HEAL-SEALABLE PACKAGING AND ASSOCIATED MANUFACTURING PROCESS

Abstract

Heat-sealable packaging comprising an inner container (1) formed from a first flat sheet (3) of cellulose material, an outer shell (2), linked to an upper end of the container (1) in the vicinity of its upper opening, formed from a second sheet (6) of cellulose material, flat and die-cut, comprising at least one outer perimeter surface (9) giving rise to a flat surface around the upper opening of the container (1) for closing the container by heat-sealing of a plastic sheet, and a plastic coating film covering at least the inner side of the container (1) and the outer perimeter surface (9) of the enclosure (2). The first sheet (3) and the second sheet (6) have different and independent perimeter dimensions and outlines.

Claims

1. Heat-sealable packaging comprising: an internal container (1) with at least one upper opening, made from a flat first sheet (3) of cellulose material, die-cut and that comprises folding lines delimiting on said first sheet (3): a central sector (4) of polygonal geometry that gives rise to a container base (1); and first side flaps (5) which start from each side of the central sector (4) and lead to a closed side wall of the container (1); an outer shell (2), linked to the upper end of the container (1) near its upper opening, made from a second sheet (6) of cellulose material, flat and die-cut, which comprises: a polygonal central opening (7), passing through between front and rear sides of the second sheet (6); a perimeter folding line (8), essentially parallel to an external perimeter edge of the second sheet (6); an external perimeter surface (9), delimited between the perimeter folding line (8) and the external perimeter edge of the second sheet (6), which gives rise to a flat surface around the upper opening of the container (1) for closing the packaging by heat-sealing a plastic sheet; diagonal folding lines (10) extending from each corner of the central opening (7) in the direction of the corners of the second sheet (6) until they intersect with the perimeter folding line (8); and second side flaps (11) bounded by diagonal folding lines (10) to give rise to side walls of the shell (2), intended to cover at least partially the outer face of the closed side wall of the container (1) to provide a connecting surface between the shell (2) and the container (1); and a plastic coating film that covers at least the inner side of the container (1) and the outer perimeter surface (9) of the shell (2), and in which the first sheet (3) and the second sheet (6) have different and independent dimensions and perimeter contours.

2. The heat-sealable packaging of claim 1, wherein each of the second side flaps (11) of the second sheet (6) additionally comprises a bottom folding line (12), located in the vicinity of the central opening (7) and essentially parallel to the corresponding side of this central opening (7), to delimit at the bottom end of each second side flap (11) from a corresponding bottom flap (13).

3. The heat-sealable packaging of claim 1, wherein the cellulose material of the first sheet (3) and the second sheet (6) is compact cardboard.

4. A process of manufacturing the heat-sealable packaging of claim 1 on an assembly machine comprising: first sheet (3) and second sheet (6) loading elements; and elements for applying pressure and heat; the process comprising: loading a first sheet (3); loading a second sheet (6) and positioning it on a mold, with the first sheet (3) located above the second sheet (6); applying pressure on the upper face of the first sheet (3), to fold and form the closed side wall and the base of the container (1); positioning of the container (1) already formed over the second sheet (6); applying pressure on the upper side of the container (1) base to fold the second sheet (6); applying heat for mutual sealing between the container (1) and the already formed shell (2); and applying the plastic coating film on the internal side of the packaging.

5. The process of claim 4, wherein each of the second side flaps (11) of the second sheet (6) additionally comprises a bottom folding line (12), located in the vicinity of the central opening (7) and essentially parallel to the corresponding side of this central opening (7), to delimit at the bottom end of each second side flap (11) from a corresponding bottom flap (13).

6. The process of claim 5, wherein the cellulose material of the first sheet (3) and the second sheet (6) is compact cardboard.

7. The process of claim 4, wherein the cellulose material of the first sheet (3) and the second sheet (6) is compact cardboard.

8. The heat-sealable packaging of claim 2, wherein the cellulose material of the first sheet (3) and the second sheet (6) is compact cardboard.

Description

DESCRIPTION OF THE DRAWINGS

[0020] To complement the description being made and in order to help a better understanding of the characteristics of the invention, in accordance with a preferential example of practical implementation of the same, is accompanied as an integral part of that description a set of drawings where, for illustrative purposes and not limited, the following has been represented:

[0021] FIG. 1.—Shows a top perspective view of the packaging according to a first preferential realization.

[0022] FIG. 2.—Shows an exploded view of the packaging of FIG. 1.

[0023] FIG. 3.—Shows a plan view of the die-cut sheet that makes up the internal container of the packaging of FIG. 1.

[0024] FIG. 4.—Shows a plan view of the die-cut sheet that makes up the outer shell of the packaging of FIG. 1.

[0025] FIG. 5.—Shows an upper perspective view of an exploded packaging according to a second preferred embodiment.

[0026] FIG. 6.—Shows a top perspective view of the packaging of FIG. 5.

[0027] FIG. 7.—Shows a bottom perspective view of the packaging of FIG. 5.

[0028] FIG. 8.—Shows a plan view of the die-cut sheet that makes up the internal container of the packaging of FIG. 5.

[0029] FIG. 9.—Shows a plan view of the die-cut sheet that makes up the outer shell of the packaging of FIG. 5.

[0030] FIG. 10.—Shows a plan view of the die-cut sheet that forms the internal container of a packaging according to a third preferred embodiment.

[0031] FIG. 11.—Shows a plan view of the die-cut sheet that makes up the outer shell of a packaging according to the third preferred embodiment.

[0032] FIG. 12.—Shows a schematic view of the sequence of operations in the packaging manufacturing process.

PREFERRED EMBODIMENT OF THE INVENTION

[0033] A detailed explanation of an example of a preferred embodiment of the object of the present invention is given below with the help of the above-mentioned figures.

[0034] The heat-sealable packaging described herein is made up of two parts which are mutually superimposed and linked, as illustrated in FIGS. 1 and 2, with these parts being an inner part or container (1), with at least one upper opening, and an outer part or shell (2), linked to an upper end of the container (1) in the vicinity of its upper opening. Both parts are linked together by standard forming procedures.

[0035] The container (1) is designed to hold a product, and is made from a first sheet (3) of cellulose material, in this case cardboard, flat and die-cut as shown in FIG. 3. This first sheet (3) has a front face and a back face, and on it folding lines are defined to delimit portions in the sheet, more specifically a central sector (4) with a polygonal geometry and first side flaps (5) which start from each of the sides of the central sector (4).

[0036] Once the folding lines of the first sheet (3) have been folded to form the container (1), the central sector (4) gives rise to a container (1) base, while the first side flaps (5) give rise to a closed side wall of the container (1), as illustrated in FIG. 1.

[0037] The shell (2) is designed to provide the container (1) with a reinforcing element which, in turn, facilitates the creation of a superior closure by means of heat-sealing. For this purpose, it is made from a second sheet (6) of cellulose material, in this case cardboard, flat and die-cut as shown in FIG. 4. As can be seen in FIG. 4 and FIG. 3, the first sheet (3) and the second sheet (6) have different and independent dimensions and perimeter contours.

[0038] The second sheet (6) has a central opening (7), which is a polygonal opening between the front and rear faces of the second sheet (6), and a perimeter folding line (8), which is essentially parallel to an external perimeter edge of the second sheet (6), so that between it and the perimeter folding line (8) there is a portion of sheet intended to form an external perimeter surface (9) of the shell (2), which in turn is intended to subsequently generate a lip or flat flange that acts as a sealing surface for the packaging, around a perimeter edge of the upper opening of the container (1).

[0039] Diagonal folding lines (10) extend from each corner of the central opening (7) towards the corners of the second sheet (6) until they intersect with the perimeter folding line (8). These diagonal folding lines (10) delimit second side flaps (11) on the second sheet (6).

[0040] Once the folding lines of the second sheet (6) have been folded to form the shell (2), the second side flaps (11) give rise to side walls of the shell (2), designed to cover at least part of the external face of the closed side wall of the container (1) to act as a connecting surface between the shell (2) and the container (1) when the packaging is made.

[0041] In this first embodiment of the packaging, the closed side wall of the container (1) has high longitudinal dimensions, giving rise to a deep packaging with an elongated configuration, of the type usually used to contain popcorn. FIGS. 5-11 illustrate second and a third embodiments of the packaging, in which the closed side wall of the container (1) is smaller in length, giving rise to a shallow tray-type packaging of the type normally used to contain fruit or pieces of meat.

[0042] As can be seen in these figures, it is envisaged that in the second sheet (6) each of the second side flaps (11) would additionally include a lower folding line (12), located in the vicinity of the central opening (7) and essentially parallel to the corresponding side of this central opening (7), in order to delimit a corresponding lower flap (13) at the lower end of each second side flap (11).

[0043] Once the folding lines of the second sheet (6) have been folded to form the shell (2), each lower flap (13) provides an additional surface for joining the shell (2) to the container (1), in this case to cover at least part of the external face of the base of the container (1) when making the packaging.

[0044] FIGS. 10 and 11 illustrate a third embodiment of the packaging, in which the container (1) is formed from a first sheet (3) of octagonal geometry.

[0045] Once the packaging has been formed after the mutual union of container (1) and shell (2), the preferred embodiment of the packaging further incorporates a plastic coating film, not shown in the attached figures. This sheet covers at least the internal face of the container (1), which is intended to be in direct contact with the contents of the packaging, and the external perimeter surface (9) of the shell (2), which provides the surface for heat sealing.

[0046] The heat-sealable packaging described above is produced on an assembly machine comprising first (3) and second sheet (6) loading elements and elements for applying pressure and heat, as shown in schematic form in FIG. 12.

[0047] This procedure comprises the following sequence of steps: [0048] loading a first sheet (3); [0049] loading a second sheet (6) and positioning it on a mould, with the first sheet (3) located above the second sheet (6); [0050] applying pressure on the upper face of the first sheet (3), to fold and form the closed side wall and the base of the container (1); [0051] positioning of the container (1) already formed over the second sheet (6); [0052] applying pressure on the upper side of the container (1) base to fold the second sheet (6); [0053] applying heat for mutual sealing between the container (1) and the already formed shell (2); and [0054] applying the plastic coating film on the internal side of the packaging.