Food packaging

Abstract

The invention relates to food packaging comprising: a cardboard tray (74) having a base and four sides arranged in pairs opposite each other with respect to said base, said four sides defining four vertices (76, 78, 80, 82) delimiting an opening; a transparent film (110) attached to said four vertices (76, 78, 80, 82) for closing said opening. The two vertices (76, 78) of two opposite sides among the four sides each comprise a foldable edge (54, 56), the two foldable edges being folded towards each other; and said transparent film (110) is attached to said two folded edges (54, 56). Figure to be published with the abstract: Fig. 5

Description

Title of the invention: Food packaging

[0001] The present invention relates to a food packaging that allows the contents to be viewed from the outside.

[0002] One envisaged field of application is in particular, but not exclusively, that of the packaging of fruits and vegetables.

[0003] It is known to package perishable goods in cardboard trays. The trays have a base and four sides arranged in pairs opposite each other with respect to the base. The sides are connected laterally to one another, thus forming a cavity suitable for receiving the goods. The four upright sides define four vertices, which delimit an opening.

[0004] It is known to close the trays using a lid made of a transparent polymer material. The lid then fits over the tops of the four sides. Usually, the lid is fitted with tabs adapted to engage in slots made in the edges of the tray in order to hold the lid in a fixed position on the tray.

[0005] Such a solution is relatively expensive since the lid must be manufactured independently of the tray by thermoforming. Consequently, such a tray has a high carbon footprint.

[0006] Another solution consists of inserting the tray, once filled with the product, lengthwise into a sleeve made of transparent polymer film and then pinching and sealing the two ends on each side of the tray. This solution requires a large quantity of polymer film and has the same drawbacks as the previous one.

[0007] It is also known to provide a transparent film with adhesive edges and to apply it to the four corners of the four sides of the tray to seal the opening. The adhesive edges are folded against the four sides on the outside to adhere to them. Thus, the transparent film is attached to the tray and seals the opening, while the perishable goods are visible from the outside through the transparent film.

[0008] The implementation of such a film is relatively complex to mechanize.

[0009] Also, a problem which arises and which the present invention aims to solve is to provide packaging which is cheap and easy to mechanize.

[0010] In order to solve this problem, it is proposed, according to a first object, a food packaging comprising: a cardboard tray having a base and four sides arranged in pairs opposite each other with respect to said base, said four erected walls defining four vertices delimiting an opening, and a transparent film connected to said four vertices to close said opening.

[0011] And the two tops of two opposite walls among the four erected walls each comprise a foldable border, the two foldable borders being folded towards each other; and said transparent film is attached to said two folded borders.

[0012] Thus, a feature of the invention lies in the implementation of two foldable edges in the two corners of two opposing walls, allowing them to be folded towards each other and a film to be extended from one corner to the other, thus securing it to the folded edges. As will be explained in more detail later in the description, such a design for closing the tray opening is both easy to implement mechanically and economical.

[0013] Furthermore, the number of erected walls of the cardboard tray is not limited to four. In particular, a tray with four main walls and four secondary walls extending respectively between the main walls is envisaged.

[0014] Advantageously, and according to the invention, said two folded edges each define an inner face located opposite said background and an opposite outer face, said transparent film being bonded to said outer faces. In other words, the two outer faces of the two folded edges extend substantially in the same plane, and it is easy to apply the transparent film flat onto the two outer faces after coating them with an adhesive. For example, a hot-melt adhesive is applied to the two outer faces for this purpose.

[0015] Furthermore, and according to a particularly advantageous embodiment of the invention, said two peaks comprising a foldable edge are substantially bent towards each other to create tension in said transparent film. Thus, the two peaks of the two opposing walls are bent towards each other while the transparent film holds them in this state. And since the walls are initially flat, the two peaks are under stress and tend to move apart. In this way, they exert tension on the transparent film, which is then flat. This feature allows the contents of the tray to be perfectly visible without distortion due to the transparent film.

[0016] Preferably, the cardboard used to make the tray is a double-sided corrugated cardboard. In other words, it has a corrugated paper sandwiched between two sheets of smooth paper. Consequently, it exhibits significant flexural stiffness, ensuring a relatively high restoring force on the transparent film when it is flexed.

[0017] Furthermore, according to the invention, said foldable edges have two opposite ends bearing against the peaks of the two other facing walls. In this way, the foldable edges are held against the peaks by via the transparent film that connects them. Consequently, the transparent film itself is kept in a fixed position and does not obstruct the view of the food from outside the tray.

[0018] Also, each of the vertices of the two other opposing walls advantageously has, according to the invention, two opposing corners and a notch in each of said corners. In this way, the deflection of the two vertices of the opposing walls can be increased. Consequently, greater tension is applied to the transparent film. As a result, the transparent film remains taut despite the significant deformations undergone by the tray during its transport.

[0019] Furthermore, and according to a particularly advantageous embodiment of the invention, said four walls are generally isosceles trapezoidal in shape and have a short side connected to said base to form a conical tray. Consequently, the trays can be pre-shaped and stacked for storage.

[0020] According to another object, in accordance with the invention, a cardboard blank is proposed for the production of packaging as described above. It comprises: a central panel having two first sides opposite each other and two second sides opposite each other; two first panels respectively hinged on said two first sides and two second panels respectively hinged on said two second sides; and it comprises two edges respectively hinged on said first panels along a fold line, each opposite said central panel.

[0021] Also, according to the invention, said two second panels advantageously each have two opposite cut angles.

[0022] In addition, said two borders each have two ends opposite each other extending respectively beyond said fold line.

[0023] Furthermore, the blank according to the invention comprises two sets of two tabs respectively hinged opposite each other on said first two panels. As will be explained below, the two sets of two tabs allow the walls to be held together laterally. They are preferably glued.

[0024] According to yet another object, in accordance with the invention, a method for packaging foodstuffs is proposed. It comprises the following steps: a) a transparent film and a blank as described above are provided; b) said first two panels and said second two panels are arranged relative to said central panel to form a tray having a base and four sides arranged in pairs opposite each other relative to said base, said four arranged sides defining four vertices delimiting an opening, two vertices of two opposite sides comprising respectively said hinged edges; c) said tray is filled with foodstuffs food; d) the said edges are folded towards each other; and, e) the said transparent film is secured to the said folded edges.

[0025] Preferably, the panels are connected to each other via the aforementioned tabs.

[0026] Advantageously, a hot melt adhesive is applied to the folded edges before applying a transparent film. In this way, the transparent film adheres to the folded edges after the adhesive has cooled.

[0027] According to a preferred feature of the invention, before step e), the two vertices comprising the articulated edges are brought together, and the vertices are held together during step e). In other words, the two vertices of the two folded edges are brought together before the transparent film is attached to them. Then, the film is attached to them. Finally, the two vertices are released, which then puts the film under tension.

[0028] Other features and advantages of the invention will become apparent from the following description of a particular embodiment of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

[0029] [Fig.1] is a schematic top view of a blank according to the invention;

[0030] [Fig.2] is a schematic perspective view of an element of the invention obtained thanks to the object of the [Fig.1];

[0031] [Fig.3A] is a schematic top view of the object of [Fig.2] in a first phase of the process according to the invention;

[0032] [Fig.3B] is a schematic rear view of the object in [Fig.3A];

[0033] [Fig.4A] is a schematic top view of the object in [Fig.3B] in a second phase of the process according to the invention;

[0034] [Fig.4B] is a schematic rear view of the object in [Fig.4A];

[0035] [Fig.5] is a schematic top view of the object in [Fig.4B] in a third phase of the process according to the invention; and,

[0036] [Fig.6] is a flowchart of the steps of the process according to the invention.

[0037] Figure 1 shows, viewed from above, a blank 10 cut from a cardboard sheet corrugated and allowing the formation of a tray as will be explained below. The blank 10 extends along a longitudinal direction D, and over a length between 250 mm and 300 mm in the example presented here. It has a first face 12 oriented towards the front of [Fig. 1] and a second opposite face 14 oriented towards the rear of [Fig. 1].

[0038] The corrugated cardboard used is double-sided, with a fluted paper sandwiched between two sheets of flat paper. The fluted paper is between 1 mm and 2 mm thick. Of course, corrugated cardboard of a different shape and dimensions can be used as needed.

[0039] Thus, the blank 10 comprises a central rectangular panel 16. This central panel 16 has two first short sides opposite each other 18, 20 and two first long sides opposite each other 22, 24.

[0040] The blank 10 also includes two large panels 26, 28 respectively hinged opposite each other on the first two large opposite sides 22, 24, and two small panels 30, 32 respectively hinged opposite each other on the first two small opposite sides 18, 20.

[0041] It will be observed that the two large panels 26, 28 are symmetrical to each other with respect to a longitudinal median line, while the two small panels 30, 32 are symmetrical to each other with respect to a transverse median line.

[0042] Furthermore, the two large panels 26, 28 are of isosceles trapezoidal shape. They thus have two second short sides respectively common with the two first opposite long sides 22, 24 and two second opposite and parallel long sides 34, 36.

[0043] They also have, one of the two large panels 26, two first inclined sides 38, 40 along which are mounted articulated two first tongues 42, 44, the other of the two large panels 28, two second inclined sides 46, 48, along which are mounted articulated two second tongues 50, 52.

[0044] In addition, the two large panels 26, 28 have two edges 54, 56 respectively articulated on the two second large sides 34, 36, which large sides 34, 36 respectively form two fold lines.

[0045] The two borders 54, 56 each have two opposite ends 58, 60 which extend in projection beyond the two second long sides 34, 36. Their projecting extensions are in the form of circular segments.

[0046] As regards the two small panels 30, 32, they are also generally isosceles trapezoidal in shape. They respectively have two opposite free edges 62, 64 parallel to the first two small sides 18, 20.

[0047] It will be observed that the distance which extends respectively between the free edges 62, 64 and the first two short sides 18, 20 is substantially equal to the distance which extends between the two second long sides 34, 36 of the two large panels 26, 28 and the corresponding first two long sides 22, 24.

[0048] According to one embodiment of the invention, the distance between the first two long sides 22, 24 is 80 mm, while the distance between the first two short sides 18, 20 is 150 mm. The distance between the free edges 62, 64 and the first two short sides 18, 20 is 60 mm. According to this embodiment, the two edges 54, 56 have a width of 20 mm.

[0049] The dimensions of the different elements of the flan 10 of this method of implementation are obviously not limiting.

[0050] Moreover, the two small panels 30, 32 each have two opposite cut angles 66, 68.

[0051] Furthermore, it will be observed that the blank 10 is cut from the corrugated cardboard sheet so that the flutes are oriented in a direction perpendicular to the longitudinal direction D of the blank 10.

[0052] Reference will now be made to both the logic diagram of [Fig.6] and the side 10 of [Fig.1]. Thus, in a first step 70, the first two tabs 42, 44 are oriented towards the front of [Fig.1] relative to the large panel 26, along the first two inclined sides 38, 40 and the second two tabs 50, 52 are also oriented towards the front of [Fig.1] relative to the other large panel 28 along the second two inclined sides 46, 48.

[0053] Furthermore, the first 42, 44 and second 50, 52 tabs are coated with an adhesive on the second face 14 of the blank 10, i.e., on the rear. Preferably, the adhesive is a hot-melt polymer, for example a polyamide or a polyester.

[0054] In a second step 72, the two large panels 26, 28 are erected in relation to the central panel 16, and then the two small panels 30, 32 are erected so that they come to rest respectively against the first 42, 44 and second 50, 52 tabs, on their coated face.

[0055] A tray 74 is thus formed as illustrated in [Fig. 2]. On the one hand, there is the central panel 16 forming a base, and on the other hand, the two large panels 26, 28 and the two small panels 30, 32, which then form two large walls and two small walls, respectively, facing each other. The two large walls thus define two large vertices 76, 78, and the small walls define two small vertices 80, 82.

[0056] The two borders 54, 56 are also found at the top of the two large walls, respectively. They extend respectively in the planes defined by the two large panels 26, 28.

[0057] Also, at the vertices 80, 82 of the small walls we find the free edges 62, 64 of the two small panels 30, 32. We also find the two opposite ends 58, 60 of the two borders 54, 56 which extend in projection beyond the two free edges 62, 64 respectively.

[0058] Thus, the tray 74 defines a housing 84 having an opening 86 delimited by the four vertices 76, 78, 80, 82.

[0059] Furthermore, it will be observed that the two opposite cut angles 66, 68 of the blank 10 form a notch 88 in each upper corner of the tray 74.

[0060] The tray 74 thus formed is, in a third step 90, subjected to filling. Thus, foodstuffs 85, for example, are poured through the opening 86 into the compartment 84 that it defines.

[0061] This gives us a tray 74 filled with the foodstuffs 85, as illustrated in [Fig.3A].

[0062] Then, in a fourth step 92, the tray 74 is driven along its longitudinal direction along the arrow F, relative to a pair of upper guide ramps 94, 96 and a pair of lower guide ramps 98, 100 shown schematically in [Fig.3A].

[0063] Figure 3B shows the tray 74 seen from the front and, on the one hand, the pair of upper guide ramps 94, 96 and on the other hand, the pair of lower guide ramps 98, 100.

[0064] Thus, as the tray 74 is driven along arrow F through the pair of upper guide ramps 94, 96, the two edges 54, 56 are progressively driven pivotally towards each other along arrows T and -T, around the two folding lines formed respectively by the two second large sides 34, 36.

[0065] Simultaneously, the lower guide rails 98, 100, which bear against the two large walls formed by the two large panels 26, 28, below the two fold lines formed respectively by the two second large sides 34, 36, exert stresses along the arrows R, -R and cause the two vertices 76, 78 to move closer together. Consequently, these two large walls deflect significantly. The extent to which the two vertices 76, 78 move closer together is increased by the notches 88. Also, due to the orientation of the grooves, the walls deflect perpendicularly to these grooves. In this way, the resistance to deflection is greater, and the resulting forces will be correspondingly greater, as will be explained below.

[0066] Also, the two edges 54, 56 are pivoted by substantially more than 90° and their two opposite ends 58, 60 respectively rest on the two opposite free edges 62, 64, as illustrated in [Fig. 4B]. Thus, the two edges 54, 56 are held in a fixed position against the opposite free edges 62, 64. They have an inner face corresponding to the first face 12 of the blank 10, oriented towards the central panel 16 forming a base, and an outer face corresponding to the second face 14 of the blank 10 and oriented outwards.

[0067] Furthermore, the two vertices 76, 78 remain close to each other. Consequently, the two edges 54, 56 are also maintained in a position in which they are substantially close to each other.

[0068] Also, as illustrated in [Fig.4A], in a fifth step 102, while keeping the two edges 54, 56 close together by means of the lower guide ramps 98, 100, not shown, a hot melt adhesive 104 is applied to the outer face of the two edges 54, 56 by means of two injection nozzles 106, 108. The hot melt adhesive 104 is applied over the entire length of the two edges 54, 56.

[0069] As the adhesive 104 is applied, a strip of transparent film 110 made of a polymer, for example biodegradable, is unrolled. Transparent and biodegradable polyester films exist, for example.

[0070] The transparent film 110 has a width substantially equal to the maximum width of the tray 74 and is compressed on the adhesive 104.

[0071] Upon cooling, the hot melt adhesive seals the transparent film 110 simultaneously on both edges.

[0072] The transparent film strip 110 is then cut transversely when a length corresponding to the maximum length of the tray 74 has been unrolled. Reference is made to [Fig. 5] showing the tray 74 viewed from above after the transparent film strip 110 has been cut.

[0073] Also, the constraints exerted according to the arrows R, -R on the vertices 76, 78, remain there for a short time by means of the lower guide ramps 98, 100, so as to allow the cooling of the adhesive and a perfect sealing of the transparent film 110 on the two edges 54, 56.

[0074] After this brief moment, lasting a few seconds, the moving tray 74 leaves the lower guide rails 98, 100, and the two peaks 76, 78 are released. In this way, the two large flexed walls formed by the two large panels 26, 28 tend to return to their original shape and thus exert tension on the transparent film 110 in two opposite directions T, -T, via the two edges 54, 56. The return forces exerted by the two large panels 26, 28 are relatively significant due to the aforementioned orientation of the grooves.

[0075] In this way, the transparent film 110 extends along a plane and thus offers an undistorted view of the foodstuffs contained inside the tray 74.

[0076] According to a particularly advantageous embodiment of the invention, at least one 54 of the two edges 54, 56, at one of its ends 60, has an elongation 55 shown as a dashed line on the side 10 of [Fig. 1]. In addition, the fold line formed by the long side 34 between the edge 54 and the large panel 26 is a perforation line.

[0077] The elongation 55 is found in [Fig. 5], at the end 60 of the edge 54. Thus, the elongation 55 forms a tab that extends freely beyond the edge of the transparent film 110. In this way, opening the tray is facilitated by grasping the tongue and by applying sufficient traction to it to tear the edge 54 along the folding line.

Claims

Demands

1. Food packaging comprising: - a cardboard tray (74) having a base (16) and four upright walls arranged in pairs (26, 28) and pairs (30, 32) opposite each other with respect to said base, said four upright walls defining four vertices (76, 78, 80, 82) delimiting an opening (86); - a transparent film (110) attached to said four vertices (76, 78, 80, 82) for closing said opening (86); characterized in that the two vertices (76, 78) of two opposite walls among the four upright walls each comprise a foldable edge (54, 56), the two foldable edges being folded towards each other, while each of the vertices (80, 82) of the other two opposite walls has two opposite corners and a notch (66, 68) in each of said corners; and in that said transparent film (110) is attached to said two folded edges (54, 56).

2. Packaging according to claim 1, characterized in that said two folded edges (54, 56) each define an inner face located opposite said base (16) and an opposite outer face, said transparent film (110) being attached to said outer faces.

3. Packaging according to claim 1 or 2, characterized in that said two peaks (76, 78) comprising a foldable border are substantially flexed towards each other to cause tension in said transparent film (110).

4. Packaging according to any one of claims 1 to 3, characterized in that said foldable edges (54, 56) respectively have two opposite ends (58, 60) resting on the tops (62, 64) of the two other facing walls (30, 32).

5. Packaging according to any one of claims 1 to 4, characterized in that said four walls (26, 28, 30, 32) are generally isosceles trapezoidal in shape and have a small side connected to said bottom (16) to form a conical tray (74).

6. Cardboard blank for making packaging according to any one of claims 1 to 5, characterized in that it comprises: - a central panel (16) having two first sides opposite each other (22, 24) and two second sides opposite each other (18, 20); - two first panels (26, 28) respectively hinged on said two first sides (22, 24) and two second panels (30, 32), each having two opposite cut corners (66, 68), respectively hinged on said two second sides (18, 20); and in that it comprises two borders (54, 56) respectively hinged on said first panels (26, 28) along a fold line (34, 36), each opposite said central panel (16).

7. Flan according to claim 6, characterized in that said two edges (54, 56) each have two opposite ends (58, 60) extending respectively beyond said fold line.

8. Flan according to claim 6 or 7, characterized in that it comprises two sets of two tabs (42, 44; 50, 52) respectively articulated opposite each other on said first two panels (26, 28).

9. A food packaging method characterized in that it comprises the following steps: a) a transparent film (110) and a blank (10) according to any one of claims 6 to 8 are provided; b) said first two panels (26, 28) and said second two panels (30, 32) are erected relative to said central panel (16) to form a tray having a base and four sides erected two by two opposite sides relative to said base, said four erected sides defining four vertices (76, 78, 80, 82) delimiting an opening (86), two vertices (76, 78) of two opposite sides comprising respectively said hinged edges (54, 56); c) said tray (74) is filled with food (85); d) said edges (54, 56) are folded towards each other; and, e) we attach said transparent film (110) to said folded edges (54, 56).

10. Packaging method according to claim 9, characterized in that before step e), said two vertices (76, 78) comprising said hinged edges (54, 56) are brought together, and the vertices are kept together during step e).

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