Method for packaging a stack of sheet-like material

Abstract: A method for packaging a stack (15) of sheet-like material in a box comprises the steps of: providing a cardboard blank (1), which comprises parts (2, 3, 4) for forming the top part, side walls and base of the box, folding over two opposite parts (3, 4), connected at the top part (2), of the cardboard blank (1), in order to form two opposite side walls, making a fold line in one part (4) which comprises a side wall, at a distance from the top part (2) which is equal to the height of the stack (15), forming a side wall (19) and a base (20) connected thereto, folding over the base (20) onto the stack (15), folding over a fastening lip (21) at the free end of the base (20), fastening the fastening lip (21) to the opposite side-wall part (3), turning round the box formed such that the base (20) of the box comes to lie on the underside and the top part (2) on the top side.

Description: The invention relates to the packaging of a stack of sheet-like material. In particular, it relates to sheet-like material which is suitable for printers, such as are used in word processing, copying activities and the like. The sheets are usually packaged in a packaging paper in stacks of 500 pieces. It is usual to package a number of, for example five, packages of this kind in a box. Such boxes form a convenient unit which can be carried without major problems. The boxes are usually printed with information about the contents. A box having a separate lid which has a fairly high peripheral rim is known. This rim surrounds the box on the top side. The height of the peripheral rim must be such that the lid always fits, i.e. such that the box can close completely at those heights of the stack of sheets which occur most. Moreover, the height of the walls of the box must always be less than the minimum height of the stack. If this is not the case, the lid will not rest on the stack, as a result of which the packaging cannot be clamped securely using strips. A further drawback is that these strips, which are placed around the box with the purpose of keeping the latter closed, can tear the cardboard. The height of the stack of sheets may vary with an otherwise identical number of sheets. This variation in height is related to the variation in thickness of the individual sheets, which is a function of the moisture content of the paper material of the sheet. A result of this varying height of the stack of sheets is that a relatively large upper rim of the box cannot be printed on, since this may be covered by the peripheral rim of the lid if the stack of sheets is relatively low. Furthermore, a method for packaging a stack of sheets is known, in which a cardboard blank is folded around the stack. The box formed in this way can be adapted in a simple manner to the height of the stack. However, a disadvantage is that the location of the lid of the box is not well defined and depends on this height. It is therefore not readily possible to print on the lid of the cardboard blank at the correct location. A further drawback is that the box cannot be used for presenting the stack of sheets. As soon as the lid part is removed, the box falls apart, as a result of which only the stack remains. The object of the invention is to provide a method which avoids these disadvantages. This object is achieved by a method for packaging a stack of sheet-like material in a box, comprising the steps of: providing a cardboard blank, which comprises parts for forming the top part, side walls and base of the box, folding over two opposite parts, connected at the top part, of the cardboard blank, in order to form two opposite side walls, making a fold line in one part which comprises a side wall, at a distance from the top part which is equal to the height of the stack, forming a side wall and a base connected thereto, folding over the base onto the stack after making said fold line in said one part, folding over a fastening lip at the free end of the base, fastening the fastening lip to the opposite side-wall part, turning round the box formed such that the base of the box comes to lie on the underside and the top part on the top side. In the method according to the invention, the stack of sheets is placed on that part of the cardboard blank which in the finished product forms the lid. The lid can be well defined in advance by means of, for example, fold lines made in advance, and can consequently be printed on in the desired location. After being turned over, the packaging is ready for use. The total area of the packaging taken up by the lid and the major part of the adjoining side walls can be printed on without restrictions. A blank region, associated with the variable height of the stack, remains only in the region of the underside of one of the walls, to which in any case the attention of the public is less drawn. The fastening lip may be of various widths without harming the outside of the packaging. From GB-A-850540 a package is known comprising a pre-formed wrapper of heat-sealing material for an amount of tobacco and similar materials. Said package is obtained from a blank from heat-sealing foil which comprises parts for forming the top part, side walls and base thereof. The method applied for forming said package comprises the steps of folding over two opposite parts, connected to an intermediate part of the blank, in order to form two opposite side walls, folding over one of said opposite parts at a distance from said intermediate part which is equal to the height of the amount of tobacco, forming a side wall and a top wall connected thereto, folding over the top wall onto said amount of tobacco, folding over a fastening lip at the free end of the top wall, and fastening the fastening lip to the opposite side-wall part. In this method, no fold line is made in the respective part for forming a side wall and a top wall, after the amount of tobacco is placed on the blank. The stack of sheet-like material can be placed on the top part of the cardboard blank before the fold line is made between the base and the side wall connected thereto. The fold line is then formed by using the stack as an outline. In accordance with a variant, the stack of sheet-like material may be placed on the top part after the side-wall parts have been folded over. To facilitate formation of the side walls, the cardboard blank is provided with at least two fold lines made in advance, the mutual distance of which corresponds to the length or width dimension of a sheet, which fold lines define the top part. After the side walls have been folded over, the base, which is connected to one of these side walls, can be folded over onto the stack. Then, the fastening lip can also be folded over and fastened to the other side wall. This latter side wall is of a height which is smaller than the height of the stack, so that the base can always be placed taut over the stack. In order also to surround the stack of sheet-like material at least partially on the other two side walls, the cardboard blank has strips on two opposite edges, which strips project beyond the parts which form the base, two opposite side walls and top part and which strips are folded over against the stack of sheet-like material. In this case, the strips must be interrupted at the location of the fold lines between top part and side walls. With regard to the variable height of the stack, the strips may be cut through, before folding over the base onto the stack, at the location of the fold to be formed. Also, the strips are shortened, before folding over the fastening lip, as far as the fold to be formed. The invention also relates to a cardboard blank for use in the method described above. In this case, the top part is provided with a tear line which extends between the two fold lines which define the said top part. The packaging produced with the cardboard blank may be used as a presentation box if the tear lines in the side-wall parts run obliquely towards the strip adjoining the side-wall part, and this strip has a tear line adjoining the oblique tear line, or else the fold line of the said strip is formed as a tear line. Since the top part of the cardboard blank is always situated at the correct location with respect to the stack, the part of the box which is to be torn away is likewise situated at the correct location. To facilitate removal of the said part, the tear line in the top part is provided with at least one engagement opening. The invention will be explained in more detail below with reference to an exemplary embodiment, depicted in the figures, of the method, cardboard blank and packaging according to the invention. Figure 1 shows a perspective view of the various steps for manufacturing a packaging from the cardboard blank according to the invention. Figure 2 shows a perspective view of the box according to the invention, with a portion torn away. Figure 3 shows a top view of the cardboard blank. In the steps illustrated diagrammatically in Figure 1 relating to the formation of a box from the cardboard blank according to the invention, the associated machines are omitted for the sake of clarity. These machines are all known. The cardboard blank with the stack is transported, for example, on a moving belt; machines which are known per se are likewise used for folding over the various parts of the cardboard blank. The cardboard blank 1 illustrated in Figure 1 comprises a part 2 for forming what later becomes the top part of the box, as well as parts 3, 4 for forming the side walls of the box. The top part 2 is separated from these parts 3 and 4 by means of fold lines 5, 6 made in advance. At the longitudinal edges of the cardboard blank 1, pairs of mutually opposite strips 7, 8, 9 are connected via fold lines 10, 11. Finally, tear lines 12 and 13, respectively, are made in the parts 2, 3, 4, tear line 12 containing an engagement opening 14. The fold line 10 is likewise partly formed as a tear line 33. In a first method step, the parts 3, 4 are folded over about their fold lines 5, 6 over approximately 90° with respect to the top part 2. Then, the stack of sheet-like material, indicated in its entirety by 15, is placed on the top part 2 and between the parts 3, 4. This stack 15 comprises small stacks 16 of, for example, 500 sheets, packaged in packaging paper, in the illustration in Figure 4 a total of 5 such small stacks 16. The height of this stack 15 may vary depending, for example, on the moisture content of the paper in the stack. For these reasons, the height of the part 3 which forms the side wall is chosen such that it is always slightly less than the minimum height of the stack 15. A fold line can now be made in the part 4 at the location of the surface of the stack 15. Since the width of the stack 15 is known, a fold line for a fastening lip can at the same time be folded over. In the next method step, therefore, two fold lines 17 and 18, respectively, are made. The fold line 17 forms the border between the side wall 19 and the base 20 of the box. The fold line 18 forms the border between the said base 20 and the fastening strip 21. When making the fold line 17, slots 22 are simultaneously punched in the strips 7, forming two strips 23 connected to the side wall 19 and two strips 24 connected to the base 20. Furthermore, when forming the fold line 18, each strip 24 is shortened, so that the width thereof approximately corresponds to the width of the stack of sheets 15. When forming the fold line 17 and slots 22, a tool is used comprising a punching blade 25 having two double blades 26 at the end. When forming the fold line 18, a punching blade 27 having in each case a single cutting blade 28 at the ends is used. The punching blades and cutting blades interact with respective stops 29, 30. The base 20 and fastening strip 21 formed in this way are folded over in the following method step, the fastening strip 21 being adhesively bonded to the part 3, forming a side wall 31. Finally, the strips 9, 23 are folded over, and then the strips 8, 24 are glued to these folded-over strips 9, 23, still with the base 20 facing upwards. Finally, therefore, in a last method step, the packaging is turned over, such that the lid part 2 comes to lie at the top and the packaging rests on its base part 20. The tear line 12, 13, 33 with engagement opening 14 can then be reached and can be removed if desired. After removing the parts of the box which are bordered by the tear lines 13, 14, 33, the box can also be used as a presentation box, as illustrated in Figure 2. The packs 16 of, for example, 500 sheets of paper can easily be removed from the box, while on the other hand the stack nevertheless remains well held, since the box has for the most part remained intact. Figure 3 additionally shows a top view of a cardboard blank, diagrammatically illustrating the folds 17, 18 to be made later as well as the associated slots 22 to be made later and sections 32 of the strips 24 which are to be cut away.

Claims: Method for packaging a stack (15) of sheet-like material in a box, comprising the steps of: providing a cardboard blank (1), which comprises parts (2, 3, 4) for forming the top part, side walls and base of the box, folding over two opposite parts (3, 4), connected at the top part (2), of the cardboard blank (1), in order to form two opposite side walls, making a fold line (17) in one part (4) which comprises a side wall, at a distance from the top part (2) which is equal to the height of the stack (15), forming a side wall (19) and a base (20) connected thereto, folding over the base (20) onto the stack (15) after making said fold line (17) in said one part (4), folding over a fastening lip (21) at the free end of the base (20), fastening the fastening lip (21) to the opposite side-wall part (3), turning round the box formed such that the base (20) of the box comes to lie on the underside and the top part (2) on the top side. Method according to Claim 1, the stack (15) of sheet-like material being placed on the top part (2) of the cardboard blank (1) before the fold line (17) is made between the base (20) and the side wall (19) connected thereto. Method according to Claim 1 or 2, the stack (15) of sheet-like material being placed on the top part (2) after the side-wall parts (3, 4) have been folded over. Method according to one of the preceding claims, the cardboard blank (1) being provided with at least two fold lines (5, 6) made in advance, the mutual distance of which corresponds to the length or width dimension of a sheet, which fold lines (5, 6) define the top part (2). Method according to one of the preceding claims, one of the side-wall parts (3) having a smaller height dimension than the stack (15). Method according to one of the preceding claims, the cardboard blank (1) having strips (7, 9) on two opposite edges, which strips project beyond the parts (2, 3, 4) which form the base, two opposite side walls and top part and which strips (7-9) are folded over against the stack (15) of sheet-like material. Method according to Claim 6, the strips (7-9) being interrupted at the location of the fold lines (5, 6) between top part (2) and side-wall parts (3, 4). Method according to Claim 6 or 7, the strips (7) being cut through, before folding over the base (20) onto the stack (15), at the location of the fold (17) to be formed. Method according to Claim 6, 7 or 8, the strips (7) being shortened, before folding over the fastening lip (21), as far as the fold (18) to be formed. Blank (1) for use in the method according to one of the preceding claims for packaging material, said blank (1) comprising parts (2, 3, 4) for forming the top part, side walls and base of the box, the part (2) for forming the top part being connected through two parallel fold lines (5, 6) to respectively the parts (3, 4) for forming the said walls and base, characterized in that the blank (1) is of cardboard for packaging a stack (15) of sheet-like material in a box, and in that one part (4) of said blank (1) has a base (20) and a side wall (19) to be defined by a fold line (17) which is not present in the blank (1) and which is applied in the blank (1) only after placing said stack of sheet- like material on the top part (2). Blank according to Claim 11, the parts (3, 4) which define the side walls each possessing an obliquely running tear line (13), which tear lines (13) adjoin the tear line (12) in the top part (2). Blank according to Claim 11, the tear lines (13) in the side-wall parts (3, 4) running obliquely towards a strip (7, 9) adjoining the side-wall part (3, 4), and at least one of the strips (7, 9) having a tear line adjoining the oblique tear line (13), or else the fold line (10) of the said strip (7) being formed as a tear line (33). Blank according to one of Claims 10-12, the tear line (12) in the top part being provided with at least one engagement opening (14).

Inventors: BAKKER ROB, BAKKER, ROB
Applicants: GELDERSE PAPIERGROEP N V, GELDERSE PAPIERGROEP N.V.
Application year: 1996
Main classification: B65D5
IPC codes: B65D5