Zigzag folded stack of paper railroad ties, especially for further processing as packaging material

Description

[0001] The invention relates to a zigzag-folded paper web stack according to claim 1. Furthermore, a zigzag-folded paper web stack is provided, in particular for further processing as packaging material, for example by means of a packaging material machine which mechanically transforms the unfolded paper web into a packaging material, such as a cushioning material, in particular without adding additional materials to the paper web.

[0002] An example of a zigzag-folded paper web stack for producing a packaging material stack and of a packaging material machine suitable for this purpose are known from EP 1 345 757 B1, in particular Figure 3 and the associated figure description part of EP 1 345 757 B1, which shows the zigzag-folded paper web stack.

[0003] In order to increase the stack height and the folding capacity of the paper web, it is known to perforate the folds of the paper web stack, thereby weakening the material web, in order to predefine the fold path of the material web with precise positioning, to reduce the fold space and to enable later tearing off of the material web converted into packaging material with precise positioning.

[0004] It is known to form folds in the zigzag-folded paper web stack with a perforation-folding ridge row. An example of a known perforated fold is schematically illustrated in the attached Figure A. The perforation-folding ridge row (e) is continuous along its entire longitudinal extent in the fold longitudinal direction q, which is parallel to the paper web transverse direction, with a constant fold ridge width and perforation width. The ratio of perforation width to fold ridge width is 2:1 or 3:1 in favor of a larger perforation width. It is known that the fold ridge (b) along the fold (a) has a maximum longitudinal extent (x') in the fold longitudinal direction (q) of at most 1 mm. On the other hand, the perforation (c), i.e. the through hole or elongated hole, is formed in the paper web with a maximum longitudinal extension (y') of 2mm to 3mm.

[0005] US 2010 / 0160132 A1 discloses a selectively tearable stock material for a cushioning conversion machine and a corresponding method.

[0006] US 4 745 835 A discloses a fine tooth perforation for a paper web.

[0007] US 4 735 437 A discloses a quick-tear computer paper.

[0008] It was shown that, particularly when using a folded paper web stack made of short-fiber paper material, the paper web tears at the weakened fold during unfolding and feeding into the packaging machine, disrupting the automated packaging material production process. Especially when the feed speed of the paper web into the packaging material machine increases, the unfolding forces increase to such an extent that tear-free unfolding of the paper web stack can no longer be guaranteed with sufficient reliability.

[0009] It is an object of the invention to overcome the disadvantages of the prior art, in particular to provide a zigzag-folded paper web stack, in particular made of recycled paper, in particular based on 100% waste paper, in which on the one hand a position-predefined and space-saving folding is facilitated and on the other hand an unwanted tearing of the paper web is prevented, in particular during mechanical processing into a packaging material, wherein in particular a simple, position-accurate tearing of the packaging material produced from the paper web stack is facilitated.

[0010] This object is achieved by the features of claim 1. Preferred embodiments are specified in the subclaims.

[0011] According to the invention, a zigzag folded paper web stack is provided according to claim 1.

[0012] A zigzag-folded paper web stack, in particular a paper web stack made of recycled paper, for example based on 70% to 100% waste paper, is provided, which is intended to be further processed into packaging material. At least one fold of the zigzag-folded paper web stack is formed with a row of perforated folding webs. Preferably, the majority of the fold, in particular the entire fold path, is formed with a row of perforated folding webs. In a preferred embodiment of the invention, all folds of the zigzag-folded paper web stack are provided with the row of perforated folding webs. Folding webs of a fold of the paper web stack couple two folded folding web sheets of the paper web stack to one another and serve as a folding hinge to ensure that the folded sheets of the stack are positioned flush with one another.The more accurately the folding is achieved by the folding webs, the more space-saving the paper web stack according to the invention can be. The folding web and the perforation of the perforation-folding web row each have an individual, maximum longitudinal extent (perforation-web-individual maximum width) in the longitudinal direction of the fold (in particular transverse to the longitudinal direction of the paper web). The perforation of the perforation-folding web row should preferably be an elongated hole shape, wherein the hole edges are preferably rounded in the longitudinal direction of the fold and the long sides of the elongated hole are parallel to one another. In a special embodiment, the perforation can also have an approximately circular hole edge shape. In a preferred embodiment of the invention, it is conceivable that notches or small tears can be located at the edges of the perforation, which influence the tear resistance of the paper web, in particular at the perforation-folding web row.The folding webs are formed as one piece with the folding web sheets coupled to them and are delimited in the longitudinal direction of the fold by the two adjacent perforations, unless the folding web forms the longitudinal edge of the paper web. In this case, only one perforation is adjacent to the edge web. Preferably, the longitudinal edges of the paper web are continuously perforation-free and straight and are formed by the edge folding web at the web height of the fold. The longitudinal extent of the folding web and / or the longitudinal extent of the perforation can vary or be the same along the perforation-folding web row, wherein in particular the longitudinal extent of the folding web can be just as large as the longitudinal extent of the perforation. At least one section of the fold comprises a reinforced perforation-folding web row consisting of at least five or ten alternating folding webs and perforations.A fold section can form an entire fold, or multiple fold sections can extend along a fold. Each fold of the paper web stack can be configured accordingly. The ratio of a total longitudinal extent of the summed maximum individual longitudinal extents of the fold webs within the fold section under consideration to a total longitudinal extent of the summed maximum individual longitudinal extents of the perforations of the same number within the fold section defined above is greater than or equal to 0.8, preferably greater than or equal to 1 or 1.5.

[0013] In a preferred embodiment of the invention, the total longitudinal expansion ratio is less than 3 or less than 4 or less than 5.

[0014] Preferably, the total longitudinal expansion ratio is between 1 and 2.5.

[0015] In a further development of the invention, the fold section of at least five folding webs is arranged near the lateral end edge of the paper web or is arranged in a central region of the paper web. The reinforced central region of the paper web can then be deformed, in particular embossed, by a tool, such as embossing wheels, of the packaging material machine.

[0016] In a further development of the invention, the pleated section extends over the entire longitudinal extent of the paper web. Alternatively, at least one further differently designed pleated section can adjoin the first pleated section, which in particular comprises a different overall longitudinal expansion ratio than the first pleated section of greater than or equal to 0.8, preferably greater than or equal to 1 (1.5).

[0017] In a preferred embodiment of the invention, the longitudinal extent of the folding webs and / or the perforations within the fold section is the same. Alternatively or additionally, the longitudinal extent of the folding web can be at least the same size as or greater than that of the perforation, in particular at least twice as large.

[0018] The fold bars of the perforation-fold bar series can be of different sizes. One or the perforation that is exceptionally larger than the adjacent bar can be connected to the fold bar in the longitudinal direction of the fold. At least one fold bar is larger than 1.5 mm, preferably larger than 2 mm or 3 mm. Particularly with large fold bars of over 2 mm, especially at the end edge of the paper web, some perforations (less than 10%) along the fold may be larger than some of the other paper bars (less than 2 mm).

[0019] In a further development of the invention, the edge fold, due to its longitudinal extension of greater than 1.5 mm, ends at the lateral end edge of the paper web, which is particularly straight along the paper web. Alternatively or additionally, a fold, which is also greater than 1.5 mm, can be arranged in the central region of the paper web.

[0020] In a further development of the invention, at least 1 / 5 of all folds of a fold are larger than 1.5 mm, preferably larger than 2 mm or 3 mm. In particular, at least half of the folds of a fold, at least 75%, preferably at least 90%, or essentially all of the folds of a fold are larger than 1.5 mm, preferably larger than 2 mm or larger than 3 mm.

[0021] The fold bars and the perforation preferably have a constant maximum longitudinal dimension, although this may vary. According to a section of one stack fold, a perforation-fold bar row has at least five or ten alternately arranged fold bars and perforations. The individual longitudinal dimension of each fold bar within the fold section is at least as large as, greater than, or twice as large as the individual longitudinal dimension of the perforation within the section.

[0022] In a preferred embodiment of the invention, the paper webs and / or perforations each have a constant longitudinal extent along the entire fold.

[0023] Further properties, advantages and features of the invention are explained by the following description of preferred embodiments with reference to the accompanying drawings, in which: Fig. 1 shows a schematic view of a section of a zigzag-folded paper web stack in the region of a perforated fold with several rows of perforation and folding webs; Fig. 2 shows a further preferred embodiment of a perforated fold of a paper web stack with several rows of perforation and folding webs; Fig. 3 shows a further embodiment of a perforated fold of a paper web stack according to the invention with several rows of perforation and folding webs; and Fig. 4 shows a further embodiment of a perforated fold of a paper web stack according to the invention with several rows of perforation and folding webs.

[0024] In Figure 1 only a portion of the zigzag folded paper web stack according to the invention is shown generally with the reference number 1, wherein a complete paper web stack in the Figure 3 the above-cited patent specification EP 1 345 757 B1. The Figure 3 be fully incorporated into the description as a disclosure. The Figure 1The paper web stack section 1 shown has two parallel, opposing longitudinal edges 3, 5, which form the wide surfaces of the cuboid-shaped paper web stack. A fold 7 of the zigzag-folded paper web stack extends essentially perpendicular to the longitudinal edges 3, 5. Two parallel serpentine lines crossing the fold 7 illustrate graphically that not the entire width in the longitudinal fold direction q of the paper web is shown, but rather, for the sake of simple visual representation, several perforation-folding web rows 11, 21 in different designs along the longitudinal fold direction q have been reproduced as detailed areas of the perforated fold 7. The perforation-folding web rows are shown oversized.

[0025] In a first configuration of the perforation-folding web row 11, three perforations 13 are provided adjacent to the longitudinal edge 3.

[0026] The perforation fold line 11 according to Figure 1 shows four folding bars 15, which can be of different lengths or the same length. Figure 1 In the embodiment of the perforation folding web row 11 shown, an edge folding web 15a is provided which measures a longitudinal extent x 11 in the longitudinal direction of the fold q which is greater than 1 mm, wherein in the Figure 1 illustrated example of the edge folding web 15a has a longitudinal extension x 1 of 2mm or 2.5mm.

[0027] The further paper webs 15 adjoining the edge fold web 15a in the longitudinal direction q of the fold can have a constant longitudinal extension x 2 of approximately 1 mm or 1.5 mm, whereby a changing longitudinal extension for the three fold webs 15 can also be provided. Figure 1A special feature of the perforation-folding web row 11 shown is that the perforation 13 (three are shown, although five to ten perforations can also be provided for the perforation-folding web row 11 arranged at the edge region of the paper web) has a constant longitudinal extent y. The longitudinal extent y is 1 mm or 1.5 mm for the perforations 13, whereby at least in sections it must be ensured that when considering the perforation-folding web row of at least five folding webs 15 / perforations 13 arranged alternately directly in a row, a ratio of the total longitudinal extent of the summed individual longitudinal extents is not less than 0.8, preferably greater than or equal to 1 or 1.5.

[0028] For this purpose, the following equation shall apply to the overall longitudinal expansion behavior of directly adjacent fold bars and perforations of the perforation-fold bar series (where n is the equal number of fold bars and perforations): ∑ i = 1 n x i y i ≥ 0 , 8 oder ≥ 1 oder ≥ 1 , 5 i = running fold bar / perforation number along a fold section, in particular along the entire fold, preferably all folds of the paper web stack.

[0029] Especially in the Figure 1The relatively wide dimensions of the edge folding web 15a are evident in the embodiment shown. It was found that during feeding and / or forming of the paper web stack to be unfolded, large tensile forces act particularly at the edge area. A particularly wide folding web 15a significantly reduces the likelihood of the paper web stack being damaged at this critical point during unfolding and during insertion in the unfolded state into the packaging machine. Webs 15 of smaller dimensions can be provided following the edge folding web 15a, so that the longitudinal expansion ratio (but above the minimum limit defined above) decreases, thereby facilitating the space-saving folding of the zigzag-folded paper web stack.

[0030] At other critical sections of the paper web stack, which are subject to high operating load forces, particularly during unfolding and during feeding and processing into a packaging material machine (for example according to EP 1 345 757), folding webs larger than 1.5 mm, preferably larger than 2 mm or 3 mm, are to be provided. An example of such a critical section is the center of the paper web, which is optionally reshaped by embossing wheels to form a soft cushioning property for the packaging material. In such an area, a perforation folding web row 21 can be provided, which, as in Figure 1shown, lies in the central region of the illustrated paper web stack section 1. The illustrated perforation-folding web row 21 has at least one, two or three (in particular at least five) folding webs 25, which have a longitudinal extent x 2 of 2.5 mm to 3 mm, wherein the adjacent perforations 23 have a longitudinal extent y 2 of approximately 1 mm or 1.5 mm.

[0031] The perforation-folding-rib row can comprise at least five directly consecutive paper ribs / perforations according to the respective Figures 1 to 4 indicated perforation-folding-rib row 11 to 81. It should be understood that the longitudinal extent xi of n folding ribs can vary, being at least as large as or up to twice as large as the smallest or preferably largest longitudinal extent yi of the n perforations.

[0032] It should be understood that the longitudinal extent yi of the perforations can also vary. However, in the critical fold sections (deforming central area, edge area), the longitudinal extent yi of the perforations should preferably be smaller than the longitudinal extent xi of the fold webs 15.

[0033] In Figure 1 Adjacent to the longitudinal edge 5, a paper web 25a is provided, which opens into the longitudinal edge 5. The dimension in the longitudinal fold direction q for the folding web 25a is larger, in particular twice as large as the adjacent perforation 23.

[0034] In Figure 2 Two different perforation-folding-rib rows are marked with the reference numbers 31 and 41. The perforation-folding-rib row 31 differs from the one (11) according to Figure 1in that a smaller absolute longitudinal dimension x 31 is used for the edge fold 35a. Rather, the longitudinal dimension x 31 of the folds 35 in the longitudinal fold direction q within the perforation fold row 31 is essentially the same, with a width of 1.5 mm or 1 mm being used for the maximum longitudinal dimension x 3. Particularly in the perforation fold row 31, the constant maximum longitudinal dimension y 3 of the perforations 33 is smaller than that of the folds 35 and is in particular less than 1 mm, preferably approximately 0.5 mm thick. In the perforation fold row 31, the edge fold 35a is of the same size as the subsequent folds 35, but the edge fold 35a is significantly larger than the adjoining perforation 33.

[0035] In the perforation-folding web row 41 folded on the right-hand section of the paper web stack section 1, significantly larger perforations 44 are introduced into the paper web, which can have a maximum longitudinal extent y 4 of more than 2 mm, preferably 3 mm to 4 mm. It should be understood that the intermediate folding webs 43 (43a) can be the same size or larger than the perforations 44. In the perforation-folding web row 41, it is even possible that some folding webs 43 can be slightly smaller than the perforations 45. In particular, with paper webs 43 larger than 1.5 mm and 2 mm, the perforations can be larger than the paper webs 43. However, when relatively large perforations are selected, the edge web 43a should be at least the same size as the adjacent perforation 45.

[0036] In the paper web stacking section 1 according to Figure 3Also shown are two perforation-folding web rows 51, 61, in which the perforation-folding web row 51 represents four perforations 53, some of which have different longitudinal dimensions y 5, and five folding webs of different longitudinal dimensions x 5. It is evident that the longitudinal expansion ratio of the folding webs 55 (55a) to the perforations 53 is greater than 1. Particularly evident in the design of the perforation-folding web row 51 is the always different selection of longitudinal dimensions x 5 for the folding webs 55 (55a), whereby the longitudinal dimensions x 5 can be between 1.5 mm and 4 mm.

[0037] Particularly important in the design of the perforation folding strip series 51 according to Figure 3that a folding web 55 distal from the longitudinal edge 3 is larger than the otherwise larger edge folding web 55a. This configuration is particularly feasible if a longitudinal extension of greater than 3 mm is selected for the edge folding web 55a. Subsequently, folding webs 55 of larger extension can be provided for more stable foldability, which can alternate with smaller folding webs.

[0038] In the second perforation fold line row 61 according to Figure 3 A particularly stable, tear-resistant paper web is provided, in which the edge fold 65a adjacent to the longitudinal edge 5 is dimensioned significantly larger than 3 mm, preferably over 4 mm. A smaller perforation 63 with a dimension of approximately 2 mm can be connected to this.

[0039] In Figure 4 For the paper web stacking section 1, two perforation folding web rows 71, 81 are again provided, whereby the two perforation folding web rows 71, 81 are particularly tear-resistant.

[0040] In the perforation-folding-rib row 71, the folding ribs 75 (75a) are of equal size and 1 mm or smaller than 1 mm, with the constant longitudinal dimension y 7 of the perforations 73 being half the longitudinal dimension x 7 of the folding ribs 75 (75a). The longitudinal dimension x 7 of the folding ribs is approximately 0.8 mm to 1 mm, while the maximum longitudinal dimension y 7 of the perforations 73 can be 0.5 mm or less.

[0041] The total longitudinal expansion ratio between the fold line and the perforation is significantly higher than 1.5 in the perforation-fold line series.

[0042] For the further perforation-folding-rib row 81 according to Figure 4 The fold bars 85 are of a constant size in the longitudinal fold direction q and are approximately 1.5 mm to 2 mm. The perforations 83 are of a constant size and are significantly less than 1 mm. The maximum longitudinal dimension y 8 can vary along the perforation-fold bar row 81.

[0043] In the Figure 1 to Figure 4 For illustrative purposes, fewer than five alternating fold bars and perforations are shown in the perforation-folding-rib rows 11-81. However, for calculating the total longitudinal extent of the fold bars of the perforations, at least five perforations / fold bars should be connected in a row. For the perforation-folding-rib rows 11-81 shown, the respective sequences of perforations and fold bars should be continued to obtain a minimum of five fold bars and perforations. List of reference symbols

[0044] 1Paper web stack 3, 5Long edge 7Fold 11, 21, 31, 41, 51, 61, 71, 81, ePerforation-folding strip row 13, 23, 33, 43, 53, 63, 73, 83Perforation 15, 25, 35, 45, 55, 65, 75, 85Folding strip 15a, 25a, 35a, 45a, 55a, 65a, 75a, 85aEdge folding strip qFold longitudinal direction x', x 1 , x 2 , x 3 , x 4 , x 5 , x 6 , x 7 , x 8 Longitudinal extent y', y 1 , y 2 , y 3 , y 4 , y 5 , y 6 , y 7 , y 8 Longitudinal extent aFold bFolding web cPerforation ePerforation-folding web row

Claims

1. Zig-zag folded stack of paper web, in particular zig-zag folded stack of recycling paper web, wherein at least one fold (7) of the zig-zag folded stack of paper web is formed with a perforation-tie-row (11, 21, 31, 41, 51, 61, 71, 81), wherein ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) of the fold (7) couple two fold-web-sheets folded above one another, wherein the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) and the perforations (13, 23, 33, 43, 53, 63, 73, 83) each have a maximal longitudinal extension (xi; yi) in longitudinal fold direction (q), wherein several sections of a fold each comprise a perforation-tie-row (11, 21, 31, 41, 51, 61, 71, 81) of at least five alternatingly arranged ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) and perforations (13, 23, 33, 43, 53, 63, 73, 83) each, wherein a ratio of a summed total longitudinal extension of the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) within each fold section with respect to a summed total longitudinal extension of the perforations (13, 23, 33, 43, 53, 63, 73, 83) of the same number within the fold section is larger than or equal to 1, wherein the single longitudinal extension (xi) of each tie (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) within each fold section is at least as large as the single longitudinal extension (yi) of each perforation (13, 23, 33, 43, 53, 63, 73, 83) within the fold section, wherein at least one tie (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) is larger than 1.5 mm, preferably larger than 2 mm or 5 mm.

2. Zig-zag folded stack of paper web according to claim 1, wherein the total longitudinal extension ratio is smaller than 3 or 4.

3. Zig-zag folded stack of paper web according to one of the preceding claims, wherein a fold section ends in a lateral, preferably along the course of the paper web straight end edge (3, 5) of the paper web, or wherein the fold sections are arranged in a central area of the paper web.

4. Zig-zag folded stack of paper web according to one of the preceding claims, wherein the fold sections extend across the total longitudinal extension of the paper web, or wherein a first fold section is followed by a further fold section, which comprises, with respect to the one fold section, a different total longitudinal extension ratio larger or equal to 1.

5. Zig-zag folded stack of paper web according to one of the preceding claims, wherein the longitudinal extension of the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) and / or of the perforations (13, 23, 33, 43, 53, 63, 73, 83) within each fold section is the same and / or wherein the longitudinal extension of the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) is at least as large as or larger than that of the perforations (13, 23, 33, 43, 53, 63, 73, 83), in particular being about at least twice as large.

6. Zig-zag folded stack of paper web, wherein the at least one tie ends in a lateral end edge (3, 5) of the paper web and / or is arranged in a central area of the paper web.

7. Zig-zag folded stack of paper web according to one of the preceding claims, wherein at least 1 / 5 of all ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) of the fold (7) of the paper web are larger than 1.5 mm, preferably larger than 2 mm or 3 mm, wherein in particular at least half of the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) of a fold (7) or essentially all ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) of a fold (7) are larger than 1.5 mm, preferably larger than 2 mm or 3 mm.

8. Zig-zag folded stack of paper web according to one of the preceding claims, wherein the single longitudinal extension (xi) of each tie (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) within each fold section is larger than or twice as large as the single longitudinal extension (yi) of each perforation (13, 23, 33, 43, 53, 63, 73, 83) within the fold section.

9. Zig-zag folded stack of paper web according to one of the preceding claims, wherein the ties (15a, 15, 25a, 25, 35a, 35, 45a, 45, 55a, 55, 65a, 65, 75a, 75, 85a, 85) and the perforations (13, 23, 33, 43, 53, 63, 73, 83) comprise, each along the fold (7), a constant longitudinal extension (xi; yi).