EP2614955A1 - Method for folding corrugated cardboard blanks for manufacturing folding boxes and assembly for the same - Google Patents

Abstract

The method involves providing folding blanks (1) with a fold-line structure for defining folding locations at which a corrugated board is to be folded or bent, where the structure is selected from the group consisting of grooves (11, 11a), scores and perforations aligned parallel to or perpendicular to a course of corrugation parts (10) of the board. Liquid is applied to the structure prior to a folding operation to render the board relatively flexible at the respective structure than remaining parts of the board. The liquid is used as a mixture of water and alcohol, such as ethanol or petroleum ether, with the water content having a proportion of 20 to 80 percentages by volume, and the alcohol content having a proportion from 80 to 20 percentages by volume of the mixture. The alcohol is selected from the group consisting of ethanol and petroleum ether. An independent claim is also included for an assembly for folding blanks.

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. are formed along which folds or buckling can be made.

The subject invention further relates to a plant for the folding of corrugated cardboard blanks for the production of 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 on the outside, an inner flat paper web and two corrugated paper webs, which are located on both sides of the inner flat paper web and within 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.

In corrugated cardboard is further distinguished between different types of waves and combinations of these types of waves, and according to the wave heights and wave splits u.a. 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. Rather, 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 '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.

The objective of the present invention is to avoid these disadvantages. This is inventively achieved in a method for folding blanks for the production of folding cartons in that in the region of at least a portion of at least approximately parallel to the course of the corrugated corrugated corrugated grooves, scratches, perforations or the like., Along which a convolution takes place before the folding process, a liquid is introduced, whereby the like in the region of these grooves, cracks, perforations or the like. made corrugated board is made pliable.

Due to the fact that in the region of grooves, cracks, perforations or the like. Material is made pliable by moistening, the subsequent convolution occurs regardless of the area of the shaft is made, exactly along the line provided for this purpose, whereby the blanks are folded exactly and the closure takes place on the lateral surface exactly at the right place , As a result, the adverse effects in the production of semi-finished products for the production of cartons, which are referred to as 'fishtailing' and as 'gap' are thus avoided, whereby the quality of these semi-finished products is substantially increased in terms of their dimensional accuracy. A high dimensional accuracy is especially important for the automatic filling of cartons.

Preferably, the liquid is in the grooves, cracks, perforations or the like. injected. In particular, a liquid is used which penetrates the corrugated cardboard within a short time. Preferably, this liquid consists of a mixture of water and an alcohol such as spirit or petroleum ether (mineral spirits), wherein the water is a proportion of 20 vol .-% to 80 vol .-%, in particular of about 50 vol .-%, and the Alcohol has a proportion of 80 vol .-% to 20 vol .-%, in particular of about 50 vol .-%, having. In particular, distilled water is used.

A plant for folding the blanks for the production of corrugated cardboard cartons, wherein the blanks with at least approximately parallel to the course of the waves and possibly also with transversely aligned grooves, scratches, perforations or the like. are provided along which folds or buckling can take place, has a device for folding the blanks along a part of the parallel to the course of the Shafts aligned grooves, cracks, perforations or the like. in which, according to the invention, the device for folding the blanks has at least one device for introducing a liquid into the region of at least part of the grooves, scratches, perforations or the like aligned at least approximately parallel to the course of the waves of the corrugated cardboard, along which a folding takes place; upstream.

In particular, by this means, the liquid in the grooves, cracks, perforations or the like. sprayed.

Preferably, such a liquid is applied by the means for introducing a liquid, through which the corrugated cardboard is penetrated within a short time.

This penetration is achieved in particular by a mixture of preferably distilled water and an alcohol, such as spirit or petroleum ether (surgical spirit).

Preferably, a system according to the invention is formed with a device through which the at least approximately aligned parallel to the course of the waves grooves, scratches, perforations or the like. produced in the blanks. Furthermore, this system can also have a device by which the two mutually associated end portions of the lateral surface are interconnected. In particular, this system can have a device by which an adhesive is applied to at least one of the two end parts of the lateral surface which are used to produce the closure of the lateral surface, and further comprises a device, by which the lateral surface folds together associated end portions of the lateral surface brought to bear against each other and thereby glued together.

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 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 performed 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 (13)

Method for folding blanks (1) made of corrugated cardboard for the production of folding cartons (2), wherein the blanks (1) are provided with at least approximately parallel to the course of the corrugations (10) of the corrugated cardboard and optionally also with grooves (11, 11a, 12), scratches, perforations or the like. are formed along which folds or buckling can be made, characterized in that in the region of at least a portion of at least approximately parallel to the course of the corrugations (10) of the corrugated cardboard aligned grooves (11), scratches, perforations or the like., along which a folding takes place, before the folding process, a liquid is introduced, whereby in the region of these grooves (11), scratches, perforations or the like. made corrugated board is made pliable. A method according to claim 1, characterized in that the liquid in the grooves, cracks, perforations or the like. is sprayed. Method according to one of the claims 1 and 2, characterized in that a corrugated cardboard penetrating within a short time liquid is used. Method according to one of the claims 1 to 3, characterized in that a mixture of water and an alcohol, such as spirit or petroleum ether (sparkling mineral), is used as the liquid, wherein the water accounts for 20% by volume to 80% by volume. % and the alcohol has a content of 80% by volume to 20% by volume, and preferably the mixture has about 50% by volume of water and about 50% by volume of alcohol. Method according to claim 4, characterized in that distilled water is used. Plant for folding the blanks (1) for the production of corrugated cardboard folding cartons (2), wherein the blanks (1) with at least approximately parallel to the course of the shafts (10) and optionally also with transversely aligned grooves (11), scratches, perforations or the like. along which folds can take place, with a device (8) for folding the blanks (1) along a part of the grooves (11) aligned parallel to the course of the waves, scratches, perforations or the like, characterized in that Means (8) for folding the blanks (1) at least one device (6) for introducing a liquid into the region of at least part of the grooves (11), scratches, perforations or the like oriented at least approximately parallel to the course of the corrugations of the corrugated cardboard. , along which a folding takes place, upstream. Installation according to claim 6, characterized in that by the means (6) for introducing liquid, the liquid in the grooves (11), cracks, perforations or the like. is sprayed. Installation according to one of the claims 6 and 7, characterized in that by the means (6) for introducing a liquid, such a liquid is applied, through which the corrugated cardboard is penetrated within a short time. Installation according to one of the claims 6 to 8, characterized in that through the means (6) for introducing a liquid, a mixture of water and an alcohol, such as spirit and petroleum ether (mineral spirits), is applied. Installation according to one of the claims 6 to 9, characterized in that the liquid consisting of 20 vol .-% to 80 vol .-%, especially about 50 vol .-% water and 80 vol .-% to 20 vol .-%, especially about 50% by volume, alcohol, preferably using distilled water. Installation according to one of the claims 6 to 10, characterized in that it comprises means (5) through which the at least approximately parallel to the course of the waves (10) aligned grooves (11), scratches, perforations or the like. in the blanks (1) are produced. Installation according to one of the claims 6 to 11, characterized in that it comprises a device (8) through which the two mutually associated end portions of the lateral surface (21) of the folding box (2) are interconnected. Installation according to one of the claims 6 to 12, characterized in that it comprises means (7) through which on at least one of the two mutually associated end portions of the lateral surface of the folding box (2), which serve for the production of the closure of the lateral surface (21) , An adhesive is applied and that it further comprises means (8) through which by folding the lateral surface (21), the mutually associated end portions of the lateral surface (21) are brought into contact with each other and thereby glued together.

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