METHOD AND DEVICE FOR SEQUENTLY WINDING A FOIL TRAY AND FOIL ROLL

Description

[0001] The invention relates to a method for successively winding a film web according to the preamble of claim 1, an associated device according to the preamble of claim 8 and a film roll according to the preamble of claim 14.

[0002] In a process for successively winding a film web onto multiple reels, the film web is first wound onto an initial reel. Once this reel has reached its target size, the film web must be cut, and the resulting new web start wound onto a new reel. For this purpose, an empty winding core is typically provided, and / or—as in the case of coreless winding—a winding shaft is used. The winding core and / or the winding shaft, along with the film web, are brought close together while the film web continues to be wound onto the first reel. The film web is then cut, creating the aforementioned new web start. Since the film web is cut before the first reel (viewed from the transport direction), the remaining portion of the film web between the cutting device and the first reel is not guided and lies undefined on the reel.The problem is exacerbated if the web is under tension before it reaches the first reel. If the severing device then performs a sudden severance, the remaining portion of the film web springs onto the first reel. This results in a poorly usable beginning of the film in subsequent processing steps, leading to poor winding quality at the end of the reel. Furthermore, malfunctions in the winding device can occur if the film web wraps around rollers or other components. A prior art method, device, and film reel are disclosed, for example, in US 5,368,253 A.

[0003] The object of the present invention is therefore to propose a method, a device and a film roll which produces an improved quality of the winding, including the end resulting from the separation.

[0004] According to the invention, this problem is solved by all the features of claim 1. Possible embodiments of the invention are specified in the dependent claims.

[0005] According to the present invention, the film web is partially cut in the transverse direction to separate it, i.e., only an incomplete separation is achieved in the transverse direction. This creates a separation edge that, viewed transversely, does not extend completely across the film web. However, this incomplete separation already defines the end of the film web that is wound onto the first reel. The new beginning of the film web, which is wound onto the new core or winding shaft, is also defined by this. "Cutting" here means that cuts are made in the film web, for example, using at least one knife.

[0006] Furthermore, it is intended that at least one uncut section remains. This means that despite the defined end and beginning of the film web, they remain connected by a connecting piece. Finally, it is intended that this uncut section will subsequently be torn or cut off. "Torn off" refers to a passive process in which the film web is separated by applying force to the new end and beginning, whereas "cut off" refers to an active process in which a cutting device, such as a cutting knife, is used to sever the uncut section. "Subsequently" means a later point in time compared to when the incomplete cut edge defines the new end and beginning of the film web.

[0007] The term "film web" preferably refers to a plastic film web which, due to its elastic properties, can usually withstand high tensile stress.

[0008] The described separation preferably takes place downstream of the new core and / or winding shaft. The terms core or winding also include several cores or windings arranged side by side that are wound simultaneously and to which the claimed method is applied at the same time. Several cores or windings are generally wound simultaneously when a film web is separated longitudinally, resulting in several individual webs, so-called panels.

[0009] The advantage lies in the fact that, due to the initial connection between the new end and the new beginning of the web, the generated end of the web remains under tension and can therefore be wound further without creasing or other defects. The subsequent, complete separation can then occur closer to the first winding or by tearing, which can also occur closer to the first winding.

[0010] It is preferred if less than 50% of the total width of the film web remains as an initially uncut area, particularly less than 30%. However, less than 20% is especially advantageous, as tearing requires only moderate force with many material compositions. The invention is, of course, to be understood as meaning that more than 0%, particularly more than 1%, of the total width of the film web remains as an initially uncut area.

[0011] After the incomplete transverse cutting and the subsequent separation or tearing of the uncut section, the uncut section is stretched. This stretching is caused by applying a force to the film web that is significantly greater than the original web tension. This increases the distance between the cut edge of the film end and the new beginning of the film web. As a result, the free path of the film end before it reaches the first reel is shortened. At least a portion of the stretched section is then transferred to the first reel. This section then forms a gripping area for subsequent unwinding of the film web from the reel, which an operator or device can easily grasp to begin the unwinding process.With previous wrapping methods where the end of the film web was cut completely across its width, locating and removing the web end was always problematic. This problem is particularly serious with thin and / or sticky film webs. Therefore, the combination of the present invention with thin and / or sticky film webs, especially stretch film webs, is advantageous.

[0012] It is particularly advantageous if the film web is stretched in the uncut area at least until at least one cutting edge rests substantially on the first reel. Only then is the previously uncut area torn or separated. A cutting device can be provided for this purpose. A cutting device with which the separation can be carried out can generally, i.e., not only with regard to the aforementioned embodiment, consist of at least two parts, one part being activated at a later time than the other to bring about the separation. Alternatively, a cutting device can be provided which separates sections of the film web at intervals. When the new end of the film web rests on the reel, the usable part of the film extends to just before the end of the film web, and this usable part has, in this case, also been wound under tensile stress.A loss of quality was therefore avoided.

[0013] To perform the separation of the initially uncut section, it is advantageous to drive the first winding until the uncut section is completely torn or cut off. This easily creates a stretch in the initially uncut section. Special machine components for this purpose are unnecessary; the drive already present for winding is sufficient. The counterforce that holds the new beginning of the film web can be provided in various ways, independent of the embodiment just described. It is suitable here to utilize the blocking effect of a cutting device designed for introducing the cutting edge. The new beginning of the film web then remains at the cutting device, while the new end continues to wind. The uncut section can thus be stretched or elongated.However, alternative or additional means of applying a counterforce to the new end may also be provided, such as clamping jaws or other clamping, holding or braking elements that slow down or stop the further transport of the new beginning of the film web.

[0014] It is also advantageous to provide a fixing force to secure the film web to the second core and / or winding shaft, thus creating a counterforce to prevent tearing. This fixing force can increase or replace the counterforce provided by clamping, holding, or braking elements. This fixing force can also serve to fix the completely severed film web to the new winding core and / or winding shaft. The fixing force can be an electrostatic force, for example, by applying an electrical charge to the film web and / or the new winding core and / or winding shaft, creating an attractive force. The new winding core and / or winding shaft can be provided with an adhesive layer, such as double-sided adhesive tape or an adhesive coating, to which the film web can adhere.A pressure roller, which is positioned to fix the new winding sleeve and / or winding shaft for the purpose of fixing it, may also be provided.

[0015] In a specific embodiment of the invention, at least one knife is inserted into the film web for partial cutting. This knife has at least one cutting edge that includes interruptions. Thus, at least one cutting edge can be introduced into the film web, with the interruption of the cutting edge creating the uncut area. The interruption can, for example, be a recess in the knife at the cutting edge. However, several knives spaced apart in the transverse direction of the film web's transport path are also conceivable. In this case, it is advantageous if the multiple knives are movable relative to each other in order to keep the uncut area variable and adapt it to specific requirements, such as the type of film.Even a protective element that can be attached to areas of the cutting edge can render the cutting edge ineffective in that area, thus creating an interruption. Other measures and / or elements are conceivable, but these are also included under the term "interruptions."

[0016] In this context, it is advantageous if at least two knives are provided for partially cutting the film web, their cutting edges being parallel to each other and arranged on different lines. The two knives are therefore not only spaced transversely to the film web's transport path, but also parallel to it. The spacing can also be varied, for example, by making the knives rotatable around an axis perpendicular to the film web. This allows for the simple elimination of interruptions, enabling the conventional state—where the film web can be cut seamlessly across its entire width—to be achieved for certain types of film, such as particularly tear-resistant films.

[0017] In another advantageous embodiment of the invention, at least one beam, comprising electro-optical waves, in particular a laser beam, can be guided transversely to the film web for partial cutting of the film web, wherein the beam is at least partially interrupted during its guidance. The beam causes local heating of the film material, which leads to separation. "Transverse" also includes a direction of movement that contains a transverse component with respect to the film web. Such a system can operate completely or at least partially without contact, meaning in particular that, for example, no web jam can occur upstream of the cutting blade, which can lead to undesirable operating conditions.

[0018] The above-mentioned problem is also solved by a winding device with all the features of claim 8 for carrying out the method according to any one of claims 1 to 7, with a first winding station in which the film web can be wound into a first wind, a second winding station in which a winding sleeve and / or a winding shaft can be provided, a movement device with which the winding sleeve and / or the winding shaft and the film web can be brought close to each other and / or into contact upstream of the first wind, a cutting device with which the film web can be cut, wherein an end of the film web can be produced which can be wound onto the first wind and wherein a new beginning of the film web can be produced which can be wound onto the winding sleeve and / or the winding shaft wherein the separating device comprises at least one separating area with which at least one separating edge can be produced in the transverse direction of the film web, which has interruptions in the transverse direction of the film web.

[0019] The winding device according to the invention achieves the same advantages as those already described in connection with the method according to the invention. Definitions given in connection with the method according to the invention also apply in connection with the winding device according to the invention.

[0020] Because the separating edge has interruptions, an uncut area can be created at the separating edge. At least one separating area of ​​the separating device can also have an interruption. Device embodiments of such a separating device have already been described in connection with the method according to the invention.

[0021] A motion device is understood to be a device that causes the first winding to move relative to the new winding core and / or winding shaft, but also to move a machine element that allows the film web to be moved. For example, a deflection roller can be introduced into the transport path of the film web so that the transport path can be changed.

[0022] In a further advantageous embodiment of the winding device according to the invention, a control device is provided with which a drive, with which the first winding can be driven in a rotary direction, can be controlled, wherein the control device sends a control signal to the drive to stop the rotary drive after the film web has been torn or cut off at the interruption of the separating edge.

[0023] The control device ensures that, unlike prior art winding devices, the first winding is driven by rotation until the film web tears or is subsequently cut to separate the initially unseparated section. For this purpose, the control device can receive a signal from a sensor device that detects the tearing or cutting. An optical sensor or a motor current monitoring sensor can be used, which detects that the motor no longer needs to apply the torque required to stretch or tear the film web. Alternatively, the control device can also send the control signal to stop the rotational drive after a specific elapsed time.

[0024] Furthermore, it is advantageous if at least one force-providing element is provided with which the film web can be fixed to the winding core and / or the winding shaft, so that a counterforce for tearing can be provided. Such force-providing elements can be, for example, an electrostatic charging device, a double-sided adhesive tape, or an adhesive coating. Further details have already been described in connection with the method according to the invention, which are also valid here.

[0025] It is also advantageous if the cutting device includes at least one knife for insertion into the film web, wherein the knife has at least one cutting edge with interruptions. In particular, it is advantageous if the interruption is located in the middle of the knife, so that the initially uncut area of ​​the film web is also centrally located when viewed transversely. However, a continuous knife is also conceivable, the cutting edge of which is shorter than the width of the film web, so that an uncut area is created at one or both edges of the film web.

[0026] The aforementioned problem is further solved by a film roll with a wound film web, wherein the beginning of the film web, viewed radially, is located on the inside and the end of the film web is located on the outside, and which, according to the invention, is characterized in that the end of the film web comprises at least a region with at least one cut edge and at least a region that projects beyond the cut edge in the winding direction. In other words, the rear end, viewed in the direction of travel of the film web, is not cleanly cut in the transverse direction, but has at least a region that projects beyond the cut edge. The entire cut edge thus has an irregular shape and may be somewhat frayed. The winding direction of the film roll is opposite to the transport direction of the film web in the winding device, i.e., it runs along the film web from the inside to the outside.The film roll thus has a gripping section with which the end of the film can be easily detached from the outer circumference of the film roll, either manually or within a machine.

[0027] It is advantageous if the area extending beyond the cut edge exhibits an elongation that is particularly greater than the elongation of the film web of the rest of the roll. The elongated area is generally characterized by different material and geometric properties, especially a reduced film thickness and a different elasticity compared to the film web of the rest of the roll.

[0028] Furthermore, it is advantageous if the area extending beyond the cutting edge includes a tear-off edge, which in particular has a random edge profile. Such an edge profile is therefore not reproducible.

[0029] Further advantages, features, and details of the invention will become apparent from the following description, in which various exemplary embodiments are explained in detail with reference to the figures. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination thereof. Within the scope of the entire disclosure, features and details described in connection with the inventive method and / or with the inventive film roll naturally also apply in connection with the inventive winding device and / or with the inventive film roll, and vice versa, so that the disclosure always makes, or can make, reciprocal references to the individual aspects of the invention. The individual figures show: Fig. 1 Side view of a schematic representation of a winding device according to the invention. Fig. 2 How Figure 1 , however, with a newly brought-in winding shaft Fig. 3 How Figure 2 , however, in top view Fig. 4How Figure 3 , however, with the film web being transported further onto the first reel.

[0030] The Figure 1Figure 1 shows a schematic diagram of a winding device 1, in which only the essential components of the invention are depicted. First, the film web 2 is shown, which is conveyed in the transport direction z along a transport path. Not shown is the fact that the film web can also be transported over further rollers or cylinders, so that the transport path is not necessarily straight. The film web 2 is wound onto a first reel 3, which rotates around a winding shaft 4 of the winding device 1 in the direction of rotation D to wind up the film web 2. The winding shaft 4 can carry a winding sleeve 5, which is part of the reel 3 in that, after the reel 3 is completed, it is pushed off the winding shaft 4 together with the wound film web. Alternatively, so-called sleeveless winding is also possible, in which the film web can be wound directly onto the winding shaft 4.

[0031] The winding shaft 4 is connected directly or indirectly to the machine frame of the winding device. Often, the winding shaft 4 is rotatably mounted on a component that can be displaced relative to the machine frame. Such a component can be, for example, a slide or, particularly in a so-called reversing winder, a turntable. The new winding shaft 5, whose function is described in more detail below, can be inserted into the slide at the position of the first winding shaft 4 before or after the winding change, or—in the case of a turntable—can also be rotatably mounted in the turntable. Further winding shafts are conceivable, which can also be arranged in a turntable. It is also possible, though not shown, that the winding shafts can be detached from the turntable at least at one end, while the other end preferably remains mounted in the turntable.This allows the finished wrap, or in the case of multi-use wraps, the finished wraps to be easily removed from the respective wrapper shaft.

[0032] The new winding shaft 6 already carries a winding sleeve 7 and is located near the transport path of the film web 2. A cutting device, which in the illustrated embodiment comprises a knife 8, is also arranged near the transport path of the film web 2 and is in an inactive position, in which it is held ready to cut the film web 2. The knife 8 is arranged on a knife carrier 9. In order to be able to move the knife relative to the film web 2 for the purpose of carrying out the cutting, it is preferably provided that the knife carrier comprises at least one lever arm 10, which is rotatable about a pivot axis 11, so that the knife can be pivoted into an active position in the transport path of the film web 2 in order to provide it with cutting cuts.The lever arm 10 can be mounted on the machine frame or on the component that moves the winding shafts relative to the machine frame, such as a turntable or slide, via the axis of rotation 11.

[0033] The Figure 2 now shows the same changing device as the Figure 1 , however, with a new winding shaft 6 already brought closer to the film web 2 and with a cutting device just introduced into the transport path of the film web 2. The new winding shaft 6 is preferably arranged upstream, i.e., against the transport direction z, of the knife 8.

[0034] The Figure 3 shows the same situation as the Figure 2, however, in a top view. It is particularly easy to see in this view that the cutting device, in the illustrated embodiment the knife 8, comprises a cutting edge 12 which has a break 13. The effect of this interrupted cutting edge is clearly shown in Figures 4 to 8.

[0035] The Figure 4 represents the same view as the Figure 3 However, with the film web 2 transported further onto the first reel 3. Due to the interruption 13 of the cutting edge 12 of the knife 8, separation edges 14 have formed, since the cutting edge 12 has severed the film web, but the film web has not been altered in the area of ​​the interruption 13, with the separation edges in the illustrated embodiment running approximately in the transverse direction y to the transport direction z. The separation edges 14 now form the new end of the film web 2. The respective counterparts of the separation edges 14 are shown in the view of the Figure 4hidden behind the cutting blade 8, they form the new beginning of the film web 2, which is to be wound onto the new reel. However, in the area of ​​the interruption 13 of the cutting edge 12, an uncut section 15 of the film web 2 remains, which is now stretched due to the continued rotational movement of the reel (force) and the counter-movement of the new beginning of the film web 2 against the blade 8 (counterforce). This situation is in the Figure 5 to recognize.

[0036] In the Figure 6A particularly preferred embodiment of the invention is now shown, in which the uncut section 15 continues to be stretched until the cutting edges 14 rest on, or at least almost rest on, the underlying layer of the wound film web. In a final step, the uncut section 15 is then cut. It is shown that the winding 3 continues to be subjected to a driving force until the uncut section tears, which occurs in the Figure 7 This is shown. A further separating edge 16 is created, which is set back from the separating edges 14, i.e., it projects beyond the separating edges 14 in the opposite direction of transport z. The separating edge 16 has a random edge profile, which is therefore generally not reproducible.

[0037] Separation can also be actively carried out by a suitably designed separating device. An additional blade may be provided for this purpose. However, it is also possible that the interruption 13 of the cutting edge 12 is merely an orthogonal x (see Figure 1 The recessed section 17 of the cutting edge is located in the transport path of the film web 2. To create the separation edges 14, the knife 8 can be advanced far enough into the transport path of the film web 2 that the cutting edge 12 creates the separation edges, but the recessed section 17 of the cutting edge has not yet come into contact with the unseparated area 15. If complete separation is to be achieved at a later time, the knife 8 can be moved further in a subsequent step so that the recessed section 17 also enters the transport path of the film web and cuts it. Reference symbol list 1 Changing unit 2 Foil web 3 wrap 4 winding shaft 5 winding sleeve 6 winding shaft 7 winding sleeve 8 Knife 9 Knife carrier 10 Lever arm 11 axis of rotation 12 Cutting edge 13 Interruption 14 Separating edge 15 Uninterrupted area 16 Separating edge 17 Retracted section D Direction of rotation x Orthogonal direction y transverse direction z Direction of transport

Claims

1. Method for successively winding up a film web (2) on a plurality of spools (3), wherein - the film web (2) is wound to form a first spool (3), - a sleeve (7) and / or winding shaft (6) for forming a subsequent second spool and the film web (2) are moved together and / or brought into contact upstream of the first spool, - a separation of the film web (2) is brought about, wherein an end (14, 16) of the film web (2) which is wound onto the first spool (3) is produced and wherein a new beginning of the film web (2) which is wound onto the second sleeve (7) is produced, in order to separate the film web (2) it is partially severed in the transverse direction (y), wherein in the transverse direction (y) at least one separation edge (14) and at least one non-severed region (15) remains, wherein the non-severed region (15) is subsequently torn off or separated, wherein after partially severing the film web (2) and before tearing off or separating the at least one initially non-severed region (15) the film web (15) is stretched in the non-severed region, and wherein the initially non-severed and stretched region (15) is at least partially supplied to the first spool (3), characterized in that this region forms a gripping portion for a subsequent unwinding operation.

2. Method according to the preceding claim, characterized in that the film web (2) is stretched in the non-severed region (15) at least until the at least one separation edge (14) rests substantially on the first spool (3).

3. Method according to any one of the preceding claims, characterized in that the first spool (3) is driven until the non-severed region (15) is completely torn off or separated.

4. Method according to any one of the preceding claims, characterized in that a fixing force is provided by means of which the film web (2) is fixed to the second sleeve (7) and / or winding shaft (6) in order to provide a counter-force to the tearing-off action.

5. Method according to any one of the preceding claims, characterized in that in order to partially sever the film web (2) at least one blade (8) is introduced into the film web (2), wherein the blade (8) has at least one cutting edge (12) which comprises interruptions (13).

6. Method according to the preceding claim, characterized in that in order to partially sever the film web (2) at least two blades (8), the cutting edges (12) of which are arranged parallel with each other and on different lines, are provided.

7. Method according to any one of the preceding claims, characterized in that in order to partially sever the film web (2) at least one beam which severs the film web (2), comprising electro-optical waves, in particular a laser beam, is guided transversely relative to the film web (2), wherein the beam is at least partially interrupted during the guiding.

8. Winding device (1) for carrying out a method according to any one of claims 1 to 7, with - a first winding location, in which the film web (2) can be wound up to form a first spool (3), - a second winding location, in which a winding sleeve (7) and / or a winding shaft (6) can be provided, - a movement device, by means of which the winding sleeve (7) and / or the winding shaft (6) and the film web (2) can be moved together and / or brought into contact upstream of the first spool (3), - a separation device (8, 9, 10, 11), by means of which the film web (2) can be separated, wherein an end (14, 16) of the film web (2) which can be wound on the first spool (3) can be produced, and wherein a new beginning of the film web which can be wound on the winding sleeve and / or the winding shaft can be produced, wherein the separation device (8, 9, 10, 11) has at least one separation region (12) by means of which in the transverse direction (y) of the film web (2) at least one separation edge (14) which has interruptions (15) in the transverse direction (y) of the film web (2) can be produced.

9. Device (1) according to the preceding claim, characterized in that a control device is provided by means of which a drive, by means of which the first spool (2) can be rotatably driven, can be controlled, wherein the control device supplies a control signal in order to end the rotary driving of the drive after the film web (2) has been torn or separated at the interruption (15) of the separation edge (14).

10. Device (1) according to any one of the two preceding claims, characterized in that at least one force provision element is provided by means of which the film web (2) can be fixed to the winding sleeve (7) and / or the winding shaft (6) so that a counter-force can be provided for tearing off.

11. Device according to any one of the three preceding claims, characterized in that the separation device (8, 9, 10, 11) comprises at least one blade (8) for introducing into the film web (2), wherein the blade (8) comprises at least one cutting edge (12) with interruptions (13).

12. Device according to any one of the four preceding claims, characterized in that the separation device (8, 9, 10, 11) comprises at least two blades (8) for introducing into the film web (2), the cutting edges (12) of which are preferably arranged parallel with each other and on different lines.

13. Device according to any one of the five preceding claims, characterized in that the separation device (8, 9, 10, 11) comprises at least one beam which severs the film web (2), comprising electro-optical waves, in particular a laser beam, which can be guided transversely relative to the film web (2), wherein the beam can be at least partially interrupted during the guiding.

14. Film roll (3) having a wound-up film web (2), wherein the beginning of the film web (2) when viewed in a radial direction is arranged at the inner side and the end of the film web (2) is arranged at the outer side, wherein the end of the film web (2) comprises at least one region having at least one cutting edge (14) and at least one region (15) which protrudes over the cutting edge (14) in the winding direction (z), wherein the region (15) which protrudes over the cutting edge has an elongation and characterized in that the roll further forms a gripping portion for subsequent unwinding.

15. Film roll (3) according to the preceding claim, characterized in that the region (15) which protrudes over the cutting edge (14) comprises a tear-off edge (16) which in particular comprises a random edge path.