Device for strapping products
By forming a folding mechanism on the strapping material, the problem of breaking the strap under high tension is solved, and a higher strength and sustainable strapping effect is achieved.
Patent Information
- Application Number
- CN202380091777.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-21
- Filing Date
- 2023-12-21
- Publication Date
- 2025-08-29
AI Technical Summary
Existing tie-up straps are prone to break when subjected to tensions greater than 300N, and the tie-up straps are highly strong but not sustainable enough.
The folding mechanism is used to fold the strapping material in the longitudinal direction of the strapping material, so that its side edges form folds, forming a double-layer structure to enhance tear resistance, and retain the sustainability and information carrier function of the strapping belt.
Improves the tear resistance and tensile strength of the bundling material, allowing heavier items to be tied while maintaining the sustainability and information display of the bundling belt.
Smart Images
Figure CN120569331A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an apparatus for bundling products, and in particular to an apparatus for bundling products, comprising a feeding mechanism for feeding a bundling material from a supply roller to a packaging device along a feeding direction so as to form a loop around a space for receiving products at an end of the bundling material, wherein the feeding mechanism comprises a conveying device for clamping the bundling material over a portion of its length and conveying it to the packaging device in a guided manner, and a driving device for driving the conveying device. Background Art
[0002] Strapping involves placing a wrapping material (also known as a strap) around one or more products. Among other reasons, the strap is placed to bundle multiple products, to impart strength to one or more products, and / or as a carrier for information about the products. Strapping machines typically form a loop of strapping material around the products, which is then tightened to place the strap more or less tightly around the products using a determined strapping tension.
[0003] Strapping is typically a thin strip of paper or film, which can be printed or unprinted. The advantage of strapping is that it allows products to be bundled, labeled, and / or sealed in a sustainable manner using just a single strip of paper or film. Strapping is a particularly sustainable packaging technology because it can save up to 80% of packaging material compared to traditional packaging techniques, and because strapping is often made from sustainable materials such as paper.
[0004] Due to the properties of its material, its small thickness and good flexibility, strapping is generally suitable for bundling products that may or may not be pressure-sensitive, where the expected tensile force is less than 100N to 300N, all depending on the material of the strapping and its thickness. If the expected tensile force is greater than 300N, the risk of the strapping breaking is high.
[0005] A known alternative to tying with strapping tape with an expected tensile force greater than 300 N is to use so-called strapping bands. Large stacks of newspapers are often tied with strapping bands. Strapping bands can withstand significant tensile forces (up to 1000 N), but due to the material they are made of (often containing plastic), strapping is generally not as sustainable as tying. Strapping bands are typically made of polyester (PET) or polypropylene (PP). Summary of the Invention
[0006] The object of the present invention is to provide an alternative to strapping which also has the advantages of strapping.
[0007] To this end, the present invention provides an apparatus of the type set out above, characterized in that the apparatus further comprises a folding mechanism, which is arranged between a feed roller and a packaging device and is configured to fold the strapping material in its longitudinal direction as it is fed to the packaging device. Since the side edges of the strip extending in its longitudinal direction are folded by the folding mechanism, the side edges of the strip are formed into a folded state by the folded strapping material. The wrinkles generated by the folding of the strip on both sides give the strip a significantly higher tear resistance than a strip of unfolded strapping material. Since the strip consists of a double layer of strapping material covering at least a portion of the width of the strip, the tensile strength of the strip is also increased. At the same time, the advantages of known strapping tapes are also retained, such as the sustainability of the material and its function as an information carrier.
[0008] In a preferred embodiment of the apparatus according to the present invention, the folding mechanism is configured to fold the strapping material along its length at each of its two opposing long side edges. The folding mechanism is preferably configured to fold the strapping material along its length at each of its two opposing long side edges such that the free outer ends of the strapping material, extending in the longitudinal direction of the strapping material, are oriented toward each other. In other words, the folding mechanism folds the edges of the strapping material toward each other such that the folded portion of the strapping material is positioned to one side of the strapping material. This ensures that the folded portion is positioned inwardly of the strapping material to be applied during strapping, which has the advantage that the folded portion does not unfold when the strapping material is applied around the product. The folding mechanism is preferably configured to fold the strapping material along its length at each of its two opposing long side edges along a first fold line and a second fold line, respectively, wherein the first fold line and the second fold line extend in the longitudinal direction of the strapping material and wherein the first fold line and the second fold line are different from each other.
[0009] In another preferred embodiment, the folding mechanism is configured to fold the strapping material along its length at each of its two opposite long side edges so that, at least when viewed in the unfolded state of the strapping material, each of the first and second fold lines is located closer to the respective nearest long side edge of the strapping material than to the center line of the strapping material extending in the longitudinal direction of the strapping material. In this way, the above-mentioned technical advantages of the folded side edges are achieved while, at the same time, this results in the visible portion of the strapping to be arranged (i.e., the unfolded central portion of the strap) remaining relatively wide, thereby leaving sufficient space for printing information on said visible portion.
[0010] In a preferred embodiment, the strapping material is substantially made of paper, wherein the thickness of the paper is between about 90 μm and about 160 μm, and the folding mechanism is configured to fold the strapping material in a longitudinal direction of the strapping material such that, as viewed in a cross-section of the strapping material in the longitudinal direction, the strapping material has a U-shape at the bend thereof, wherein the minimum radius of curvature of the portion of the strapping material extending between the legs of the U is greater than 10 μm, preferably greater than 50 μm, and more preferably greater than 100 μm. The greater the radius of curvature of the fold, the greater the tear resistance of the folded strap. The greater tear resistance of the strap enables the strap to be used to wrap heavier bales and to transport the bales with a controlled risk of the strap completely tearing.
[0011] In a preferred embodiment, the folding mechanism includes a base plate and a guide member, the base plate being used to carry the strapping material thereon, the guide member being arranged opposite the base plate and having a guide surface oriented toward the base plate, wherein the strapping material is carried between the base plate and the guide surface along the guide surface. The folding mechanism also includes a pair of walls that stand upright relative to the base plate and extend parallel to each other in the direction of the strapping material. The guide member is arranged between the upright walls, close to the upstream end faces of the upright walls. The mutual distance between the upright walls is less than the width of the strapping material. The guide member is arranged so that the strapping material moves along the guide surface and is guided between the upright walls when being fed, wherein the upright walls fold the strapping material against the opposite side edges of the guide member at a respective folding line of each of its two opposite long side edges along the length of the strapping material, so that the long side edges of the strapping material move toward the surface of the guide member oriented away from the guide surface.
[0012] In a preferred embodiment, the conveying device includes a conveyor belt, the folding mechanism includes a plate-shaped guide member and a first pair of folding rollers, the plate-shaped guide member having a flat guide surface for guiding the tying material along it, wherein the tying material is conveyed between the conveyor belt and the guide surface along the guide surface, wherein the plate-shaped guide member is substantially rectangular and extends substantially in the longitudinal direction of the tying material, its width is narrower than the width of the tying material, and is arranged so that the tying material moves along the guide surface when being fed and is guided toward the first pair of folding rollers, wherein each of the first pair of folding rollers takes a form and is arranged relative to the plate-shaped guide member so that the first pair of folding rollers fold the tying material against the opposite side edges of the plate-shaped guide member at a respective folding line of each of its two opposite long side edges along the length of the tying material so that the long side edges of the tying material move toward the second surface of the plate-shaped guide member that is oriented away from the guide surface.
[0013] In another preferred embodiment, each of the first pair of folding rollers takes a form and is arranged relative to the plate-like guide member such that the folding rollers fold the long side edges of the strapping material against the side edges of the plate-like guide member such that the folded portions of the strapping material extend substantially perpendicular to the longitudinal direction of the strapping material.
[0014] In a preferred embodiment, the folding mechanism further comprises a second pair of folding rollers, which are arranged downstream relative to the first pair of folding rollers as seen in the feed direction of the tying material, wherein an outer surface of each of the second pair of folding rollers oriented toward an end of the plate-like guide member is tapered so as to further fold the tying material at each respective fold line, wherein the tapered ends of the second pair of folding rollers are located on the sides of, but not necessarily between, the second surface of the plate-like guide member, are oriented toward each other and extend inwardly relative to the long side edges of the plate-like guide member.
[0015] In a preferred embodiment, the folding mechanism further comprises a third pair of folding rollers, which are arranged downstream relative to the second pair of folding rollers as seen in the feed direction of the tying material, wherein an outer surface of each of the third pair of folding rollers oriented toward an end of the plate-like guide member is tapered so as to further fold the tying material at each respective folding line, wherein the tapered ends of the third pair of folding rollers are located laterally of, but not necessarily between, the second surface of the plate-like guide member, are oriented toward each other and extend inwardly relative to the long side edges of the plate-like guide member, wherein the taper of the third pair of folding rollers is smaller than the taper of the second pair of folding rollers, and the ends of the third pair of folding rollers are located closer to the conveyor belt than the ends of the second pair of folding rollers.
[0016] In a preferred embodiment, the folding mechanism further comprises a second plate-shaped guide member, which is arranged downstream relative to the third pair of folding rollers as seen in the feed direction of the tying material and has a flat guide surface for guiding the tying material along it, wherein the tying material is conveyed between the conveyor belt and the guide surface of the second plate-shaped guide member along the guide surface of the second plate-shaped guide member, wherein the distance between the guide surface of the second plate-shaped guide member and the surface of the conveyor belt directed towards the guide surface is such that the tying material is folded more sharply at each respective folding line.
[0017] In a further or alternative preferred embodiment, the first pair of folding rollers and / or the second pair of folding rollers and / or the third pair of folding rollers are positioned substantially opposite each other.
[0018] In another preferred embodiment, the device further comprises means for cutting off the ends and means for closing the loop. The means for closing the loop preferably comprises splicing means for connecting the ends of the loop to each other by splicing. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will be further described with reference to the following drawings, which are not intended to limit the scope of protection of the present invention in any way, wherein:
[0020] Figure 1 A preferred embodiment of the device according to the invention is shown;
[0021] Figure 2 Shown Figure 1 a folding mechanism of a preferred embodiment of the device shown, wherein a solid line of lashing material is arranged in the folding mechanism;
[0022] Figure 3 Shown Figure 2 a side view of a cross section of;
[0023] Figure 4 Shown Figure 2 The folding mechanism is shown in cross-sectional states at different viewing angles.
[0024] Figure 5 Schematically shows the state of the strapping material at the position of the folding mechanism;
[0025] Figure 6 A perspective view of the folding mechanism is shown;
[0026] Figure 7 Shown with Figure 6 Perspective views of different folding mechanisms. DETAILED DESCRIPTION
[0027] Figure 1 A perspective view of a strapping machine 100 is shown. The strapping machine 100 carries strapping material 101 (essentially paper) from a supply roll 102 through the machine 100 and to a packaging device in the form of a banding arch 103. On its way to the banding arch 103, the strapping material 101 is sequentially carried by a first feed mechanism 104, guided through a buffer mechanism 201, and conveyed to the banding arch 103 by an arch feed mechanism 106. The banding arch 103 then forms a loop of strapping material 101 around a product 107 to be strapped. Finally, the loop of strapping material 101 is closed beneath the product 107, for example by gluing, and the closed loop is severed from the upstream strapping material 101 by a cutting device.
[0028] It is inherent in the strapping process that more strapping material 101 is wound around the strapping arch 103 than is needed to strap the product 107. This is because the product 107 is always smaller than the inner circumference of the strapping arch 103. As the strapping material 101 is tightened around the product 107, the excess strapping material 101 is pulled back and buffered in the buffer space 210 by the buffer mechanism 201. To strap subsequent products, the used strapping material 101 wrapped around the product 107 needs to be fed again from the supply roller 102.
[0029] To advance and retract the strapping material 101 , the arched feed mechanism 106 can convey the strapping material 101 in two mutually opposite directions, thereby retracting the strapping material 101 to tighten the strapping material 101 loop formed by the strapping arches 103 around the product 107 to be strapped before closing the loop.
[0030] Figure 1 and Figure 2 The diagram shows the path of the strapping material 101 through the first feed mechanism 104, via the buffer mechanism 201, and toward the arch feed mechanism 106. The strapping material 101 is introduced into the first feed mechanism 104, passing to the left of the buffer mechanism 201. Here, the strapping material 101 is introduced between two toothed belts 1050 and 1051, where the backs of the toothed belts 1050 and 1051 convey the strapping material 101 to the buffer mechanism 201. Downstream of the buffer mechanism 201, the strapping material 101 crosses a second set of toothed belts 1052 and 1053 and is carried to the strapping arch 103.
[0031] To fold the strapping material 101, the feed mechanism 104 includes a folding mechanism 300. In the folding mechanism 300, the strapping material 101 is fed past a first guide plate 301 to a plurality of sets of folding rollers. The folding rollers gradually fold the strapping material 101 inward. Downstream of the folding rollers, as viewed in the direction of conveyance of the strapping material 101 through the feed mechanism 104, the folded strapping material 101 passes over a second planar guide plate 302, against which the folded strapping material 101 is pressed by the back surface of a toothed belt 1051 to suppress the wrinkles.
[0032] As seen in the conveying direction of the tying material 101 through the feeding mechanism 104, the plurality of sets of folding rollers include, in order, a first pair of folding rollers 303, 304, a second pair of folding rollers 305, 306, and a third pair of folding rollers 307, 308. The guide plate 301 has a flat guide surface 309 along which the tying material 101 is guided so that the tying material 101 is conveyed along the guide surface 309 between the back side of the conveyor belt 1051 and the guide surface 309.
[0033] like Figure 6 and Figure 7As shown, the planar guide plate 301 is substantially rectangular and extends substantially in the longitudinal direction of the strapping material 101. The width of the portion of the guide plate 301 located near the first pair of folding rollers 303, 304 is narrower than the width of the strapping material 101. The narrower portion 310 of the guide plate 301 is referred to below in this regard. The guide plate 301 is arranged such that the strapping material 101 moves along the guide surface 309 and is guided to the first pair of folding rollers 303, 304 as it is conveyed to the strapping arch 103. The narrower width of the narrower portion 310 of the guide plate 301 near the first pair of folding rollers 303, 304 ensures that the folding rollers of the first pair of folding rollers 303, 304 fold the strapping material 101 against the opposing side edges 311, 312 of the narrower portion 310 of the guide plate 301 at a respective fold line along the length of the strapping material 101 (see V1).
[0034] Each of the first pair of folding rollers 303, 304 is arranged relative to the guide plate 301 so that the folding rollers 303, 304 fold the long side edges of the strapping material 101 against the side edges 311, 312 of the narrower portion 310 of the guide plate 301 so that the folded portions 401, 402 of the strapping material 101 extend substantially perpendicular to the longitudinal direction of the strapping material 101.
[0035] The folding mechanism 300 further includes a second pair of folding rollers 305, 306. As viewed in the feed direction of the strapping material 101, the folding rollers of the second pair of folding rollers 305, 306 are located downstream relative to the first pair of folding rollers 303, 304 and are configured to further fold the strapping material 101 (see V2) at the fold line formed by the first folding rollers 303, 304. Each of the second pair of folding rollers 305, 306 is tapered toward the outer surface of the end portions 313, 314 of the guide plate and extends inward relative to the long side edges 311, 312 of the narrower portion 310 of the guide plate 301.
[0036] The folding mechanism 300 further includes a third pair of folding rollers 307, 308. As seen in the feed direction of the strapping material 101, the folding rollers of the third pair of folding rollers 307, 308 are located downstream relative to the second pair of folding rollers 305, 306, and are configured to further fold the strapping material 101 at the folding line arranged by the first and second folding rollers (see V3). The outer surface of each of the ends 315, 316 of the third pair of folding rollers 307, 308 oriented toward the guide plate is also tapered and extends inwardly relative to the long side edges 311, 312 of the narrower portion 310 of the guide plate 301. The taper of the third pair of folding rollers 307, 308 is smaller than the taper of the second pair of folding rollers 305, 306. The ends 315, 316 of the third pair of folding rollers 307, 308 are also located closer to the conveyor belt 1051 than the ends of the second pair of folding rollers 305, 306. As Figure 6 and Figure 7 As shown, a first pair of folding rollers 303, 304, a second pair of folding rollers 305, 306, and a third pair of folding rollers 307, 308 are positioned relative to each other.
[0037] Finally, the folded strapping material 101 passes through the second planar guide 302 , against which the folded strapping material 101 is pressed by the back side of the toothed belt 1051 so as to press the wrinkles downwards.
[0038] The folding mechanism, which creates folds on both sides of the paper strapping material 101, imparts significantly greater tear resistance to the strapping material 101 than to an unfolded paper strapping material. Because the strapping material comprises a double layer of strapping material covering at least a portion of the strapping material's width, the tensile strength of the strapping material 101 is also increased. At the same time, the advantages of conventional strapping tapes, such as the material's sustainability and its ability to function as an information carrier, are also retained.
[0039] Figure 8An assembly of an alternative buffer mechanism 20 and an alternative folding mechanism 10 is shown. The folding mechanism 10 includes a profile 30 with a base surface 11, a guide member 12 for carrying a strapping material 101 thereon, and a guide member 12 disposed opposite the base surface 11 and having a guide surface oriented toward the base surface 11, wherein the strapping material 101 is carried along the guide surface between the base surface 11 and the guide surface. The folding mechanism 10 further includes a pair of walls 13 that stand upright relative to the base surface and extend parallel to each other in the direction of the strapping material 101. The guide member 12 is disposed between the upright walls 13, proximate the upstream end faces of the upright walls 13. The distance between the upright walls is less than the width of the strapping material 101. The guide member 12 is arranged such that the strapping material 101 as it is fed moves along the guide surface and is guided between the upright walls 13, wherein the upright walls 13 fold the strapping material against the opposite side edges of the guide member 12 at a respective fold line at each of its two opposite long side edges along the length of the strapping material so that said long side edges of the strapping material 101 move towards a surface of the guide member 12 directed away from the guide surface. Figure 12 and Figure 13 As shown, the guide member 12 consists of two guide components 12a and 12b. While the guide component 12a forms the fold, the guide component 12b guides the portion of the strapping material 101 folded by the guide component 12a along the inner surfaces 13a and 13b of the upright walls 13. Before the strapping material 101 reaches the guide member 12, that is, upstream of the guide member 12, a flat plate 14 is located opposite the base surface 11. The strapping material 101 is carried between this flat plate 14 and the base surface 11, where the flat plate 14 ensures that the strapping material 101 moves smoothly over the base surface 11 before reaching the guide member 12. This ensures proper operation of the guide member 12 and the upright walls 13 it interacts with, resulting in the strapping material 101 folding in the desired manner: along the direction of extension of the strapping material 101 and at a desired distance from the long side edges. Located downstream of the guide member 12 and the upright walls 13 is a second flat plate 15, opposite the base surface 11. The strapping material 101 partially folded by the guide members 12 and the upright walls 13 is carried between the second flat plate 15 and the base surface 11 so as to completely fold the side edges folded by the guide members 12 and the upright walls 13 against the side of the strapping material 101 that is oriented away from the side of the strapping material 101 that rests against the base surface 11. The second flat plate 15 here presses the folded portion of the strapping material 101 against the side of the strapping material 101 that is oriented away from the base surface 11.
[0040] The invention is not limited to the embodiments shown, but also extends to other embodiments falling within the scope of protection of the accompanying claims.
Claims
1. A device for bundling products, comprising: A feeding mechanism for feeding the strapping material from a supply roller to the packaging device along a feeding direction so as to form a loop around a space for receiving the product at the end of the strapping material, wherein the feeding mechanism includes a conveying device and a driving device, the conveying device being used to clamp the strapping material along a portion of its length and convey it to the packaging device in a guided manner, and the driving device being used to drive the conveying device. It is characterized by: A folding mechanism is disposed between the supply roller and the packaging device and is configured to fold the bundling material in a longitudinal direction of the bundling material when the bundling material is conveyed to the packaging device.
2. The device according to claim 1, wherein The folding mechanism is configured to fold the strapping material at each of its two opposing long side edges along its length.
3. The device according to claim 1 or 2, wherein: The folding mechanism is configured to fold the strapping material at each of its two opposing long side edges along its length such that free outer ends of the strapping material extending in a longitudinal direction of the strapping material are oriented towards each other.
4. The apparatus according to any one of claims 1 to 3, wherein The folding mechanism is configured to fold the strapping material along a length of the strapping material at each of its two opposing long side edges along a first fold line and a second fold line, respectively, wherein the first fold line and the second fold line extend in a longitudinal direction of the strapping material, and wherein the first fold line and the second fold line are different from each other.
5. The device according to claim 4, wherein The folding mechanism is configured to fold the strapping material at each of its two opposite long side edges along its length so that, at least when viewed in an unfolded state of the strapping material, each of the first fold line and the second fold line is located closer to the respective nearest long side edge of the strapping material than to a centerline of the strapping material extending in the longitudinal direction of the strapping material.
6. The apparatus according to any one of claims 1 to 5, wherein: The strapping material is substantially made of paper, wherein the thickness of the paper is between about 90 μm and about 160 μm, and wherein the folding mechanism is configured to fold the strapping material in the longitudinal direction of the strapping material so that the strapping material has a U-shape at the location where it is bent, as seen in a cross-section in the longitudinal direction of the strapping material, wherein the minimum radius of curvature of the portion of the strapping material extending between the legs of the U is greater than 10 μm, preferably greater than 50 μm, and more preferably greater than 100 μm.
7. The apparatus according to any one of claims 1 to 6, wherein: The folding mechanism comprises: a base plate for carrying the strapping material thereon, and a guide member arranged opposite the base plate and having a guide surface oriented toward the base plate, wherein the strapping material is carried between the base plate and the guide surface along the guide surface, and a pair of walls standing upright relative to the base plate and extending parallel to each other in the direction of the strapping material, wherein the guide member is arranged between the upright walls, close to the upstream end faces of the upright walls, wherein the mutual distance between the upright walls is smaller than the width of the strapping material, wherein the guide member is arranged such that the strapping material moves along the guide surface and is guided between the upright walls when being fed, wherein the upright walls fold the strapping material against the opposite side edges of the guide member at a respective folding line at each of two opposite long side edges thereof along the length of the strapping material so that the long side edges of the strapping material move towards a surface of the guide member that is directed away from the guide surface.
8. The apparatus according to any one of claims 1 to 6, wherein: The conveying device comprises a conveyor belt, and wherein the folding mechanism comprises: a plate-like guide member with a flat guide surface for guiding the strapping material along it, wherein the strapping material is conveyed along the guide surface between the conveyor belt and the guide surface, and The first pair of folding rollers, wherein the plate-like guide member is substantially rectangular and extends substantially in the longitudinal direction of the strapping material, has a width narrower than the width of the strapping material, and is arranged so that the strapping material moves along the guide surface and is guided toward the first pair of folding rollers when being fed, and wherein each of the first pair of folding rollers is in a form and is arranged relative to the plate-like guide member such that the first pair of folding rollers fold the strapping material against the opposite side edges of the plate-like guide member at a respective folding line of each of the two opposite long side edges along the length of the strapping material so that the long side edges of the strapping material move toward a second surface of the plate-like guide member that is oriented away from the guide surface.
9. The apparatus according to claim 8, wherein Each of the first pair of folding rollers takes a form and is arranged relative to the plate-like guide member such that the folding rollers fold the long side edges of the strapping material against the side edges of the plate-like guide member such that the folded portions of the strapping material extend substantially perpendicular to a longitudinal direction of the strapping material.
10. The apparatus according to claim 8 or 9, wherein The folding mechanism further comprises a second pair of folding rollers, which are arranged downstream relative to the first pair of folding rollers as seen in the feed direction of the strapping material, wherein an outer surface of each of the second pair of folding rollers oriented toward an end of the plate-like guide member is tapered so as to further fold the strapping material at each respective fold line, wherein the tapered ends of the second pair of folding rollers are located to the side of, but not necessarily directly on, the second surface of the plate-like guide member, are oriented toward each other and extend inwardly relative to the long side edges of the plate-like guide member.
11. The apparatus according to claim 10, wherein The folding mechanism further comprises a third pair of folding rollers arranged downstream relative to the second pair of folding rollers as seen in the feed direction of the strapping material, wherein an outer surface of each of the third pair of folding rollers oriented toward an end of the plate-like guide member is tapered so as to further fold the strapping material at each respective fold line, wherein the tapered ends of the third pair of folding rollers are located to the side of, but not necessarily directly on, the second surface of the plate-like guide member, are oriented toward each other and extend inwardly relative to the long side edges of the plate-like guide member, wherein the taper of the third pair of folding rollers is smaller than the taper of the second pair of folding rollers, and wherein ends of the third pair of folding rollers are located closer to the conveyor belt than ends of the second pair of folding rollers.
12. The apparatus according to claim 11, wherein The folding mechanism further comprises a second plate-like guide member which is arranged downstream relative to the third pair of folding rollers as seen in the feed direction of the tying material and has a flat guide surface for guiding the tying material along it, wherein the tying material is conveyed between the conveyor belt and the guide surface of the second plate-like guide member along the guide surface of the second plate-like guide member, wherein the distance between the guide surface of the second plate-like guide member and the surface of the conveyor belt directed towards the guide surface is such that the tying material is folded more sharply at each respective folding line.
13. The apparatus according to any one of claims 8 to 12, wherein The first pair of folding rollers are positioned substantially opposite each other.
14. The apparatus according to any one of claims 10 to 13, wherein The second pair of folding rollers are positioned substantially opposite each other.
15. The apparatus according to any one of claims 11 to 14, wherein The third pair of folding rollers are positioned substantially opposite each other.
16. Apparatus according to any one of the preceding claims, wherein The feeding mechanism includes the folding mechanism.
17. Apparatus according to any preceding claim, further comprising means for severing the end and means for closing the loop.