Cutting device and processing table with the device

Abstract

Disclosed is a cutting device (1) for fabricating a fiber-based shell (10). The cutting device (1) has a first mandrel (20) which can rotate about an axis of rotation (D1) and on which the fiber-based shell (10) can be arranged. The cutting device (1) has a knife (30) which can rotate about an axis of rotation (M). The axis of rotation (D) of the first mandrel (20) and the axis of rotation (M) of the knife (30) are adjacent to each other.

Description

[0001] The present invention relates to a cutting device for preparing a fiber-based cover and to a preparation table comprising a cutting device for preparing a fiber-based cover according to the preamble of the independent claims.

[0002] Various containers for holding liquids are known in the prior art. For example, glass bottles or plastic bottles for holding beverages are known. Containers made of fiber-based materials have also been proposed.

[0003] A fiber-based container was proposed in WO 2012 / 139590 A1. To manufacture this container, so-called pulp is placed in a mold and pressed against a corresponding wall of the mold using a flexible balloon, thus compressing it.

[0004] Pulp is a mixture of fibers and water, particularly natural fibers such as hemp fibers, cellulose fibers, or flax fibers, or a mixture thereof. The pulp may contain additives, such as those known from PCT / EP2019 / 076839, which, for example, improve the curing of the compressed pulp, influence its final appearance, or generally alter the properties of the pulp or the final container.

[0005] These containers are at risk of softening due to the liquid stored inside, potentially causing leaks or allowing substances to diffuse from the container into the liquid.

[0006] It has been proposed to equip such fiber-based containers with an inner layer of plastic, in particular to place a plastic bottle inside the fiber-based container, which can then perform the corresponding barrier functions. In this case, the fiber-based container merely provides a shell for a thin-walled plastic container. Such a combination is known from WO 2018 / 167192 A1.

[0007] It is known that certain inaccuracies can occur during production of both fiber-based containers that are subsequently coated with an inner layer of plastic (i.e., fiber-based shells) and fiber-based containers without such a layer. Since the containers and / or shells are formed in a negative mold, very high dimensional accuracy can be achieved with respect to their outer contour. The inner contour, or rather the inner surface of the container / shell, is subject to varying degrees of deviation, depending on the specific properties of the pulp from which the container / shell is formed. These deviations are typically negligible, with the exception of deviations in the area of ​​an opening in the container into which a plastic container is later inserted and / or to which a container closure is attached.Due to the material properties of the pulp, the upper, closing edge of the opening is subject to larger tolerances and is regularly fibrous. This is particularly disadvantageous because it forms an interface with the aforementioned plastic containers and / or container closures, and this interface must be dimensionally accurate.

[0008] The object of the invention is to overcome one or more disadvantages of the prior art. In particular, it aims to create a device that enables the precise manufacturing of fiber-based casings.

[0009] This problem is solved by the device according to claim 1. Further embodiments are described in the dependent claims.

[0010] In this context, a fiber-based shell is understood to be an object into which another object, such as a plastic container, can be inserted. A fiber-based container is understood to be a container into which a substance, such as a liquid, can be directly introduced. A fiber-based container typically has a base, a body, and a neck to which the opening is attached. A fiber-based shell may also have these elements, but this is not mandatory. A fiber-based shell can also be, for example, simply tubular and have two openings. In this case, it is conceivable that a container to be inserted into this shell could protrude from the fiber-based shell with both its base and its neck.With regard to an opening to be finished, this includes container openings as well as openings at tubular ends of a casing. US 2002 / 056346 A1 discloses a cutting device for trimming a plastic container, wherein the cutting device has two blades that are rotatable about mutually perpendicular axes of rotation.

[0011] A cutting device according to the invention for preparing a fiber-based casing, in particular a fiber-based container, comprises a first mandrel on which it is rotatable about an axis of rotation and on which the fiber-based casing can be arranged. Furthermore, the cutting device comprises a knife which is rotatable about an axis of rotation. The axis of rotation of the first mandrel and the axis of rotation of the knife are adjacent to each other, in particular at an angle of less than 10° to each other, preferably less than 5° to each other, and preferably parallel to each other.

[0012] It goes without saying that the knife is positioned opposite the mandrel in the direction of one of the axes of rotation, i.e. along the axis of rotation.

[0013] The mandrel is preferably essentially circular-cylindrical. However, in the direction opposite to the receiving direction of the fiber-based sheath, the mandrel can also be at least partially conical to facilitate the insertion of the mandrel into the fiber-based sheath, or the application of the sheath onto the first mandrel. The receiving direction of the fiber-based sheath is the direction in which the fiber-based sheath must be moved to position it on the mandrel.

[0014] This arrangement allows the blade and mandrel to roll against each other, thus performing a cutting motion. This makes it possible to separate a fiber-based sheath positioned between the mandrel and the blade and create a defined cut edge on the fiber-based sheath.

[0015] Adjacent to each other means that the axes of rotation run essentially in the same direction.

[0016] As an alternative to the mandrel described above, it is possible to design the mandrel with a variable diameter. For example, the mandrel can be designed as a spreader with radially movable segments or sectors.

[0017] It may be provided that the first mandrel has a drive device.

[0018] The drive mechanism allows a fiber-based sheath applied to the first mandrel to rotate together with the mandrel. This rotation enables the entire circumference of the fiber-based sheath to pass by a specific position, particularly the point where the rotating blade engages. Furthermore, continuous rotation allows a specific section of the fiber-based sheath's circumference to be passed by the blade multiple times. This enables very gentle cutting of the fiber-based sheath.

[0019] It may be provided that the knife is mounted to rotate freely and can be driven or is driven by contact with the mandrel or a fiber-based sheath arranged on the mandrel.

[0020] This passive drive of the knife ensures that no relative movement occurs between the knife and the surface being cut. This is because the friction of the knife on the mandrel, or on the fiber-based sheath being cut, drives it precisely at the circumferential speed of the fiber-based sheath, neglecting any slippage. Thus, the circumferential speed of the fiber-based sheath and the circumferential speed of the knife are identical. This reduces the risk of fiber tear-out caused by a speed difference between the knife and the surface of the fiber-based sheath.

[0021] However, in addition to or as an alternative to the drive device for the mandrel, the knife can also have a drive device. Accordingly, the mandrel and the knife can be driven simultaneously. This allows for the adjustment of a specific slippage between the knife and the fiber-based casing. Preferably, this slippage is reduced to zero.

[0022] It is also possible to use the knife to drive the spike and thus the fiber-based casing.

[0023] Preferably, the rotatable knife is arranged to be displaceable relative to the first mandrel, such that a distance between the axis of rotation of the first mandrel and the axis of rotation of the knife can be adjusted.

[0024] The mandrel, especially when combined with its drive mechanism, can thus be stationary, for example, on a finishing table. This allows only the knife to be spaced further apart from the mandrel when applying the fiber-based sheath. Furthermore, it is easy to accommodate different wall thicknesses of the fiber-based sheath.

[0025] This may involve the knife being arranged on a sled or on a swiveling console.

[0026] Mounting the knife on a carriage allows it to be moved linearly towards or away from the mandrel. Alternatively, mounting it on a pivoting console allows it to be moved towards or away from the mandrel by pivoting. The carriage can be designed to allow at least slight pivoting for centering the knife and / or compensating for tolerances in the fiber-based casing being cut. Preload elements on the carriage can be used for this purpose.

[0027] For example, the knife can be positioned with a preload towards the mandrel, and the mandrel is guided past the knife, rotating as it passes. In this case, the knife is located in a clearance space in front of the mandrel and, upon impact with the mandrel or a fiber-based sheath, is moved away from the mandrel according to its diameter. Simultaneously, the knife is driven by the mandrel, and the fiber-based sheath is cut.

[0028] The cutting device can have a second mandrel that is rotatable about an axis of rotation and on which a further fiber-based sheath can be arranged. The axis of rotation of the second mandrel and the axis of rotation of the knife are adjacent to each other, in particular at an angle of less than 10° to each other, preferably less than 5° to each other, and preferably parallel to each other.

[0029] By adding a second mandrel, two fiber-based casings can be assembled together simultaneously with a single knife.

[0030] The second mandrel may have a drive device.

[0031] The drive mechanism allows a fiber-based sleeve applied to the second mandrel to rotate together with the second mandrel. This rotation enables the entire circumference of the fiber-based sleeve to pass by a specific position, particularly the point where the rotating blade engages. Furthermore, continuous rotation allows a specific section of the fiber-based sleeve's circumference to be passed by the blade multiple times. This enables very gentle cutting of the fiber-based sleeve.

[0032] Preferably, the first mandrel and the second mandrel have a common drive device.

[0033] This ensures that both mandrels, and therefore both fiber-based sheaths applied to the respective mandrel, have the same rotational speed and thus the same circumferential speed.

[0034] When designing the cutting device with two mandrels, it can be provided that the knife is arranged on a rotating plate between the first mandrel and the second mandrel for centering.

[0035] A pivot point of the turntable is arranged in the area of ​​an axis of symmetry between the two mandrels, whereby this area can extend on both sides of the axis of symmetry up to the respective mandrel.

[0036] By arranging the knife on a turntable, it is possible to position it uniformly relative to the two mandrels. In particular, such an arrangement allows for the equalization of the distance between the axis of rotation of the first mandrel and the axis of rotation of the knife, as well as the distance between the axis of rotation of the second mandrel and the axis of rotation of the knife.

[0037] A rotational or pivoting movement of the turntable can be limited by elastic stops such as springs. It is conceivable that a spring is pre-tensioned in each of the two rotational or pivoting directions, pressing the knife and the turntable into a neutral position. This neutral position corresponds to the alignment of the knife and the turntable with the axis of symmetry.

[0038] This allows, for example, the absence of a fiber-based covering on one of the two mandrels to prevent excessive stress on the uncovered mandrel, as the corresponding spring presses the knife into the axis of symmetry and thus moves it in the direction of the second, covered, mandrel.

[0039] Furthermore, these elastic stops make it possible to create a compensation that balances fluctuations in the wall thickness of the fiber-based shell.

[0040] The diameter of the first mandrel and, if applicable, the second mandrel can each be larger than the inner diameter of the fiber-based sheath that is to be applied to the respective mandrel.

[0041] This design allows the fiber-based sheath to be held on the mandrel without the need for additional retaining elements. The fiber-based sheath is thus held on the mandrel solely by clamping action. If the mandrel has a variable diameter, a first diameter can be smaller than the inner diameter of the fiber-based sheath, and a second diameter larger. This allows the mandrel to be inserted into the fiber-based sheath effortlessly and without friction, and the sheath is then held in place by the larger diameter of the mandrel.

[0042] The cutting device can have one or more stripping devices for removing a detached section of the fiber-based sheath. These are arranged in a receiving direction downstream of the blade on the first and, if applicable, on the second mandrel.

[0043] In the intake direction in front of the knife, a fan nozzle can be arranged on the cutting device for each mandrel, in particular below the respective mandrel. An arrangement below the respective mandrel means that a nozzle opening of the fan nozzle is arranged in the intake direction in front of the mandrel, but at a radial distance from the mandrel so that the fan nozzle does not collide with a fiber-based sleeve arranged on the respective mandrel.

[0044] The fan nozzle makes it possible to blow a cut-off section, which is stripped from the respective mandrel, in a desired direction out of a working space in order to collect it, for example, in a suitable container.

[0045] The first and / or second mandrel can each have an elastic, in particular cut-resistant, coating, especially a plastic coating. This can, for example, be in the form of polyester-urethane rubber.

[0046] A coating can delay excessive wear and / or dulling of the knife.

[0047] Each mandrel can have a groove shaped to match the cutting edge of the knife. The groove is designed so that the knife extends beyond the wall thickness of the fiber-based sheath to be cut, thus reaching into a curve of the mandrel. The groove, which faces the knife, allows the knife to be moved behind the mandrel's surface without damaging it.

[0048] This configuration ensures that the fiber-based sheath can be completely severed without damaging the surface of the spike.

[0049] Another aspect of the present invention relates to a finishing table for finishing fiber-based covers. The finishing table comprises a cutting device for finishing a fiber-based cover as described herein. The finishing table has a first conveying device for feeding unfinished fiber-based covers and a second conveying device for removing finished fiber-based covers.

[0050] This training enables the continuous processing of fiber-based casings.

[0051] It may be provided that a rotary table is arranged on the assembly table to convey the fiber-based casings to the cutting device.

[0052] In particular, the rotary table is designed to convey fiber-based casings from the first conveying device to the cutting device and from the cutting device to the second conveying device.

[0053] Designing a fabrication table with a rotary table simplifies its design and enables continuous conveying of fiber-based casings and thus continuous processing.

[0054] A process for manufacturing fiber-based casings includes, in particular, the following steps: Feeding a fiber-based sheath to a cutting device, arranging the fiber-based sheath on a rotatable mandrel, positioning a rotatable knife towards the mandrel such that the fiber-based sheath to be processed, i.e., trimmed, is arranged between the mandrel and the knife, rotating the mandrel around its axis of rotation, whereby the rotation of the mandrel and the fiber-based sheath arranged on it drives the knife and thus cuts off a section of the fiber-based sheath.

[0055] In subsequent steps, the finished fiber-based casing is removed from the mandrel. The detached section is then removed from the mandrel, particularly using a stripping device, and blown out of the working area with a fan nozzle positioned in front of the mandrel in the receiving direction.

[0056] The invention is explained below with reference to schematic figures and exemplary embodiments. These show: Figure 1: A perspective view of a cutting device; Figure 1A: A bottom view of the cutting device from the Figure 1 Figure 2: a perspective view of the cutting device of the Figure 1Figure 3: a schematic view of a knife-mandrel combination; Figure 4: a schematic view of another knife-mandrel combination; Figures 5 to 10: a finishing process; Figure 11: a top view of a finishing table; Figure 12: a perspective view of another finishing table; Figure 13: a detail view of the finishing table from the Figure 12 .

[0057] The Figure 1 shows a perspective view of a cutting device 1. The cutting device 1 has a first mandrel 20 and a second mandrel 40. The first mandrel 20 is rotatable about the axis of rotation D1, and the second mandrel 40 is rotatable about the axis of rotation D2. A knife 30 is arranged essentially on an axis of symmetry between these two mandrels 20 and 40. The knife 30 is rotatable about its axis of rotation M.

[0058] The knife 30 is linearly displaceable on a carriage 31. The carriage 31, in turn, is rotatably mounted on a rotary table 50. The rotary table 50 and the mandrels 20 and 40 are arranged on a common, unspecified, support.

[0059] In the present representation according to the Figure 1 Below the knife 30 are two fan nozzles 60, each fan nozzle 60 being assigned to a mandrel 20, 40. The fan nozzles 60 are spaced radially apart from the respective mandrel 20, 40.

[0060] A stripping device 22 is assigned to the first mandrel 20. A stripping device 42 is also assigned to the second mandrel 40. The stripping devices 22 and 42 are arranged to be displaceable along the first axis D1 and the second axis D2, respectively.

[0061] The Figure 1A shows a bottom view of the cutting device 1 from the Figure 1 .In this figure, the knife 30 is positioned centrally between the two prongs 20, 40, but is not yet engaged with any fiber-based sheaths potentially located on the prongs. As already mentioned in the Figure 1 As explained, the entire knife 30 is arranged on a turntable 50. Two elastic stops, designed as springs, are arranged on this turntable 50. Together, these form a spring balancer 51. The spring balancer 51 limits the rotational movement of the turntable 50 and presses it into the neutral position shown here.

[0062] The Figure 2 shows a perspective view of the cutting device 1 of the Figure 1 . In the illustration according to the Figure 2The drive devices 41 and 42 of the respective mandrels 20 and 40 are shown. The two drive devices 41 and 21 are each designed as gears, which are moved by a central gear driven by a motor. The mandrels 20 and 40 thus share a common drive device.

[0063] From the Figure 2 It is also evident that a pneumatic cylinder is provided for each of the scraper device 22 and the scraper device 42. However, these are not described in more detail here.

[0064] The Figure 3Figure 1 shows a schematic view of a knife-mandrel combination consisting of a knife 30 rotatably mounted about an axis of rotation M and a first mandrel 20 rotatably mounted about an axis of rotation D1. The knife 30 is pivotally mounted about point P on a pivotable console (not shown). By pivoting the knife 30 about point P, the axis of rotation M can be aligned with the axis of rotation D1 of the mandrel 20. A fiber-based sheath located on the mandrel 20 is thus clamped between the knife 30 and the mandrel 20. By rotating the mandrel 20, this fiber-based sheath can be cut open.

[0065] The Figure 4 Figure 1 shows a schematic view of another knife-mandrel combination consisting of a knife 30, a first mandrel 20, and a second mandrel 40. This representation essentially corresponds to the operating principle of the cutting device 1 from the Figure 1 The knife 30 is mounted on a slide 31 not shown here (see Figure 1 ) arranged and linearly displaceable along the direction of arrow P2. The carriage 31 is mounted on a rotary table 50 (see Figure 1 The blade 30 is rotatably mounted about point P and pivotable in the direction of arrow P3. By moving the blade 30 in the direction of arrow P2 towards the mandrels 20 and 40, the blade 30 is automatically centered between the two mandrels 20 and 40. In other words, a distance between the axis of rotation D1 and the axis of rotation M corresponds to a distance between the axis of rotation D2 and the axis of rotation M.

[0066] The Figures 5 to 10 This illustrates a packaging process. The packaging process is explained in connection with the first mandrel 20. However, the process steps are equally applicable to the second mandrel 40. In a first step, which is described in the Figure 5 As can be seen, a fiber-based sheath 10 is provided relative to a first mandrel 20. The stripping device 22 is visible on the first mandrel 20. In a second step, which is described in the Figure 6As can be seen, the fiber-based sheath 10 is applied to the mandrel 20 in the receiving direction A. In the next step, which is described in the Figure 7 As can be seen, a knife is 30, as in the Figures 3 and 4 The described process involves positioning the fiber-based sleeve 10 with its axis of rotation M towards the axis of rotation D1, such that the fiber-based sleeve 10 is clamped between the knife 30 and the mandrel 20. The mandrel 20, together with the fiber-based sleeve 10 mounted on it, is then rotated. This rotation also drives the knife 30, which rotates around its axis of rotation M. This rotation, combined with the uniform pressure of the knife 30 on the fiber-based sleeve 10, cuts off a section 11 of the fiber-based sleeve 10. The now-finished fiber-based sleeve 10' is then removed from the mandrel 20 in the opposite direction to the receiving direction A (see figure). Figure 6 ) removed and only the cut-off section 11 remains on the mandrel 20, as shown in the Figure 8as is evident. In the following step, which is in the Figure 9 As illustrated, the scraper device 22 is moved against the direction of intake A, which is indicated by the arrow in the Figure 9 This is illustrated. This movement strips the detached section 11 from the mandrel 20. As soon as the detached section 11 releases from the mandrel 20, air is blown into the fan nozzle 60, and this burst of air blows the section 11 out of the working area. The stripping device 22 is then returned to its original position as shown. Figure 5 moved. The procedure described here also applies to a second mandrel.

[0067] The Figure 11Figure 1 shows a top view of a finishing table 5. The finishing table 5 has a cutting device 1, which has two mandrels. A multitude of fiber-based sleeves 10 are located on a conveyor 70 (not shown in detail). These fiber-based sleeves 10 are transferred from the conveyor 70 to a rotary table 90, which moves them towards the cutting device 1. In the cutting device 1, the fiber-based sleeves 10 are finished as described above. The finished fiber-based sleeves 10' are moved by the rotary table 90 to a conveyor 80 (not shown in detail) and discharged onto it.

[0068] The Figure 12Figure 1 shows a perspective view of a finishing table 5. The finishing table 5 has a cutting device 1, which has two mandrels. A large number of fiber-based casings are conveyed by a conveyor 70 to a rotary table 90 and transferred there. The rotary table then conveys them to the cutting device. In the cutting device 1, the fiber-based casings are finished as described above. The finished fiber-based casings are moved by the rotary table 90 to a conveyor 80 and discharged onto it.

[0069] The Figure 13 shows a detailed view of assembly table 5 from the Figure 12This illustration shows two fiber-based sleeves 10, held by the rotary table 90 and mounted on mandrels (not visible here). The fiber-based sleeves 10 are fed to the finishing table 5 via the conveyor 70. The illustration shows the process just before the knife 30 of the cutting device 1 is moved towards the mandrels. The right side of the image shows one of several finished fiber-based sleeves 10'. These are removed from the finishing table 5 via the conveyor 80.

Claims

1. Cutting device (1) for fabricating a fiber-based shell (10), in particular a fiber-based container, wherein the cutting device (1) has a first mandrel (20) which can rotate about an axis of rotation (D1) and on which the fiber-based shell (10) can be arranged, and has a knife (30) which can rotate about an axis of rotation (M), wherein the axis of rotation (D) of the first mandrel (20) and the axis of rotation (M) of the knife (30) are adjacent to each other, in particular at an angle of less than 10° relative to each other, preferably less than 5° relative to each other, preferably parallel to each other.

2. Cutting device (1) according to Claim 1, characterized in that the first mandrel (20) has a drive device (21).

3. Cutting device (1) according to Claims 1 or 2, characterized in that the knife (30) is mounted so as to be freely rotatable and can be driven by contact with the mandrel (20) or a fiber-based shell (10) arranged on the mandrel (20).

4. Cutting device (1) according to Claims 1 or 2, characterized in that the knife (30) has a drive device.

5. Cutting device (1) according to any one of Claims 1 to 4, characterized in that the rotatable knife (30) is arranged displaceably relative to the first mandrel (20) such that a distance between the axis of rotation (D1) of the first mandrel (20) and the axis of rotation (M) of the knife (30) is adjustable6. Cutting device according to Claim 5, characterized in that the knife (30) is arranged on a carriage (31) or is arranged on a pivotable bracket.

7. Cutting device (1) according to any one of Claims 1 to 6, characterized in that the cutting device (1) has a second mandrel (40) which can rotate about an axis of rotation (D2) and on which a further fiber-based shell (10) can be arranged, wherein the axis of rotation (D) of the second mandrel (20) and the axis of rotation (M) of the knife (30) are adjacent to each other, in particular at an angle of less than 10° relative to each other, preferably less than 5° relative to each other, preferably parallel to each other.

8. Cutting device (1) according to Claim 7, characterized in that the second mandrel (40) has a drive device (41).

9. Cutting device (1) according to Claims 7 or 8, characterized in that the knife (30) is arranged on a rotary plate (50) for centering between the first mandrel (20) and the second mandrel (40).

10. Cutting device (1) according to any one of Claims 1 to 9, characterized in that a diameter of the first mandrel (20) and optionally of the second mandrel (40) is in each case greater than an inner diameter of the fiber-based shell (10).

11. Cutting device (1) according to any one of Claims 1 to 10, characterized in that a stripping device (22, 42) is arranged in a receiving direction (A) after the knife (30) on the first mandrel (20) and optionally on the second mandrel (40).

12. Cutting device (1) according to any one of Claims 1 to 11, characterized in that a fan nozzle for each mandrel (20, 40) is arranged in a receiving direction (A) before the knife (30), in particular below the respective mandrel (20, 40).

13. Cutting device (1) according to any one of Claims 1 to 12, characterized in that each mandrel (20, 40) has a resilient, in particular cut-resistant, coating.

14. Cutting device (1) according to any one of Claims 1 to 13, characterized in that each mandrel (20, 40) has a groove which is shaped corresponding to the cutting edge of the knife so that the knife projects beyond the wall thickness of the fiber-based shell to be cut.

15. Fabricating table (5) for fabricating fiber-based shells (10) comprising a cutting device for fabricating a fiber-based shell (10) according to any one of Claims 1 to 14, characterized in that the fabricating table (5) has a first conveying device (70) for feeding non-fabricated fiber-based shells (10) and has a second conveying device (80) for conveying away fabricated fiber-based shells (10').

16. Fabricating table (5) according to Claim 15, characterized in that a rotary plate (90) for conveying the fiber-based shells (10) to the cutting device (1) is arranged on the fabricating table (5).

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