U.S. patent application number 11/942940 was filed with the patent office on 2008-12-18 for grooved lid for packaging of fresh fruits, vegetables and flowers in corresponding modified atmosphere trays.
This patent application is currently assigned to FRESHXTEND TECHNOLOGIES CORP.. Invention is credited to Juan Eduardo Cacace, William A. Gough, Cheong Kit Leung, Perry D. Lidster.
Application Number | 20080308439 11/942940 |
Document ID | / |
Family ID | 40129159 |
Filed Date | 2008-12-18 |
United States Patent
Application |
20080308439 |
Kind Code |
A1 |
Lidster; Perry D. ; et
al. |
December 18, 2008 |
Grooved Lid for Packaging of Fresh Fruits, Vegetables and Flowers
in Corresponding Modified Atmosphere Trays
Abstract
This invention relates to novel designs of tray lids and tray
bases for modified atmosphere packaging of fresh fruit, vegetables
and cut flowers. More particularly, this invention relates to novel
designs of landscaped lids and corresponding tray bases which
enable cooling air to be circulated in single or multiple
directions through stacked lid and tray combinations that contain
fresh fruits, vegetables and cut flowers in a modified atmosphere
environment. The gas-permeable modified atmosphere package
comprises a lid constructed of a polymer, the lid having on the top
surface thereof at the mid-regions of each side a plurality of
raised load supports and in between grooves; and a base with a
hollow interior constructed of corrugated kraft paper polymer and
having a configuration at the top edges which conforms with the
interior profile of the lid; the grooves enabling air to be
circulated over the lid when one package combination is stacked on
another.
Inventors: |
Lidster; Perry D.; (Yarrow,
CA) ; Gough; William A.; (Surrey, CA) ; Leung;
Cheong Kit; (Vancouver, CA) ; Cacace; Juan
Eduardo; (Penticton, CA) |
Correspondence
Address: |
OYEN, WIGGS, GREEN & MUTALA LLP;480 - THE STATION
601 WEST CORDOVA STREET
VANCOUVER
BC
V6B 1G1
CA
|
Assignee: |
FRESHXTEND TECHNOLOGIES
CORP.
Vancouver
CA
|
Family ID: |
40129159 |
Appl. No.: |
11/942940 |
Filed: |
November 20, 2007 |
Current U.S.
Class: |
206/423 |
Current CPC
Class: |
B65D 5/68 20130101; B65D
21/0217 20130101; B65D 2565/388 20130101; B65D 81/2076 20130101;
B65D 85/505 20130101; B32B 27/10 20130101; B65D 85/34 20130101;
B32B 27/32 20130101 |
Class at
Publication: |
206/423 |
International
Class: |
B65D 85/50 20060101
B65D085/50; B65D 85/52 20060101 B65D085/52 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 13, 2007 |
CA |
PCT/CA2007/001056 |
Claims
1. A gas-permeable modified atmosphere package combination
comprising: (a) a lid constructed of a polymer, the lid having on
the top surface thereof at the mid-regions of each side a plurality
of raised load supports and in between grooves; and (b) a base with
a hollow interior constructed of corrugated kraft paper polymer and
having a configuration at the top edges which conforms with the
interior profile of the lid; the grooves enabling air to be
circulated over the lid when one package combination is stacked on
another
2. A combination as claimed in claim 1 wherein the top surface of
the lid has around its periphery at least one raised load support
in the mid-region of each end and at least one raised load support
in the mid-region of each side, and a depressed area between the
raised end and side load supports.
3. A combination as claimed in claim 1 wherein the top surface of
the lid has around its periphery at least two raised load supports
in the mid-region of each end and at least three raised side
supports in the mid-region of each of the two sides of the lid, and
a depressed area between the raised end and side load supports.
4. A combination as claimed in claim 1 wherein the top surface of
the lid has around its periphery at least two raised load supports
in the mid-region of each end and at least four raised side
supports in the mid-region of each of the two sides of the lid, and
a depressed area between the raised end and side load supports.
5. A combination as claimed in claim 1 wherein the corners of the
top surface of the lid have diagonal grooves therein.
6. A combination as claimed in claim 1 wherein the grooves at the
sides of the lid are disposed laterally while the grooves at the
ends of the lid are disposed longitudinally.
7. A combination as claimed in claim 1 wherein the grooves of the
surface of the lid have an "X" type pattern.
8. A combination as claimed in claim 1 wherein the lid and the base
are 60 cm in length and 40 cm in width.
9. A combination as claimed in claim 1 wherein the base comprises a
first outer layer of kraft paper, a first intermediate layer of
corrugated kraft paper, a second intermediate layer of polymer and
a second outer layer of kraft paper.
10. A combination as claimed in claim 1 wherein the polymer in the
base is selected from the group consisting of ethylene vinylacetate
(EVA), ethylbutyl acetate (EBA), a crosslinked ionomer resin, cast
polyester (PET), a polyamide and polycarbonate (PC).
11. A combination as claimed in claim 1 wherein the polymer is low
density polyethylene.
12. A combination as claimed in claim 1 wherein the polymer is high
density polyethylene.
13. A combination as claimed in claim 1 wherein the polymer is a
copolymer of low density polyethylene and ethylenebutylacetate.
14. A combination as claimed in claim 1 wherein the gas
permeability of the polymer of the base is between about 50 and
100,000 cc.sup.3/m.sup.2 24 hr. 1 atm.
15. A lid for a gas-permeable modified atmosphere package
comprising a top surface which includes a plurality of raised load
supports and in between grooves arranged around its periphery, the
grooves enabling air to be circulated over the lid when one package
is stacked on another.
16. A lid as claimed in claim 15 wherein each end of the lid has in
the mid-region thereof at least one raised load support and each
side of the lid has in the mid-region thereof at least one raised
load support and a depressed area exists between the raised end and
side load supports.
17. A lid as claimed in claim 15 wherein each end of the lid has in
the mid-region thereof at least two raised load supports and each
side of the lid has in the mid-region thereof at least three raised
side supports.
18. A lid as claimed in claim 15 wherein each end of the lid has in
the mid-region thereof at least three raised load supports and each
side of the lid has in the mid-region thereof at least four raised
side supports.
19. A lid as claimed in claim 15 wherein the grooves at the sides
of the lid are disposed laterally while the grooves at the ends of
the lid are disposed longitudinally.
20. A lid as claimed in claim 15 wherein the top surface of the lid
has diagonally disposed grooves at each of the four corners of the
lid.
21. A combination as claimed in claim 15 wherein the grooves of the
surface of the lid have an "X" type pattern.
22. A lid as claimed in claim 15 wherein the lid is rectangular and
60 cm in length and 40 cm in width.
23. A lid as claimed in claim 15 wherein the lid is formed of
transparent polymer.
24. A lid as claimed in claim 15 wherein the polymer is low density
polyethylene.
25. A lid as claimed in claim 15 wherein the polymer is high
density polyethylene.
26. A lid as claimed in claim 15 wherein the lid has a planar top
surface and is formed of a transparent material.
27. A lid as claimed in claim 26 wherein the top surface of the lid
is square or rectangular and the transparent material is a
transparent polymer.
28. A lid as claimed in claim 26 wherein the lid is deployed on a
hollow base constructed of paperboard.
29. A lid for a modified atmosphere box base wherein the lid is
formed of transparent polymer, has a top surface with a square
configuration and a plurality of raised load supports and in
between grooves positioned around its periphery.
30. A lid as claimed in claim 29 wherein the raised supports are
located at the mid-regions of the top sides of the lid.
31. A lid as claimed in claim 29 wherein the raised supports are
located at the corners of the top sides of the lid.
Description
TECHNICAL FIELD
[0001] This invention relates to novel designs of tray lids and
tray bases for modified atmosphere packaging of fresh fruit,
vegetables and cut flowers. More particularly, this invention
relates to novel designs of landscaped lids and corresponding tray
bases which enable cooling air to be circulated in single or
multiple directions through stacked lid and tray combinations that
contain fresh fruits, vegetables and cut flowers in a modified
atmosphere environment.
BACKGROUND
[0002] The quality attributes of fresh fruits, vegetables and cut
flowers should be maintained as much as possible for as long as
possible to ensure consumer acceptability. Quality deterioration of
horticultural produce such as fresh fruits, vegetables and flowers
comes about through inherent plant tissue enzyme reactions
including respiration, ripening and senescence. Deterioration also
occurs through microbial growth and water loss from the tissue. A
method of inhibiting the deteriorative enzyme reactions, and the
growth of yeasts, molds and bacteria in fresh produce involves the
reduction of the produce temperature to between 1.degree. and
12.degree. C., and the creation of low O.sub.2/high CO.sub.2
modified atmosphere (MA) around the produce. Another quality
reducing factor is that water in fruits and vegetables can be lost
readily under low relative humidity conditions thereby causing
dehydration, skin wrinkling, wilting and reduction in crispness and
firmness of the fruits, vegetables and flowers. The rate of water
loss from such fresh produce can be restricted by storing the
produce in closed package systems consisting of walls with low
moisture permeability.
[0003] Corrugated paperboard boxes and cartons are used
commercially for the storage and transport of fresh horticultural
commodities. Advantages of corrugated paperboard boxes and cartons
include relatively low cost per unit volume, low thermal energy
conductivity, impact absorption which prevents bruising of
commodities and ease of disposal at the receiving end of the
shipping route. One type of globally used corrugated paperboard box
is known as a Eurotray. It has a standard horizontal dimension of
40 cm width and 60 cm length which is compatible for storage in
stacks on pallets in ISO conforming containers.
[0004] Conventional corrugated paperboard has a very high gas and
moisture permeability and as such is unsuitable for modified
atmosphere packaging of horticultural produce. The fresh produce
industry incorporates the use of stackable corrugated fiberboard
cartons or returnable plastic crates of various sizes and shapes to
accommodate a wide array of fresh fruits and vegetables for
transportation to market. In general, there are two broad
categories of stackable fiberboard cartons used in the produce
industry, namely open style cartons which incorporate apertures
such as hand-holds and concavities for refrigerated air circulation
and closed style cartons which do not include the apertures and
concavities but incorporate selective gas permeable membranes to
limit gas exchange between the interior headspace of the sealed
cartons and ambient atmosphere.
[0005] Open style cartons are advantageous because they allow for
direct field packing of the harvested produce in the cartons,
followed by refrigeration and shipment to market. The simple
packaging and cooling of the produce provides significant time,
labor and cost savings. A main disadvantage of this type of
packaging is that the free movement of oxygen around the harvested
produce maintains produce respiration rates and thus reduces the
amount of time the produce can be stored and/or transported without
quality deterioration. To offset some of these deleterious effects,
produce is conventionally harvested earlier in the growing season
while the produce is still green. This is before optimal
nutritional values and desirable tastes have developed in the
produce, thus reducing the quality of the produce delivered to
market. Another disadvantage of the open style packaging is the
minimal protection afforded to ambient temperature fluctuations
frequently encountered during transportation to market.
[0006] Closed style cartons, known also as modified atmosphere
packaging (MAP), have an advantage because the produce can be
harvested when ripe. Such packaging of fruits, vegetables and
flowers involves: [0007] 1. Harvesting the produce at full
ready-to-eat maturity; [0008] 2. Pre-packaging treatment of the
produce, including sanitizing, grading and pre-cooling; [0009] 3.
Packing of the produce in a controlled gas-permeable package
system; [0010] 4. Introduction of a predetermined CO.sub.2 and
O.sub.2 containing gas mixture into the headspace of the package
system or the retention of existing air in the head-space of the
package system; [0011] 5. Closure and sealing of the modified
atmosphere (MA) package system; and [0012] 6. Re-cooling of the
packaged produce to transport temperature.
[0013] During storage, the fruits, vegetables and flowers respire
and convert O.sub.2 from the headspace to CO.sub.2 with the result
that the O.sub.2 content in the headspace decreases while the
CO.sub.2 content increases. The respiring fruits, vegetables or
flowers generate heat which offsets refrigeration. An objective in
the design of an effective package system for MAP of fresh produce
is to regulate the influx of O.sub.2 into the package and the
efflux of CO.sub.2 from the package headspace. In this way, it is
possible to achieve and maintain a desirable low O.sub.2, high
CO.sub.2 modified equilibrium atmosphere and controlled temperature
in the headspace around the stored produce for optimum retention of
the fresh quality attributes and for the reduction of microbial
growth while the fruits, vegetables and flowers are being shipped
from source to destination, and storage at the destination.
[0014] Low levels of O.sub.2 and elevated levels of CO.sub.2 in the
headspace around a horticultural commodity reduce the respiration
and ripening rates, and the growth of spoilage organisms
(spoilogens) of the commodity. Unsuitable modified atmospheres
around fresh produce in a package system can induce physiological
damage, inhibit wound healing, enhance senescence and cause
formation of off-flavor components in the produce. Oxygen levels of
less than 1% vol. bring about anaerobic respiration and off-flavor
development, whereas CO.sub.2 levels of about 10% vol. or higher
inhibit microbial growth. CO.sub.2 levels greater than 20% vol.
over an extended period may cause tissue damage to
CO.sub.2-sensitive fresh produce.
[0015] Package systems for MAP must be designed and constructed
with specific packaging materials to meet the following
requirements: [0016] 1. Maintain definitive beneficial equilibrium
levels of CO.sub.2 and O.sub.2 in the headspace of the package
system; [0017] 2. Obviate gas pressure build-up within the package
system; [0018] 3. Minimize moisture loss from fresh produce
contained in the MA package; [0019] 4. Prevent fresh produce
crushing and bruising; [0020] 5. Inhibit water migration from the
package interior into the walls of the package system to thereby
retain structural strength of the walls; and [0021] 6. Transmit
fresh product respiration heat away from the package system.
[0022] The gas and moisture permeabilities of the package
components of MA package systems are critical parameters. The
technology of plastic polymeric films has advanced to such an
extent that a specific gas permeability requirement can be met with
a single plastic film or a multi-layer film combination, with or
without vent pinholes.
[0023] In 1960, Eaves (J. Hort. Sci. 37:110, 1960) reported the
effectiveness of gas-permeable, flexible polymeric barrier film as
a package system for extending the life of fresh commodities.
Tomkins (J. Appl. Bacteriol. 25:290, 1962) used polymeric
film-covered trays as package systems to determine their
effectiveness in establishing equilibrium MA around apples. Prior
art on the use of bags made from polymeric plastic, gas permeable
film such as polyethylene and polyvinylchloride, for prolonging of
shelf-life of stored fruits and vegetables, is exemplified by U.S.
Pat. No. 3,450,542, Badran, U.S. Pat. No. 3,450,544, Badran et al.,
and U.S. Pat. No. 3,798,333, Cummin. A more complex package system
has been described by Rumberger (U.S. Pat. No. 3,630,759) in that
an inner plastic pouch containing the produce is enveloped by an
outer pouch containing an atmosphere of less than 15% O.sub.2. Both
pouches are to be constructed from gas-permeable films.
[0024] U.S. Pat. No. 5,575,418, issued 19 Nov. 1996, Wu et al.,
relates to novel package systems for refrigerated modified
atmosphere packaging of fresh fruit, vegetables and cut flowers.
More particularly, the patent discloses the design, construction,
closure, sealing and use of gas-permeable corrugated paperboard
package systems for prolonging the storage life of fresh fruits,
vegetables and cut flowers under modified atmosphere in the
headspaces of the closed package system. The corrugated gas
permeable paperboard comprises: (a) a first layer of kraft paper;
(b) a layer of polymer having a gas permeability which permits gas
to be transmitted through the polymeric film at prescribed levels;
(c) a second layer of kraft paper, said first and second layers of
kraft paper sandwiching the polymer between them; (d) a corrugated
fluting; and (e) a third layer of kraft paper affixed to the
corrugated fluting.
[0025] U.S. Pat. No. 5,609,293, issued 11 Mar. 1997, Wu et al.,
relates to the design, construction and use of lined or coated
corrugated paperboard package systems (e.g. boxes, cartons) for
prolonging the storage life of fresh fruits and vegetables under
modified atmospheres (MA) in the headspaces of the closed package
systems. The plastic-paperboard construction comprises a first
layer of polymeric film, a second layer of kraft paper adjacent the
first layer, a kraft paper corrugated flute adjacent the second
layer and a fourth layer of kraft paper adjacent the flute.
[0026] U.S. Pat. No. 6,050,412, issued 18 Apr. 2000, Clough, et
al., relates to a novel method and apparatus for packaging and
shipping horticultural products including cut flowers. In
particular, the patent discloses a novel method of and packaging
for packaging cut flowers in a modified atmosphere package to
prolong shelf life in shipping the packaged flowers to the
destination, and then at the destination, opening the package and
rehydrating the cut flowers in the package by saturating the stems
of the flowers with water.
[0027] Patent Cooperation Treaty application Serial No.
PCT/CA2006/001404, 25 Aug. 2006, discloses novel Eurotray
compatible package systems for refrigerated modified atmosphere
packaging of fresh fruit, vegetables and cut flowers. More
particularly, the application relates to the design, construction,
closure, sealing and use of gas-permeable paperboard package
systems and shipping trays for prolonging the storage life of fresh
fruits, vegetables and cut flowers under modified atmosphere in the
headspaces of the closed package system. A gas permeable paperboard
comprising: (a) a first layer of kraft paper; (b) a layer of
polymer having a gas permeability which permits gas to be
transmitted through the polymeric film at prescribed levels; (c) a
second layer of kraft paper, said first and second layers of kraft
paper sandwiching the polymer between them.
[0028] None of the foregoing cited references discloses a stackable
lid and tray system which incorporates modified atmosphere
technology, allows single or dual angular direction cooling and
ventilation of stacked and/or palletized packages or facilitates
visual inspection of the package contents without opening the
sealed package.
[0029] There is a need for a closed stackable lid and tray package
system which incorporates modified atmosphere technology, allows
harvesting and packaging of produce in either the field or in a
centralized facility, allows single or dual direction of cooling
and ventilation of stacked and/or palletized packages to offset
produce respiration, allows visual inspection of the packaged
produce at any point following packaging and provides the ability
to refrigerate the fresh produce during transit.
[0030] U.S. Pat. No. 6,880,748,B2, Machado, discloses a modified
atmosphere packaging system and method which allows field and/or
centralized facility packing of fresh produce and refrigerated air
to circulate throughout a palletized stack of cartons. The
packaging includes a transparent lid with raised stacking supports
at the four corners. The lid is sealingly attached to a corrugated
fiberboard carton with a gas permeable membrane. The transparent
lid allows for inspection of perishable produce contained therein
without breaching an established modified atmosphere. A problem
with this system is that when the cartons are stacked on one
another, unless care is taken to ensure that the upper carton is
squarely mounted on the lower carton, the lower corners of the
upper carton can miss the corner supports and drop into the grooves
in the lid on the lower carton. Another shortcoming is that the
total surface area of the raised supports at the four corners of
the carton is not large and load bearing capability is
minimized.
[0031] The foregoing examples of the related art and limitations
related thereto are intended to be illustrative and not exclusive.
Other limitations of the related art will become apparent to those
of skill in the art upon a reading of the specification and a study
of the drawings.
SUMMARY OF THE INVENTION
[0032] The following embodiments and aspects thereof are described
and illustrated in conjunction with systems, tools and methods
which are meant to be exemplary and illustrative, not limiting in
scope. In various embodiments, one or more of the above-described
problems have been reduced or eliminated, while other embodiments
are directed to other improvements.
[0033] The invention is directed to a gas-permeable modified
atmosphere package combination comprising a lid constructed of a
polymer, the lid in one embodiment having on the top surface
thereof at the mid-regions of each side a plurality of raised load
supports and in between grooves; and a base with a hollow interior
constructed of corrugated kraft paper polymer and having a
configuration at the top edges which conforms with the interior
profile of the lid; the grooves enabling air to be circulated over
the lid when one package combination is stacked on another.
[0034] The top surface of the lid can have around its periphery at
least one raised load support in the mid-region of each end and at
least one raised load support in the mid-region of each side, and a
depressed area between the raised end and side load supports. The
top surface of the lid can have around its periphery at least two
raised load supports in the mid-region of each end and at least
three raised side supports in the mid-region of each of the two
sides of the lid, and a depressed area between the raised end and
side load supports. The top surface of the lid can have around its
periphery at least two raised load supports in the mid-region of
each end and at least four raised side supports in the mid-region
of each of the two sides of the lid, and a depressed area between
the raised end and side load supports.
[0035] The corners of the top surface of the lid can have diagonal
grooves therein. The grooves at the sides of the lid can be
disposed laterally while the grooves at the ends of the lid can be
disposed longitudinally. The grooves of the surface of the lid can
have an "X" type pattern. The lid and the base can be 60 cm in
length and 40 cm in width.
[0036] The base can comprise a first outer layer of kraft paper, a
first intermediate layer of corrugated kraft paper, a second
intermediate layer of polymer and a second outer layer of kraft
paper. The polymer in the base can be selected from the group
consisting of ethylene vinylacetate (EVA), ethylbutyl acetate
(EBA), a crosslinked ionomer resin, cast polyester (PET), a
polyamide and polycarbonate (PC). The polymer can be low density
polyethylene or high density polyethylene, or a copolymer of low
density polyethylene and ethylenebutylacetate.
[0037] The gas permeability of the polymer of the base can be
between about 50 and 100,000 cc.sup.3/m.sup.2 24 hr. 1 atm.
[0038] The invention is also directed to a lid for a gas-permeable
modified atmosphere package comprising a top surface which can be
rectangular or square, said surface including a plurality of raised
load supports and in between grooves arranged around its periphery,
the grooves enabling air to be circulated over the lid when one
package is stacked on another.
[0039] Each end of the lid can have in the mid-region thereof at
least one raised load support and each side of the lid can have in
the mid-region thereof at least one raised load support and a
depressed area can exist between the raised end and side load
supports. Each end of the lid can have in the mid-region thereof at
least two raised load supports and each side of the lid can have in
the mid-region thereof at least three raised side supports. Each
end of the lid can have in the mid-region thereof at least three
raised load supports and each side of the lid can have in the
mid-region thereof at least four raised side supports.
[0040] The grooves at the sides of the lid can be disposed
laterally while the grooves at the ends of the lid can be disposed
longitudinally. The top surface of the lid can have diagonally
disposed grooves at each of the four corners of the lid. The lid
can be formed of transparent polymer.
[0041] The lid can have a planar top surface and can be formed of a
transparent material. The top surface of the lid can be
quadrilateral such as square or rectangular and the transparent
material can be a transparent polymer. The lid can be deployed on a
hollow base constructed of paperboard.
[0042] The lid can be formed of transparent polymer, can have a top
surface with a square configuration and a plurality of raised load
supports and in between grooves positioned around its periphery.
The raised supports can be located at the mid-regions or the
corners of the top sides of the lid.
[0043] In addition to the exemplary aspects and embodiments
described above, further aspects and embodiments will become
apparent by reference to the drawings and by study of the following
detailed descriptions.
BRIEF DESCRIPTION OF DRAWINGS
[0044] Exemplary embodiments are illustrated in referenced figures
of the drawings. It is intended that the embodiments and figures
disclosed herein are to be considered illustrative rather than
restrictive.
[0045] FIG. 1 illustrates an isometric view of a lid with a
plurality of raised supports and in between grooves around the
circumference of the lid for packaging fruit and vegetables,
according to a first embodiment of the invention.
[0046] FIG. 2 illustrates an isometric view of a corresponding tray
base for the lid illustrated in FIG. 1.
[0047] FIG. 3 illustrates an isometric view of a lid with a
plurality of raised supports around the circumference for packaging
cut flowers, according to a second embodiment of the invention.
[0048] FIG. 4 illustrates a corresponding tray base for the lid
illustrated in FIG. 3.
[0049] FIG. 5 illustrates an isometric view of an "X"-grooved lid,
according to a further embodiment of the invention.
[0050] FIG. 6 illustrates an isometric view of a tray base for the
lid illustrated in FIG. 5.
[0051] FIG. 7 illustrates a plan view of the lid illustrated in
FIG. 1.
[0052] FIG. 8 illustrates a side elevation view of the lid of FIG.
7.
[0053] FIG. 9 illustrates an end view of the lid of FIG. 7.
[0054] FIG. 10 illustrates a section view of taken along lines A-A
of FIG. 7.
[0055] FIG. 11 illustrates a plan view of a blank for a tray base,
as illustrated in FIG. 2.
[0056] FIG. 12 illustrates a plan view of a standard ISO container
with a grouping of pallets loaded with stacked lid and tray base
containers according to the embodiment illustrated in FIGS. 1, 2
and 7 to 11 of the invention.
[0057] FIG. 13 illustrates a plan view of the lid illustrated in
FIG. 3.
[0058] FIG. 14 illustrates a side elevation view of the lid of FIG.
13.
[0059] FIG. 15 illustrates an end view of the lid of FIG. 13.
[0060] FIG. 16 illustrates a plan view of a blank for a tray base,
as illustrated in FIG. 4.
[0061] FIG. 17 illustrates a plan view of a standard ISO container
with a grouping of pallets loaded with stacked lid and tray base
containers according to the embodiment illustrated in FIGS. 3, 4
and 13 to 16 of the invention.
[0062] FIG. 18 illustrates a plan view of an "X" grooved lid as
illustrated in FIG. 5.
[0063] FIG. 19 illustrates a side elevation view of the lid
illustrated in FIG. 18.
[0064] FIG. 20 illustrates an end view of the lid of FIG. 18.
[0065] FIG. 21 illustrates a section view of the lid taken along
lines A-A of FIG. 18.
[0066] FIG. 22 illustrates a plan view of a blank for a tray base,
as illustrated in FIG. 6.
[0067] FIG. 23 illustrates a plan view of a standard ISO container
with a grouping of pallets loaded with stacked lid and tray base
containers according to the embodiment illustrated in FIGS. 5, 6
and 18 to 22 of the invention.
[0068] FIG. 24 illustrates an isometric view of a modified Eurobox
with recessed sides and ends.
[0069] FIG. 25 illustrates an isometric view of a MAP box with a
transparent lid.
[0070] FIG. 26 illustrates an isometric view of a modified Eurobox
holding a plurality of MAP packages with transparent lids.
[0071] FIG. 27 illustrates an isometric view of an alternative
embodiment of a MAP box with a plurality of raised supports around
the circumference of the lid.
[0072] FIG. 28 illustrates an isometric view of a further
alternative embodiment of a MAP box with raised supports at the
corners.
[0073] FIG. 29 illustrates an isometric view of a further
alternative embodiment of a MAP box with raised supports at the
corners mounted on a MAP box base.
DESCRIPTION
[0074] Throughout the following description specific details are
set forth in order to provide a more thorough understanding to
persons skilled in the art. However, well known elements may not
have been shown or described in detail to avoid unnecessarily
obscuring the disclosure. Accordingly, the description and drawings
are to be regarded in an illustrative, rather than a restrictive,
sense.
[0075] To deal with the long distance and the time required for
continental and overseas shipment of MAP preserved fruits,
vegetables and flowers, we have invented a unique family of lids
having an uneven top surface comprising a series of raised load
bearing areas around the circumference of the lid and grooves
between the raised areas and a central depressed area. In one
aspect, the invention includes a family of corresponding congruent
tray base designs. Together the lid and tray base can be used for
the shipment of fresh fruit such as grapes, peaches, nectarines and
the like, vegetables such as sweet peppers, spinach, lettuce,
tomatoes and the like, and fresh flowers in a modified atmosphere
environment.
[0076] In one preferred version of the lid and tray base, the lid
and tray base can measure 60 cm by 40 cm to conform with Eurotray
standards. The modified Eurotray, according to the invention, has a
top lid surface incorporating a plurality of raised supports around
the circumference and a plurality of in between grooves. The
grooves enable cooling air to circulate between Eurotrays when such
trays are stacked on a pallet and stored in a refrigerator or
shipped in an ISO conforming container. The cool air circulated
through the stacked Eurotrays helps to offset heat generated by the
respiring vegetables, fruit or flowers packaged in the Eurotrays.
The top surfaces of the raised areas can be roughened or have a
friction creating pattern thereon to enhance grip between trays
when stacked.
[0077] A common request from customers of packaged fruits,
vegetables and flowers is a capability of viewing the packaged
product without opening the package. The lid of the subject
invention is preferably formed of a transparent polymer.
[0078] Since the packaged product is refrigerated and since
moisture is present in the interior of the package from respiration
of the packaged fruit, vegetables or flowers, the interior of the
lid typically collects condensation. The raised supports and
grooved lid can, if desired, be molded from a polymer which
contains an anti-fog agent. Alternatively, a moisture resistant
agent can be applied to the interior surface of the lid.
[0079] A common problem with conventional modified atmosphere
packaged fruit, vegetables or flowers is that they are packaged in
corrugated paperboard containers which inherently provide
insulation, which retains heat. If the fruit or vegetable product
in the package is warm, time is required to cool the packaged
fruit, vegetables or cut flowers to acceptable modified atmosphere
refrigeration levels. A transparent lid is useful because it is
reasonably heat conductive and transmits respiration heat from the
packaged produce to the atmosphere, whereas conventional corrugated
linerboard packaging inhibits heat transmission. The grooved
surface of the lid enables cooling air to be circulated through
stacked trays and thereby cool the produce quickly to refrigeration
temperatures, and subsequently to maintain the produce in a cool
condition.
[0080] Specific embodiments of the invention will now be discussed
in association with the drawings. FIG. 1 illustrates an isometric
view of a lid with a plurality of raised supports and in between
grooves around the circumference of the lid for packaging fruit and
vegetables, according to the invention. As seen in FIG. 1, the lid
2 is constructed of molded polymer, preferably transparent, such as
polyethylene or acrylic, and has two groups of two raised
wedge-shaped end supports 4 at the ends and two groups of three
raised side supports 6 at the sides. These raised supports 4 and 6
are distributed around the periphery of the lid 2 and define
between them a plurality of in between grooves and a central valley
or depression 8 on the top of the lid 2. The lid 2 also includes
two downwardly extending end panels 10 and two downwardly extending
side panels 12. These end and side panels 10 and 12 fit over the
top exterior of the base 14, as seen in FIG. 2. The lid 2 can be
performed by any number of conventional techniques but vacuum
molding or drawing is particularly suitable. Normally, the lid 2 is
constructed of a gas-impermeable transparent polymer but it can, if
required, be constructed of a suitable gas permeable transparent or
non-transparent polymer. In one version, the lid can be 40 cm in
width and 60 cm in length to conform with Eurotray standards. The
top surfaces of the end supports and side supports 4 and 6 can be
roughened to enhance friction grip when trays are stacked one upon
the other.
[0081] FIG. 2 illustrates an isometric view of a corresponding tray
base for the lid illustrated in FIG. 1. In particular, FIG. 2
illustrates a tray base with uneven top edges on the two sidewalls
and the two end walls to conform with the interior contours of the
end and side supports of the lid as shown in FIG. 1. As seen in
FIG. 2, the one piece tray base 14 is constructed with two end
panels 16 with upper edges 22 and two side panels 18 with upper
edges 24, which respectively conform with the configurations of the
interior of the two end supports 4 and the two side supports 6 of
the lid 2 as shown in FIG. 1. The tray base 14 may be formed of
conventional multi-layer corrugated kraft paper or two or more
layers of kraft paper, with gas permeable polymer film between,
such as constructions of the type disclosed in U.S. Pat. Nos.
5,575,418, 5,609,293 and 6,050,412. The two end supports 16 and the
two side supports 18 form between them a bottom panel 20. It is
understood that the top edges of the tray base may be even in
elevation. However, it is preferred that the top edges be uneven
because this adds strength to the lid and tray base
combination.
[0082] FIG. 3 illustrates an isometric view of a lid with a
plurality of raised supports around the circumference for packaging
cut flowers according to a second embodiment of the invention. As
seen in FIG. 3, the lid 26 is constructed of molded polymer,
preferably transparent, such as polyethylene or acrylic, and has a
pair of wedge-shaped raised end supports 28 and two groups of four
side supports 30 at each side. These end supports 28 and side
supports 30 are raised and define between them a plurality of
grooves and a central valley or depression 36 on the top of the lid
26. The lid 26 also includes two downwardly extending end panels 32
and two downwardly extending side panels 34. These end and side
panels 32 and 34 fit over the exterior of the tray base 38 as seen
in FIG. 4.
[0083] FIG. 4 illustrates a corresponding tray base for the lid
illustrated in FIG. 3. In particular, FIG. 4 illustrates a tray
base with uneven top edges on the two side walls and two end walls
to conform with the interior contours of the lid as shown in FIG.
3. As seen in FIG. 4, the one piece base 38 is constructed with two
end panels 40 with upper raised edges 46 and two side panels 42
with raised upper edges 48. The two end panels 40 and side panels
42 define between them a tray base 44. The elevations of the top
edges of the two groups of end panels 46 and four groups of side
edges 48 conform with the interior configurations of the end
supports 28 and side supports 30 of the lid 26 as shown in FIG.
3.
[0084] FIG. 5 illustrates an isometric view of a transparent
"X"-grooved lid, according to a further embodiment of the
invention. As seen in FIG. 5, the lid 52 is constructed of molded
polymer, preferably transparent, such as polyethylene or acrylic,
and has two broad area triangular raised end supports 54 and two
broad area triangular raised side supports 56. These supports 54
and 56 define between them an "X" shaped valley or depression 57 on
the top surface of the lid 52. The lid 52 also includes two
downwardly extending end panels 58 and two downwardly extending
side panels 50. These end and side panels 58 and 50 fit over the
tray base 62, as seen in FIG. 2. The lid 52 can be formed by any
number of conventional techniques, but vacuum molding or drawing is
particularly suitable. In one version, the lid 52 can be 40 cm in
width and 60 cm in length to conform with Eurotray standards.
[0085] FIG. 6 illustrates an isometric view of a tray base with
uneven top edges on the two side walls and two end walls to conform
with the interior contours of the lid 52 as shown in FIG. 5.
Specifically, as seen in FIG. 6, the one-piece tray base 62 is
constructed with two end panels 63 with upper edges 64 of two
elevations and two side panels 65 with upper edges 66 of two
elevations which respectively conform with the interiors of the two
end supports 54 and the two side supports 56 of the lid 52 as shown
in FIG. 5. The base 62 may be formed of conventional multi-layer
corrugated kraft paper or two or more layers of kraft paper with a
gas permeable polymer film between, such as constructions of the
type disclosed in U.S. Pat. Nos. 5,575,418; 5,609,293; and
6,050,412. It will be understood that while uneven top edges of the
base are shown, the invention includes bases with straight upper
edges. Uneven upper edges which conform with the profile of the lid
are preferred because this provides greater strength to the lid and
base combination for stacking purposes.
[0086] FIG. 7 illustrates a plan view of the lid illustrated in
FIG. 1. As seen in FIG. 7, the lid 8 has a pair of end supports 4
at each end, and a trio of side supports 6 at each side. These
raised supports have grooves between them to enable cooling air to
be circulated over the lids. The top surfaces of the end and side
supports 4 are roughened to enhance grippability and discourage
shifting when the trays are stacked.
[0087] FIG. 8 illustrates a side elevation view of the lid of FIG.
7. FIG. 8 illustrates the raised end supports 4, raised side
supports 6 and side panel 12.
[0088] FIG. 9 illustrates an end view of the lid of FIG. 7. FIG. 9
illustrates the end panel 10, raised end supports 4 and raised side
supports 6.
[0089] FIG. 10 illustrates a section view taken along section A-A
of FIG. 7 and in particular, illustrates the central depressed area
8 and the pair of raised side supports 6.
[0090] FIG. 11 illustrates a plan view of a blank for a tray base,
as seen in FIG. 2. In particular, FIG. 11 illustrates a paperboard
blank 20 with a pair of side panels 18 and a pair of end panels 22.
When folded along the stippled lines, the erected paperboard blank
forms a tray base 14 with base 20 as illustrated in FIG. 2. The
blank 20 is typically formed of corrugated paperboard. The arrow
shown in FIG. 11 indicates the direction of the corrugated flutes
that are in the interior of the paperboard blank 20. The triangular
arrow denotes that the direction of the corrugated flutes of the
paperboard from which the tray is formed. The flutes extend
laterally rather than longitudinally. This flute orientation
provides strength to the base. If the flutes extend longitudinally,
the base 62 is prone to bending in a longitudinal direction.
[0091] FIG. 12 illustrates a plan view of a standard ISO container
with a grouping of pallets loaded with stacked lid and tray base
containers according to the embodiment illustrated in FIGS. 1, 2
and 7 to 1 of the invention. The arrow denotes the typical
direction of air flow in the container.
[0092] FIG. 13 illustrates a plan view of the lid illustrated in
FIG. 3. Specifically, FIG. 13 illustrates a plan view of a lid 36
used for shipping cut flowers according to the invention. The lid,
as seen in FIG. 13, has a pair of raised wedge-shaped end supports
28 at each end and two groups of four raised side supports 30 on
each side of the lid 36. The top surfaces of the end supports 28
and side supports 30 are roughened to enhance grippability so that
when trays with lids are stacked, shifting is discouraged.
[0093] FIG. 14 illustrates a side elevation view of the lid of FIG.
13, including side panel 34 and raised end supports 28 and raised
side supports 30. The grooves between the supports 30 are clearly
shown.
[0094] FIG. 15 illustrates an end view of the lid of FIG. 13,
including raised end supports 28, raised side supports 30 and end
panel 32.
[0095] FIG. 16 illustrates a plan view of a blank for a tray base,
as illustrated in FIG. 4. Specifically, FIG. 16 illustrates a
paperboard blank 44, suitable for packaging and shipping cut
flowers, including tray bottom 44, a pair of end panels 40 and a
pair of side panels 42. Raised end edges 46 and raised side edges
48 are also shown. The arrow indicates the direction of the
corrugated flutes in the paperboard that is used to make the blank
illustrated in FIG. 16. The stippled lines indicate crease lines
and when the blank is folded along the crease lines, the erected
blank forms a tray base as illustrated in FIG. 4. The triangular
arrow denotes that the direction of the corrugated flutes of the
paperboard from which the tray is formed. The flutes extend
laterally rather than longitudinally. This flute orientation
provides strength to the base. If the flutes extend longitudinally,
the base 62 is prone to bending in a longitudinal direction.
[0096] FIG. 17 illustrates a plan view of a standard ISO container
with a grouping of pallets loaded with stacked lid and tray base
containers according to the embodiment illustrated in FIGS. 3, 4
and 13 to 16 of the invention. The arrow indicates the typical
direction of air flow in the container in which the palettes of
trays are stored.
[0097] FIG. 18 illustrates a plan view of an "X" diagonal-grooved
lid 52 of FIG. 5 with two raised broad area triangular end supports
54 and two raised broad area triangular side supports 56, which
together form an "X" shaped channel, valley or depression 57 in the
top of the lid 52. The lid 52 can be fitted over the top of the
modified base 62 of FIG. 6 to provide a strong modified atmosphere
package for shipping and stacking of fresh fruits, vegetables and
cut flowers. The shaped channel between the two end supports 54 and
side supports 56 enables air to be circulated between stacked
Eurotrays. The broad areas of the four triangular shaped supports
54 and 56 provide broad load bearing sites so a reasonable number
of trays can be stacked upon one another without distorting or
crushing the bottom tray in the stack. The broad areas of the
supports 54 and 56 also provide tolerance so that trays will still
support one another, even though they may not be stacked in close
alignment. The top surfaces of the supports 54 and 56 can be
roughened to enhance grippability. The top surfaces of the supports
54 and 56 can have grooves therein to enhance air circulation over
the top of the lids.
[0098] FIG. 19 illustrates a side elevation view of the Eurotray
lid 52, with raised side support 56 and raised end supports 54, and
side 60.
[0099] FIG. 20 illustrates an end view of the lid 52 with raised
end support 54, raised side supports 56, and end panel 58.
[0100] FIG. 21 illustrates a section view taken along lines A-A of
FIG. 18, showing the two side supports 56 and the central groove
57.
[0101] FIG. 22 illustrates a plan view of a corrugated paperboard
blank for forming the tray base 62 illustrated in FIG. 6. The blank
can include an intermediate layer of gas permeable film (not
visible). The blank can be folded and erected to form a base 62 as
shown in FIG. 6. The upper edges of the end panels 64 and the side
panels 66 are visible. The triangular arrow denotes that the
direction of the corrugated flutes of the paperboard from which the
tray is formed. The flutes extend laterally rather than
longitudinally. This flute orientation provides strength to the
base. If the flutes extend longitudinally, the base 62 is prone to
bending in a longitudinal direction.
[0102] FIG. 23 illustrates a plan view of a standard ISO container
with a close grouping of pallets loaded with stacked containers
according to a further embodiment of the invention. As seen in FIG.
23, each pallet, as indicated by the bold lines, bears three "X"
Eurotray packages arranged in side by side relation and two "X"
Eurotray packages arranged in end to end relation. The "X" shaped
channels or grooves in the tops of the lids enable cooling air to
be circulated through the stacked lid and base packages. Also, the
triangular shape of the two end and two side supports provide large
load bearing areas for stacked trays and minimize crushing.
[0103] FIG. 24 illustrates an isometric view of a modified Eurobox
with recessed sides and ends. As seen in FIG. 24, the modified
Eurotray 50 is sized to standardized shipping container
specifications, namely 40 cm.times.60 cm, and has downwardly
recessed sides 54 and downwardly recessed ends 56. In the
embodiment shown in FIG. 24, the tray 50 also has reinforced
corners 58, which enable the trays to be stacked. The recessed
sides 54 and ends 56 enable refrigerated air to be circulated
through both the sides and ends of stacked Eurotrays 40. The depth
of the tray 50 can be increased two or more times to enable
multiple layers of the boxes to be packed. A tray as shown in FIG.
24 is disclosed in U.S. patent application Ser. No. 11/458,951,
filed 20 Jul. 2006.
[0104] FIG. 25 illustrates an isometric view of a MAP box
embodiment of the invention. The MAP box 60 has a corrugated
paperboard base 62 and a transparent lid 64, with downwardly
extending sides 66 which fit snugly over the top and partially down
the sides of the base 62. The transparent lid 64 enables the
contents of the MAP box 60 to be viewed without opening the box 60.
The sides 66 can be taped to the base 62 to provide a seal for the
MA environment inside the box 60.
[0105] FIG. 26 illustrates an isometric view of a modified Eurobox
holding a plurality of MAP packages. As seen in FIG. 26, the
modified Eurotray 50, with reinforced corners 58 and recessed sides
54 and ends 56, is filled with rows of MA boxes 60. The MA boxes 60
are loaded with fresh fruit, vegetables or flowers, as the case may
be. It will be recognized that while three rows of four, totaling
twelve MA containers 60, are shown in FIG. 26, the sizes of the
containers can be varied so that larger MA containers can fill the
modified Eurotray 50, such as six or eight MA packages to a
Eurotray. Also, it will be understood that the depth of the trays
50 can be increased to hold two or more layers of boxes 60.
[0106] FIG. 27 illustrates an isometric view of an alternative
embodiment of a MAP box with a plurality of raised supports around
the circumference of the lid. As seen in FIG. 27, the MAP box lid
70 has a plurality of raised supports 72 around its periphery.
These supports 72 allow the MAP boxes to be stacked and permit air
to be circulated through the grooves between the lids.
[0107] FIG. 28 illustrates an isometric view of a further
alternative embodiment of a MAP box with raised supports at the
corners. As seen in FIG. 28, the alternative design of MAP lid 74
has raised supports 76 located at the four corners. These supports
76 allow the MAP boxes to be stacked and permit air to be
circulated through the grooves between the lids.
[0108] FIG. 29 illustrates an isometric view of a further
alternative embodiment of a MAP box with raised supports at the
corners mounted on a MAP box base. As seen in FIG. 29, a MAP lid 70
as illustrated in FIG. 27 is mounted on a MAP box base 78. The
raised supports 72 allow the MAP boxes to be stacked and permit air
to be circulated through the grooves between the lids.
[0109] The modified lid and tray base are preferably sized to
standardized shipping container specifications (ISO
specifications), namely 40 cm width.times.60 cm length. The grooves
in lid 2 of FIG. 1, lid 26 of FIG. 3, and the "X" configured
diagonal-grooves in lid 52 of FIG. 5 enable refrigerated air to be
circulated through both the sides and ends of the lid and base
combinations when they are stacked, and maintain modified
atmosphere packaged produce in optimum condition.
[0110] Storage life of fresh fruits and vegetables is dependent on
storage temperature, gas composition around the produce and degree
of physical abuse leading to bruises, abrasions and cuts. Storage
and transportation of fruits and vegetables is facilitated by the
packing of the produce in suitable package systems which provide
features such as prolonging storage life, reducing physical abuse
and lowering the rate of water loss of produce.
[0111] Corrugated paperboard boxes and cartons are used
commercially for the storage and transportation of fresh fruits and
vegetables for the following reasons: [0112] 1. Relatively low cost
per unit volume; [0113] 2. Low thermal conductivity; [0114] 3.
Impact absorbing ability to prevent produce bruising; [0115] 4.
Ease of disposal at the receiving end; and [0116] 5. Moderate
stacking strength.
[0117] Corrugated paperboard has very high O.sub.2 and CO.sub.2
permeabilities, so this material by itself is generally unsuitable
for the construction of MA package systems. However, in the MAP lid
and base package according to the invention, the base can be formed
of a paperboard construction with an intermediate gas permeable
film as disclosed in U.S. Pat. Nos. 5,574,418 and 5,609,293. By
utilizing a gas-permeable polymer in the paperboard construction,
the lid can be customized to provide a gas barrier or specific gas
and moisture permeabilities.
[0118] In some cases, it may be advisable to have the lid formed of
a gas permeable polymer. The gas permeable polymeric lid can be
formed from homopolymers or copolymers produced as a monolayer or
coextruded layers with specific formulation and caliper selected to
produce the required oxygen (O.sub.2) and carbon dioxide (CO.sub.2)
permeabilities. The polymers are usually selected from the
polyolefin family, typically Low Density Polyethylene (LDPE),
linear low density polyethylene (LLDPE), medium and high density
polyethylene (MDPE and HDPE), polypropylene (PP). However, other
polymers such as ethylenevinylacetate (EVA), ethyl butyl acetate
(EBA), ionomer resins (cross-linked), cast polyester (PET), nylon
(polyamide) and polycarbonate (PC) may also be considered.
[0119] A further unique embodiment of this invention is the ability
of the base and lid to maintain internal equilibrium under varying
gas compositions in the headspace. The gas permeability of the base
and lid prevents a vacuum condition developing which can occur in
conventional MAP systems if the packaged produce begins to absorb
carbon dioxide. If such conditions were to develop in the permeable
base and lid, the controlled influx of gases through the gas
permeable polymer film in the base will not allow a deleterious
vacuum to develop in the interior headspace of the lid and
base.
[0120] For specific product applications, the rate of gas exchange
within the base and lid combination may be achieved by controlled
film porosity of the gas permeable intermediate polymer film layer.
Porosity may also be achieved by piercing predetermined holes
through the polymer containing inner liner either at the
corrugating stage, die cutting operation, box forming stage, or in
the completed box. Hole size, either single or multiple, may vary
depending on the required gas exchange rate but typical hole
diameters would be in the range of 0.25 to 2.00 mm. Hole positions
on the base or lid will vary depending on the optimum location for
each packaged product and the gas flow dynamics within the base and
lid combination. Once the produce is packaged in the base and lid
combination, the lid, if desired, can be sealed to the base by tape
or some other sealing mechanism.
[0121] The oxygen (O.sub.2) and carbon dioxide (CO.sub.2) gas
exchange rates through the lid and base of the invention should
preferably be within the range 50-100,000 cc.sup.3/m.sup.2 24 hr. 1
atm.
[0122] It has also been found that the following additional factors
must be critically controlled if consistent polymer characteristics
are to be achieved: [0123] Process conditions: Extrusion rate, melt
temperature, melt pressure, nip pressure, nip position, chill roll
temperature, corrugating process conditions, board die cutting
conditions. [0124] Polymer characteristics: Melt flow index,
additives (processing aids). [0125] Paper characteristics: Fibre
length, virgin or recycled pulp, smooth or rough side, with or
without calender process.
[0126] The base, preferably of Eurotray dimensions, may be
constructed of multiple layers of kraft paper, or of a plastic film
membrane sandwiched between two sheets of kraft paper to form a
tri-layer complex. The film membrane may be a gas-permeable plastic
film or a plastic coating applied to one of the sheets of kraft
paper, and then sealed between the two adjoining sheets. The
membrane can be bonded to both of the kraft paper sheets when the
plastic is in semi-molten state and the two paper sheets are
pressed together.
[0127] When 25 g/m.sup.2 low density polyethylene was used, and
extrusion laminated on 40 g/m.sup.2 and 125 g/m.sup.2 MG kraft, the
O.sub.2 and CO.sub.2 permeabilities were 1300 and 2200 cc/m.sup.2
24 hr. 1 atm. respectively. When a 35 g/m.sup.2 coating of 17% EBA
and LDPE was extrusion laminated, the O.sub.2 and CO.sub.2
permeabilities were 2300 and 4700 cc/m.sup.2 24 hr. 1 atm.
respectively.
[0128] Studies have been carried out on fruits and vegetables
packaged in sealed polymeric, plastic film bags in a corrugated
paperboard box (Prince, 1989). However, several disadvantages of
using a bag-in-a box are evident: [0129] 1. Loss of headspace
around produce with the shrinkage of the bag under negative
pressure created by respiratory CO.sub.2 dissolution in the produce
tissue; [0130] 2. Extra handling of two packages, namely, the bag
and the box; [0131] 3. The thickness of the bag film must be at
least 6 mil to ensure bag durability during the handling, and thus
high package cost and low gas permeability of the bag is
unavoidable. [0132] 4. Thin plastic film serves as a cold surface
for condensation of water emitted from the produce, and can result
in weight loss of produce.
[0133] A benefit of injecting gas into an hermetically sealed MA
box is that it is possible to include a trace gas, typically helium
or sulphur hexafluoride as a leak detection method. Provided the MA
box is relying on gas permeability and not porosity, it is possible
to sense gas escape through cracks, unwanted pinholes or faulty
glue seals.
[0134] Upon the insertion of a gas nozzle into the inlet aperture
and upon the flow of the pressurized gas mixture through the
headspace of the package system, plugs with vent pinholes or
styrofoam plugs can be used for produce with high respiration rates
and gas-impermeable plastic plugs may be used for low respiration
rate produce.
[0135] While a number of exemplary aspects and embodiments have
been discussed above, those of skill in the art will recognize
certain modifications, permutations, additions and sub-combinations
thereof. It is therefore intended that the following appended
claims and claims hereafter introduced are interpreted to include
all such modifications, permutations, additions and
sub-combinations as are within their true spirit and scope.
* * * * *