Technical Field of the Invention
[0001] The present invention generally relates to the technical field of containers for
transporting products, and more specifically to cardboard boxes or trays for transporting
wet products.
[0002] An object of the present invention is to provide, starting from a single compact
cardboard sheet, a tray for transporting wet products provided with a completely leak-tight
bottom.
Background of the Invention
[0003] Wet products, such as fish, meat or other perishables, are usually transported today
in expanded polystyrene packages or "white cork" which allows protecting the products
and keeping them fresh throughout the entire cold chain.
[0004] This type of package has serious environmental drawbacks because it is highly contaminating
material which is virtually impossible to recycle. Once the packages are disposed
of in a landfill, polystyrene is inert and does not break down, but rather will remain
there forever, which has even caused it to be prohibited in some countries.
[0005] There are some solutions in the state of the art that deal with this problem by means
of using alternative materials such as cardboard, however, although there are patent
documents such as
ES2384907 which use waterproof compounds for getting the material, corrugated cardboard in
this case, to conserve its structural properties in wet conditions, they do not assure
suitable leak-tightness because they do not provide any solution for the conventionally
weaker points in this aspect, such as the lower corners. Furthermore, the handles
located on the lower edges also play against the leak-tightness of the package. Finally,
the need to use other elements to reinforce the structure, such as fiberglass mesh
in this case, make the subsequent recycling process more complex.
[0006] A package, tray or box for transporting wet products which, without using polystyrene,
has similar strength and leak-tightness features, or such features being at least
sufficient to transport perishables, maintaining the cold chain, would therefore be
a valuable contribution to the state of the art.
Brief Description of the Invention
[0007] The object of the present invention is a leak-tight tray for transporting wet products,
such as fresh fish, for example, formed from a compact cardboard sheet with main folding
lines defining a base and four side walls facing one another in twos. The tray comprises
a tab arranged in each of the four corners of the base, where each of the tabs in
turn comprises two folding lines joining it to two side walls and a third diagonal
folding line running from the corner of the base to a free edge of the tab, where
said tab is folded towards the inside of the tray when the side walls are raised during
assembly of the tray.
[0008] Advantageously, the structure of the tray of the present invention provides complete
leak-tightness as a result of the combination of the chosen material, i.e., compact
cardboard, and the solution presented for the corners of the base. The foldable tabs
assure complete insulation and prevent any damage caused by the moisture of the transported
good. It must be pointed out that the corners and edges in materials of this type
are critical points in that they are the weakest points with respect to moisture.
Reinforcement of the base in this sense is therefore fundamental to achieve certain
durability in trays containing wet products.
[0009] According to one of the embodiments of the invention, the tabs are quadrangular-shaped
and the diagonal folding line runs from the corner of the base to a free corner of
the tab formed by two cutting lines.
[0010] Additionally, the side walls can comprise at the ends thereof prolongations defined
by folding lines coinciding with the vertical edges of the tray. Said prolongations
in turn comprise at least one additional folding line which allows forming a polyhedral
structure when folding the prolongations towards the inside of the tray. For example,
according to one of the particular embodiments of the invention, the prolongations
can have two additional folding lines, therefore splitting each of the prolongations
into 3 portions and forming a polyhedral structure having a triangular section when
the intermediate portion is folded towards the inside of the tray and the outermost
portion is folded towards the outside of the tray, being placed against the side wall.
A column is thereby advantageously formed in each of the corners of the tray which
structurally reinforce it and allows stacking several trays.
[0011] Optionally, it is contemplated that the side walls can comprise an upper flap defined
by a longitudinal folding line which allows covering the upper section of the polyhedral
structures when the flaps are folded towards the inside of the box. A support surface
for stacking other trays while at the same time reinforcing the structure of the tray
is thereby advantageously achieved.
[0012] It is contemplated in one of the embodiments of the invention that the upper flaps
comprise at each of their ends a wing, the only contact of which with the flap being
a folding line, where the wing is placed against the adjacent side wall when it is
folded towards the inside of the box. The tray is advantageously structurally reinforced,
trapping the adjacent side wall between one of the columns and one of the wings in
a sandwich-type structure.
[0013] The use of compact cardboard in the present invention provides the tray with sufficient
rigidity and strength to dispense with additional materials, unlike other solutions
of the state of the art which have to use fiber meshes on the base of the tray. The
recycling of the present invention is therefore more complete and simple to process,
being entirely environmentally friendly.
[0014] The leak-tightness of the base also involves the advantage of retaining any liquid
derived from the transported wet products, which assures the maintenance of cleanliness
and hygienic conditions of warehouses or means of transport used.
Description of the Drawings
[0015] To complement the description that is being made and for the purpose of aiding to
better understand the features of the invention according to preferred practical embodiments
thereof, a set of drawings is attached as an integral part of this description, in
which the following has been depicted with an illustrative and non-limiting character:
Figure 1 shows a plan view of a tray in the unfolded position, according to one of
the embodiments of the invention.
Figure 2 shows in detail the folding of the wings forming the reinforcement columns
according to one of the embodiments of the invention.
Figure 3 shows a 3-dimensional detail view of the lower tabs of the tray that is half-folded,
according to one of the embodiments of the invention.
Figure 4 shows a 3-dimensional view of the leak-tight tray for transporting wet products
completely assembled, according to one of the embodiments of the invention.
Preferred Embodiment of the Invention
[0016] In view of the described drawings, it can be seen how the tray proposed in the preferred
embodiment of the present invention comprises a compact cardboard sheet (1) with several
cuts and main folding lines defining a base or bottom and four side walls which in
the unfolded position are prolongations of the base, but with the box assembled, they
are vertically arranged with respect to the base and facing one another in twos.
[0017] As can be observed in Figure 1, where the unfolded sheet is depicted, there is arranged
a tab (2) in each of the corners of the base (3) of the tray. Said tab is attached
to two consecutive side walls by means of the corresponding folding lines (21), the
other two edges of the tab being free as a result of the respective cutting lines
(22). The tab thus defined is therefore a common prolongation for two consecutive
side walls and for the base. The tab has an additional folding line (23) running along
one of its diagonals, specifically the diagonal joining the corner of the base defined
by the crossing of the main folding lines with the opposite corner of the tab, such
that when assembling the tray, it allows folding, as shown in Figure 3, the tab along
said folding line towards the inside of the tray, thereby achieving complete leak-tightness
on the bottom of the tray.
[0018] The side walls (4) of one of the pairs of facing side walls have foldable wings (41)
which can be folded by means of the corresponding folding line (42). In turn, said
side wings have additional folding lines (43, 44) which, once the tray is assembled,
form polyhedral structures in the form of a column in each of the corners of the tray.
For example, with the two folding lines of this preferred embodiment, which is shown
in detail in Figure 2, a column having a triangular section (45) is obtained, where
the last part (46) of the wing, defined by the folding line (44) closest to the end,
is arranged parallel to the side wall and preferably attached to it by means of glue.
[0019] Preferably, the last part of the wing (46) is adhered at a point of the side wall
such that the first part of the wing is arranged perpendicular to the side wall and
the second part of the wing runs diagonally from the corresponding folding line (43)
to the following folding line (44), which is in contact with the side wall.
[0020] Greater compressive strength of the tray is thereby assured, which allows stacking
several trays.
[0021] The two pairs of facing side walls are of a different size such that the assembled
tray has, as can be seen in Figure 4, two sides having a greater height (4) and two
sides having a smaller height (5). Advantageously, stacking trays according to this
preferred embodiment assures the entrance of air for aerating the transported products.
In other embodiments, the side walls can be of the same dimensions, being able to
achieve the same aeration effect for the products transported in the tray by means
of different folding lines in the upper part of the side walls or directly by means
of a recess in the central part thereof.
[0022] The sides having a greater height, according to the preferred embodiment, are narrower
than the sides having a smaller height, these measurements being defined by the base,
but the proportions may vary according to other embodiments of the invention and even
be identical in width in the case of a square base.
[0023] Two of the facing sides, preferably the ones having a greater height, have openings
or grooves in the form of handles (6) for transporting the trays. Preferably, these
handles are located in a central or upper position of the side walls so as to not
jeopardize the leak-tightness of the tray.
[0024] The handles have a small tab (7) in their upper part which is joined to the side
wall by means of a folding line. This tab can be folded towards the inside of the
tray to make transport easier for an operator who, upon introducing their hands in
the handles, finds a larger contact surface and prevents or reduces possible discomforts
or even cuts.
[0025] The side walls having a greater height have an upper portion (47) defined by a folding
line (48), where said upper portion in turn has a wing (49) at each of its ends, also
defined by its corresponding folding line. The upper portion is configured for being
folded towards the inside of the tray along its folding line such that with the tray
in assembled position, it covers the upper end of the columns having a triangular
section and furthermore provides a surface for stacking other trays. The wings of
the ends are configured for being folded along the corresponding folding line and
being fixed to the adjacent side wall, preferably by means of gluing, in order to
reinforce the structure of the tray.
[0026] The side walls having a smaller height (5) have two cutting lines (51) close to their
upper corners and arranged perpendicular to the main folding line. There has been
provided between the cutting lines a folding line (52) parallel to the main folding
line such that a flap (53) is defined between the cutting lines and said folding line.
The flap is folded along the folding line in order to reinforce the structure of the
box and eliminate sharp edges in the upper part of the tray. Preferably, the flap
is fixed by means of gluing to the inner face of the side wall on which it is folded.
The upper ends (54) which are arranged on both sides of the flap, between the cutting
lines and the outer edges of the side wall, are trapped once the tray is assembled,
between the columns (45) and the wings (49) in a sandwich-type structure in order
to reinforce the structure of the tray.
[0027] As regards the process for assembling the tray, starting from the unfolded sheet
as shown in Figure 1, such process starts by folding the wings (41), as illustrated
in Figure 2. Then the compact cardboard sheet (1), with the columns (45) already formed,
is sent to an erecting machine which erects all the side walls, arranging them in
a perpendicular position with respect to the base (3) of the tray. During erection,
a tool of the erecting machine pushes the tabs (2) in each of the corners of the base
towards the inside of the tray, such that the tab, as can be seen in Figure 3, is
folded along the diagonal (23) and the base of the tray is completely leak-tight as
its four corners are closed, as shown in Figure 4. Additionally, a line of hot melt-type
glue is dispensed in the area of the sides close to the tab to assure leak-tightness
from bottom to top.
[0028] Generally each of the parts which are folded over others receives gluing which reinforces
the attachment and maintains the shape and structure of the tray.
[0029] The preferred material for this embodiment is compact cardboard, given that its structural
properties of hardness, rigidity, strength and impermeability are suitable for the
envisaged use of transporting wet products without requiring additional materials
or treatments. Nevertheless, other embodiments of the present invention contemplate
other similar materials for the sheet, such as corrugated cardboard, reinforcement
materials at given points or waterproof treatments.
1. Leak-tight tray for transporting wet products formed from a compact cardboard sheet
(1) with main folding lines defining a base (3) and four side walls (4, 5) facing
one another in twos, characterized in that it comprises a tab (2) arranged in each of the four corners of the base, where each
of the tabs in turn comprises two folding lines (21) joining it to two side walls
and a third diagonal folding line (23) running from the corner of the base to a free
edge (22) of the tab, where said tab is folded towards the inside of the tray when
the side walls are raised during assembly of the tray.
2. Tray according to claim 1, where the tab is quadrangular-shaped and where the diagonal
folding line runs from the corner of the base to a free corner of the tab formed by
two cutting lines.
3. Tray according to any of the preceding claims, where at least one of the side walls
further comprises at the ends thereof prolongations (41) defined by folding lines
(42) coinciding with the vertical edges of the tray, where said prolongations in turn
comprise at least one additional folding line (43) which allows forming a polyhedral
structure when folding the prolongations towards the inside of the tray.
4. Tray according to claim 3, where the prolongations comprise two additional folding
lines (43, 44) splitting each of the prolongations into 3 portions and forming a polyhedral
structure having a triangular section when the intermediate portion is folded towards
the inside of the tray and the outermost portion is folded towards the outside of
the tray, being placed against the side wall.
5. Tray according to any of claims 3, 4, where at least one of the side walls comprises
an upper flap defined by a longitudinal folding line which allows covering the upper
section of the polyhedral structures when the flaps are folded towards the inside
of the box.
6. Tray according to claim 5, where the flap further comprises at each of its ends a
wing the only contact of which with the flap being a folding line, where the wing
is placed against the adjacent side wall when it is folded towards the inside of the
box.