FOOD PACKAGING

Description

[0001] The invention relates to a food packaging comprising a container made of a foldable cardboard blank which forms a base, walls and triangular corner flaps between the walls which can be folded against each other, a peripheral edge flange projecting from the container and made of edge webs provided on the walls and a lid sealed to the container.

[0002] In order to be able to use folding boxes for liquid- and gas-tight food packaging, it is known (WO 2021 / 230753 A1) to unfold a container from a liquid- and gas-tight sealed cardboard blank, which forms walls delimited from a base by fold lines and triangular corner flaps between the walls, which are connected to each other and to the walls along fold lines. So that when the cardboard blank is unfolded, the triangular corner flaps are folded against each other and the paired corner flaps are placed against one of the two walls abutting in the corner area. The corner flaps, which continuously connect the walls in the corner area and replace the adhesive flaps otherwise used to connect the walls, result in a gas- and liquid-tight container shell due to the absence of adhesive flaps.To seal this container shell with a lid, edge ribs are provided on the walls. These protrude from the container shell and complement each other to form a circumferential edge flange. To create a seamless sealing surface for the lid, the edge ribs of opposing walls can be provided with edge tabs folded into the underside of the edge ribs, which protrude beyond the edge ribs limited to the wall length. Since the edge ribs of the adjacent walls do not have folded edge tabs and protrude beyond the wall length, the protruding edge tabs overlap with the protruding edge ribs in the corner area, with the edge ribs lying in one plane.Another way to provide a continuous sealing surface is to have the edge webs of the walls form a butt joint in the corner area, but this requires an additional cardboard frame to be attached to the underside of the edge flange.

[0003] Regardless of whether the edge strips form a butt joint in the corner area or overlap each other with folded edge flaps, there is a risk of a leaky seal with the lid. JP2011235952A discloses a food packaging according to the preamble of claim 1.

[0004] The invention is therefore based on the object of creating a gas- and liquid-tight sealable food packaging using a container made from a cardboard blank.

[0005] Starting from a food packaging of the type described at the outset, the invention achieves the stated object in that the edge flange carries a cardboard frame which is connected to the edge flange in a gas-tight manner by an adhesive layer running along the edge flange, which has inwardly folded edge flaps which encompass the edge flange projecting from the container and which is sealed to the lid.

[0006] The cardboard frame, tightly bonded to the container's edge flange, easily creates a sealing surface for the lid that meets all requirements and is independent of manufacturing tolerances and the design of the edge webs in the corner area. All that is required is a gas- and liquid-tight connection between the cardboard frame and the container's peripheral edge flange, which can be easily achieved using a peripheral adhesive layer. The cardboard frame, which surrounds the container flange on both sides, creates a sealing surface against which a lid can be pressed even with greater pressure, provided the container flange, which is stiffened by the cardboard frame, is appropriately supported, without having to worry about any flange steps, joints, or impacts on the sealing surface being forced through.In addition, by folding the edge flaps around the edge flange, the cardboard frame is aligned with the edge flange without the need for any special measures.

[0007] To facilitate folding in the edge flaps, the cardboard frame can be cut in sections along the fold lines for the edge flaps. The resulting slits also allow any air bubbles from the adhesive layer to escape while the cardboard frame is pressed against the edge flange.

[0008] Advantageous construction conditions are also ensured by assembling the cardboard frame from two frame parts, because in this case the waste when punching out the blanks for the cardboard frame can be kept small, especially if the cardboard frame is divided diagonally.

[0009] The drawing shows an example of the subject matter of the invention. Fig. 1 shows a food packaging according to the invention in a section in the area of ​​a wall in a partially torn-open plan view, Fig. 2 shows a section along the line II-II of Fig. 1 on a larger scale, Fig. 3 shows a cardboard blank for unfolding a container for a food packaging according to the invention and Fig. 4 shows a blank for the cardboard frame covering the edge flange of the container.

[0010] A cardboard blank for unfolding a container for a food packaging according to the invention forms, according to the Fig. 3 the base 1, the walls 3, 4 of the container separated from the base 1 by fold lines 2, and triangular corner flaps 5, 6, which are connected to each other by a fold line 7 and to the adjoining walls 3, 4 by fold lines 8. The walls 3, 4 are provided with edge webs 11, 12 separated by fold lines 9, 10.

[0011] When unfolding the container from the cardboard blank, the walls 3, 4 are bent upwards around the fold lines 2 relative to the base 1, whereby the triangular corner flaps 5, 6 are folded against each other around the fold line 7 while simultaneously pivoting around the wall-side fold lines 8. The corner flaps 5, 6, folded either outwards or inwards, are then placed against one of the adjoining walls 3, 4 and glued. In the illustrated embodiment, the corner flaps 5, 6, folded inwards, are tucked against the inside of the walls 3 and glued to these walls 3.

[0012] The edge webs 11, 12 bent outwards around the fold lines 9 complement each other when the container is unfolded to form a circumferential edge flange 13, wherein the ends of the edge webs 11, 12 projecting beyond the wall lengths preferably adjoin one another in a butt-jointed manner, as is particularly the case with the Fig. 1 can be removed.

[0013] In contrast to known containers of this type, however, the peripheral edge flange 13 does not form a sealing surface for a lid 14, which is usually in the form of a film, but instead supports a separate cardboard frame 15 to form a sealing surface, which is connected to the edge flange 13 in a gas- and liquid-tight manner by means of a peripheral adhesive layer 16. The adhesive layer 16 allows any steps, joints, or gaps along the edge flange 13 to be easily compensated for.

[0014] A blank for such a cardboard frame 15 is shown in the Fig. 4 As can be seen from this cut, the cardboard frame 15 is provided with edge flaps 17, which are folded along fold lines 18 by 180° around the projecting edge flange 13 of the container, as can be seen in particular from the Fig. 2 This measure not only stiffens the edge flange 13 of the container, which is glued between the cardboard frame 15 and the folded, inwardly folded edge flaps 17 of the cardboard frame 15, but also improves the conditions for sealing the lid 14, particularly in mass production, because with appropriate support of the edge flange 13, the lid 14 can be pressed under appropriate pressure against the sealing surface of the cardboard frame 15, which remains flat even under this pressure load.

[0015] In order to facilitate the folding of the edge flaps 17 of the cardboard frame 15 around the fold lines 18, the cardboard frame 15 can be severed in sections along the fold lines 18, so that slits 19 are created along the fold lines 18, through which any air inclusions from the adhesive layer 16 can escape when the cardboard frame 15 is glued to the edge flange 13 of the container.

[0016] By folding the edge flaps 17 around the edge flange 13 of the container, the cardboard frame 15 is automatically aligned with respect to the edge flange 13, which facilitates the production of the food packaging.

[0017] To ensure that the edge flaps 17 of adjacent legs of the cardboard frame 15 do not overlap when folded around the edge flange 13, a corresponding cut is required. For this purpose, the edge flaps 17 form a butt joint between them, for example in the form of a miter cut according to the Fig. 4 , which, however, is by no means mandatory, in particular if it is to be prevented that the edge webs 11, 12 of the container and the edge flaps 17 of the cardboard frame 15 have a matching butt joint.

Claims

1. Food packaging, comprising a container made of a fold-out carton blank which forms a base (1), walls (3, 4) and triangular corner tabs (5, 6) between the walls (3, 4) which corner tabs (5, 6) can be folded towards one another, a circumferential edge flange (13) projecting from the container and consisting of edge webs (11, 12) provided on the walls (3, 4), and a lid (14) sealed to the container, characterized in that the edge flange (13) carries a carton frame (15) connected to the edge flange (13) in a gas-tight and liquid-tight manner by an adhesive layer (16) running along the edge flange (13), which carton frame (15) has inwardly folded edge flaps (17) engaging around the edge flange (13) projecting from the container and is sealed to the lid (14).

2. Food packaging according to claim 1, characterized in that the carton frame (15) is severed in sections along folding lines (18) for the edge flaps (17).

3. Food packaging according to claim 1 or 2, characterized in that the carton frame (15) is put together from two frame parts.