Folding carton
The cardboard blank design with reinforcing flaps and a three-layered corner structure addresses the stability and material efficiency issues of folding cartons, enhancing load-bearing capacity and reducing waste while facilitating production.
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- RED U
- Filing Date
- 2025-10-01
- Publication Date
- 2026-04-22
AI Technical Summary
Existing folding cartons lack sufficient stability, especially in corner areas, and are inefficient in material usage, particularly when handling heavier goods, and require improvements for broader application and ease of production.
A cardboard blank design with reinforcing flaps in the corner areas, forming an additional inner wall layer, and a specific unfolding technique to create a three-layered structure in the corners, enhancing stability and reducing material waste.
The design significantly increases the load-bearing capacity of the carton corners, reduces material waste, and allows for easier production, making it suitable for heavier loads and diverse applications.
Smart Images

Figure IMGAF001_ABST
Abstract
Description
Technical environment
[0001] The invention relates to a folding carton consisting of a flat cardboard blank in the unfolded state with a plurality of fold lines, from which a three-dimensional cuboid cardboard format with a bottom area, two longitudinal wall areas and two transverse wall areas can be folded. State of the art
[0002] Folding cartons of the type described above are known in various designs from the prior art. They are used, for example, for packaging purposes, and for storing such folding cartons, a flat arrangement of the cardboard blanks in their unfolded state is advantageous.
[0003] Another use for such folding cartons is to use them for the presentation of goods, whereby for this purpose one of the longitudinal wall areas of the folding carton is provided with a cutout which allows access to the goods inside, even if several of the folding cartons are stacked on top of each other.
[0004] The folding cartons used for the various applications have generally proven their worth in practice, although greater stability of the folding cartons, especially in the corner areas, would often be desirable, particularly for heavier goods, and the cardboard blanks intended for unfolding the folding cartons could be produced with less waste. Object of the invention
[0005] The object of the present invention is therefore to further develop a folding carton of the generic type in such a way that material resources are conserved as much as possible during the production of such cartons and that the range of applications of the folding cartons is expanded due to their greater load-bearing capacity. Furthermore, the folding cartons should be inexpensive to produce and easy to unfold, even for untrained personnel. Solution to the task
[0006] According to the invention, the problem set out for a folding carton with the features mentioned in the generic part of the main claim is solved by the inventive combination of features set out in the characterizing part.
[0007] Essential to the invention for solving the problem is that the cardboard blank has a rectangular, closed base with two parallel, spaced-apart fold lines for folding the longitudinal wall sides from the horizontal into the vertical, and two intersecting fold lines arranged at right angles to these fold lines and spaced apart, for folding the transverse wall sides from the horizontal into the vertical, defining the edges of the central base area, wherein in each of the four corner areas of the base of the cardboard blank bounded by the fold lines, a reinforcing flap is arranged, separated from the rest of the cardboard blank by cut lines, which is connected to the transverse wall side by a fold line on its side adjacent to the outer edge of the cardboard blank and facing a transverse wall side.so that, in the unfolded state of the folding carton, the respective reinforcing flap forms an additional inner third wall layer reinforcing the corresponding corner area of the folding carton.
[0008] The novel reinforcing flap according to the invention necessitates a novel method of unfolding such folding cartons from their flat cardboard blank. This unfolding technique makes it possible, instead of the usual two cardboard layers in the area of the vertical transverse walls in the heavily stressed corner areas of conventional folding cartons, to arrange three layers in these areas, both on the transverse walls and at the ends of the longitudinal walls. This significantly increases the stability of these corner areas and thus makes the folding carton according to the invention more load-bearing overall.
[0009] The cardboard blank itself forms the aforementioned rectangular base, with all areas of the blank belonging to this rectangular base being used to create a folding carton with more stable corners. This eliminates cardboard waste, unlike conventional cardboard blanks for folding cartons.
[0010] Specific embodiments of the subject matter of the invention result, in conjunction with the technical teaching of the main claim, additionally from the features of the dependent claims relating back to the main claim.
[0011] It has proven particularly advantageous that a first cutting line for separating the reinforcing flap from the rest of the cardboard blank lies in the extension of the fold line existing between the bottom area and the longitudinal wall sides at the outer edge of the transverse wall sides, and that the other second cutting line runs from the outer edge of the cardboard blank perpendicularly to the first cutting line at the outer edge of the transverse wall sides up to this first cutting line.
[0012] The aforementioned design ensures that the reinforcing flap is large enough to fulfill its function of increasing the load-bearing capacity of the cardboard.
[0013] Furthermore, it may be advantageous if the respective reinforcement flap has a fold line running parallel to and spaced apart from the second cutting line, so that a foldable edge flap is formed, the width of which corresponds to the length of the fold line between the transverse wall side and the reinforcement flap.
[0014] A further advantageous embodiment of the invention provides that the respective reinforcing flap, in the unfolded state of the folding carton, is hooked with a retaining tongue in a recess at the edge of the bottom area to the transverse wall sides connected to the bottom area by the fold lines. Character description
[0015] An embodiment of the subject matter of the invention is explained in more detail below with reference to the accompanying figures: Figure 1 shows a top view of the cardboard blank of the folding carton according to the invention in its unfolded state; Figure 2 shows a three-dimensional view of the cardboard blank made of Figure 1 To illustrate the first two folding steps for producing the folding carton, Figure 3 shows a spatial view of the cardboard blank. Figure 1 in a subsequent phase of the folding steps Figure 2 To illustrate the positioning process for the reinforcing flap on the left side of the folding carton, Figure 4 shows a spatial view during the assembly of the folding carton. Figure 3 the final folding steps to complete the left transverse wall side of the folding carton according to the invention, Figure 5 a spatial view of the folding carton according to the invention with the left transverse wall side fully unfolded, Figure 6 a spatial view of the folding carton made of Figure 5 during the final folding steps to complete the right transverse wall side and Figure 7 the completed folding carton is ready for use after completion of all folding steps.
[0016] The basis of the folding carton according to the invention is the one described in the Figure 1 The illustrated flat cardboard blank 1. In the illustrated embodiment, this cardboard blank 1 has a rectangular closed base without edge cuts, so that no offcuts and therefore no waste are generated for such a cardboard blank 1.
[0017] Of course, it is also conceivable to design the floor plan as a rectangle if required.
[0018] Cardboard blank 1 has a rectangular base area 2 in its center, which is bounded by four fold lines. The longer sides of the base area 2 are bounded by fold lines 7 and 8, which are spaced apart and parallel to each other, while the shorter sides of the base area 2 are bounded by fold lines 9 and 10. Fold lines 7 and 8, as well as 9 and 10, are arranged at right angles to each other and intersect at the corners of the base area 2.
[0019] The base surface 2 is connected by the fold lines 7, 8, 9 and 10 to a longitudinal wall side 3 at the front of the folding box to be constructed from the cardboard blank 1, a longitudinal wall side 4 at the back of the folding box, a transverse wall side 5 on the right side of the folding box and a transverse wall side 6 on the left side of the folding box.
[0020] The fold lines 7, 8, 9, and 10 allow the longitudinal wall sides 3 and 4, as well as the transverse wall sides 5 and 6, to be raised vertically from the flat plane of the cardboard blank 1, resulting in a trough-shaped folding box. The longitudinal wall sides 3 and 4 can have a closed, flat design, but they can also be, as shown in the Figure 7As shown, the folding carton is provided with a cutout 32 that allows access from the side to the goods inside. This access is particularly important when the folding carton according to the invention is used for product presentation and not just for transport. The cutout 32 is created by incising lines 33 and 34 into the front longitudinal wall 3, extending inwards from the outer contour of the plan view. As in the present case, these lines initially run perpendicular to the outer contour and then curve slightly. This design results in an attractive shape for the access opening or cutout 32.
[0021] The further design of the cardboard blank 1 includes, in addition to the introduction of fold lines 7, 8, 9, 10, a series of cutting lines. These lines serve, firstly, to create folding flaps 35, 36, 37 and 38 on the vertical edges of the longitudinal sides 3 and 4 when unfolded. These folding flaps 35, 36, 37, 38 are movably connected to the longitudinal sides 3 and 4 by fold lines 9 and 10, which extend from the inside of the cardboard blank 1 outwards to the outer outline edge.
[0022] The insertion tabs 35, 36, 37 and 38 are separated from the transverse wall sides 5 and 6 by an extension of the section lines 11A, 12A, 13A 14A.
[0023] The particular design of the folding carton according to the invention provides that, in the corner areas of the cardboard blank 1, reinforcing flaps 15, 16, 17, 18 are arranged next to the folding flaps 35, 36, 37, 38, which are separated from the folding flaps 35, 36, 37, 38 by the cutting lines 11B, 12B, 13B, 14B. The reinforcing flaps 15, 16, 17 and 18 have a rectangular base and are connected to the cardboard blank 1 only by the fold lines 20, 21, 22 and 23, which are aligned with the central fold lines 7 and 8.
[0024] In addition, the reinforcing flaps 15, 16, 17 and 18 each have a fold line 24 or 25 within their outline, which extends over the entire width of the narrow side of the cardboard blank, resulting in an edge flap 26, 27, 28 and 29 on each reinforcing flap 15, 16, 17, 18, the width of which corresponds to the length of the fold lines 20, 21, 22 and 23.
[0025] The special constructive design of the cardboard blank 1 described above, with a plurality of cutting, folding and crease lines, enables a special folding technique for the folding carton according to the invention, which ensures a special stability of the folding carton after completion of the unfolding process.
[0026] In the following Figures 2 to 7 The various successive folding steps will be explained in more detail.
[0027] First, as is done in the Figure 2As shown, the longitudinal side 3 on the front of the cardboard blank 1 (see arrow X) and the longitudinal side 4 on the back of the cardboard blank 1 are folded upwards from their flat state. This unfolding simultaneously causes the folding flaps 35, 36, 37 and 38 on the side edges of the longitudinal sides 3 and 4 to rise, and are then brought into a position perpendicular to the longitudinal sides 3 and 4 (arrows B1 and B2).
[0028] Then the items in the Figure 3 The further folding steps shown were then carried out. To clarify the process, the following is shown in the Figure 3Initially, only the folding of the left side of the folding carton is shown, that is, the unfolding of the left transverse wall side 6. This transverse wall side 6 is first folded upwards at a right angle from the horizontal position, as indicated by arrow Y, and brought into contact with the outer sides of the folding flaps 37 and 38. Subsequently, the inner areas of the two reinforcing flaps 17 and 18, facing away from the outer contour of the carton blank 1, are brought upwards into a horizontal position (arrows Z), which is ensured by the fold line 25. Then, the reinforcing flaps 17 and 18 are rotated at a right angle to the interior of the folding carton as a result of the fold lines 22 and 23 (arrows W). After the folding steps described above have been carried out, the reinforcing flaps 17 and 18 are located in the position indicated by arrows Z and W. Figure 3 position shown.
[0029] Subsequently, the two reinforcing flaps 17 and 18, together with the upper edge region of the transverse wall side 6, which is movable relative to the vertical portion of the transverse wall side 6 due to the fold line 25, are folded inwards towards the interior of the folding carton (arrow V). The undersides of the reinforcing flaps 17 and 18 thus come into contact with the inner sides of the two folding flaps 37 and 38, resulting in a triple overlap of the transverse wall side 6, the folding flaps 37 and 38, and the reinforcing flaps 17 and 18 in the corner regions of the folding carton, which provides the particular stability of the folding carton according to the invention.
[0030] After completing the folding process according to arrow V, the following result is obtained for the left side of the folding box: Figure 5 The illustrated design. The reinforcing tabs 17 and 18, which are provided with retaining tongues 30 at their lower end facing the base area 2, are shown in the Figure 1 , 3 and 4 As can be seen, these retaining tongues 30 are inserted into recesses 31 in the edge area of the base area 2 and locked into place, resulting in a stable position of the transverse wall side 6. This stable position is further supported by the fact that retaining tongues 39 on the upper side of the insertion tabs 37, 38 also engage in corresponding recesses 40 at the upper edge of the transverse wall side 6.
[0031] In the Figure 6 It is shown that on the right transverse side of the folding box, the unfolding steps are analogous to the above description and the illustration in the Figures 2 to 5 This results in the following: Figure 7 The illustrated fully unfolded folding carton can be produced from a flat cardboard blank 1 without the usual cuts and waste and has an unprecedented stability in its corner areas due to the special folding technique.
[0032] Of course, the design of the floor plan of the reinforcement tabs 15, 16, 17, 18 in conjunction with the size of the insertion tabs 35, 36, 37, 38 can be different by a different arrangement of the section lines 11B, 12B, 13B and 14B, without moving outside the scope of protection of the invention. Reference symbol list:
[0033] 1 Cardboard cutout 2 Bottom area 3 Longitudinal side (front) 4 Longitudinal side (back) 5 Transverse side (right) 6 Transverse side (left) 7 Fold line 8 Fold line 9 Fold line 10 Fold line 11 Corner area 11A Cut line 11B Cut line 12 Corner area 12A Cut line 12B Cut line 13 Corner area 13A Cut line 13B Cut line 14 Corner area 14A Cut line 14B Cut line 15 Reinforcement flap 16 Reinforcement flap 17 Reinforcement flap 18 Reinforcement flap 19 Outer edge (cardboard cutout) 20 Crease line 21 Crease line 22 Crease line 23 Crease line 24 Fold line 25 Fold line 26 Edge flap 27 Edge flap 28 Edge flap 29 Edge flap 30 Retaining tongue 31 Recess 32 Cutout 33 Cutting line 34 Cutting line 35 Fold-in flap 36 Fold-in bottle 37 Fold-in flap 38 Fold-in flap 39 Retaining tongue 40 Recess
Claims
1. Folding carton consisting of a flat cardboard blank in its unfolded state with a plurality of fold lines, from which a three-dimensional cuboid cardboard format with a bottom area, two longitudinal wall sides and two transverse wall sides can be folded, characterized by the fact thatThe cardboard blank (1) has a rectangular, closed base with two parallel fold lines (7, 8) spaced apart from each other for folding the longitudinal wall sides (3, 4) from the horizontal into the vertical, and two fold lines (9, 10) arranged at right angles to these fold lines (7, 8) and intersecting them, for folding the transverse wall sides (5, 6) from the horizontal into the vertical, which define the edges of the central base area (2), wherein in the four corner areas (11, 12, 13, 14) of the base of the cardboard blank (1) bounded by the fold lines (7, 8, 9, 10) there is a reinforcing flap in each of the four corner areas (11, 12, 13, 14) of the base of the cardboard blank (1) separated from the rest of the cardboard blank (1) by cut lines (11A, 11B, 12A, 12B, 13A, 13B, 14A, 14B). (15, 16, 17, 18) is arranged, the side adjacent to the outer edge (19) of the cardboard blank (1), facing a transverse wall side (5, 6) by a fold line (20, 21, 22, 23) with the transverse wall side (5,6) is connected, so that the respective reinforcing flap (15, 16, 17, 18) in the unfolded state of the folding carton forms an additional inner third wall layer reinforcing the associated corner area of the folding carton.
2. Folding carton according to claim 1, characterized by the fact that a first cutting line (11A, 12A, 13A, 14A) for separating the reinforcing flap (15, 16, 17, 18) from the rest of the cardboard blank (1) lies in the extension of the fold line (7, 8) existing between the bottom area (2) and the longitudinal wall sides (3, 4) at the outer edge of the transverse wall sides (5, 6) and the other second cutting line (11B, 12B, 13B, 14B) runs from the outer edge (19) of the cardboard blank (1) perpendicularly to the first cutting line (11A, 12A, 13A, 14A) at the outer edge of the transverse wall sides (5, 6) up to this first cutting line (11A, 12A, 13A, 14A).
3. Folding carton according to claim 2, characterized by the fact thatThe respective reinforcement flap (15, 16, 17, 18) has a fold line (24, 25) running parallel to the second cutting line (11B, 12B, 13B, 14B), resulting in a foldable edge flap (26, 27, 28, 29) whose width corresponds to the length of the fold line (20, 21, 22, 23) between the transverse wall side (5, 6) and the reinforcement flap (15, 16, 17, 18).
4. Folding carton according to claim 3, characterized by the fact that the fold line (24, 25) running to the second section line (11B, 12B, 13B, 14B) continues in the upper edge area of the transverse wall sides (5, 6) over the entire width of the transverse wall sides (5, 6).
5. Folding carton according to one or more of claims 1 to 3, characterized by the fact that The respective reinforcing flap in the unfolded state of the folding carton is hooked with a retaining tongue (30) in a recess (31) at the edge of the bottom area (2) to the transverse wall sides (5, 6) connected to the bottom area (2) by the fold lines (9, 10).
Citation Information
Patent Citations
Tray
JP2019202784A
A tray made of a single blank having reinforced corners
GB2504067A
Built up box
JP1997012020A
Interlocking corner structure on tray for frozen fruits and vegetables
US4537344A