Method for producing paper bags
The innovative paper bag design with two separate layers and a bottom flap allows for increased height and capacity, addressing production limitations by doubling output on existing machines.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MONDI AG
- Filing Date
- 2025-11-06
- Publication Date
- 2026-05-15
AI Technical Summary
The production height of traditional paper bags is limited by the dimensions of the manufacturing machine, restricting the throughput and capacity of paper bags produced.
The paper bag design consists of two separate layers, with one layer having a bottom flap extending beyond the bottom, allowing for increased bag height and capacity by folding over the flap to connect with the adjacent layer, and the manufacturing process involves producing two bags simultaneously using a pair of paper layers.
The method increases the producible bag height by 30% or more on existing machines without modifications, doubling production capacity by creating nested bags with enhanced structural integrity and alignment.
Smart Images
Figure EP2025082075_15052026_PF_FP_ABST
Abstract
Description
[0001]
[0002] Mondi AG legal file:
[0003] Marxergasse 4A 0229-0097 DE-1
[0004] 1030 Vienna
[0005] Austria Date: November 5, 2025
[0006] Manufacturing process for paper bags
[0007] The invention relates to a manufacturing process for paper bags. These paper bags are sometimes also referred to as paper pouches or paper bags, so these terms are used synonymously.
[0008] State of the art
[0009] Paper bags have long been known in the art and are used as packaging and transport containers for a wide variety of goods, such as bulk materials. For example, paper bags are used to transport mortar, cement, or other building materials in powder form. These materials and goods should preferably be transported in a way that adequately protects them from moisture, as moisture can impair their original functionality.
[0010] Specifically, the invention relates to a paper bag which extends along its height from a lower end to an opening and across its width from a first edge to a second, opposite edge, comprising a back and a front, each containing a layer of paper, wherein the back and front are connected at their edges to form a volume enclosed by the paper bag. Preferably, a closure flap extending over the height of the bag is provided on the back, designed to close the opening.
[0011] Such paper bags are well known in the prior art and are sometimes also referred to as tubular bags because they are made from a single sheet of paper forming the back and front of the bag, and are folded or creased at the bottom to fold the front onto the back, creating a step, also called a "stepped step", at the top of the bag.
[0012] A closure flap is formed on the back of the bag to close the bag opening.
[0013] The invention relates to a manufacturing method for a paper bag made from a paper web, wherein the paper bag extends in a height from a bottom end to an opening and in a width from a first edge to a second edge, wherein a closure flap extending over the height of the bag can be provided on the back of the bag, with which the opening can be closed, preferably by folding over the opening, wherein the paper layer forms a front and a back of the bag, and wherein the paper layer, preferably separated from a paper web, forms a front and a back of the paper bag.
[0014] The known manufacturing process for such a paper bag comprises the following process steps:
[0015] Provide a sheet of paper,
[0016] Fold the paper layers together so that the back of the bag is offset upwards by the height of the closure flap relative to the front of the bag in relation to the insertion opening to form the closure flap.
[0017] Joining the paper layers at the side edges.
[0018] When the paper layer is folded together to form the back and front of the bag, a paper tube is created, which is why the manufacturing machines for well-known paper bags are also called tube machines.
[0019] Problems with the state of the art
[0020] Currently, paper bags of the aforementioned type are essentially manufactured by forming a paper tube, i.e., by providing a strip of paper cut from a paper roll, preferably in an elongated, rectangular shape with a length greater than its width. This paper strip is then folded along its width to form a paper tube with a front and back for the bag. The edges of this paper tube are then folded against each other and joined together. This creates a three-sided closed bag, or paper bag, which is thus joined at the edges and folded over at the bottom.
[0021] This manufacturing process is already very economical, but has certain disadvantages because the production height of the paper bag is limited by the dimensions of the production machine. For the purposes of the invention, the production height is defined as the distance from the bottom of the bag to the top of the closure flap, as this represents the maximum height that can be produced on a machine. This height is preferably greater than the bag height by the height of the closure flap, i.e., the distance from the bottom of the bag to the bag opening or filling opening of the paper bag, excluding the closure flap, which allows the bag opening to be closed by folding or folding the closure flap over the front of the bag.
[0022] Task
[0023] Based on the aforementioned prior art and its associated disadvantages, the invention aims to at least partially avoid these disadvantages and, in particular, to increase the throughput of paper bags produced on a machine.
[0024] invention
[0025] This task is already solved by the independent claims. Preferred, but not mandatory, further developments are set out in the dependent claims.
[0026] In a paper bag according to the invention, this problem is thus solved by the fact that the back and front of the bag comprise two separate layers of paper from a paper layer pair, i.e., the back and front of the bag each represent a separate layer of paper, and that at least one paper layer, i.e., the front or back of the bag, has a bottom flap extending beyond the bottom of the bag, which is designed to be connected to the adjacent paper layer. The paper layers of the paper layer pair comprising the back and front of the bag each have inner surfaces facing each other and outer surfaces facing away from each other.
[0027] The front of the bag thus determines the dimensions of the paper bag in terms of height, i.e., the bag height H from the bottom of the bag to the opening, and in terms of width B from one edge of the bag to the opposite edge. The paper layers can be joined in all known ways, e.g., by gluing with adhesive, with adhesive tape, or by sewing.
[0028] According to the invention, only one bottom flap needs to be provided on one paper layer, which can be connected to the other paper layer to close the bottom of the bag. However, it is also within the scope of the invention to provide bottom flaps on both paper layers, which are then connected to each other or to the other paper layer.
[0029] The connection of the bottom flap to the adjacent or adjoining paper layer can be made either with the inside of the adjacent paper layer without a bottom flap or, preferably, with the outside or the side of the adjacent paper layer facing away from the bottom flap. This has the advantage that the bottom flap, sometimes also referred to as the "bottom bend edge", completely surrounds or encloses the lower edge of the adjacent paper layer, resulting in a particularly strong connection.
[0030] Preferably, the closure flap extends upwards beyond the opening formed between the back and front of the bag and measures between 2 and 60 cm, preferably 5 to 30 cm, typically 5, 10, or 30 cm, depending on the application. However, this can vary depending on the size of the paper bag and the specific application.
[0031] However, an embodiment without a closure flap is possible, in which the front and back of the bag have the same height, namely the bag height. The bag is preferably closed with an externally applied closure strip (tape), preferably one that completely encircles the bag opening, or with an adhesive or tape applied between the front and back of the bag.
[0032] The bottom flap is usually connected to the paper layer via a crease or fold (bottom flap fold) so that it can be folded more easily around the adjacent paper layer.
[0033] The bottom flap can also be adapted as needed to reinforce the bag bottom. Normally, the bottom flap has a length of 1 to 5 cm, particularly 2 to 3 cm. The length of the bottom flap is defined as the distance from the crease or fold of the bottom flap to the outer edge of the bottom flap. The manufacturing process according to the invention is characterized by the following process steps:
[0034] - Providing a first layer of paper intended as the back of the bag and a second layer of paper intended as the front of the bag, i.e., two separate layers of paper,
[0035] - Providing the paper layers so that the back of the bag is offset upwards by the height of the closure flap relative to the front of the bag in relation to the bag opening to form the closure flap and
[0036] - Connecting a bottom flap on at least one of the paper layers to the adjacent paper layer at the bottom of the bag.
[0037] In contrast to the prior art, in which the front and back of the bag consist of a continuous paper web which is folded at the bottom of the bag to form the longer back of the bag with the closure flap and the shorter front of the bag which extends only from the bottom of the bag to the bag opening or filling opening, the paper bag according to the invention is now composed of a pair of paper layers comprising two separate paper layers, namely the back of the bag which is longer by the closure flap and thus extends over the section of the closure flap over the height of the bag from the bottom of the bag to the bag opening, and the front of the bag which extends in height only from the bottom of the bag to the bag opening.
[0038] The bottom flap according to the invention is provided on one of the two paper layers. This flap or extension preferably extends along the entire length of the bottom and is formed integrally on either the front or back of the bag. It can be folded over the complementary, adjacent paper layer(s) to form the paper bag or pouch, so that the bottom flap preferably encompasses the end face of the complementary, associated paper layer and is preferably connectable to the second paper layer on the side facing away from the first. The bottom flap can be joined to the complementary paper layer using any suitable joining technique, preferably by gluing, but also by using adhesive tape or by sewing.
[0039] Preferably, the bottom flap, like the closure flap, is formed integrally with or attached to the respective paper layer. The bottom flap and the closure flap can be formed on different paper layers or on the same paper layer. Particularly preferred are closure flaps on the back of the bag and the bottom flap on the front.
[0040] The inventive method allows the bag height to be increased by 30 percent or more on existing production machines by providing the paper bag or the paper webs used to manufacture the paper bag with a widthwise fold, so that the resulting foldable "folding section" can be placed onto the paper bag or the paper webs. This folded-over section can then be folded downwards by the user for use, and the paper bag can be used, with the extended, i.e., no longer folded, folding section increasing the bag height and thus the capacity of the paper bag.
[0041] The invention relates to a manufacturing process for producing multiple paper bags by simultaneously producing two paper bags. In this process, two first layers of paper from a first paper layer pair are placed on top of two second layers of paper from a second paper layer pair to form a second paper bag. Each paper bag comprises a paper layer pair consisting of two layers, namely a first paper layer pair for the first paper bag and a second paper layer pair for the second paper bag, for a total of four paper layers. Each paper layer pair comprises the paper layer forming the back of the bag and the paper layer forming the front of the bag.
[0042] In the production of the paper bags, the first pair of paper layers is joined together at the bag edges, and the second pair of paper layers is joined together at the second bag edges.
[0043] In addition, a bottom flap formed on one paper layer of the first paper layer pair at the bottom of the bag is connected to the other paper layer of the first paper layer pair, and a bottom flap formed on one paper layer of the second paper layer pair at the bottom of the bag is connected to the other paper layer of the second paper layer pair.
[0044] Thus, after being joined at the edges, the first pair of paper layers forms a first paper bag with a first bag volume for holding a good, and the second pair of paper layers forms a second paper bag with a second bag volume for holding a good.
[0045] The first layers of paper in the first paper bag and the second layers of paper in the second paper bag are then joined together at their respective bag edges. Finally, the first layers of paper in the first bag are joined together at the bottom by the first bottom flap, and the second layers of paper in the second paper bag are joined together at the bottom by the bottom flap of the second paper bag. This allows two paper bags to be produced simultaneously and very economically on existing machines.
[0046] Depending on the number of layers and size of the bags available as options, the process can be extended to up to 4 bags in one production run.
[0047] This method can also be used for paper bags with and without closure flaps. When manufacturing paper bags with closure flaps, the first layers of paper are arranged so that the back and front of the first bag are offset vertically, forming a first closure flap. Similarly, the second layers of paper are arranged so that the back and front of the second bag are offset vertically, forming a second closure flap. The closure flaps can be at the same or different heights.
[0048] When two paper bags are manufactured simultaneously, the first bag has a first width fold and the second bag has a second width fold. Width folds are folds that extend parallel to the bottom of the bag across its width. The paper layers are then arranged so that the first width fold forms an outer fold and the second width fold forms an inner fold; thus, the first (inner) paper bag is folded into the second (outer) one.
[0049] - Paper bag placed inside or the second paper bag almost completely encloses the first paper bag on the outside or at least partially surrounds it.
[0050] Particularly good positioning of the paper bags in relation to each other, also for transport, is achieved by arranging the second width fold of the second paper bag inside the first width fold of the first paper bag.
[0051] Preferably, the first and second width folds are offset from each other by at least the height of the closure flaps or bottom flaps in the bag height, but they can also have other heights. The output of the production machines for manufacturing the paper bags can be doubled by producing two paper bags simultaneously on one machine. This is achieved by using two second layers of paper – a second pair of paper layers.
[0052] - to form a second paper bag on top of two first layers of paper - a first pair of paper layers - to form a first paper bag.
[0053] According to the invention, at least two paper bags are manufactured simultaneously by providing the second pair of paper layers on top of the first pair of paper layers, so that the first pair of paper layers forms the outer pair of paper layers which surrounds or encloses the second pair of paper layers.
[0054] Depending on requirements, this manufacturing process can be expanded to produce up to four paper bags simultaneously.
[0055] The first layers of paper in the first paper bag are preferably arranged such that the back of the bag is offset upwards by the height of the closure flap relative to the front of the bag, in relation to the bag opening, to form the closure flap. Furthermore, the second layers of paper in the second paper bag are also preferably arranged such that the back of the bag is offset upwards by the height of the closure flap relative to the front of the bag, in relation to the bag opening, to form the closure flap. However, this is not mandatory in either case, meaning that the front and back of each bag can have the same dimensions.The pair of paper layers, that is, the layers of the first paper bag and the pair of paper layers of the second paper bag, are then joined at the bag edges, and the bottom flaps of the first and second paper bags are joined together at the bottom of the bag. Thus, only the paper layers of a corresponding or matching pair are joined together at the bag edges and at the bottom to form the bag volume, so that the connection always occurs either between the first layers of the first paper layer pair or the second layers of the second paper layer pair. This creates two paper bags sealed on three sides. The bottom flap of the first paper bag is therefore joined to the corresponding layer of paper without a bottom flap of the first paper bag, and the bottom flap of the second paper bag is joined to the corresponding layer of paper without a bottom flap of the second paper bag.
[0056] The height of paper bags produced on existing machines can be easily increased by the inventive method, in that the first paper bag has a first width fold extending along the width of the first paper bag and the second paper bag has a second width fold extending along the width of the second paper bag.
[0057] In other words, a first width fold can be formed in the first pair of paper layers and a second width fold in the second pair of paper layers.
[0058] Thus, the first width fold forms an outer fold, and the second width fold forms an inner fold that can be inserted into the outer fold of the first paper bag. In other words, the second paper bag, with its second width fold and its back with the closure flap and front, can be inserted into the outer, enclosing first paper bag with its first width fold in such a way that the defined inner width fold of the second paper bag lies within the receiving outer width fold of the outer paper bag. This allows for particularly good and simple alignment of the paper bags relative to each other. On an existing machine with a defined bag height, the producible format range can thus be increased by the height of the folding section with surprisingly simple means, without any modifications to the existing machines.To improve the positioning of the paper bags relative to each other, the width fold of the second (inner) paper bag is preferably arranged within the width fold of the first (outer) paper bag, so that the first width fold forms an outer fold and the second width fold an inner fold. However, this is not mandatory.
[0059] According to the procedure, the first and second paper bags have the same dimensions in height H and width B, but they could also have different dimensions. The first and second width folds can also have different or the same dimensions. They will have different dimensions, in particular, if the bags have the same dimensions.
[0060] The area of the paper bag from the width fold to the respective bottom end of the bag thus forms a fold-over section that can be folded around the width fold, preferably onto the front of the bag.
[0061] A vertical offset is preferably provided between the width fold of the first paper bag and the width fold of the second paper bag, so that the folded sections have different heights. In the case of nested paper bags, i.e., with the width fold of the second or inner paper bag positioned within the width fold of the first or outer paper bag, this ensures, for example, that the upper end of the closure flap of the first, outer paper bag extends beyond the closure flap of the second, inner paper bag by this offset. Thus, both closure flaps of nested paper bags can be fitted with closures and / or tear-off devices without having to separate the paper bags.
[0062] Geometrically, the vertical offset between the lateral folds of nested or slid paper bags can be aligned so that the closure flaps of the outer and inner paper bags are accessible for applying closures and / or opening aids. This offset can also simplify access to the bottom flaps of both paper bags without having to separate them. The offset between the lateral folds depends on the size of the paper bags, but is typically 2 to 10 cm, particularly 3 to 5 cm.
[0063] Although not strictly necessary, the paper plies are preferably dimensioned and arranged such that the first paper ply of the first paper bag is provided with the back and front of the first paper bag offset from each other to form a first closure flap, and the second paper ply of the second paper bag is preferably provided with the back and front of the second paper bag offset from each other to form a second closure flap. The closure flaps of the two paper bags can be of the same or different sizes. Preferably, the paper bags and the closure flaps have the same dimensions, but the folded sections are offset.Preferably, the width folds are offset from each other by at least the height of the closure flaps or the bottom flaps in the bag height, but can in principle have any dimension.
[0064] According to the invention, the side edges of the inner paper bag and the outer paper bag can also be connected to each other at the side edges without separating the two paper bags from each other.
[0065] The joining is carried out using known methods, namely preferably by gluing using an adhesive or adhesive tape or by sewing, possibly also by ultrasonic welding.
[0066] Preferably, the connection is made in the edge area and in the bottom area at the closure flap over a width of 1 to 5, preferably 2 to 3, in particular 2 cm.
[0067] The proposed manufacturing process using a width fold allows the maximum achievable paper bag height on existing production machines to be increased by the amount of the folded-over section, without requiring any machine modifications or retrofitting. For example, if a previous machine could only produce a maximum bag height of 1.20 m, the width fold and unfolding of the folded-over section now allow for a maximum bag height of 160 cm on the same machine with a folded-over section of 40 cm. With a maximum machine width of 120 cm, this represents a 33% increase in product height. Product height is defined as the length from the bottom of the bag to the opening between the back and front of the bag.
[0068] According to the invention, the two paper bags can be the same size or different sizes.
[0069] For the production of paper bags, a strong paper is preferably used, which is why it is also called kraft paper. Such kraft papers are particularly preferably produced using a sulfate process or kraft pulping process, either solely from cellulose or wood, or with a recycled content. Depending on the required strength, kraft papers with a basis weight of 40 to 130 g / m² per paper layer are particularly suitable.
[0070] The stability of the paper bag can be customized by using paper with different grammage (gram weight per square meter of paper) in combination with single- or multi-layer design.
[0071] The following detailed description of the figures refers to the accompanying drawings, which form part of this description of the invention and illustrate specific embodiments with which the invention can be carried out. In this context, directional terminology such as "top," "bottom," "front," "back," "anterior," "rear," etc., is used to refer to the orientations of the described figure(s). Since components of embodiments can be positioned in a number of different orientations, this directional terminology serves only for illustration and is in no way limiting. It is understood that other embodiments may be used and structural or logical modifications may be made without deviating from the scope of protection of the present invention. The following detailed description is not to be interpreted as limiting.
[0072] Within the scope of this description, the terms "connected," "attached," and "integrated" are used to describe both direct and indirect connections, direct or indirect links, and direct or indirect integrations. Unless otherwise specified, the indefinite and definite articles do not refer to a single component but are to be understood as "at least one." The terminology includes the aforementioned words, variations thereof, and similar meanings. Furthermore, it should be understood that the terms "approximately," "essentially," and similar terms, when used in conjunction with the dimensions and a property of a component of the invention, do not define the described dimension and property as strict limits or parameters and do not exclude minor variations thereof that are functionally similar.At least, descriptive parts with numerical parameters also include modifications of these parameters according to the mathematical and manufacturing principles of the prior art, e.g. rounding, deviations and other systematic errors, manufacturing tolerances, etc.
[0073] In the figures, identical or similar elements are provided with corresponding identical reference symbols, which are supplemented by a letter.
[0074] Reference lines are lines that connect the reference symbol to the relevant part. An arrow, on the other hand, which does not touch any part, refers to the entire unit to which it points.
[0075] The figures are not necessarily to scale. Certain areas may be exaggerated to illustrate details. Furthermore, the drawings may be simplified for clarity and may not include every detail that might be present in the actual construction.
[0076] The paper bag according to the invention and the manufacturing process are described below by way of example with reference to the figures. All features of the respective embodiment are disclosed here independently and separately from other features of the respective embodiment. Likewise, the features mentioned above and those described further can each be used individually or in any combination according to the invention. The embodiments shown and described are not to be understood as an exhaustive list, but rather serve as examples for the description of the invention.
[0077] Figure 1 shows a top view of a front of a paper bag according to the invention;
[0078] Figure 2 shows a top view of two paper bags according to the invention, provided with width folds, in the unfolded state and slightly shifted against each other along their width;
[0079] Figure 3 shows a top view of the two paper bags according to Figure 2 in the folded state, i.e. with folded overhangs and
[0080] Figure 4 shows an isometric side view, partly in section, of the nested paper bags according to Figure 3.
[0081] Figure 1 shows a top view of an opened paper bag 2 according to the invention.
[0082] The paper bag 2 has a bag height H, which extends from a bag bottom 4 to a bag opening 6, through which a product or bulk material can be introduced or filled into the paper bag 2.
[0083] The paper bag 2 extends along a bag width B from a first bag edge 8 to an opposite second bag edge 10.
[0084] The front of the bag thus defines the bag's dimensions in height, i.e., the bag height H from the bottom of the bag 4 to the bag opening 6, and in width B from the first bag edge 8 to the opposite bag edge 10. If the bottom of the bag is not a straight line, the bag height is the distance from a tangent drawn at the lowest point of the bottom of the bag to the bag opening.
[0085] The paper bag 2 is formed by a first, larger layer of paper, which forms the back of the bag 12, and a front of the bag 14, whose dimensions are adapted to the back of the bag 12, which is formed from a second layer of paper but is shorter than the back of the bag 12 by the difference in height of the closure flap 16. The paper layers of the back of the bag 12 and the front of the bag 14 each have inner sides facing each other and outer sides facing away from each other.
[0086] At the upper end of the closure flap 16, an adhesive strip 17 made of double-sided adhesive tape is glued on, the protective strip of which is removable so that the adhesive strip can be connected to the front of the bag 14 to close the paper bag 2.
[0087] The closure flap 16 therefore extends upwards beyond the bag opening 6 formed between the back of the bag 12 and the front of the bag 14, and in typical cases measures 2 to 60 cm, preferably 5 to 30 cm, typically 5, 10 or 30 cm. However, this can vary depending on the size of the paper bag and the specific application.
[0088] In the embodiments, the bottom flap 18 is formed on the front of the bag 14 and represents a flap-like extension which can be folded over or folded down at the connection point at the bottom of the bag 4 in order to be connected to the adjacent outer surface of the back of the bag 12, facing away from the front of the bag 14, to close the bottom of the bag 4. The bottom flap 18 is folded back to grip the back of the bag 12, which is why it is not visible in Figure 1. The bottom flap 18 is thus part of the front of the bag, but extends over the bottom of the bag 4 and is therefore not included in the calculation of the bag height.
[0089] In the figures, the connection points, preferably the glued joints, are shown with circles only at the edge between the respective back of the bag 12 and the front of the bag 14. However, the area of the connection is sometimes wider than that shown by the circles and can be 2–3 cm.
[0090] Figures 2 and 3 show two paper bags 2A, 2B, nested inside each other and manufactured simultaneously, with the paper bag 2B in the foreground representing the inner paper bag and all its components marked with the letter B after the number, and the paper bag 2A in the background forming the outer paper bag and its components marked with the letter A after the component number.
[0091] Accordingly, the outer paper bag 2A consists of a first bag back 12A and a first bag front 14A, and the inner paper bag 2B consists of a second bag back 12B and a second bag front 14B, which are connected to each other at the opposite bag edges 8A, 8B; 10A, 10B in the manner described above and each has a bottom flap 16A, 16B formed on the bag front 14A, 14B at the respective bag bottom end 4A, 4B, which is folded over onto the opposite outside of the corresponding bag back 12A, 12B and connected to the outside to close the bag bottom end 4A, 4B.
[0092] Each of the paper bags 2A, 2B has a width fold 20A, 20B that extends along the entire width of the paper bag 2A, 2B and is located approximately 10 to 15 cm from the bottom end 4A, 4B of the bag. This creates fold-over sections 22A, 22B at the bottom ends of the paper bags 2A, 2B, which extend from the respective width fold 22A, 22B to the respective bottom end 4A, 4B and can be folded over or folded down.
[0093] Figure 2 shows the folding sections 22A, 22B unfolded, and Figure 3 shows them folded over. The bottom flaps 18A, 18B are clearly visible in Figure 3; these are glued to the outside of the back of the bag 12A, 12B, enclosing the respective bottom ends 4A, 4B.
[0094] Since the two paper bags 2A and 2B are the same size, the width fold 20B of the inner paper bag 2B is approximately 10 cm longer than the width fold 20A of the outer paper bag 20A. This ensures that, as shown in Figure 4, when the paper bags are inserted with the inner width fold 20B into the outer width fold 20A, the folding section 22B of the inner paper bag 2A protrudes below the first, outer folding section 22A. This allows both bottom flaps 18A and 18B to be glued to the outer surface of the adjacent paper layer, thus sealing the respective bottom ends 4A and 4B of the bags. If the paper bags have different dimensions, the width folds can also have the same dimensions.
[0095] The closure flaps 16A, 16B, with the adhesive strips 17A, 17B attached to them on the inner sides of the paper layers, are also offset from each other by the same amount, as can be seen in Figure 3. This offset also corresponds to the distance between the bottom ends of the two nested paper bags.
[0096] The two paper bags can be manufactured simultaneously on the same machine. For this purpose, the first (outer) paper bag has a first width fold 20A, and the second (inner) paper bag has a second width fold 20B, so that the first width fold 20A forms an outer fold and the second width fold 20B forms an inner fold. The second paper bag 2B is thus inserted, or can be inserted, with its second width fold 20B, its back with the closure flap 16B, and its front facing inwards, into the outer paper bag 2A, which has its first width fold 20A, such that the defined inner width fold 20B of the second paper bag 2B sits within and is positioned by the receiving outer width fold 20A of the outer paper bag 2B.
[0097] The width folds 20A, 20B of the nested paper bags are offset from each other by at least the height difference between the upper ends of the closure flaps 16A, 16B, so that closure elements and / or tear-open elements can be applied to the closure flaps 16A, 16B. Furthermore, this ensures that both the outer bottom flap 18A of the outer paper bag 2A and the inner bottom flap 18B of the inner paper bag 2B are accessible.
[0098] In summary, the invention relates to a manufacturing method for producing paper bags, namely a first paper bag with a first bag volume for holding goods and a second paper bag with a second bag volume for holding goods. Each paper bag extends in height from a bottom end to an opening and in width from a first edge to an opposite second edge. Each paper bag comprises two pairs of paper layers, namely a first pair for the first paper bag and a second pair for the second paper bag. Each pair of paper layers comprises a layer forming the back of the bag and a layer forming the front. The first pair of paper layers is joined together at the edges of the bag, and the second pair of paper layers is joined together at the edges of the bag.Furthermore, a bottom flap formed on one paper layer of the first paper layer pair at the bottom of the bag is connected to the other paper layer of the first paper layer pair, and a bottom flap formed on one paper layer of the second paper layer pair at the bottom of the bag is connected to the other paper layer of the second paper layer pair. To shorten production time, the invention proposes to manufacture two paper bags simultaneously by placing the second paper layer pair B on top of the first paper layer pair A.A manufacturing process for a paper bag made from a single layer of paper, wherein the paper bag 2, 2A, 2B extends in a bag height H from a bag bottom end 4, 4A, 4B to a bag opening 6, 6A, 6B and in a bag width B from a first bag edge 8, 8A, 8B to an opposite, second bag edge 10, 10A, 10B, wherein the bag front 14, 14A, 14B is only as high as the bag height H, wherein the paper layer forms a bag back 12, 12A, 12B and a bag front 14, 14A, 14B of the paper bag.To increase production capacity without modifying the production machines, the invention proposes the following process steps: providing a first paper layer, designated as the back of the bag 12, 12A, 12B, and a second paper layer, designated as the front of the bag 14, 14A, 14B; providing the paper layers; joining the paper layers at the side edges 8, 8A, 8B; 10, 10A, 10B; and joining a bottom flap 18, 18A, 18B on one paper layer to the other paper layer at the bottom of the bag. This allows at least two such paper bags 2, 2A, 2B to be produced simultaneously on one machine.
[0099] The subject matter of the present invention arises not only from the subject matter of the individual claims, but from the combination of the individual claims with one another. All information and features disclosed in the documents – including the abstract – in particular the spatial configuration depicted in the drawings, are claimed as essential to the invention insofar as they are novel, individually or in combination, compared to the prior art.
[0100] Reference symbol list
[0101] B Bag width H Bag height
[0102] 2, 2A, 2B Paper bag
[0103] 4, 4A, 4B Bottom of bag
[0104] 6, 6A, 6B Bag opening
[0105] 8, 8A, 8B bag edge 10, 10A, 10B bag edge
[0106] 12, 12A, 12B Back of bag
[0107] 14, 14A, 14B Bag front
[0108] 16, 16A, 16B Closure flap
[0109] 17, 17A, 17B Adhesive strips 18, 18A, 18B Bottom flap
[0110] 20A, 20B Width fold
[0111] 22A, 22B Transfer section
[0112] Circles of glued areas (can be significantly wider than indicated)
Claims
G in treal l emc t uma! pr Lopienr tsy Mondi AG Legal File: Marxergasse 4A 0229-0097 PCT-1 1030 Vienna Austria Date: 05.11.2025 Patent claims 1. A manufacturing process for producing paper bags, namely a first paper bag with a first bag volume for holding goods and a second paper bag (2A) with a second bag volume for holding goods, wherein each paper bag (2, 2A, 2B) extends in a bag height (H) from a bag bottom end (4, 4A, 4B) to a bag opening and in a bag width (B) from a first bag edge (8, 8A, 8B) to an opposite, second bag edge (10, 10A, 10B), wherein each paper bag comprises two pairs of paper layers, namely a first pair of paper layers for the first paper bag (2A) and a second pair of paper layers for the second paper bag (2B), wherein each pair of paper layers comprises a paper layer forming a bag back and a paper layer forming a bag front, wherein the first pair of paper layers is joined together at the bag edges of the first pair of paper layers.wherein the second pair of paper layers is joined together at the second edges of the bag, wherein a bottom flap formed on one paper layer of the first pair of paper layers at the bottom of the bag is joined to the other paper layer of the first pair of paper layers, wherein a bottom flap formed on one paper layer of the second paper layer pair at the bottom of the bag is connected to the other paper layer of the second paper layer pair, INDICATED BY the fact that two paper bags (2A, 2B) are manufactured simultaneously by providing the second pair of paper layers on top of the first pair of paper layers.
2. Manufacturing method for producing paper bags according to claim 1, characterized in that a first width fold (20A) is provided in the first pair of paper layers, and that a second width fold (20B) is provided in the second pair of paper layers.
3. Manufacturing method for producing paper bags according to claim 1 or 2, characterized in that the first width fold (20A) forms an outer fold and the second width fold (20B) forms an inner fold, such that the second width fold (20B) can be or is arranged in the first width fold (20A).
4. Manufacturing process according to any one of claims 1 to 3, INDICATED BY the fact that the first and second paper bags have different or the same dimensions.
5. Manufacturing process according to any one of claims 1 to 4, INDICATED BY the fact that the first width fold (20A) and the second width fold (20B) have different or the same dimensions.
6. Manufacturing process according to any one of claims 1 to 5, INDICATED BY THIS, that the first pair of paper layers of the first paper bag (2A) is provided such that the back of the bag (12A) of the first paper bag (2A) and the front of the bag (14A) of the first paper bag (2A) are arranged offset from each other in such a way that a first closure flap (16A) of the first paper bag (12A) is formed, and that the second pair of paper layers of the second paper bag (2B) is provided such that the back of the bag (12B) of the second paper bag (2B) and the front of the bag (14B) of the second paper bag (2B) are arranged offset from each other in such a way that a second closure flap (16B) of the second paper bag (12B) is formed.
7. Manufacturing process according to any one of claims 1 to 6, INDICATED BY the fact that the first closure flap (16A) of the first paper bag (12A) is the same size or different in size from the second closure flap (16B) of the second paper bag (12B).
8. Manufacturing process according to any one of claims 1 to 7, DISTINGUISHED BY the fact that the bottom flaps (18, 18A, 18B) each encompass the other paper layer of a paper layer pair and are connected to the side of the other paper layer of a paper layer pair that is facing away from the adjacent paper layers.
9. Manufacturing process according to any one of claims 1 to 7, INDICATED BY the fact that the bottom flaps (18, 18A, 18B) are connected to a facing side of the other paper layer of a paper layer pair.
10. Manufacturing method according to one of the preceding claims, characterized in that the width folds (20A, 20B) are arranged offset from each other by at least the height of the closure flaps (16A, 16B) or the bottom flaps (18A, 18B) in the bag height (H).