Device and method for perforating a label strip

Abstract

The invention relates to a device and a method for perforating a label tape, in particular a folded film tube, with two opposing tension rollers 6, 7 that convey the label tape in the transport direction T. The device comprises a cutting roller, on the circumferential surface of which several circumferentially spaced perforating blades are arranged, and a counter-cutting roller opposite the cutting roller, wherein the label tape 5 can be perforated between the cutting roller 1 and the counter-cutting roller. The counter-cutting roller has a surface that serves as a counter-blade for the perforating blades over its entire circumference. The cutting roller and counter-cutting roller have separate drives, and the counter-cutting roller can rotate at a constant speed.

Description

[0001] The invention relates to a device for perforating a label strip, in particular a folded film tube, and a corresponding method according to the preambles of claims 1 and 10, as known, for example, from DE102014216190A1.

[0002] To equip containers, such as bottles, cans, or the like, with tubular films or label sleeves, the so-called sleeves, equipment machines are used that have a device for unfolding a flat, folded film tube and cutting or tearing off films or label sleeves to a desired length. To shorten endless chains to a specific length, they can either be cut or perforated and then torn off. For perforation, as is particularly evident from Figure 5The label strip 5 is moved in the conveying direction 8 by means of the pull rollers 6, 7. The cutting rotor 1 punches the perforations into the label strip with the perforation knives 3 and the counter-cutting bars located on the counter-cutting roller 2. To ensure that the knives and counter-cutting bars always meet synchronously, the cutting rotor 1 and the counter-cutting roller 2 are coupled to each other. If the circular segment 9, i.e. the distance between two perforation knives 3 on the circumference of the cutting rotor or cutting roller 1, is significantly shorter or longer than the desired distance 12 of the perforations 13 (see Figure 4) on the label strip 5, the two coupled axes must strongly accelerate and then brake the cutting rotor 1 and the counter-cutting roller 2 between each perforation 13. In addition, the surface speed during cutting / perforation must exactly match the strip speed. This requires a very high drive torque and a very high load on the entire mechanical construction. Furthermore, the design of the two axes for the cutting rotor and the counter-cutting roller as well as their coupling must be very light and dynamic on the one hand, but also very stable on the other in order to be able to withstand the high loads. In order to reduce the torque, the distance 9 between the perforation knives 3 must be adapted to the required label length 12 by means of variants in the mechanical design. This increases the effort for the customer if different label lengths are to be processed.The necessary variety of variants also increases production costs.

[0003] Based on this, the present invention is based on the object of providing an improved device and an improved method in which, in particular, the mechanical stress and wear are reduced.

[0004] According to the invention, this object is achieved by the features of claims 1 and 10. In the device according to the invention for perforating a label strip in the form of a folded film tube, two opposing pull rollers are provided, which convey the label strip in the transport direction. Furthermore, the device comprises a cutting roller, on the circumferential surface of which a plurality of perforating knives are arranged, spaced apart in the circumferential direction. Furthermore, the device also has a counter-cutting roller, which is opposite the cutting roller, wherein the label strip can be perforated between the cutting roller and the counter-cutting roller. According to the invention, the counter-cutting roller now has a surface which serves over its entire circumference as a counter-cutting edge or counter-bearing for the perforating knives.

[0005] Because there are no longer any counter-cutting bars, but rather the entire circumference of the counter-cutting roller's surface serves as the cutting edge for the perforating knives, the cutting roller and counter-cutting roller no longer need to be coupled to each other. This means that the cutting roller and counter-cutting roller can have different drives. This is particularly advantageous because the cutting roller drive can be made significantly smaller, as there are no longer such large masses to accelerate and decelerate. Because the entire circumference of the counter-cutting roller is designed as a counter-cutting edge, the counter-cutting roller can operate at a constant speed, meaning that the highly dynamic movement of the counter-cutting roller does not need to be taken into account when designing the counter-cutting roller. This significantly reduces wear.It is essential that the counter-cutting roller can move continuously independently of the cutting roller and, in particular, that there is no relative movement between the knife and the counter-cutting roller.

[0006] The fact that the counter-cutting roller runs or is moved at a constant speed means that the counter-cutting roller runs continuously, ie while several perforations are formed one after the other, at a constant speed.

[0007] In addition, the counter-cutting roller can be manufactured more cost-effectively than in the state of the art, since no counter-cutting bars need to be incorporated.

[0008] It is particularly advantageous if the counter-cutting roller has a smaller diameter d 2 than the cutting roller, wherein in particular the diameter d 2 of the counter-cutting roller = 25% to 75% of the diameter d 1 of the cutting roller.

[0009] Due to the essentially constant speed and the smaller size and / or lower mass, a relatively small drive for the counter-cutting roller is sufficient, which can also significantly reduce costs.

[0010] In general, the main advantage of the invention is that the counter-cutting roller no longer needs to be moved by the cutting roller drive, thus significantly reducing the load on this drive. With this decoupling, the size of the counter-cutting roller is no longer important, because it is no longer subject to such high accelerations.

[0011] The advantage of a smaller counter-cutting roller is that the production of the hardened surface is more cost-effective compared to a larger counter-cutting roller.

[0012] Due to the continuously usable surface of the counter-cutting roller, the length of the circumference of the counter-cutting roller is independent of the label length and production speed and can therefore be optimized according to costs and production requirements.

[0013] Advantageously, the surface is made of hard metal, especially a carbide, e.g., hard metal HM G 20 from HHT Hartmetall GmbH & CO KG. These materials are particularly well suited as counter-blades.

[0014] For these materials, the surface hardness, for example, is in a range of 1500 to 1800 HV 30 according to Vickers.

[0015] The surface of the counter-cutting roller, which serves as a counter-cutting edge or counter-bearing for the perforating knife, has a flat, i.e., in particular, no elevations or depressions.

[0016] Furthermore, it is now possible for the counter-cutting roller to be coupled to the pull rollers and share the same drive, i.e., a shared motor. This offers the advantage that only two drives, i.e., two motors, are required for the entire perforating device. However, the drive for the cutting roller can be significantly smaller than in the prior art, and the motor for the pull rollers and the counter-cutting roller can also be made smaller, since these rollers run continuously at a constant speed.

[0017] The counter-cutting roller is coupled to the pull rollers in such a way that the peripheral speed of the counter-cutting roller consistently corresponds to the transport speed of the label strip.

[0018] It is particularly advantageous if the cutting roller drive is designed as a direct drive, e.g., a servo motor. Consequently, no mechanical transformations of the drive torque are necessary, which would have to be designed for the high dynamics of the cutting roller. These transformations, such as gears or belts, are the components that limit the service life. The inevitable wear would result in high maintenance costs.

[0019] In the method according to the invention for perforating a label strip in the form of a folded film tube, the label strip is conveyed in the transport direction by two opposing pull rollers. Viewed in the transport direction upstream of the pull rollers, the label strip is perforated between a cutting roller, on whose circumferential surface several perforating knives are arranged at a distance from each other in the circumferential surface, and an opposite counter-cutting roller. The label strip is perforated between one of the perforating knives and the circumferential surface of the counter-cutting roller, which serves as the counter-blade. This means that the label strip is no longer perforated between a cutting knife and a counter-cutting bar, but that the respective cutting knives interact directly with the surface on the counter-cutting roller and perforate the label strip. Thus, for certain label lengths, only the cutting roller needs to be accelerated or adjusted accordingly.can be slowed down, and the counter-cutting roller can then be driven at a constant speed, which can significantly reduce wear. For this purpose, the cutting roller and counter-cutting roller are driven by different drives and are not coupled to each other.

[0020] Then the peripheral speed of the counter-cutting roller can always correspond to the transport speed of the label strip, regardless of the length of the corresponding individual label.

[0021] During perforation, the peripheral speed of the cutting roller should ideally match the transport speed of the label strip. However, only one roller, the cutting roller, now needs to be accelerated and decelerated.

[0022] The folded film tube can be made, for example, from the following material: PET, OPS, PVC, particularly for shrink film tubes, and LDPE, particularly for stretch films, and particularly as a shrink film tube.

[0023] The invention is explained in more detail below with reference to the following figures. Figure 1 shows a roughly schematic embodiment of a device for perforating a label strip. Figure 2 shows a perspective view of a cutting roller and a counter-cutting roller. Figure 3 shows a rough schematic of the unwound surface of the counter-cutting roller. Figure 4 shows schematically the folded label tape. Figure 5 shows a device for perforating. Figure 6 shows a rough schematic of the device according to the invention together with an expanding mandrel. Figure 6shows a device for unfolding and tearing off a label strip 5, wherein the label strip 5 is perforated by means of a perforating device 20 along a line perpendicular to the transport direction T, as will be explained in more detail below. The label strip, for example a folded film tube, is then guided in the direction of an expanding mandrel 17, for example by means of a deflection roller 16. Figure 6 shows only the essential components. Of course, a buffer device for buffering a specific length of the label strip or other components can also be provided in front of the expanding mandrel 17.

[0024] The label strip perforated at points 13 is then spread by means of an expanding mandrel 17 and torn off via rollers 22a, 22b by changing the relative speed at the respective perforation 13 and shot onto a container 19. Figure 6shows only one example of such rolls. For example, rolls 22b run faster than rolls 22a, allowing the label strip to tear off at perforation 13 and then be shot onto container 19 by rolls 22b. Container 19 with the applied label, i.e., tube, can then be transported in the direction of arrow P, e.g., to a thermal shrink-fitting device 23, and shrunk using the heat generated in the tunnel, or simply applied as a stretch label instead of a shrink tube.

[0025] In Figure 1The device for perforating the label strip 5 is explained in more detail. The perforating device has two opposing pull rollers 6, 7, which convey the label strip 5 in the transport direction T. The transport speed of the label strip is, for example, 1.0 to 3.0 m / s in the transport direction. A cutting roller 1 is provided in front of the pull rollers, on whose circumferential surface 14 several perforating blades 3 are arranged, spaced apart in the circumferential direction. The perforating blades 3 are spaced apart by a distance 9 from one another. Figure 1 For example, three perforating blades 3 are evenly distributed around the circumference. The perforating blades extend perpendicular to the transport direction, that is, in a direction of the rotational axis A of the cutting roller 1. The perforating blades 3 create perforations 13 in the label strip, that is, in particular in the folded film tube, with a spacing 12 as in Figure 4which corresponds to the length of the label that is applied to the container. The perforating blade 3 can have several tips, as for example in Figure 2 shown to apply the label tape in a variety of places such as Figure 4 to perforate.

[0026] The cutting roller 1 can be driven by a direct motor, such as a servo motor. Consequently, no mechanical gears or belts are required, which must be designed for the high dynamics of the cutting roller 1. If the distance 9 does not correspond to the distance 12 between two perforations and the peripheral speed of the cutting roller corresponds to the transport speed of the label strip, the cutting roller would have to be significantly accelerated or decelerated between the creation of consecutive perforations 13.

[0027] The device further comprises a counter-cutting roller 10 opposite the cutting roller 1, wherein the label strip 5 is guided and perforated between the cutting roller 1 and the counter-cutting roller. The counter-cutting roller 10 has a surface 15 that serves as a counter-blade for the perforating blades 3 over its entire circumference. Figure 2 shows cutting roller 1 and counter cutting roller 10 in perspective. As can be seen from Figure 3As can be seen, the developed surface 15 of the counter-cutting roller 10 is flat and in particular has no elevations, depressions or inserts, as in the prior art. The counter-cutting roller 10 is also driven, but has a different drive than the cutting roller 1. The counter-cutting roller 10 also has a smaller diameter d 2 than the cutting roller with a diameter d 1 , where d 2 = 0.25 to 0.75 d 1 . This means that the counter-cutting roller is significantly smaller than the cutting roller 1. As a result, the counter-cutting roller can also be lighter than the cutting roller. Since the counter-cutting roller is no longer driven by the same drive as the cutting roller 1, the drive for the cutting roller 1 can be significantly smaller.

[0028] Since the counter-cutting roller is small and lightweight, a very small drive is also necessary, or in a particularly advantageous manner, the counter-cutting roller 10 can be coupled to the pull rollers 6, 7 and have the same drive. Thus, in this exemplary embodiment, the device according to the present invention also has only two drives, i.e. two motors, although these can be designed to be smaller overall than in the prior art, so that considerable costs can be saved. Because the surface of the counter-cutting roller does not have counter-cutting bars, the counter-cutting roller 10 does not have to be positioned precisely for perforation and can be operated continuously and thus with little wear. The surface of the counter-cutting roller is particularly hard and has a hardness in a range of 1500 to 1800 HV 30 according to Vickers.The surface 15 can, for example, advantageously be formed from hard metal, in particular a carbide, e.g. hard metal HM G 20 from HHT Hartmetall GmbH & CO KG.

[0029] As is particularly evident from Figure 6 As can be seen, the device 20 is connected to a controller 21 designed such that during perforation, i.e., when a knife 3 is in the cutting position opposite the counter-cutting roller 10, the peripheral speed of the cutting roller 1 substantially corresponds to the transport speed of the label strip 5 (+ / - 0.1%). The pull rollers and the counter-cutting roller 10 can be driven at the same peripheral speed, whereby the label strip has a corresponding transport speed.

[0030] The counter-cutting roller 10 is designed and coupled to the pull rollers 6, 7 in such a way that the peripheral speed of the counter-cutting roller consistently corresponds to the transport speed of the label strip 5.

[0031] A method for perforating a label strip 5 according to a preferred embodiment is described in more detail below.

[0032] The label strip 5, for example a folded film tube, for example a shrink film tube, is conveyed in the transport direction T and conveyed over the opposite pulling rollers 6, 7 in the transport direction T. The folded tube 5 is conveyed between the cutting roller 1 and the counter-cutting roller 10. The cutting roller 1 is controlled in such a way that successive cutting knives 3, which create the perforation on the opposite counter-cutting roller, are brought into the perforation position (as shown in Figure 1) one after the other, such that the perforations 13 have the desired distance 12, as can be seen from Figure 4 The cutting roller 1 has a peripheral speed, at least during perforation, that essentially corresponds to the transport speed of the label strip 5. In contrast, due to the smooth surface 15, the counter-cutting roller 10 can be driven continuously.

[0033] Since the peripheral speed of the counter-cutting roller 10 is constant and, as previously stated, the counter-cutting roller is small and light, it can be coupled with the pulling rollers 6, 7 and driven by the same drive. The peripheral speed of the pulling rollers 6 and 7 corresponds to the transport speed T. Subsequently, as previously explained in connection with Figure 6 As described, the label strip or the folded film tube is unfolded by means of an expanding mandrel 17 and torn off by means of further pairs of rollers 22a, b and shot onto a container 19 and the label sleeve, i.e. the sleeve, is then shrunk on, for example.

[0034] The invention enables a device that is extremely wear-resistant and where manufacturing costs can be saved.

Claims

1. Device (20) for perforating a label strip (5), in the form of a folded film tube, with two opposing draw rollers (6), (7), with which the label strip (5) can be conveyed in the transport direction T, with a cutting roller (1), on the circumferential surface (14) of which a plurality of perforating knives (3) spaced apart in the circumferential direction are arranged, and with a counter-cutting roller (10) located opposite the cutting roller (1), wherein the label strip (5) can be perforated between the cutting roller (1) and the counter-cutting roller (10), characterized in that the counter-cutting roller (10) has a surface (15) which serves as a counter-cutting edge for the perforating knives (3) over its entire circumference, and that the cutting roller (1) and the counter-cutting roller (10) have different drives such that the counter-cutting roller (10) can run at a constant speed.

2. Device according to claim 1, characterized in that the counter-cutting roller (10) has a smaller diameter d2 than the cutting roller, which has a diameter d1, where d2 = 0.25 to 0.75 d1.

3. Device according to claim 1 or 2, characterized in that the surface (15) is made of a hard metal, in particular a carbide.

4. Device according to one of claims 1 to 3, characterized in that the surface (15) of the counter-cutting roller (10) has a hardness in a range of 1500 - 1800 HV 30 according to Vickers.

5. Device according to one of claims 1 to 4, characterized in that the unwound surface (15) of the counter-cutting roller (10) is flat, in particular has no elevations or depressions.

6. Device according to one of claims 1 to 5, characterized in that the counter-cutting roller (10) is coupled to the draw rollers (6), (7) and have the same drive.

7. Device according to one of claims 1 to 6, characterized in that the device has a drive for the cutting roller (1) and a common drive for the counter-cutting roller (10) and the traction rollers (6), (7).

8. Device according to one of claims 1 to 7, characterized in that the circumferential speed of the counter-cutting roller (10) corresponds throughout to the transport speed of the label strip (5).

9. Device according to one of claims 1 to 8, characterized in that the drive of the cutting roller (1) is designed as a direct drive.

10. Method for perforating a label strip (5), in the form of a folded film tube, in particular with a device according to one of claims 1 to 9, wherein the label strip (5) is conveyed in the transport direction T by two opposing draw rollers (6), (7) and as viewed in the transport direction in front of the draw rollers (6), (7) between a cutting roller (1), on the circumferential surface (14) of which a plurality of perforating knives (3) spaced apart in the circumferential direction are arranged, and an opposing counter-cutting roller (10), characterized in that the label strip (5) is perforated between one of the perforating knives (3) and the circumferential surface (15) of the counter-cutting roller (10), which serves as a counter-cutter, and the cutting roller (3) and the counter-cutting roller are driven by different drives, and in that the counter-cutting roller runs at a constant speed.

11. Method according to claim 10, characterized in that the circumferential speed of the counter-cutting roller (10) always corresponds to the transport speed of the label strip (5), and in particular the counter-cutting roller (10) and the draw rollers are driven by the same drive.

12. Method according to one of claims 10 to 11, characterized in that the peripheral speed of the cutting roller (1) during perforating corresponds to the transport speed of the label tape.

13. Method according to one of claims 10 to 12, characterized in that the folded film tube is formed from the following material: PET, OPS, PVC, in particular as for shrink tubing or LDPE, in particular for stretch films.

14. Method according to one of claims 10 to 13, characterized in that the label strip is unfolded in the transport direction after the draw rollers (6), (7) with the aid of an expanding mandrel (17) and is shot onto a container via further rollers (22a, b).

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