U.S. patent number 3,761,011 [Application Number 05/280,747] was granted by the patent office on 1973-09-25 for food packaging tray.
This patent grant is currently assigned to Diamond International Corporation. Invention is credited to Kenneth D. Bixler, Richard F. Reifers.
United States Patent |
3,761,011 |
Reifers , et al. |
September 25, 1973 |
FOOD PACKAGING TRAY
Abstract
A food packaging tray is molded of wood pulp or plastic and is
intended for the packaging of food products in conjunction with a
transparent overwrap plastic film. The tray has an improved
peripheral lip which resists inward collapse of the side and end
walls of the tray from the pressure exerted by the transparent
overwrap plastic film.
Inventors: |
Reifers; Richard F. (New
Canaan, CT), Bixler; Kenneth D. (Huntington, NY) |
Assignee: |
Diamond International
Corporation (New York, NY)
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Family
ID: |
23074453 |
Appl.
No.: |
05/280,747 |
Filed: |
August 15, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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246600 |
Apr 24, 1972 |
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111578 |
Feb 1, 1971 |
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Current U.S.
Class: |
229/407;
217/26 |
Current CPC
Class: |
B65D
1/34 (20130101) |
Current International
Class: |
B65D
1/34 (20060101); B65d 001/00 (); B65d 065/00 () |
Field of
Search: |
;229/2.5,29 ;217/26
;206/45.33 ;99/174 ;D9/219 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moorhead; Davis T.
Parent Case Text
This is a continuation-in-part application of copending
application, Ser. No. 246,600 filed Apr. 24, 1972, which in turn is
a continuation-in-part of then copending application, Ser. No.
111,578 filed Feb. 1, 1971.
Claims
What is claimed is:
1. In a generally rectangular molded tray for the packaging of
meat, fish, poultry or produce in conjunction with a transparent
overwrap film heat-sealed thereabout, said tray comprising: a pair
of upwardly and outwardly inclined side walls, each said side wall
forming a long side of said tray; a pair of upwardly and outwardly
inclined end walls, each said end wall being adjacent to ends of
said side walls, and thereby forming the rectangular configuration
of said tray; a generally rounded corner between each said side
wall and each said end wall; bottom wall means for supporting the
meat, fish, poultry or produce comprising a bottom wall connecting
the bottom portions of said end and side walls; and a peripheral
lip extending outwardly from said side and end walls and defining
the periphery of the tray, the improvement wherein
said peripheral lip comprises a relatively large and thick portion
dome-shaped in cross-section defining the uppermost portion of the
tray, and a horizontal portion extending outwardly from said
dome-shaped portion at a location substantially below the top of
the dome-shaped portion.
2. A tray in accordance with claim 1 wherein said end and side
walls are bowed.
3. A tray in accordance with claim 2 of wood pulp.
4. A tray in accordance with claim 3 wherein said wood pulp tray
has a large capacity to accept free liquid.
5. A tray in accordance with claim 2 of foam plastic.
6. A tray in accordance with claim 1 wherein said horizontal
portion of said lip is located at least two-sevenths of the
distance from the top to the bottom of the tray.
Description
FIELD OF THE INVENTION
The present invention relates to a food packaging tray and, more
particularly, to a food packaging tray for use in the packaging of
fresh meat, poultry, fish or produce in conjunction with a
transparent overwrap film, and where an improved peripheral lip is
provided to assist in preventing inward collapse of the side and
end walls of the tray due to the pressures exerted by the overwrap
film.
BACKGROUND
Food trays molded from wood or paper pulp or from clear or foam
plastic are customarily used in most retail food markets today,
particularly for the packaging of fresh meat, poultry, fish,
produce or other commodities. These containers are usually in the
form of shallow, generally rectangular trays in which the
commodities are placed, with a transparent sheet or heat sealable
cellophane or of heat shrinkable or stretchable plastic film
tightly wrapped about the tray and heat sealed along the bottom to
form a complete package.
Food trays play an important part in merchandising various
commodities, and the ultimate appearance of the packaged food is an
important factor in the sale of the product, i.e. a neat,
clean-appearing package has an important relationship to the sales
appeal of the goods being sold, and an unattractive package can be
a sales deterrent. Accordingly, a tray for the packaging of such
products should not have collapsed or cracked or broken side
walls.
Additionally, with the advent of production line packaging, a
vertical stack of food trays is generally stored in a hopper or
magazine for either mechanical and/or manual denesting prior to
packaging, and it is important that molded trays be readily
denestable by providing sufficient denesting clearance between
adjacent nested trays. In particular, the area of the lip normally
provides a good denesting area.
Furthermore, the food packaging trays must be strong enough to
resist rough handling and retain their shape and appearance, not
only for the reasons indicated above with regard to sales appeal,
but also to maintain the packaged food in a clean environment, to
protect the food from physical damage, and to prevent spilling of
the goods from a damaged container.
Additionally, food trays are one-use, throw-away items and for this
reason the cost must be kept to a minimum. Thus, while the
strength, neat appearance and ability to form a good package must
be maximized, the cost of the package must be minimized since it is
entirely a merchandising cost.
Molded wood or paper pulp food trays have served the food packaging
industry well for many years for the packaging of meat, fish,
poultry and produce. Such trays have the advantage, besides low
price and low cost to the consumer, of being clean, sturdy and
safe; of being biode-gradable so as to minimize the solids
pollution problem; of being capable of assimilating the free juices
which exude from some meats and poultry; and of being air and vapor
permeable so as to maintain color and freshness of meat. Thus, the
molded wood pulp trays previously manufactured were very
satisfactory for the purpose for which they were intended; however,
a constant endeavor is being made to afford even better trays
without an increase in cost to the retailer or ultimate
consumer.
Paperboard trays, i.e. cut and scored trays formed from flat sheets
of paperboard, are not especially adapted for use with shrink and
stretch plastic films, since the side walls of such board trays do
not have the requisite side wall characteristics to afford
uniformly appearing packages after overwrapping with the film. Foam
plastic trays are in general not sufficiently strong, are not
usually biodegradable, cannot assimilate free juices and are not
air and vapor permeable. The so-called clear plastic trays have
even greater defects; besides having all the defects of the foam
plastic trays mentioned above, they often have sharp edges which
cut the overwrap film permitting contamination of the food products
and leakage of the contents and, in addition, color and freshness
of meat packaged in such trays are not normally maintained very
long.
Earlier trays molded of wood pulp were first produced without an
upper peripheral lip. These trays were highly practical and
satisfactory for the purpose intended. Later trays had essentially
straight side walls and a flat peripheral lip; these trays served
the trade successfully for many years and leant themselves to form
a highly desirable package when wrapped with non-shrink or
non-stretch films such as heat-sealable cellophane. However, as the
nature of transparent plastic wrap film changed and non-elastic and
non-shrink cellophane was replaced with more elastic thermoplastic
shrink or stretch overwrap films, the tray in accordance with the
Reifers U.S. Pat. No. 3,185,371 was developed, improving the tray
performance.
SUMMARY
The present invention involves a novel tray and package and
incorporates the desirable advantages and benefits of prior trays
and is especially designed for use with heat-shrinkable or
stretchable overwrap plastic film, although it may be used as well
with heat-sealable cellophane. This novel tray and package formed
therewith give increased benefits to the consumer without an
appreciable increase in cost.
It is, accordingly, an object of the present invention to overcome
the deficiencies of the prior art, such as indicated above.
It is another object of the present invention to provide for the
improved packaging of food products.
It is another object of the present invention to provide an
improved food tray for the packaging of meat, fish, poultry or
produce.
It is another object of the present invention to provide a food
tray which may be fabricated of various materials, and one which is
preferably molded of wood pulp or plastic.
It is another object of the present invention to provide a molded,
nestable tray, preferably of wood or paper pulp or the like, for
the packaging of meat, fish, poultry or produce, which has
increased side wall cave-in resistance.
It is another object of the present invention to provide for the
clean, safe and effective packaging of food products.
It is another object of the present invention to provide a food
packaging tray which is not only effective but which is
inexpensive.
It is another object of the present invention to provide a molded
food tray which affords a substantially rectangular appearance
before and after a package is formed therewith, which is adapted
for use with a package forming wrapper, and which provides for a
special structure and shape maintaining the desired rectangular
shape and resistance to internally directed forces on side walls
when forming a package utilizing a shrink or stretch film.
A still further object of the present invention is to provide a
novel food tray which includes an improved peripheral lip structure
insuring improved nesting and denesting clearances.
And yet another object of the present invention is to provide a
novel package which includes improved structure to present a
substantially rectangular appearing package of greater strength
than was heretofore thought possible.
It is another object of the present invention to provide a
construction which reduces movement of exuded liquids from the
inside to the outside of the package.
These and other objects in the nature and advantages of the instant
invention will be more apparent from the following detailed
description of a specific embodiment, such a specific embodiment
being described below with reference to the attached drawing, it
being understood that such embodiment is intended as merely
exemplary and in no way limitative.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a tray in accordance with the
present invention;
FIG. 2 is a vertical sectional view taken along line 2--2 of FIG.
1;
FIG. 3 is a vertical sectional view taken along line 3--3 of FIG.
1; and
FIG. 4 is a partial sectional view showing a completed package.
DETAILED DESCRIPTION OF EMBODIMENT
A novel food tray in accordance with the present invention is shown
generally at 10 in FIG. 1. The tray 10 has a suitable bottom wall
12 of any desired configuration, such as that shown in parent
application, Ser. No. 246,600, although for simplicity a simple
flat, uniform and imperforate bottom is shown. In addition the tray
has a pair of opposite facing side walls 14 and a pair of opposite
facing end walls 16. Extending about the upper edge of the walls 16
and 14 and integral therewith is a downwardly angled, peripheral
lip 18, the details of which form the major aspects of the present
invention, and which are described in greater detail below. The
side walls 14 and end walls 16 are preferably arcuately bowed as is
described in the Reifers U.S. Pat. No. 3,185,371.
Referring to FIG. 4 there is seen a cut of meat 22 packaged using
the tray of the present invention in conjunction with an overwrap
transparent film 25. The peripheral lip 18, as is best seen in this
figure, has an outwardly extending horizontal terminal portion 19
and an upper rounded domed portion 20. The horizontal terminal
portion 19 is located at a level substantially below the top of the
domed portion 20; furthermore, the portion 19 extends outwardly far
more than do the conventional lips heretofore used in prior
practice.
As seen in FIG. 4, the film 24 contacts the lip 18 along two
distinct and separated portions, i.e. the end of the terminal
portion 19 and the top of the domed portion 20 and this provides a
double gasket or sealing function. With the "problem cuts" of beef,
namely the 10-15 percent of packaged meat which bleeds profusely,
the peripheral lip 18 tends to prevent the travel of free liquid by
capillary action between the film 24 and the lip from the inside to
the outside of the tray 10 where it would cause the plastic heat
seal of the plastic film 24 to open effecting leakage and
unwrapping of the package, besides providing an unsightly
appearance.
However, the lip 18 has highly important mechanical advantages
regardless of the product packaged in the tray. The lip 18 is
provided with a greater material mass which provides additional
beam strength and also has additional cave-in resistance strength
so as to resist inward force provided by the tension exerted by the
stretched film 24. In addition, the horizontal portion 19, being at
a height considerably lower than the domed portion 20, absorbs
inwardly directed forces in a manner that stresses the side wall
less because the resultant lever arm is lower, e.g. 30-35 percent
lower. Additionally vector analysis shows that the net effect in
inward deflection resulting from inward force is reduced and there
is 12 percent less bending moment.
Thus, it would be understood that the horizontal portion 19, as
illustrated, is at a height of about two-sevenths, or even more, of
the distance from the top to the bottom of the tray.
While the tray of the present invention is preferably molded of
conventional wood or paper pulp stock which may be formed or
preformed from a water slurry, it will be understood that the
construction provided is particularly suitable to the manufacture,
preferably by molding, of trays from other materials, particularly
foam plastic or even solid plastic. Thus, the tray of the present
invention may be formed of other, equivalent materials, the
structural advantages of the tray deriving from its geometry. Among
other materials there may be mentioned conventional polystyrene
foam, structural cellular polystyrene foam, porous polyolefin
material, open cell polystyrene foam, or biodegradable foam
polystyrene. If formed of materials having different strength
characteristics, certain advantages may be absent.
When the tray is molded of a special wood pulp having a large
capacity to accept free liquids, the tray 10 has particular
effectiveness in the packaging of the "problem cuts" of meat or
"heavy bleeders," as they are often called. In such cases the
combination of the special furnish and the double gasket seal
provided by the lip 18 effectively prevents the movement of exuded
fluids from the inside to the outside of the tray.
It will be obvious to those skilled in the art that various changes
may be made without departing from the scope of the invention and
the invention is not to be considered limited to what is shown in
the drawings and described in the specification.
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