Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
[001] THERMOFORMED PACKAGING TRAY
FIELD
[002] The invention relates to the field of thermoformed packaging trays.
BACKGROUND
[003] Presently, thermoformed packaging trays are used to package food items
such as
meats for sale in grocery stores. Food items are selected, and placed on the
thermoformed
packaging trays, which are then encased with overwrap film. Overwrap film can
be placed on
manually, or a wrapping machine can be used to speed efficiency. Standard
thermoformed
packaging trays do not work well with wrapping machines as the overwrap film
tends to tear
during the process of applying the overwrap. Moreover, thermoformed packaging
trays can
collapse or become damaged during the wrapping process. This slows down the
efficiency of
wrapping machines. Finally the overwrap may wear along the sharper edges of
the
thermoformed packaging trays resulting in holes and leakage. Contamination of
the food
product can occur as a result of holes in the overwrap, and surrounding items
may also
become contaminated.
SUMMARY
[004] 'There is provided thermoformed packaging tray which includes a
container having
a bottom surface, an integrally formed peripheral side wall extending upwardly
from the
bottom sur.Face. The sidewall defines an open top. A rigid lip is provided on
a top edge of the
peripheral side wall; and a remote end of the lip which diminishes in
thickness to become
flexible.
BRIEF DESCRIPTION OF THE DRAWINGS
[005] 'These and other features will become more apparent from the following
description in which reference is made to the appended drawings, the drawings
are for the
purpose of illustration only and are not intended to be in any way limiting,
wherein:
FIG. 1 is a perspective view of the thermoformed packaging tray.
FIG. 2 is a side elevation view of the thermoformed packaging tray.
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FIG. 3 is a front elevation view of the thermoformed packaging tray.
FIG. 4 is a side elevation view, in section, of the thermoformed packaging
tray.
FIG. 5 is a detailed side elevation view, in section, of the thermoformed
packaging tray.
FIG. 6 is a top plan view of the thermoformed packaging tray.
FIG. 7 is a bottom plan view of the thermoformed packaging tray.
FIG. 8 is a front elevation view of the thermoformed packaging tray containing
a
product and wrapped in transparent overwrap.
FIG 9 is perspective view of the thermoformed packaging tray containing a
product and wrapped in transparent overwrap.
FIG 10 is a top plan view of the thermoformed packaging tray with
strengthening
portions in the diagonal flow channels.
FIG 11 is a top plan view on an elongated rectangular packaging tray with more
than one strengthening portion.
DETAILED DESCRIPTION
[006] A thermoformed packaging tray generally identified by reference numeral
10, will
now be described with reference to FIGS. 1 through 11.
Structure and Relationship of Parts:
[007] Referring to FIG 1, there is illustrated a thermoformed packaging tray
generally
referenced by numeral 10. Thermoformed packaging tray 10 is a container 12
that has a
bottom surface 14 and an integrally formed peripheral side wall 16 that
extends upwardly
from the bottom surface 14. The sidewall 16 is at an angle from the bottom
surface 14. The
sidewall 14 defines an open top 18. In the illustrated embodiment,
thermoformed packaging
tray 10 has a first end 20, a second end 22 and two opposed sides 24 defined
by sidewall 16.
A rigid lip 26 is provided on a top edge 28 of the peripheral side wall 16. A
shoulder 30 is
provided between the top edge 28 of the peripheral side wall 16 and the lip
26. The lip 26
curves over. A remote end 32 of the lip 26 is offset at an angle, and
diminishes in thickness
by more than 60% to become flexible such that it curves downward as
illustrated in FIG 5.
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[008] Referring to FIG 4, tray 10 is thermoformed from PET (Polyethylene
terephthalate), PVC (Polyvinyl chloride), HIPS (High Impact Polystyrene), PS
(polystyrene)
and PP (polypropylene) materials with high strength that is specific for food
products such as
meat, fish, and poultry, but can also be used well with non-food products. To
increase the
strength of thermoformed packaging tray 10, and prevent fracture or collapse
of the tray 10,
bottom surface 14 rises convexly upwardly toward its centre 34. Referring to
FIGS 2 and 4,
leaf shaped. ribs 36 are provided along peripheral wall 16. Leaf shaped ribs
36 serve to
prevent any buckling effect caused by load on thermoformed packaging tray 10.
Each leaf
shaped rib 36 curves outward from convexly from sidewall 16. Each leaf shaped
rib 36 has a
central stern portion 38 and a leaf portion 40 which fans out from central
stem portion 38.
Stabilizing ribs 42 are also provided in bottom surface 14 to allow
thermoformed packaging
tray 10 to rest flat on an underlying surface 44 as shown in FIG 3
[009] Leaf shaped ribs 36 are positioned along side wall 16 in between
stabilising ribs 42
and in corners 46 that from where first end 20, second end 22 and opposed
sides 24 of
peripheral sidewall 16 join.
[0010] Referring to FIGS 6 and 7, in the illustrated embodiment, a plurality
of
intersecting; flow channels 48 are provided in bottom surface 14 for strength
as well as flow
such as drainage. In the illustrated embodiment, the intersecting flow
channels 46 are
recessed into the bottom surface 14 and preferably extend diagonally across
the bottom
surface 14, although it will be appreciated that other types of patterns such
as traversely
extending flow channels also could be used. In the illustrated embodiment the
flow channels
48 are wider near the centre 34 of the bottom surface 14, and narrower toward
the sidewall
16. Referring to FIGS 6 and 7, a recessed flow channel 50 also extends around
a perimeter
52 of the bottom surface 14. Recessed flow channel may be in communication
with the
plurality of intersecting flow channels.
[0011] Referring to FIGS 5 and 6, a groove 54 runs along an apex 56 of the lip
26 of
peripheral sidewall 16 to provide additional strength to thermoformed
packaging tray 10.
Groove 54 can be of varying dimensions and depths but it is preferable that it
is in the range
of 0.03 to 0.08 inches across.
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Variations
[0012] Referring to FIG 10, one or more of diagonally extending flow channels
48 and
peripheral flow channel 50 may have strengthening portions 58 that interrupt
the flow. These
portions 58 may be inverted portions of the flow channel 48 or filled in to as
to strengthen the
packaging tray 10. As consumers pick up packaging tray 10, typically by the
corner 48, the
packaging tray 10 may have a tendency to fold or collapse under its load.
Strengthening
portions 58 are strategically placed in the peripheral flow channel 50 on the
opposed sides
intermediate the corners 48. Strengthening portions 58 may also be placed in
the intersecting
flow channels 48. It is preferable that the strengthening portions 58 are
placed in a diamond
pattern 60 near the centre 34 of the bottom surface 14. Referring to FIG 11,
where packaging
tray 10 is an elongated rectangle, more than one diamond pattern 60 of
strengthening portions
58 may be used to prevent folding or collapse.
[0013] Referring to FIG 5, lip 26 that extends outward from top edge 28 of
peripheral side
walls 16 gradually decreases in thickness toward a remote end 44 such that lip
26 has
increased flexibility so as to curve under. The reduction in thickness is
gradual and will be
approximately 60% or less of the parent material used to fabricate
thermoformed packaging
tray 10. By way of example, if the parent material is 20 ml in thickness at
groove 54, then lip
26 will be reduced to 5 ml thickness at remote end 32. As further examples, if
the parent
material is 15 ml thickness then lip 26 will be reduced to 3.75 ml at remote
end 32, and if the
parent material is 13 ml thickness at groove 54 then lip 26 will be reduced to
3m1 thickness at
remote end 32. The thinning of lip 26 allows it to be more flexible so as to
curve under
gently. Referring to FIG 8 and FIG 9, the added flexibility helps to prevent
overwrap film 62
from being torn or ripped when thermoformed packaging tray 10 contains a
product 64 and is
being either manually or automatically wrapped in a wrapping machine (not
shown).
[0014] In this patent document, the word "comprising" is used in its non-
limiting sense to
mean that items following the word are included, but items not specifically
mentioned are not
excluded. A reference to an element by the indefinite article "a" does not
exclude the
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possibility that more than one of the element is present, unless the context
clearly requires that
there be one and only one of the elements.
[0015] The following claims are to be understood to include what is
specifically illustrated
5 and described above, what is conceptually equivalent, and what can be
obviously substituted.
Those skilled in the art will appreciate that various adaptations and
modifications of the
described embodiments can be configured without departing from the scope of
the claims.
The illustrated embodiments have been set forth only as examples and should
not be taken as
limiting the invention. It is to be understood that, within the scope of the
following claims,
the invention may be practiced other than as specifically illustrated and
described.
