Note: Descriptions are shown in the official language in which they were submitted.
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A FOOD CONTAINER
Field of the Invention
The present invention relates to a food container, in particular, a food
container that
comprises a combination of strengthening features which are adapted to
increase the
stiffness of the food container.
Description of the Prior Art
Food containers have been manufactured in a variety of sizes and shapes
depending on
specific applications. A specific type of food container is the so-called two-
piece container
comprising a body and a cover. Two-piece containers are normally relatively
small
containers. In case of larger containers, it is often needed to produce the
containers from
three pieces - a bottom, a cover and a side piece.
In EP 0 480 854, a rectangular container for canned goods is disclosed - see
Fig. 1. The
container disclosed in EP 0 480 854 is a two-piece container - meaning that
the body of
the container is made out of one piece. A cover is positioned on top of the
body for closing
the container. In order to support the container, and thereby increase the
stiffness of the
container, the sidewalls are divided into an upper and a lower part. The upper
part and the
lower part being connected by two horizontally arranged shoulders. In order to
further
increase the stiffness of the sidewall vertically arranged corrugations are
provided in the
lower part of the sidewall. The lower one of the horizontally arranged
shoulders upwardly
concludes the corrugations so that no corrugations are found in the upper part
of the
sidewall.
WO 97/11887 also relates to a rectangular container for canned goods. The
disclosed
container has vertical corrugations and two shoulders dividing the sidewall
into a lower
part and an upper part. The upper of the two shoulders concludes the vertical
corrugations so that no corrugations are found in the upper part of the
sidewall.
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Description of the Invention
It is an object of the present invention to provide a food container with an
improved
stiffness and ability to be stacked and a container that at the same time
requires only
simple manufacturing tools .
The above-mentioned objects are obtained by providing a food container
comprising:
- a bottom and an opening,
- a sidewall extending between the bottom and the opening, said sidewall
comprising an upper and a lower part,
- at least one abutment shoulder(s) connecting the upper and lower parts of
the
sidewall, said abutment shoulder(s) extending in a substantially horizontal
direction, and
- one or more strengthening features being formed in at least a part of the
upper
part of the sidewall and in a part of the lower part of the sidewall, said one
or more
strengthening features extending in a substantially vertical direction and
intersecting the at least one abutment shoulder(s).
Preferably, the upper part overhangs the lower part, so that the containers
may be
stacked in a way that prevent the containers from sticking to each other.
A top cover that is hermetically sealed to the sidewall may cover the opening.
When
sealing the coverage to the sidewall, a horizontal edge portion of the upper
part of the
sidewall may be bent together with an edge portion of the cover. When the
thickness of
the sidewall is low, prior art containers may deform in the upper part of the
sidewall and
such deformation can cause an unacceptable sealing of the container.
It has been found that the upper part of the sidewall can be provided with an
extra
stiffness by not ending the strengthening features with a shoulder. Thus, for
preventing
the above-mentioned deforming, the container according to the invention
comprises one
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or more strengthening features that extend in a substantially vertical
direction from the
lower part of the sidewall, below the at least one abutment shoulder(s) and
into the upper
part of the sidewall, above the at least one abutment shoulder(s). The
strengthening
features thus stiffen both the lower part and the upper part of the sidewall
as well as the
abutment shoulder it self. When the strengthening features are provided
unbroken from
the lower part of the sidewall and into the upper part of the sidewall a 3-
dimensional
strengthening structure can be created close to the upper edge of the
container. Such a 3-
dimensional structure provides very good stiffening of the upper part of the
sidewall close
to the opening of the container wherein the stiffness of the container is of
high importance.
The containers are typically stacked into piles of containers before they are
delivered to
the maker of the products to be packed in the containers. By the containers
known in the
art, there is a risk that vacuum arises between the stacked containers. The
vacuum can
complicate the de-stacking of the containers. The vacuum will not arise by
stacking
containers according to the present invention. Since the shoulder that serves
as support
for the next container in the stack of containers is intersected by the
strengthening
features, the chamber between the containers will always be in connection with
the
surrounding atmosphere and therefore vacuum between the containers is avoided.
Preferably one or more of the strengthening features are being formed in a
length of at
least 50 percent of the vertical size of the upper part of the sidewall. In
that way the part of
the sidewall that are near the opening of the container is being stiffened by
the
strengthening features.
The abutment shoulder(s) may form an unbroken line extending around the entire
length
of the sidewall or it may form a number of marks e.g. at corners of the
sidewall or along
rectilinear parts of the sidewall.
Depending on the required stiffness of the sidewall, the one or more
strengthening
features may extend from the bottom to the opening of the container. The one
or more
strengthening features may have predetermined lengths, and preferably the
lengths may
exceed 50% of the shortest distance between the bottom and the opening of the
container. However, the lengths may exceed 55%, such as 60%, such as 65%, such
as
70%, such as 75%, such as 80% such as 85%, such as 90%, such as 95%, such as
98%
of the shortest distance between the bottom and the opening of the container.
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Preferably, the container has a rectangular cross sectional shape with curved
corner
sections being connected by the sidewall. The one or more strengthening
features may be
positioned on the sidewall between two curved corner sections, and preferably
they may
intersect the abutment shoulder of the sidewall over a distance exceeding 50%
of the
shortest distance between the two curved corner sections. However, they may
also
intersect the abutment shoulder of the sidewall over a distance exceeding 55%,
such as
60%, such as 65%, such as 70%, such as 75% of a distance between the two
corner
sections.
In a preferred embodiment, the one or more strengthening features comprise a
corrugation that may be, e.g., die stamped in the sidewall. The corrugation
may exceed as
described above, and it may have a depth that preferably is in the range 0.1 -
2 mm, such
as 0.2 - 1.8 mm, such as 0.3 - 1.6 mm, such as 0.4 - 1.4 mm, such as 0.5 - 1.2
mm, such
as 0.6 - 1 mm, such as 0.7 - 0.9 mm. Preferably, the sidewall comprises more
than one
corrugation, such as two or three or four or five or six or seven or eight or
nine or ten or
even more than ten corrugations.
The corrugations may be positioned in the sidewall with a mutual distance, and
the
distance between two valleys of two neighbouring corrugations (also called a
corrugation
period) may be in the range 1 - 10 mm, such as 2- 9 mm, such as 3 - 8 mm, such
as 4 - 7
mm, such as 5 - 6 mm. The corrugations may be divided into one or more parts
of the
sidewall corresponding to the four rectilinear parts of the sidewall.
Furthermore, the
corrugations may have various cross-sectional shapes.
The container could be made from a number of different materials. Preferably
the
container is made from a sheet of metal such as a light-alloy metal, e.g.
aluminium or from
tinplate or ECCS etc. The sheets of metal could be formed into a container,
e.g. by die
stamping or by deep drawing. Alternatively the container is made from more
sheets of
metal, e.g. one sheet for the bottom part and one sheet for the sidewall, the
two sheets
being individually formed and welded or glued together.
The container could also be made from a sheet of a substantially rigid plastic
material
being formed into the container shape e.g. by vacuum forming or pressing.
Finally the
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container could be made from moulded or blow moulded plastic or composite
material
comprising plastic.
The sidewall may have any predetermined thickness depending on the size of the
5 containers. Preferably, the thickness of the sidewall is within the range
0.05 - 1.5 mm,
such as 0.06 - 1.3 mm, such as 0.07 - 1.2 mm, such as 0.08 - 1.0 mm, such as
0.1 - 0.8
mm, such as 0.11 - 0.6 mm, such as 0.12 - 0.4 mm, such as 0.13 - 0.3 mm, such
as 0.14 -
0.2 mm.
The above-mentioned thickness may also apply to the bottom part and to a top
coverage.
Detailed description of the invention
A preferred embodiment of the present invention will now be described in
details with
reference to the accompanying drawings Fig. 1-4, wherein
Fig. 1 shows a rectangular body of a container for canned goods according to
EP 0 480
854,
Fig. 2 is a side view of a container with a bottom and a sidewall having
strengthening
features according to the present invention,
Fig. 3 is a top view of a container according to the present invention, and
Fig. 4 is a cross-sectional view of two containers stacked in a pile.
Fig. 1 shows a rectangular body of a container for canned goods according to
EP 0 480
854. The body comprises a bottom section 1 and a sidewall 2. The sidewall 2
comprises
corrugations 3 that extend from the bottom section to a lower shoulder 4. The
embossing
mark 5 defines an upper shoulder. The flange 6 serves for the attachment of a
closure by
beading the flange 6 and a corresponding flange of the closure into sealing
engagement.
Fig. 2 and 3 shows a container that comprises a bottom section 1 and a
sidewall 2
extending from the edge of the bottom section 1 in an angle to vertical which
is greater
than zero.
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The sidewall comprises embossing marks 5, in order to increase the stiffness
of the
sidewall and to facilitate stacking of the containers without the containers
sticking to each
other.
The embossing marks 5 of the sidewall of the container comprise a horizontally
extending
rectilinear edge forming an abutment shoulder near the upper edge 6 forming a
flange for
attaching a closure to the container. The shoulder 5 of the sidewall separates
the sidewall
in two parts - an upper part 7 having an opening provided in order to cover a
larger area
than the lower part 8 of the sidewall. The abutment shoulder 5 is adapted to
provide
stiffness to the upper edge of the container. In order to ensure adequate
stiffness, the
distance from the upper edge 6 of the sidewall to the horizontally extending
edge of the
shoulder 5 is between 1 mm and 10 mm. The shoulder forms an angle with the
upper and
lower parts of sidewall, so as to support another container body being stacked
on top of
the container body.
The sidewall further comprises vertical corrugations 9 extending from the
lower part 8 to
the upper part 7 of the sidewall 2 as seen in Figs. 2 and 3. The vertical
corrugations 9 are
adapted to increase the stiffness of the sidewall of the container and are
embossed
substantially perpendicular to the shoulder 5. The corrugations 9 intersect
the shoulder 5,
so as to stiffen the abutment shoulder 5 and the upper part 7 and lower part 8
of the
sidewall. As seen in Fig. 2 the corrugations 9 fades out in the upper part 7,
close to the
flange 6. The out-fading corrugations creates a 3-dimensional embossing
structure which
provides the area of the upper part 7 close to the flange 6 with a good
stiffness.
The sidewall 2 comprises a flange 6 covering a larger area than the upper part
of the
sidewall. The flange 6 has a horizontal and plane surface 10, which is adapted
to receive
a closure/coverage for sealing the container by beating a corresponding flange
of the
closure into a sealing engagement. Furthermore, the upper edge 6 contributes
to
increasing the stiffness of the opening of the container.
As seen in Fig. 3, the bottom section 1 has embossed marks 11 for increasing
the
stiffness of the bottom section. The embossing marks 11 can have any shape
that
increases the stiffness of the bottom section in all directions such as a
round or an oval
mark.
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The embossing marks 11 on the bottom section 1 and the corrugations 9 in the
sidewall 2
is made by die stamping. Alternatively they can be made by deep-drawing or
casting, or
the features can be made in a separate process.
Fig. 4 shows a cross-sectional view of two containers being stacked in a pile.
The
abutment shoulders 5 form an edge providing a rest for containers stacked in a
pile. This
feature is provided for the reason of easy handling and storing of the
containers until the
time where they are being filled. The corrugations 9 (in Fig. 2 and 3) have
upper parts
terminating at the top point 12. As seen in Fig. 4 the corrugations 9 open a
passage 13
where air can flow into the chamber between the containers.
