  completely  filling the capsule,  the agent being a
liquid in a predetermined  temperature  range,  and freezable into a solid phase
prior to use in the packaging assembly;

     said outer container  comprising  means for packing the capsules around one
or more items to be packed,  the  container  having an opening for receiving the
capsules and items to be packed;

     the capsules each being of identical  shape and  dimensions and each having
opposed  sloping,  curved outer  surfaces for resisting  close  packing  against
adjacent  capsules in the  packaging  assembly  and for forming air gaps between
each capsule and the next adjacent capsules;

     the capsules  comprising means for cushioning an item or items around which
they are packed,  means for absorbing  shocks by moving  freely  relative to one
another  and means for  maintaining  a  predetermined  temperature  range for an
extended period of time.

2. The assembly as claimed in claim 1, in which the capsules are  pillow-shaped.

3. The  assembly as claimed in claim 1,  wherein the agent  comprises an aqueous
solution of 3% by weight  polyethylene  glycol having a molecular  weight in the
range from 7,000 to 9,000.

<PAGE>

4. The  assembly as claimed in claim 1, in which the agent  comprises a solution
of 40% propylene glycol, 50% isopropanol, and 10% deionized water.

5. A method of packing one or more items to maintain a predetermined temperature
range for an extended  period of time and to cushion  the item or items  against
shocks,  comprising  the steps of:

     taking  a  plurality  of  reusable   capsules  each  containing  a  thermal
controlling  agent which  completely  fills the  capsules  and which is a liquid
within a predetermined  temperature range and has a solid phase and freezing the
capsules until the liquid in the capsules  solidifies;  and

     packing the  capsules in a container  around at least one item to be packed
so gaps between the opposed,  curved outer surfaces of each capsule and the next
adjacent  capsules and the capsules are free to move  relative to one another to
absorb  shocks,  the  capsules  maintaining  the packed item in a  predetermined
temperature range for an extended period of time and cushioning the item against
shocks during and beyond the extended period of time; and

     subsequently  reusing the capsules by refreezing them prior to packing them
around other items to be packed.

<PAGE>

6.  A  thermal  packaging  material  for  wrapping  around  an  item  or  items,
comprising:

     a continuous  sheet  containing  a plurality  of rows of adjacent  reusable
capsules, each containing a thermal controlling agent which completely fills the
capsules,  each row being  separate from the next adjacent row by a first set of
spaced seal lines and the capsules in each row being  separate from  one'another
by a second  set of spaced  seal  lines  perpendicular  to the first  set;

     each capsule having a generally  rectangular  outer  periphery and opposing
curved  outer  surfaces  on the upper and lower face of the sheet;

     the thermal controlling agent being a liquid in a predetermined temperature
range and frozen into a solid phase having  malleable  characteristics  prior to
use in the packaging assembly; and

     the sheet being  selectively  bendable when the agent is  solidified  along
both sets of  perpendicular  seal lines to completely  wrap around an item to be
packed and an outer enclosure releasably enclosing said sheet.

7. The  packaging  material as claimed in claim 6, wherein the sheet of capsules
is formed from two opposed films sealed  together along spaced parallel lines in
two perpendicular directions to form separate capsules each having a rectangular
outer  periphery,  each  capsule  being  filled with a liquid  forcing the outer
opposed  surfaces of that capsule  outwardly  to form a generally  pillow-shaped
capsule.

<PAGE>

8. A packaging  material as claimed in claim 6, wherein the thermal  controlling
agent is a  eutectic  solution  having a liquid  phase  and at least  two  solid
phases.

9.  The  packaging  material  as  claimed  in  claim  6,  wherein,  the  thermal
controlling  agent is an aqueous solution of 30% by weight  polyethylene  glycol
having a molecular weight in the ranges from 7,000 to 9000.

10. A thermal  packaging  assembly,  comprising:

     a plurality of pillow-shaped  hollow capsules of flexible plastics material
each  containing a reusable  thermal  controlling  agent  elected from the group
consisting of an aqueous solution of 3% by weight  polyethylene  glycol having a
molecular  weight in the range from 7,000 to 9,000  which  completely  fills the
capsule  leaving no air gaps, and a eutectic  solution having a liquid phase and
at least  two solid  phases,  the agent  being a liquid  within a  predetermined
temperature range;

     enclosing  means for  packing the  capsules  around at least one item to be
packed so that the item is enclosed by and in direct  contact  with the capsules
the capsule  being  within said  enclosing  means;

     the opposed  sloping outer  surfaces of the capsules  comprising  means for
resisting close packing and for leaving air gaps between  adjacent  capsules and
between the innermost capsules and the item to be packed.

11. The assembly as claimed  in claim 10, wherein the capsule  dimensions are in
the range one square inch to three square inches,  and the capsule  thickness is
of the order of 1/4 inch.

                                                                  SMART & BIGGAR
                                                                  OTTAWA, CANADA
                                                                   PATENT AGENTS