EP2614955B1 - Method for folding corrugated cardboard blanks for manufacturing folding boxes and assembly for the same - Google Patents

Description

The subject invention relates to a method for folding of corrugated cardboard blanks for the production of cartons, wherein the blanks with at least approximately parallel to the course of the corrugated corrugations and possibly also with transverse thereto aligned grooves, scratches, perforations or the like. be formed, along which folds or bends are made, wherein in the region of at least a portion of at least approximately aligned parallel to the course of the corrugated corrugations corrugations grooves, scratches, perforations or the like., Along which a folding takes place before the folding one Liquid is introduced, whereby the corrugated cardboard located in the region of these grooves, cracks, perforations or the like is made pliable.

The subject invention further relates to a plant for the folding of corrugated board blanks for the production of folding cartons.

In the production of corrugated cardboard cartons blanks are used, which with parallel to the course of the waves and transverse thereto aligned grooves, cracks, perforations or the like. along which the blanks are folded or kinked to thereby be e.g. produce folding boxes formed with a bottom surface, a lateral surface and a top surface. Furthermore, mutually associated parts are provided on the lateral surface of the folding boxes, which are connected to one another, in particular adhesively bonded.

Corrugated cardboard consists of e.g. from two flat paper webs between which there is a corrugated paper web. This is a so-called single-layered or single-walled corrugated board. A two-layered or double-walled corrugated board consists of two flat paper webs located on the outside, of an inner flat paper web and of two corrugated paper webs which are located opposite the inner flat paper web and inside the two outer flat paper webs.

There are also known corrugated cardboard with three corrugated paper webs, which are located within two flat paper webs, wherein further between the corrugated paper webs are each flat paper webs. These are referred to as three-layer or three-wave corrugated cardboard.

With corrugated cardboard is further distinguished between different types of waves and combinations of these types of waves, where appropriate The wave heights and the wave pitches, among other things between a coarse wave, a medium wave, a fine wave and a microwave is distinguished.

In order to achieve the required stacking strength of cartons in cartons made of corrugated cardboard, the corrugated board is arranged so that in the lateral surfaces of the cartons, the waves from the bottom surface to the top surface or run the channels formed by the waves of the bottom surface to the top surface of the carton ,

In order to provide the lateral surface with the required folds or buckling and connect the mutually associated parts of the lateral surface with each other, in the lateral surface parallel to the course of the waves aligned grooves, scratches, perforations or the like. be provided, along which the lateral surface between the individual side surfaces of the carton can be folded or folded. However, the fact occurs that the grooves, cracks, perforations or the like. along a wave trough, along a wave crest or along the flank between a wave trough or a wave crest, whereby due to the rigidity of the material the subsequent folding does not take place exactly along the line required for this purpose. On the contrary, deviations from the predetermined folding line occur, which consequently result in the connection of the two end regions of the lateral surfaces assigned to one another not taking place in the correct position.

The problem that folding does not occur exactly along a given line is called 'fishtailing'. The resulting inaccuracy at the closure of the lateral surface is referred to as a 'gap'. These detrimental effects are exacerbated in the case of double-walled or three-corrugated corrugated boards and poor qualities of the papers used for the production of the corrugated board. By these effects, the dimensional accuracy of the cartons is reduced, which fact is particularly disadvantageous in the automatic filling of the cartons.

From the US no. 3270628 For example, there are known a plant and method for folding corrugated board blanks in which the corrugated board is moistened for improved folding.

According to the method known from this patent, such blanks are processed, which previously with grooves or the like. have been provided, or the like in the plant in the region of these grooves. be moistened. However, since the previously generated grooves or the like. may not be effective, grooves or the like are in the plant again. made (refresher scoring). By moistening the brittleness of the blanks should be reduced to avoid cracks during the folding process, and the production of the grooves should be facilitated. Then the folding of the blanks is made.

However, this method does not meet the requirements, since it is no longer possible after moistening the blanks, the corrugated cardboard with exactly running grooves or the like. along which form the folds take place. The method according to the invention is thus based on the object of providing a method by which an exact folding of the blanks is ensured in order to avoid the 'fishtailing' effect.

Another prerequisite for achieving a substantial improvement in folding accuracy is that such a liquid is used to effect rapid and complete penetration of the corrugated board. A rapid penetration of the corrugated board is therefore necessary because modern systems are operated at very high speeds. Full penetration is required because the entire folding area must be pliable. In addition, such a liquid must be used, which evaporates quickly and in which no residues occur.

All these requirements are met according to the invention by a method according to the features of the characterizing part of claim 1.

Due to the fact that in the region of grooves, cracks, perforations or the like. Material is made pliable by the liquid described, the subsequent convolutions are carried out regardless of the areas of the waves they are made exactly along the lines provided for this purpose, whereby the blanks are folded exactly and the closure on the lateral surface exactly at the right place he follows. As a result, the so-called 'Fishtailing' and as a 'Gap' disadvantageous Avoiding effects in the production of semi-finished products for the production of folding cartons, which significantly increases the quality of these semi-finished products in terms of their dimensional accuracy. A high dimensional accuracy is especially important for the automatic filling of cartons.

Preferably, distilled water is used for the mixture and the liquid is introduced into the grooves, cracks, perforations or the like. sprayed.

A system for carrying out the method according to the invention, such blanks are supplied, which are not formed with parallel to the waves extending grooves. This system has the features according to claim 4. It is thus compared to the system according to US no. 3270623 advantageous because in the course of the manufacturing process, the device for producing the grooves or the like. is located and after this the means for introducing the liquid is provided, wherein the liquid or the like in the grooves. is introduced. As a result, the desired exact folding is guaranteed.

FIG.1

einen Zuschnitt aus einer Wellpappe, in Draufsicht,

FIG.1A

die aus dem Zuschnitt gemäß FIG. 1 hergestellte Faltschachtel, in axonometrischer Darstellung,

FIG.2

eine Anlage zur Faltung von Zuschnitten gemäß FIG.1, um diese auf einer Palette stapeln zu können, und

FIG.2A

ein Detail der Anlage gemäß FIG.2, in Ansicht des Pfeiles B der FIG.2 und in gegenüber FIG.2 vergrößerter Darstellung.

The method according to the invention and a system for carrying out this method are explained in more detail below with reference to an exemplary embodiment. Show it:

FIG.1

a blank from a corrugated cardboard, in plan view,

1A

the from the blank according to FIG. 1 manufactured carton, in axonometric representation,

FIG.2

a system for folding blanks according to FIG.1 to be able to stack them on a pallet, and

2A

a detail of the plant according to FIG.2 , in view of the arrow B the FIG.2 and in opposite FIG.2 enlarged view.

In FIG.1 a blank 1 is shown, which for producing a in FIG. 1A illustrated quadratic folding box 2 is used. The blank 1, which is formed approximately rectangular, consists of a single-walled corrugated cardboard. The course of the waves 10 of the corrugated cardboard is shown on the right side of the blank 1. The middle region 1a of this blank 1 serves to form the lateral surface 21 of the folding box 2, the lower region 1b serves to produce the bottom surface 22 and the upper region 1c serves to produce the top surface 23 of the folding box 2.

In order to form the lateral surface 21 of the folding box 2 by folds or buckling of the blank 1 and further to connect them at their two ends, the blank 1 is formed with four grooves 11 and 11a extending at least approximately parallel to the corrugations 10 of the corrugated cardboard. In continuation of these grooves 11 and 11a are located in the lower region 1b and in the upper region 1c slots 13. Due to these grooves 11 and 11a and the slots 13, the central part 1a along the grooves 11 and 11a are folded or kinked.

Further, the blank 1 is formed between the middle portion 1a and the lower portion 1b and the upper portion 1c, respectively, with a groove 12 extending approximately at right angles to the course of the corrugations 10, through which the four portions of the lower portion 1b and the upper portion 1c can be bent relative to the central region 1a, thereby forming the bottom surface 22 and the top surface 23 of the carton 2. Further, the left end of the central portion 1a is formed with a tab 14 to which, by folding the blank 1 along the grooves 11, the right end of the central portion 1a abuts and is connected thereto e.g. is bonded by gluing, whereby the self-contained lateral surface 21 is produced.

Such blanks 1 of folding boxes are prefabricated to the effect that they are folded along the grooves 11 and that the lateral surface 21st is closed by making a closure, for example by gluing. As a result, two-layer semi-finished products are created, which are stacked on pallets and transported by means of these. In order to produce folding boxes 2 from these semi-finished products, the semi-finished products must be folded along the grooves 11, 90 ° must be made along the grooves 11a and the parts for producing the bottom surface 22 and the top surface 23 with respect to the lateral surface 21 also by 90 ° be folded, whereby the cartons 2 are completed and can be filled with the deck surface 23 open.

Since in the region of the lateral surface 21, the shafts 10 are aligned so that they extend from the bottom surface 22 to the top surface 23 of the carton 2, the required large stacking strength of the cartons is achieved.

In the production of such semi-finished products, the effect occurs that the folds along the grooves 11, which take place parallel to the course of the waves 10, may be in the region of a wave crest, a wave trough or the flank therebetween, whereby due to the different nature of the material the folds can deviate from the given line. This effect is called 'fishtailing'. As a result of these deviations in the folds, deviations also occur when closing the lateral surface of the individual blanks. This effect is called a 'gap'. Because of these effects, the folding boxes made of corrugated cardboard have only small dimensional accuracy.

The following is based on the FIG.2 a system for folding blanks explained by which these disadvantages are avoided.

In the FIG.2 The plant shown has a device 3, which serves, consisting of corrugated cardboard, located in a stack blanks 1, which the training in accordance with FIG.1 However, which are not formed with parallel to the shafts 10 extending grooves 11 and 11a for the preparation of the lateral surface 21, in the direction of movement A individually supplied to the processing. These blanks 1 are located on conveyor rollers 31, through which a blank 1 of the processing is fed under a barrier 32 in each case. The blanks 1 are passed through a printing station 4, in which they are printed. The Printing station 4 has a pressure roller 41, an inking roller 42 and pressure rollers 43.

After the printing station 4, the blanks are fed to a device 5 for producing the grooves 11 and 11a extending parallel to the shafts 10.

The device 5 consists of four upper discs 51, which are mounted on a shaft 51a and rotated by means of the shaft 51a. The four upper discs 51 are associated with the blanks 1 supporting four lower discs 52 which are mounted on a shaft 52a and rotated with this. Through the upper slices 51, the grooves 11 and 11a, which run parallel to the shafts 10, are embossed into the blanks 1.

The device 5 is followed by two spray nozzles 6, which is supplied via lines 61, a liquid and through which the liquid is sprayed into the grooves 11. It is used in such a liquid, which penetrates the corrugated board quickly. Subsequently, the blanks 1 are folded along the grooves 11 so that two-layer semi-finished products are formed, which can be stacked on a pallet. Furthermore, the lateral surfaces are closed in itself.

In 2A are the blank 1, which are located in this running along the shafts 10 grooves 11 and 11a and the grooves 11 associated spray nozzles 6.

Characterized in that in the grooves 11, a liquid is sprayed, which penetrates the corrugated cardboard, the corrugated cardboard in the region of the grooves 11 so pliable that the subsequent folding process along these grooves 11, regardless of which region of the waves, the folding is made exactly along the predetermined line, whereby the blanks 1 are folded exactly in the required manner and thus the 'fishtailing' effect is avoided.

In the trajectory of the blanks 1, a device 7 for applying an adhesive is further arranged on the tab 14. The device 7 has a roller 71, by means of which on the tab 14 in a container 72 befindlicher adhesive is applied.

In a further consequence, the blanks 1 processed in this way are fed to a device 8 for folding them along the grooves 11.

The device 8 has a conveying device, such as a conveyor belt, through which the blanks are moved further in the conveying direction A. The conveyor are associated with two moving at the speed of the conveyor belt straps 81 and 82, which are guided so that they come to rest laterally outside the grooves 11 portions of the blanks 1 to the system, said portions during their movement in the direction of arrow A. against each other along the grooves 11 are folded over the intermediate region. In this case, the folded outer surface of the right end of the blank 1 reaches the tab 14, which is coated with an adhesive, so that the two end portions of the lateral surface 21 are joined together, whereby the lateral surface 21 of the carton 1 is closed. Characterized in that the folds along the grooves 11 along the predetermined lines, the lateral surfaces 21 are closed exactly in the required manner. As a result, a very high dimensional accuracy is achieved in the cartons 2 with respect to their inner dimensions.

The thus produced two-layer and self-contained semi-finished products are stacked on pallets in the sequence and fed to these consumers.

For use as containers for goods, these semi-finished products are deployed along the grooves 11 to form prismatic bodies and folded along the grooves 11a. Furthermore, the portions of the bottom surface 22 along the predetermined grooves 12 are bent so that the formed with a bottom carton 2 is formed, which can be filled in the sequence. After filling, the sections of the top surface 23 are bent relative to the lateral surface 21, whereby the carton 2 is closed.

The fold lines or creases can by grooves, cracks, perforations or the like. be formed.

In such a system facilities for complete processing of corrugated board can be provided. Likewise, the system can be fed already largely processed blanks.

It is essential to the invention that the corrugated cardboard in the regions of folding lines oriented at least approximately parallel to the course of the waves of the corrugated cardboard be made pliable by the moistening process before the folding process for the production of a semi-finished product, whereby the folds take place exactly along the predetermined folding lines, whereby the closure of the jacket surface the right place.

For moistening the corrugated cardboard, such a liquid is used, from which the corrugated cardboard is quickly penetrated and which evaporates as a result. A rapid penetration of the corrugated board is therefore necessary because such systems operate at high speeds and must be ensured that the corrugated cardboard in the areas of the grooves and the like. is sufficiently flexible for the folding operations, so that they take place exactly along the predetermined lines.

As liquids for the moistening of the corrugated cardboard u.a. Mixtures of water and alcohols, such as spirit or petroleum ether (mineral spirits), wherein the proportion of water is 20% by volume to 80% by volume, preferably about 50% by volume, and the proportion of alcohol is 80% by volume to 20% by volume, preferably about 50% by volume. In particular, distilled water is used.

Claims (4)

1. A method for folding blanks (1) of corrugated board for the production of folding boxes (2), the blanks (1) being provided with grooves (11, 11a, 12), scored lines, perforations or the like which are oriented at least approximately parallel to the course of the corrugations (10) of the corrugated board and optionally also perpendicularly thereto and along which folding or bending may be performed, a liquid being introduced prior to the folding process into the region of at least some of the grooves (11), scored lines, perforations or the like which are oriented at least approximately parallel to the course of the corrugations (10) of the corrugated board and along which folding proceeds, whereby the corrugated board located in the region of these grooves (11), scored lines or perforations is rendered pliant, characterised in that, first of all, grooves (11), scored lines, perforations or the like oriented at least approximately parallel to the course of the corrugations (10) of the corrugated board are produced, into which a liquid is then introduced, whereupon the folding process is performed, wherein the liquid used is a mixture of water and an alcohol, such as white spirit or petroleum ether (surgical spirit), and wherein the water is present in a proportion of 20 vol.% to 80 vol.% and the alcohol in a proportion of 80 vol.% to 20 vol.% and the mixture preferably comprises approximately 50 vol.% water and approximately 50 vol.% alcohol.
2. A method according to claim 1, characterised in that distilled water is used for the mixture.
3. A method according to claim 1, characterised in that the liquid is sprayed into the grooves (11), scored lines, perforations or the like.
4. An installation for folding the blanks (1) for the production of folding boxes (2) of corrugated board using the method according to one of claims 1 to 3, which is provided with an apparatus (5) by means of which the blanks (1) are provided with grooves (11), scored lines, perforations or the like which are oriented at least approximately parallel to the course of the corrugations (10) and optionally also perpendicularly thereto and along which folding proceeds, additionally with an apparatus (6) for introducing the liquid into the region of at least some of these grooves (11), scored lines, perforations or the like, and in addition with an apparatus (8) for folding the blanks (1) along the grooves (11), scored lines, perforations or the like, characterised in that, over the course of the production method, first of all the apparatus (5) is provided, by means of which the blanks (1) are provided with grooves (11), scored lines, perforations or the like which are oriented at least approximately parallel to the course of the corrugations (10) and along which folding proceeds, and then the apparatus (6) is provided for introducing the liquid, by which the liquid is introduced into the grooves (11), scored lines, perforations or the like.

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