Arrangement for the controlled collapse of cardboard boxes

Abstract

An arrangement for the controlled collapse of cardboard boxes made from a roll of sandwich-type cardboard consisting of two cardboard sheets arranged above and below a corrugated cardboard sheet and fixed by means of adhesives, to be subsequently cut to the required size and then punched, so that they are ready for storage and delivery to users, the arrangement providing that in the lower corners of the larger lateral surfaces (12) and on flaps (17) of the lower surface (13) of the box (24) collapsing means are provided, which are formed from the combination of the following elements: - folding lines (19) and (20) each with a height (e1) and (e2) in the larger lateral surfaces (12) of the box (24), - a fold or cut-fold line (29) in the lower surface (13), - collapsing regions (21a) and (21b) delimited by the periphery (21), the collapsing regions (21b) having a width (b1) of between 1 and 5 times the thickness of the sandwich-like cardboard, and - a collapse edge zone (31) in the lower part of the larger lateral surfaces (12).

Description

Subject of the invention

[0001] The present invention relates to modifications made to the collapsing areas previously provided for stackable cardboard boxes, where the weight of the products contained in the box, when placed on top of another box with the same characteristics, causes deformation in the latter, resulting in the rows of boxes forming the lower level of the stack being rejected by the customer and subsequently having to be collected, resulting in losses for the manufacturer. State of the art

[0002] Spanish Utility Model No. 201201068, entitled "Stackable cardboard box with containers with controlled flexible collapsing zone," discloses the creation of a collapsing zone at the bottom corners of the boxes. This, combined with die-cut lines on the main surfaces of the boxes, allows the deformation caused by vertical stacking of boxes of the same type to be accommodated, without the user being aware of this controlled deformation from the outside, which has caused significant damage to the box, and thus could lead to the conclusion that the products contained in the box have also been damaged by this compression. Specifically, this refers to containers of any type, preferably, but not exclusively, those made of cardboard or similar material.

[0003] The solution proposed by the utility model, as stated in its sole claim, consists in providing, at the corners of the portion corresponding to the lower surface of the box, L-shaped cuts acting on the folding lines of that portion and on the folding lines delimiting the larger sides of the corresponding flap, the cuts forming cavities in the lower part of the corners of the box, with the particularity that, on at least one of the edges of the larger or smaller sides of the box, above the folding line, a punching or perforation line is applied, defining a controlled collapse line if the box does not withstand the load to which it is subjected.

[0004] This solution, which represents progress in this type of box to date, has not proven universally suitable due to the use of certain types of materials and their weight in box production. For economic and environmental reasons, the weight of containers has been increasingly reduced, which has naturally resulted in some cases in a loss of self-supporting capacity and thus in increased proneness to deformation.

[0005] Studies show that from 1999 to the present, there has been an average decrease in the weight of cartons of 14.8%, with uneven declines across different sectors, for example, for cleaning products by 6%, for soft drinks by 17%, for bottled water by 12% and for milk and juices by 4%.

[0006] This well-known solution is applied when the container or box deforms, causing the quality and structure of the cardboard used to collapse, wrinkle, and warp. Tests conducted to date show that the box's height loss due to stacking is between approximately 3 and 6 mm.

[0007] However, subsequent studies on the box manufactured with the collapsible system described and claimed in Spanish Utility Model No. 201201068 and its successful implementation have contributed to a different type of solution, taking into account other parameters that must be taken into account and allow for improvement.

[0008] For the production of cardboard boxes, sandwich panels are used, which consist of a corrugated sheet sandwiched between two flat cardboard sheets. The function of this sheet is to provide rigidity to the panel without significantly increasing its weight and, therefore, the weight of the box. The selection of fold and cut lines during the initial die-cutting of the panel has shown that if they are not longitudinally centered on the corrugations of the central sheet, they lose strength. Therefore, these lines must be placed at preferred locations to ensure the box's strength against the aforementioned compressive forces from stacking.

[0009] In Spanish Utility Model No. 201201068, however, the varying depth of the fold lines is not taken into account. It should be noted that the die-cut sheets are supplied to manufacturers of cleaning products, soft drinks, mineral water, milk, and juices. While they have the tools and machinery to assemble and fill the boxes with the respective products, they do not take the depth of the fold lines into account in any way, as they are all produced to the same size in the folding machines.

[0010] A further disadvantage of the state of the art is the adaptation of the fold depth to the position of the fold line in the box, whereby there is no technical solution that adapts the pressure load to the size (height) of this fold line. Objective of the invention

[0011] The aim of the invention is to perfect the collapsing arrangements so that they adapt to the stresses that each box must withstand, also depending on the weight that the box itself must support, and to avoid waste in its manufacture: therefore, folds of different depths and contours are used, the position of the fold lines is selected and ensured that they are perpendicular to the waves of the corrugated cardboard sheet of the cardboard panel used to make the boxes, at the same time using a new technique consisting of a double fold on the base of the box with different fold depths. Description of the invention

[0012] The manufacturing process by which the box with the new arrangement can be produced does not differ significantly from the known process which involves folding the conventional cardboard sheet, but care is always taken to ensure that the cutting and folding lines on the cardboard sheet are perpendicular to the flutes of the corrugated cardboard sheet arranged centrally in the sheet, so as not to lose structural strength as in the previous arrangement, where the said folding lines are parallel and not perpendicular to the flutes, which considerably reduces structural strength, unless the folding and / or cutting line is arranged on the line of contact between the flute of the corrugated cardboard sheet and the other two sheets of the cardboard sheet.

[0013] The folding and cutting lines correspond to a different standard than the one known so far, so that the former can be designed in two different ways: - high folds: folds used to form the box in the customer's automatic assembly machine and also used for manually formed boxes. - Low folds: folds used to create controlled deformation when the product to be placed inside undergoes vertical deformation.

[0014] Regarding the cutting lines, these are applied to the small side of the box's surface that rests on the floor. This creates the fold with which the box is formed in the customer's automatic machine. This also applies to manually formed boxes.

[0015] These new types of folds and cut folds have defined heights for the taper for the fold, for its thickness and other technical characteristics within the cutting die (the manufacturing tool) that creates the final shape of the box, which in this industry is called the box blank.

[0016] An arrangement in a standard panel according to the invention results in a blank comprising two larger main surfaces and two smaller lateral surfaces, which form the four verticals and are delimited in their peripheral area by fold lines and from which the corresponding flaps for closing the box protrude to the right and left after assembly, the assembly being completed with a longitudinal flap which occupies the head part of the blank and allows the upper closure of the box when it has been filled with products.

[0017] In one of the smaller faces of the blank, specifically that which performs the function of the lower face of the box and is consequently more subjected to the compressive force by the other four vertical sides or faces, two scoring lines of different types are provided, in the immediate vicinity of the larger faces, one on each side, one line above and one below, both above the fold line, which is an essential feature of the invention, one being a low score line and the other a high score line, depending on the pressure exerted by the punching tool, while the line in the smaller face is a cutting and scoring line.

[0018] According to a further feature of the invention, the configuration of the corners was modified so that the sharp edges were eliminated and replaced by semicircles, thus eliminating the cutouts and significantly improving the deformation sensitivity.

[0019] Further details and features will become apparent from the following description, with reference to the accompanying drawings which show, by way of example but not by way of limitation, a graphic representation of the invention which can be implemented using any suitable material and the necessary means. Description of the characters

[0020] The various parts of the invention are identified in the following figures with the following numbers: (10) paperboard panel, (11) perimeter of panel 10, (12) major side surfaces of the box, (13) bottom surface of the box, (14) top surface of the box, (15) flaps of top surface 14, (16) flaps of side surfaces 12, (17) flaps of bottom surface 13, (18) flap of top surface 14, (19) low fold line, (20) high fold line, (21) collapse perimeter, (21a) and (21b) collapse areas, (22) coordinate, (23) coordinate, (24) box, (25) corrugated paperboard sheet, (26) flat paperboard sheet, (27) flat paperboard sheet, (28) blank, (29) cut-fold line, (30) openings, (31) edge zone. Fig. 1 is a front view of a sandwich-type cardboard plate (10) comprising two flat sheets (26-27) and a corrugated sheet (25) arranged therebetween. Fig. 2 is a blank (28) of the box (24) made of Fig. 4, after being made from a cardboard plate as in Fig. 1 shown was punched out. Fig. 3 is a detailed view “1” according to Fig. 2, in which the arrangement of the collapse perimeter (21) at the corners of the surface (13) is shown. Fig. Figure 4 is a perspective view of the box (24) showing the collapse areas (21a and 21b) of the perimeter (21) in its corners. The Fig. 5a and Fig. 5b are schematic views of the tabs (16) and (17) and the larger area (12) respectively. Fig. Figure 6 is an enlargement of the coordinate point (21) where the collapse regions (21a-21b) meet. Fig. 7 is a plan view of one of the side floors (12) under the action of the compressive force FC. Fig. Figure 8 is a detailed view of the high fold lines (19) with width e1 and the low fold lines (20) with width e2. Description of an embodiment of the invention

[0021] In one of the preferred embodiments of the invention, as in Fig. 2, a roll of cardboard is used to produce the box, which, by cuts at predetermined intervals, forms the plate (10) which, in a conventional manner, consists of a sandwich of three layers or sheets, namely the upper and lower flat sheets (26) and (27) and the corrugated cardboard sheet (25) arranged between them.

[0022] The properly punched plate (10) takes the shape delimited by the perimeter (11), so that its blank (28) is formed by two larger lateral surfaces (12), by the lower surface (13) of the box and by the upper surface (14) crowned by the flap (18), along the sides of the blank (28) and in order to facilitate the assembly of the box with the flaps (15), (16) and (17) at the lower corners, at the lower corners formed by the converging surfaces (12) and the flaps (16), collapsing means are provided, such as the collapsing areas (21a) and (21b), as in Fig. 6 shown.

[0023] According to one of the features of the invention, the collapsing means are a combination of: - folding lines (19) and (20) with a height (e1) and (e2) respectively in the larger lateral surfaces (12) of the blank (28), the lines (19, 20) being parallel and spaced from one another; - a fold or cut fold line (29) in the lower surface (13) of the box (24), the fold or cut fold line (29) being substantially orthogonal to the lines (19, 20); - Collapse areas (21a) and (21b) which are delimited by the periphery (21) at the lower corners of the flaps (17) and the larger lateral surfaces (12), respectively, the collapse areas (21b) having a width (b1) which is between 1 and 5 times the thickness of the sandwich-like cardboard plate; - a collapsing edge zone (31) at the lower part of the larger lateral surfaces (12), said edge zone being delimited by the fold lines (19, 20) and the collapsing areas (21b).

[0024] The vertical stacking of the boxes (24), as in Fig. 7, is represented by a series of arrows “F” that generate a compressive force that must be absorbed by the collapsing means described in the previous paragraph and that is Fig. 7 and Fig. 8, with the essential feature that for a progressive collapse, fold lines of different heights (e1) and (e2) are provided, which, for a better understanding of the invention, have been defined as high fold lines (20) coinciding with a fold line, and low fold lines (19) above the line (19), as in Fig. 2 shown.

[0025] The low fold lines (19) are made with the appropriate tool (punching tool), but with a lower force on the plate (10), so that a critical point “A” is created in the immediate vicinity of its central part (see Fig. 8), so that at point “A” a different, in particular smaller, thickness remains than at the other points of the deformation curve.

[0026] The high fold lines (20) are created on the cardboard plate (10) by applying a greater force to the critical point “B” in the immediate vicinity of its central part (cf. Fig. 8) is applied so that at "B" there is a different, in particular smaller, thickness than at "A" and compared to the other points of the deformation curve.

[0027] The technical explanation for this procedure is that the conventional folding lines, which in this case we call high fold lines (20), have been calculated to facilitate the folding of the flaps in general (15), (16), (17), while the low fold lines (19) facilitate the entire folding in Fig. 7 and that, in contrast to the prior art, the folding lines (19-20) generate deformations in the larger surfaces (12) and in the lower surface (13), so that the force exerted on the upper surface (14), on which one or more boxes (24) rest, generates progressive deformations on the surfaces (12) and on the vertical flaps (16), the line (29), which was internally a folding line, now being a cutting and folding line, thus increasing the progressiveness of the deformation in combination, as in Fig. 7, is ensured by a variable width (c1) of the edge zone (31) which, for each standard type, depends on the loads of each box (24).

[0028] The tests carried out in the laboratory have shown that the width (c1) of the edge zone (31) is a function of the characteristics of the cardboard plate (10) and of the weight of the products contained in the box, whereby by reducing the width (c1) the progressive deformation is reduced, since the load that can be absorbed by the edge zone (31), with a reduction, is greater per unit area, which would lead to the collapse of the lower part of the box (24) instead of the progressive collapse in the lower area adjacent to the surface (13) of the box (24).

[0029] The increase or decrease in the width (c1) and consequently in the edge zone (31) leads to an increase or decrease in the extent of the regions (21a) and (21b) of the area delimited by the collapse perimeter (21), as shown in the Fig. 5 and Fig. 6 can be seen. In Fig. 5a the collapse areas can be seen which affect the tab (17), as well as in Fig. 5b the collapse areas affecting the larger surfaces (12).

[0030] In Fig. For a better understanding of the invention, Figure 3 illustrates the significance of the dimensions (a1) and (b1) of the collapse regions (21) as well as the influence of (b1) and (c1) on the compressive strength of the edge zone (31). In particular, the width (b1) of the collapse regions (21b) is between 1 and 5 times the thickness of the sandwich-like cardboard panel.

[0031] The progressiveness of the deformation obtained according to the present invention brings together laboratory tests carried out on the collapse of boxes due to vertical stacking, tests being carried out on different boxes: reference is made to their dimensions, as well as to the deformations induced by the greater or lesser resistance of the panels (10) depending on the type of sheets (25, 26 and 27), this being tested simultaneously with boxes (24) filled with different products, however the column effect, which will be discussed later, does not correspond to the minimum values ​​but has also varied due to the reduction in weight of the containers arranged in the box.

[0032] The columnar effect is understood to mean the effect exerted by the containers on the surfaces (13) and (14) above and below them, which, when stacked vertically, manifests itself as true structural columns that contribute to distributing the compressive force on the surfaces (13) and (14), but only up to a certain limit determined by the strength and compression of the products in question. It has been observed that the weakening of the columnar effect of the containers contributes not only to the deformation of the box but, in the most extreme cases, also to the twisting of the lateral surfaces (12), for which the prior art solution has not been able to compensate for the structural variations of the boxes and the containers. The solution to these problems does not consist in increasing or reducing the wall thickness or in changing the strength of the materials used to manufacture the panels (10).but in their combination for the standard.,

[0033] Having sufficiently described the present invention with reference to the accompanying drawings, it will be readily understood that all conceivable changes in detail may be incorporated therein, provided they do not depart from the essential characteristics of the invention as summarized in the following claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] ES 201201068 [0002, 0009]

Claims

[1] An arrangement for the controlled collapse of cardboard boxes made from a roll of sandwich-type cardboard consisting of two sheets of cardboard arranged above and below a corrugated cardboard sheet and fixed by means of adhesives, to be subsequently cut to the required size and then punched, so that they are ready for storage and delivery to users, the arrangement providing that in the lower corners of the larger lateral surfaces (12) and on flaps (17) of the lower surface (13) of the box (24) there are provided collapsing means formed from the combination of the following elements: - folding lines (19) and (20) each with a height (e1) and (e2) in the larger lateral surfaces (12) of the box (24), - a fold or cut-fold line (29) in the lower surface (13), - collapsing regions (21a) and (21b) delimited by the periphery (21), the collapsing regions (21b) having a width (b1) of between 1 and 5 times the thickness of the sandwich-like cardboard, and - a collapse edge zone (31) in the lower part of the larger lateral surfaces (12). [2] Arrangement for the controlled collapse of cardboard boxes according to claim 1, wherein the fold lines (19 and 20) are arranged at different heights (e1) and (e2) corresponding to the upper fold line (20) and the lower fold line (19) in the larger lateral surfaces (12) of the box (24). [3] Arrangement for the controlled collapse of cardboard boxes according to one of the preceding claims, wherein in the lower corners of the box (24) there are provided collapse regions (21a, 21b) of the circumference (21), each comprising end regions in the form of a semicircle. [4] Arrangement for the controlled collapse of cardboard boxes according to one of the preceding claims, wherein the height (d1) and the width (c1) of the collapsing edge zone (31) provided in the larger lateral surfaces (12) of the box (24) are formed as a function of the compressive force FC exerted by vertical stacking of the box (24). [5] Arrangement for the controlled collapse of cardboard boxes according to claim 1 or 2, wherein the thickness (e1) at the critical point "A" of the lower fold line (19) differs from the thickness (e2) at the critical point "B" of the upper fold line (20). [6] An arrangement for the controlled collapse of cardboard boxes according to any one of the preceding claims, wherein the collapse regions (21a) are formed in the lower corners of the tabs (17) of the lower surface (13) and the collapse regions (21b) are obtained in the lower corners of the larger lateral surfaces (12) defining the ends of the collapse edge zone (31).

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