Film winding system, combination of a film stretching machine and such a film winding system and use of such a combination for the production of thin films and membranes

Description

[0001] The invention relates to a film winding system, a combination of a film stretching system and such a film winding system, and the use of such a combination for producing biaxially stretched thin films, in particular battery separator films, PPK (PP capacitor film) or PETK (PET capacitor film), or membranes, such as PTFE (polytetrafluoroethylene) membranes. The PPK and PETK films are preferably BO-stretched. Thin films preferably have thicknesses less than 5 µm.

[0002] Film stretching systems are used to produce a film web from a plastic melt that has specific material properties so that it can be used for specific purposes. The film stretching systems include stretching stages in the longitudinal and / or transverse direction. The system speed is constantly increasing and currently exceeds 400 m / min. Even faster film stretching systems are to be put into operation in the future. In this context, an important aspect is how the finished product, namely the film web, is wound up. Film winding systems are provided for this purpose, which wind up the produced film web. During winding, however, it is important that no wrinkles are pressed into the film web so that the individual layers can be separated more easily later. The film web is wound up at a winding station.This comprises a corresponding base body around which the film web is wound. The film web is fed to a familiar internal winding station, but via a contact roller to ensure optimal alignment before winding.

[0003] Depending on the type of film to be produced, special system parameters must be maintained or achieved. Extremely thin films, such as battery separator film, are demanding to produce. In contrast to films made of PET or PP, for example, only low film tensions can be applied when producing thin films such as battery separator film. The film tensions are in the range of 1 N / m to 200 N / m. They are preferably in the range of 5 N / m to 15 N / m. Due to the viscoelastic properties of battery separator film, a high contact pressure of a contact roller on the film bale (winding bale) or the winding core is not possible. The contact pressure should therefore preferably be in the range of 0 N / m to 100 N / m. More preferably, the contact pressure should be in the range of 1 N / m to 10 N / m. Otherwise, winding errors, such as telescoping of the film web, can occur. These must be avoided.

[0004] The production of battery separator foils is described, for example, in DE 10 2019 112 089 and in DE 10 2019 119 600, the content of which regarding the production of the battery separator foils is hereby incorporated into this application.

[0005] DE 36 00 517 A1 discloses a device for winding webs of material. The device has three rollers, the first roller in the direction of travel being stationary. The other two rollers are movable only simultaneously by means of carriages on a rail and are driven by a servomotor.

[0006] Basically, it is difficult to adjust the low film tension and especially the low contact pressure because the overall system is very sluggish and the film bale is not ideally round.

[0007] It is therefore the object of the present invention to create a film winding system with which the lowest possible film tension and the lowest possible contact force between the contact roller and the film bale can be realized.

[0008] This object is achieved by the film winding system according to independent claim 1. Claim 14 represents a combination of a film stretching system and the film winding system. Claim 15 describes the use of the combination to produce and wind ultra-thin films and membranes. Claims 2 to 13 describe further developments of the film winding system.

[0009] The film winding system comprises a film inlet area, via which a film web to be wound can be fed into the film winding system. A first winding station is also provided. In a winding position, the first winding station is designed to wind the film web into a film bale. A contact roller and a dancer roller are also provided. The contact roller is arranged (immediately) adjacent to the first winding station (when the latter is in the winding position) and is designed to guide the film web to the first winding station. The term "immediately" is to be understood as meaning that the contact roller is in contact with the film bale, or that only the film web being wound onto the film bale runs between the contact roller and the film bale. However, a space could also be formed between the contact roller and the film bale.This clearance is preferably less than 1000 mm, 900 mm, 800 mm, 700 mm, 600 mm, 500 mm, 400 mm, 300 mm, 200 mm, 100 mm, 50 mm, 30 mm, 20 mm, or less than 10 mm. The dancer roller is arranged in front of the contact roller in the direction of movement of the film web and is designed to guide the film web to the contact roller and adjust the film tension. The wording "in the direction of movement of the film web" is to be understood as meaning that a specific area of ​​the film web first runs over the dancer roller and only then over the contact roller. Furthermore, a first adjusting device is provided and designed to move the contact roller toward the winding station or away from the winding station, whereby a specific contact pressure between the contact roller and the film bale can be set. It is particularly advantageous for the adjusting device to comprise a carriage system.The slide system can be, for example, an air bearing slide system or a hydrostatic bearing slide system. An air bearing slide system creates an air film between a slide and a rail, allowing the slide to move relative to the rail without significant friction. This minimizes friction during horizontal movement of the contact roller and allows the contact roller to be positioned with particular precision and sensitivity. Alternatively, the contact roller can also be moved via an adjusting spindle. This allows particularly heavy weights to be moved.

[0010] In a further development of the film winding system, the air bearing carriage system of the first adjustment device comprises a first rail and at least one first carriage arranged on the first rail. The first carriage comprises air outlet openings directed toward the first rail. The first carriage further comprises an air connection for supplying compressed air, which then exits from the air outlet openings, thereby enabling the first carriage to slide along the first rail.

[0011] In a further development of the film winding system, the first carriage surrounds the first rail on at least three sides. This achieves particularly high stability of the structure. In principle, it would be conceivable for the air outlet openings to be directed toward the first rail on more than one side. It would also be conceivable for the air outlet openings to be directed toward three different sides of the first rail. This achieves particularly good stabilization of the first carriage.

[0012] In a further development of the film winding system, the air bearing carriage system of the first adjustment device comprises a second rail and at least one second carriage arranged on the second rail. The second carriage comprises air outlet openings directed towards the second rail. The second carriage comprises an air connection for supplying compressed air. The compressed air then exits from the air outlet openings, whereby the second carriage can slide on the second rail. The second rail runs parallel to the first rail. In principle, the second carriage of the second rail can have the same properties as the first carriage of the first rail. By using a second rail with a second carriage, the weight of the contact roller can be better distributed and the contact roller can be held more stably.

[0013] In a further development of the film winding system, the air bearing carriage system of the first adjustment device comprises a third carriage arranged on the first rail. The third carriage comprises air outlet openings directed towards the first rail. The third carriage comprises an air connection for supplying compressed air, which then exits from the air outlet openings, whereby the third carriage can be moved in a sliding manner on the first rail. The first rail has a continuous course or is divided into two spaced-apart partial rails for the first and third carriages. By using two carriages, which can preferably be moved coaxially to one another, the stability with which the contact roller is moved can be further increased.

[0014] In a further development of the film winding system, the first adjusting device comprises a first and a second radial air bearing. The contact roller comprises first and second roller journals in the region of the first and second end faces, which are mounted in the first and second radial air bearings or in the first and second hydrostatic bearings (hydraulics). This further reduces friction when the contact roller rotates. Preferably, the contact roller is set in rotation solely by the film web resting on the contact roller. In one embodiment, the use of an electric motor could therefore be dispensed with. In another embodiment, the contact roller can nevertheless be driven by an electric motor. This electric motor is arranged directly on the contact roller or is connected to the contact roller via a power transmission means, such as a chain.A rotation of the shaft of the electric motor then also leads to a rotation of the contact roller.

[0015] In a further development of the film winding system, the first adjustment device comprises a linear motor designed to move the contact roller toward the first winding station or away from the first winding station via the air bearing carriage system or the hydrostatic bearing carriage system. By means of such a linear motor in combination with the air bearing carriage system or the hydrostatic bearing carriage system, the contact roller can be positioned very precisely. Alternatively, the first adjustment device comprises an electric motor designed to rotate the adjustment spindle, whereby the contact roller can be moved toward the first winding station or away from the first winding station.

[0016] In a further development of the film winding system, a control device is provided that is designed to control the linear motor or the electric motor of the first adjustment device such that the contact roller rests against the film bale with a predetermined contact pressure. In principle, a corresponding pressure sensor that measures the contact pressure can also be provided for this purpose.

[0017] In a further development of the film winding system, a first deflection roller is provided. The first deflection roller is arranged upstream of the dancer roller in the direction of travel of the film web. The corresponding first deflection roller can increase the degree of wrap by which the film web rests on the dancer roller. At the same time, the film web is stabilized. A "degree of wrap" is understood to be a value indicating how far the film web covers the dancer roller. The dancer roller extends over 360°. With a degree of wrap of 90°, the film web would only rest on a quarter of the outer surface of the particularly cylindrical dancer roller. With a degree of wrap of 180°, in contrast, the film web would rest on half of the outer surface of the particularly cylindrical dancer roller.

[0018] In a further development of the film winding system, the distance between the first deflection roller and the contact roller is smaller than the distance between the dancer roller and the contact roller. This allows a degree of wrap over the dancer roller that is greater than 120°, 130°, 140°, or 150° to be achieved.

[0019] In a further development of the film winding system, the first deflection roller is rotatably mounted by means of a radial air bearing or hydrostatic bearing. Due to the low friction between the deflection roller and the radial air bearing or hydrostatic bearing, the first deflection roller is preferably only set in rotation by the film web itself, so that in one embodiment the use of an electric motor can be dispensed with. In another embodiment, the first deflection roller can nevertheless be driven by an electric motor. This electric motor is arranged directly on the first deflection roller or is connected to the first deflection roller via power transmission means, such as a chain. Rotation of the shaft of the electric motor then also leads to rotation of the first deflection roller.

[0020] In a further development of the film winding system, a second deflection roller is provided. The second deflection roller is arranged downstream of the dancer roller and upstream of the contact roller in the direction of travel of the film web.

[0021] In a further development of the film winding system, the second deflection roller is also rotatably mounted by means of a radial air bearing or hydrostatic bearing. Due to the low friction between the deflection roller and the radial air bearing or hydrostatic bearing, the second deflection roller is preferably only set in rotation by the film web itself, so that in one embodiment the use of an electric motor can be dispensed with. In another embodiment, the second deflection roller can nevertheless be driven by an electric motor. This electric motor is arranged directly on the second deflection roller or is connected to the second deflection roller via a power transmission means, such as a chain. Rotation of the shaft of the electric motor then also leads to rotation of the second deflection roller.

[0022] In a further development of the film winding system, a contact roller frame is provided. The air bearing carriage system or the hydrostatic bearing carriage system of the first adjustment device is arranged on the contact roller frame, so that the contact roller can be moved relative to the contact roller frame. Alternatively, the contact roller frame is arranged on the air bearing carriage system or the hydrostatic bearing carriage system of the first adjustment device, with the contact roller being arranged on the contact roller frame, so that the contact roller and the contact roller frame can be moved together.

[0023] In a further development of the film winding system, the first deflection roller and / or the second deflection roller and / or the dancer roller are arranged on the contact roller frame. If the contact roller frame is moved via the first adjustment device, this also applies to the first and / or second deflection roller or the dancer roller. This results in a synchronous movement.

[0024] In a further development of the film winding system, a base adjustment device is provided, which comprises a base frame and an air bearing carriage system or a hydrostatic bearing carriage system or an adjustment spindle. The contact roller and the dancer roller and the first deflection roller and / or the second deflection roller are arranged on the base frame. The base adjustment device is designed to move the contact roller, the dancer roller, the first deflection roller and / or the second deflection roller toward the winding station or away from the winding station. In this case, both the first adjustment device and a higher-level base adjustment device are present, allowing particularly precise adjustment.

[0025] In a further development of the film winding system, a second adjustment device is provided and designed to move the dancer roller toward or away from the contact roller, thereby allowing a specific film tension to be set. The second adjustment device comprises an air bearing slide system, a hydrostatic bearing slide system, or an adjustment spindle. It is particularly advantageous for the dancer roller to also be moved using an air bearing slide system. Due to the low coefficient of friction, the film tension can be adjusted very precisely.

[0026] In a further development of the film winding system, the second adjustment device comprises a linear motor or an electric motor designed to move the dancer roller toward or away from the contact roller via the air bearing slide system, the hydrostatic bearing slide system, or the adjustment spindle. Such a linear motor or electric motor allows for very precise adjustment of position and force.

[0027] In a further development of the film winding system, a control device is provided which is designed to control the linear motor or the electric motor of the second adjusting device in such a way that a predetermined film tension is applied via the dancer roller.

[0028] In a further development of the film winding system, the dancer roller is rotatably mounted by means of a radial air bearing or hydrostatic bearing. Due to the low friction between the dancer roller and the radial air bearing or hydrostatic bearing, the dancer roller is preferably only set in rotation by the film web itself, so that in one embodiment the use of an electric motor can be dispensed with. In another embodiment, the dancer roller can nevertheless be driven by an electric motor. This electric motor is arranged directly on the dancer roller or connected to the dancer roller via a power transmission means, such as a chain. Rotation of the shaft of the electric motor then also leads to rotation of the dancer roller.

[0029] In a further development of the film winding system, the first winding station comprises a base body, wherein the base body of the first winding station can be set in a rotational movement and wherein the film web can be wound around the base body. There is also a second winding station with a base body, wherein the base body of the second winding station can be set in a rotational movement and wherein the film web can be wound around the base body. The first winding station is designed to be pivoted from the winding position, in which it is arranged adjacent to the contact roller, into an unloading position, wherein the wound film bale can be removed from the first winding station in the unloading position, wherein the second winding station is designed to be pivoted from the unloading position into the winding position at the same time.There is also a cutting device which is designed to cut the film web across its width when the first winding station is pivoted in the direction of the unloading position, wherein the second winding station is designed to be pivoted further into the winding position in such a way that the base body of the second winding station immediately comes into contact with the new beginning of the film web which is now being created.

[0030] In a further embodiment, the film winding system comprises at least one unloading device. The unloading device is arranged in the region of the film web and is designed to dissipate electrical charge on the film web and / or the film bale.

[0031] The discharge device preferably comprises a plurality of flexible / freely movable electrically conductive metal strips (a type of tinsel strip) that can be brought into contact with the film web. These metal strips are preferably arranged distributed across the entire width of the film web or across the majority of the width of the film web. In principle, a discharge conductor could also be used. This discharge conductor(s) would preferably be arranged at a distance from the film web. The distance should preferably be less than 200 mm, 150 mm, 100 mm, 50 mm, 40 mm, 30 mm, 20 mm, 10 mm or less than 5 mm. However, the distance is preferably greater than 5 mm. An alternating electric field is applied to this discharge conductor. This alternating electric field is a high voltage, which dissipates the static charge.

[0032] The inventive combination of the film winding system and a film stretching system, in particular a sequential stretching system known from the prior art, a simultaneous stretching system, or a battery separator film stretching system (evaporation process or WET process), allows the film winding system to be connected to an output area of ​​the film stretching system. The film stretching system comprises an input area to which a film can be fed. Furthermore, the film stretching system comprises various zones in which the plastic film is heated and stretched into a mono- or biaxially oriented film web (for example, via a longitudinal stretching stage and / or via a transverse stretching stage or oven). The resulting film web is then fed to the film winding system. In a WET process, the cast film contains a solvent (e.g., white oil), whereby the cast film is MD and TD stretched (sequentially or simultaneously).The stretched film is then introduced into a washout bath. The dichloromethane contained therein washes out the solvent (e.g., white oil). The film is then introduced into a TDO for further minimal stretching or heat treatment (annealing). The film is then wound up.

[0033] The use of this composite allows for the production and winding of ultra-thin films, such as battery separator films, PPK films, or PETK films, or membranes, such as PTFE membranes. The films can be wound even at a thickness of less than 15 µm. Battery separator films typically have a thickness in the range of 8 to 15 µm, and PPK films from 2 to 6 µm.

[0034] Various embodiments of the invention are described below by way of example with reference to the drawings. Like objects have the same reference numerals. The corresponding figures of the drawings show in detail: Figure 1: a combination of a film winding system and a film stretching system; Figure 2: an embodiment of the film winding system with a dancer roller and a contact roller; Figure 3: an embodiment of the film winding system, wherein the use of a first and a second winding station is explained; Figure 4: another embodiment of the film winding system with a dancer roller, a contact roller and two deflection rollers; Figure 5: another embodiment of the film winding system from Figure 4in spatial representation; Figure 6: an embodiment of an air bearing carriage system; Figure 7: an embodiment of a radial air bearing; Figure 8: an embodiment of the contact roller, which is mounted on a contact roller frame arranged on the air bearing carriage system; Figure 9: an embodiment of the film winding system, wherein the contact roller, the first and second deflection rollers, and the dancer roller are jointly movable via the air bearing carriage system of the first adjustment device; Figure 10: an embodiment of the film winding system, wherein the contact roller, the first deflection roller, and the dancer roller are jointly movable via the air bearing carriage system of the first adjustment device;Figure 11: an embodiment of the film winding system, wherein the contact roller, the first deflection roller, the second deflection roller, and the dancer roller are arranged together on a base frame and are movable together via a base adjustment device; Figure 12: an embodiment of the film winding system, wherein the contact roller, the first deflection roller, and the dancer roller are arranged together on a base frame and are movable together via a base adjustment device; Figure 13: an embodiment of the film winding system, wherein the contact roller, the first deflection roller, the second deflection roller, and the dancer roller are arranged together on a base frame and are movable together via a base adjustment device, and wherein a degree of wrap of the film web over the contact roller is approximately 60°;and Figure 14: an embodiment of the film winding system, wherein the contact roller, the first deflection roller, the second deflection roller and the dancer roller are arranged together on a base frame and are movable together via a base adjustment device and wherein a degree of wrap of the film web over the contact roller is approximately 180°. ;

[0035] Figure 1shows a composite 100 comprising a film winding system 1 according to the invention and a film stretching system 110. The film stretching system 110 can be designed as a longitudinal stretching system or a transverse stretching system or a sequential stretching system with a longitudinal stretching stage and a transverse stretching stage, or as a simultaneous stretching system. The film stretching system 110 serves to produce a plastic film web 2, which is also referred to below as film web 2. For this purpose, the film stretching system 110 is divided into various zones 110a, 110b, 110c, 110d, and 110e. Of course, not all of these zones 110a, 110b, 110c, 110d, and 110e actually have to be present. In the various zones 110a to 110e, the film web 2 is exposed to different temperatures in order to generate or adjust certain film properties. The first zone 110a is also referred to as the preheating zone. The second zone 110b is referred to as the stretching zone, whereas the third zone 110c is referred to as the further heating zone.The fourth zone 110d is also referred to as the neutral zone, and the fifth zone 110e as the cooling zone. In principle, there can be fewer or additional neutral zones between the individual zones 110a to 110e to ensure separation between the zones 110a to 110e, so that the individual zones 110a to 110e influence each other less strongly (the air flows from one zone 110a to 110e to the other). With the film stretching system 110 it is possible to produce film webs with a width that is greater than 2 m, 3 m, 4 m, 5 m, 6 m, 7 m, 8 m, 9 m, 10 m, 11 m or greater than 12 m, but preferably less than 13 m, 12 m, 11 m, 10 m, 9 m, 8 m, 7 m, 6 m, 5 m, 4 m or less than 3 m.

[0036] The film stretching system 110 comprises an inlet area 111, wherein a film to be stretched can be fed to the film stretching system 110 at its inlet area 111. The stretched film web 2 exits at the end of the film stretching system 110, i.e., at its outlet area 112. The outlet area 112 of the film stretching system 110 is connected to a film inlet area 3 of the film winding system 1 according to the invention.

[0037] In the following figures 2A, 2B, 3A to 3E and 4 The structure of the film winding system 1 according to the invention is described in more detail.

[0038] As stated at the beginning, different film types should be wound differently, as this is the only way to ensure that the winding process is wrinkle-free and that sufficient air is introduced between the individual layers to ensure trouble-free unwinding of the film web 2 in subsequent process steps. The winding method according to the invention also ensures that the film web 2 does not tear.

[0039] As mentioned at the beginning, winding battery separator foils is particularly challenging. Winding can only be carried out with minimal contact force and minimal foil tension.

[0040] The Figures 2 , 3 , 4 , 5show exemplary embodiments that describe the film winding system 1. The film web 2 is fed from the film stretching system 110 to the film winding system 1. This takes place via the film inlet area 3. The film web 2 then runs towards a first winding station 4, which is in a winding position. The first winding station 4 is designed to wind the film web 2 into a film bale 5 (see Figure 3 ) to wind up.

[0041] The film winding system 1 comprises a contact roller 6 and a dancer roller 8. The contact roller 6 is arranged adjacent to the first winding station 4 and is designed to guide the film web 2 to the first winding station 4. The dancer roller 8 is arranged in front of the contact roller 6 in the direction of movement of the film web 2 and is designed to guide the film web 2 to the contact roller 6 and to adjust the film tension.

[0042] Also shown is a first deflection roller 9, which is arranged in front of the dancer roller 8 in the direction of movement of the film web 2. The film web 2 is fed via the film inlet area 3 to the first deflection roller 9. From the first deflection roller 9, the film web 2 runs over the dancer roller 8 to the contact roller 6 before being wound into a film bale 5 at the first winding station 4.

[0043] There is also a first adjusting device 10 which is designed to move the contact roller 6 in the direction (X-axis) of the winding station 4 or away from the winding station 4. This allows a predetermined contact pressure to be set between the contact roller 6 and the film bale 5. If the contact pressure is above a first threshold value, the contact roller 6 is moved away from the film bale 5. If the contact pressure is below a second threshold value, the contact roller 6 is moved in the direction of the film bale 5. The first and second threshold values ​​can be the same or different. The first adjusting device 10 comprises a carriage system. The carriage system is preferably an air bearing carriage system 11. The carriage system could also be a hydrostatic bearing carriage system.As a result, the contact roller 6 can be moved with minimal energy expenditure, because in particular the jerk required to initially move the contact roller 6 from a rest position is minimal due to air bearings.

[0044] The first adjustment device 10 also includes a linear motor 12, which is designed to move the contact roller 6 via the air bearing carriage system 11 toward the first winding station 4 or away from the first winding station 4. The movement preferably occurs only horizontally (parallel to the floor).

[0045] There is also a control device (not shown) which is designed to control the linear motor 12 of the first adjusting device 10 in such a way that the contact roller 6 rests against the film bale 5 with a predetermined contact pressure.

[0046] The first adjustment device 10 also comprises a first and a second radial air bearing 13. The contact roller 6 comprises first and second roller journals 15 in the region of the first and second end faces 14. These journals are mounted in the first and second radial air bearings 13. This eliminates the need for a separate electric motor to drive the contact roller 6. The contact roller 6 is preferably rotated solely by the film tension of the film web 2. In principle, however, the use of an electric motor would still be possible. Hydrostatic bearings can also be used instead of the first and second radial air bearings 13.

[0047] A second adjustment device 16 is also provided and designed to move the dancer roller 8 toward the contact roller 6 or away from the contact roller 6, thereby allowing a specific film tension to be set. If the film tension is to be increased, the dancer roller 8 is moved away from the contact roller 6. This tightens the film. If, on the other hand, the film tension is to be reduced, the dancer roller 8 is moved toward the contact roller 6.

[0048] The second adjustment device 16 also includes an air bearing slide system 17. This allows the dancer roller 8 to be moved with minimal energy expenditure, especially because the initial jerk required to move the dancer roller 8 from a rest position is minimal due to the air bearings. The second adjustment device 16 could also include a hydrostatic bearing slide system.

[0049] The second adjustment device 16 also includes a linear motor 18. This is designed to move the dancer roller 8 toward the contact roller 6 or away from the contact roller 6 via the air bearing carriage system 17. The movement preferably occurs only horizontally (parallel to the floor).

[0050] A control device (not shown) is also provided, which is designed to control the linear motor 18 of the second adjustment device 16 such that a predetermined film tension can be applied via the dancer roller 8. The film tension can be measured using a force measuring device.

[0051] The control device for controlling the linear motor 12 of the second adjustment device 16 can also be used to control the linear motor 12 of the first adjustment device 10. However, two different control devices (for example, in different microcontrollers) can also be used.

[0052] Preferably, the dancer roller 8 is also rotatably mounted by means of a radial air bearing 19. The dancer roller 8 can also be rotatably mounted by means of a hydrostatic bearing. Further preferably, the dancer roller 8 is not actively driven. It is preferably only passively driven by the film web 2. In principle, however, the use of an electric motor to drive the dancer roller 8 would be possible.

[0053] The first deflection roller 9 can preferably not be moved relative to the dancer roller 8 and / or the contact roller 6. The first deflection roller 9 is preferably also rotatably mounted by means of a radial air bearing 20. The first deflection roller 9 can also be rotatably mounted by means of a hydrostatic bearing. The first deflection roller 9 is preferably driven passively, i.e., without an electric motor. This is achieved solely by the film tension of the film web 2. In principle, however, the use of an electric motor to drive the first deflection roller 9 would be possible.

[0054] With regard to Figure 3It is also shown that the first winding station 4 comprises a base body 4a. The base body 4a of the first winding station 4 can be set in a rotational movement. This can be done, for example, via an (electric) motor. In the simplest case, the base body 4a can be a (hollow) cylindrical piece of cardboard. However, the base body 4a is preferably made of metal or CFRP, GFRP or a composite of CFRP and GFRP. A second winding station 7 is also shown. The second winding station 7 also comprises a base body 7a. This base body 7a can also be set in a rotational movement. The film web 2 can therefore also be wound around the base body 7a of the second winding station 7. In the figures shown, the first winding station 4 has been moved into the winding position. In the winding position, the first winding station 4 is arranged adjacent to the contact roller 6.The second winding station 7, on the other hand, is moved or pivoted into an unloading position. In the unloading position, the film bale 5 can be removed from the respective, in this case, second, winding station 7. In . Figure 3it is shown by arrows that the first winding station 4 can be moved or pivoted from the winding position into the unloading position. Likewise, in this case the second winding station 7 can be moved or pivoted from the unloading position (after the film bale 5 has been removed) into the winding position. The movement from the winding position to the unloading position and back into the winding position is preferably circular or approximates a circular movement. The movement could also comprise various, preferably arcuate segments which adjoin one another or are connected to one another by straight sections. Furthermore, a cutting device (not shown) is provided. The cutting device is designed to cut the film web 2 across its entire width when the first orsecond winding station 4, 7 is pivoted in the direction of the unloading position, wherein the respective other winding station 7, 4 is then designed to be pivoted so far into the winding position that the respective base body 4a, 7a immediately comes into contact with the now created, cut-off new beginning of the film web 2 and winds this new beginning onto the base body 4a, 7a which is already set in rotation. The cutting device preferably moves obliquely (in the X direction and Y direction) in order to make a straight cut in the film web 2 due to the movement speed of the film web 2. However, the cutting device could also move straight (only in the Y direction), in which case the film web 2 would then be cut off obliquely.

[0055] In Figure 4A second deflection roller 21 is shown. The second deflection roller 21 is arranged after the dancer roller 8 and before the contact roller 6 in the direction of movement of the film web 2. The second deflection roller 21 is preferably rotatably mounted by means of a radial air bearing 22. It could also be rotatably mounted by a hydrostatic bearing.

[0056] The film web 2 preferably runs horizontally from the dancer roller 8 to the second deflection roller 21.

[0057] The second deflection roller 21 is preferably arranged stationary. It preferably cannot be moved relative to a stationary contact roller 6 and / or dancer roller 8.

[0058] The second deflection roller 21 is preferably driven passively. This means that the second deflection roller 21 is set in rotation solely by the film tension of the film web 2. An electric motor is preferably omitted. However, the use of an electric motor to drive the second deflection roller 21 would be possible in principle.

[0059] Preferably, both the dancer roller 8 and the first and second deflection rollers 9, 21 have corresponding roller journals formed on their end faces, with which they engage in the respective radial air bearing 19, 20, 22.

[0060] In Figure 5 A spatial embodiment of the film winding system 1 is shown. The first deflection roller 9, the dancer roller 8, the second deflection roller 21, the contact roller 6, and the first winding station 4 are visible.

[0061] A coordinate system is often specified in the respective drawings. The film web 2 is primarily moved along the X-axis. Naturally, the motion vector of the film web 2 includes, at least in part, a component in the Z-direction in addition to a component in the X-direction. The rollers extend in their longitudinal direction in the Y-direction.

[0062] The respective radial air bearings 13, 19, 20, 22 are not shown.

[0063] Preferably, a distance between the first deflection roller 9 and the contact roller 6 is smaller than a distance between the dancer roller 8 and the contact roller 6. As a result, as in Figure 4 As shown, a high degree of wrap of the film web 2 is achieved over the dancer roller 8. In this example, the degree of wrap is approximately 180°.

[0064] The second deflection roller 21 is preferably arranged closer to the contact roller 6 than the dancer roller 8 and preferably also closer to the contact roller 6 than the first deflection roller 9.

[0065] A diameter of the first deflection roller 9 approximately corresponds to a diameter of the second deflection roller 21, but could also be smaller than the diameter of the second deflection roller 21. The wording "approximately" encompasses deviations of preferably less than 5%. A diameter of the second deflection roller 21 could, for example, also be smaller than a diameter of the first deflection roller 9. A diameter of the dancer roller 8 is preferably smaller than a diameter of the first deflection roller 9 and / or the second deflection roller 21 and / or the contact roller 6.

[0066] The following refers to the Figures 6, 7 and 8The air bearing slide system 11 of the first adjustment device 10 comprises a first rail 23 and at least one first slide 24. The at least one first slide 24 is arranged on the first rail 23. The first slide 24 comprises air outlet openings directed toward the first rail 23. The first slide 24 further comprises an air connection 25 through which compressed air can be supplied. This compressed air then exits from the air outlet openings, allowing the first slide 24 to slide on the first rail 23.

[0067] Preferably, during operation, the first carriage 24 is lifted from the first rail 23, as shown in Figure 8 The distance between the first rail 23 and the first carriage 24 is shown here significantly enlarged. In reality, the distance is only a few hundredths of a millimeter.

[0068] The first rail 23 may additionally consist of or comprise a material having a low coefficient of friction. For example, the first rail 23 may consist of or comprise polytetrafluoroethylene.

[0069] Preferably, the first carriage 24 encompasses the first rail 23 from at least three sides. The ends of the first carriage 24 are preferably directed toward each other, so that the first carriage 24 can preferably not be completely lifted from the first rail 23. This limits the movement in the Z direction and also limits the movement in the Y direction, i.e., perpendicular to the first rail 23. Derailment is therefore not possible during operation.

[0070] Preferably, the air bearing slide system 11 of the first adjustment device 10 also comprises a second rail 26 and at least one second slide 27. The second slide 27 comprises air outlet openings directed toward the second rail 26. The second slide 27 comprises an air connection 28 through which compressed air can be supplied. This compressed air then exits from the air outlet openings, allowing the second slide 27 to slide along the second rail 26.

[0071] The second rail 26 runs parallel to the first rail 23.

[0072] In principle, it would also be conceivable for the air bearing slide system 11 of the first adjustment device 10 to comprise a third slide, which is also arranged on the first rail 23. The third slide would then also comprise air outlet openings directed in the direction of the first rail 23. The third slide would also comprise an air connection via which compressed air can be supplied. This compressed air exits from the air outlet openings, whereby the third slide can be slidably moved on the first rail 23. The first rail 23 preferably has a continuous course or could also be divided into two spaced-apart partial rails. The first slide 23 would be arranged on the first partial rail and the third slide on the second partial rail.

[0073] The same can also apply to the second rail 26 of the air bearing slide system 11 of the first adjustment device 10. A fourth slide could also be arranged here. The second rail 26 preferably has a continuous path or could also be divided into two spaced-apart partial rails.

[0074] The same applies to the air bearing carriage system 17 of the second adjustment device 16 with respect to the dancer roller 8. This air bearing carriage system 17 can also comprise a first rail and at least one first carriage arranged on the first rail. The first carriage comprises air outlet openings directed toward the first rail.

[0075] The first carriage includes an air connection for supplying compressed air, which then exits through the air outlets, allowing the first carriage to slide along the first rail. In principle, the second adjustment device could also include a second rail with a second carriage. Two carriages can also be arranged on each rail.

[0076] In Figure 7 Another embodiment of a radial air bearing 13, 19, 20, 22 is shown, on which the individual rollers can be mounted. Each radial air bearing 13, 19, 20, 22 includes an air connection 29 through which compressed air can be supplied. This compressed air then flows out through air outlet openings on the inside of the respective radial air bearing 13, 19, 20, 22, thereby minimizing the friction between the respective shaft journals 15 and the respective radial air bearing 13, 19, 20, 22.

[0077] The respective radial air bearing 13, 19, 20, 22 can consist of or comprise a material having a low coefficient of friction. For example, the first rail 23 can consist of or comprise polytetrafluoroethylene.

[0078] The Figures 9 and 10 show a further embodiment of the film winding system 1. In this case, a contact roller frame 30 is also provided. The contact roller frame 30 is arranged on the air bearing carriage system 11 or the hydrostatic bearing carriage system of the first adjustment device 10. The contact roller 6 is also arranged on the contact roller frame 30 (e.g., via corresponding supports 31), so that the contact roller 6 and the contact roller frame 30 can be moved together, i.e., synchronously.

[0079] Furthermore, it is shown that the first deflection roller 9, the second deflection roller 21, and the dancer roller 8 are also arranged on the contact roller frame 30. If the air bearing carriage system 11 of the first adjustment device 10 is actuated, the first deflection roller 9, the second deflection roller 21, and the dancer roller 8 are also moved. In this case, the movement takes place synchronously. Only the dancer roller 8 still has its second adjustment device 16 with its air bearing carriage system 17 and can be moved independently of the first adjustment device 10.

[0080] The motion vector of the first air-bearing carriage system 11 preferably runs exclusively in the X-direction, i.e., the direction in which the film web 2 runs through the film stretching system 110. The motion vector could optionally also have a component in the Z-direction, i.e., toward or away from the floor. The motion vector is preferably free of a component in the Y-direction.

[0081] In Figure 10 An embodiment of the film winding system 1 is shown without the second deflection roller 21. The film web 2 runs essentially horizontally from the dancer roller 8 to the contact roller 6. The first deflection roller 9 is preferably arranged closer to the contact roller frame 30 than the dancer roller 8 and the contact roller 6.

[0082] Figure 11describes an embodiment of the film winding system 1, wherein the contact roller 6, the first deflection roller 9, the second deflection roller 21, and the dancer roller 8 are arranged together on a base frame 32 and can be moved together via a base adjustment device 33. The base adjustment device 33 in this case comprises an adjustment spindle 34. The base frame 32 can be moved towards the winding station 4 or away from the winding station 4 via this adjustment spindle 34. Instead of the adjustment spindle 34, the base frame 32 could also be arranged on an air bearing carriage system, which is moved, for example, by means of a linear motor. At the same time, there is also a first adjustment device 10 and a second adjustment device 16. This means that the contact roller 6 and the dancer roller 8 can also be moved independently of any movement of the base frame 32.

[0083] Figure 12describes an embodiment of the film winding system 1 as already known from Figure 11 is known. In contrast to Figure 11 The film winding system 1 comprises Figure 12 no second deflection roller 21. Preferably, the film web 2 runs horizontally between the dancer roller 8 and the contact roller 6, i.e. parallel to the floor.

[0084] Figure 13 describes an embodiment of the film winding system 1 as already known from Figure 11 is known. In contrast to Figure 11 The film web 2 runs between the second deflection roller 21 and the contact roller 6 not only in the vertical direction, i.e. perpendicular to the floor, but also with both a horizontal component (movement vector in the X direction) and a vertical component (movement vector in the Z direction). This allows the degree of wrapping of the film web 2 over the contact roller 6 to be adjusted. In the example from Figure 13This is approximately 60°. The degree of wrap is preferably greater than 0.5°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or greater than 85°. Furthermore, the degree of wrap is preferably less than 95°, 90°, 85°, 80°, 75°, 70°, 65°, 60°, 55°, 50°, 45°, 40°, 35°, 30°, 25°, 20°, 15°, 10°, or less than 5°.

[0085] If the base adjustment device 33 is controlled such that it moves the base frame 32 away from the winding station 4, and the first adjustment device 10 is controlled such that the contact roller 6 is moved away from the second deflection roller 21, the degree of wrap is increased. However, if the base adjustment device 33 is controlled such that it moves the base frame 32 toward the winding station 4, and the first adjustment device 10 is controlled such that the contact roller 6 is moved toward the second deflection roller 21, the degree of wrap is reduced.

[0086] Figure 14 describes an embodiment of the film winding system 1 as already known from Figure 13 is known. In contrast to Figure 13the contact roller 6 rotates in the opposite direction (counterclockwise). The film web 2 runs between the second deflection roller 21 and the contact roller 6 preferably only in the vertical direction, i.e. perpendicular to the ground. The second deflection roller 21 is further from the ground than the contact roller 6. The degree of wrap in this case is approximately 180°. In this case, the center of the second deflection roller 21 is further from the winding station 4 than the center of the contact roller 6. The film web 2 preferably leaves the second deflection roller 21 at three o'clock and reaches the contact roller 6 at nine o'clock. After the contact roller 6 then carries the film web 180°, the film web 2 leaves the contact roller 6 at three o'clock and is fed to the winding station 4. The winding station 4 is arranged at approximately 3 o'clock with respect to the contact roller 6. The second deflection roller 21 can also be arranged closer to the ground than the contact roller 6.In this case, the contact roller 6 would rotate clockwise.

[0087] The rollers are preferably made of metal or a metal alloy, or comprise metal or a metal alloy. Chrome is preferred. Alternatively, rollers made of carbon fiber composite material or combinations of metal rollers and carbon fiber composite material rollers can be used.

[0088] The dancer roller 8 is preferably free of a pendulum.

[0089] The speed of the film web 2 at the contact roller is approximately 10 to 100 m / min. According to the invention, instead of the first adjusting device 10 on the contact roller 6, the second adjusting device 16 on the dancer roller 8 can also be used. In principle, it would also be conceivable that instead of the first adjusting device 10 on the contact roller 6, the radial air bearings 13, 19, 20, 22 on the contact roller 6, the dancer roller 8, the first deflection roller 9 and / or on the second deflection roller 21 are also used.

[0090] The invention is not limited to the described embodiments. Within the scope of the claimed invention, all described and / or illustrated features can be combined with one another in any way.

Claims

1. Film winding system (1) for a film stretching unit (110) comprising the following features: - a film entry area (3) is provided, via which a film web (2) to be wound up is feedable to the film winding system (1); - a first winding station (4) is provided, wherein the first winding station (4) is configured in a winding position to wind the film web (2) into a film bale (5); - a contact roller (6) and a compensating roller (8) are provided, wherein the contact roller (6) is arranged adjacent to the first winding station (4) in the winding position and is configured to guide the film web (2) to the first winding station (4); - the compensating roller (8) is located before the contact roller (6) in the direction of travel of the film web (2) and is configured to guide the film web (2) to the contact roller (6) and to set a film tension; - a first adjustment device (10) is provided and configured to move the contact roller (6) towards the winding station (4) or away from the winding station (4), thereby enabling the setting of a specific contact pressure between the contact roller (6) and the film bale (5); - the first adjustment device (10) comprises a slide system or an adjusting spindle.

2. Film winding system (1) according to claim 1, characterised by the following feature: - the slide system is an air-bearing slide system (11) or a hydrostatic-bearing slide system, in particular characterised by the following features: - the air-bearing slide system (11) of the first adjustment device (10) comprises a first rail (23) and at least a first slide (24) that is located on the first rail (23); - the first slide (24) comprises air outlet openings that are directed in the direction of the first rail (23); - the first slide (24) comprises an air connection (25) to allow the feeding of compressed air that then exits the air outlet openings, thereby enabling the first slide (24) to be slidable on the first rail (23), in particular wherein the first slide (24) grasps the first rail (23) on at least three sides.

3. Film winding system (1) according to claim 2, characterised by the following features: - the air-bearing slide system (11) of the first adjustment device (10) comprises a second rail (26) and at least a second slide (27) that is located on the second rail (26); - the second slide (27) comprises air outlet openings that are directed in the direction of the second rail (26); - the second slide (27) comprises an air connection (28) to allow the feeding of compressed air that then exits the air outlet openings, thereby enabling the second slide (27) to be slidable on the second rail (26); - the second rail (26) runs parallel to the first rail (23).

4. Film winding system (1) according to claim 2 or 3, characterised by the following features: - the air-bearing slide system (11) of the first adjustment device (10) comprises a third slide which is located on the first rail (23); - the third slide comprises air outlet openings that are directed in the direction of the first rail (23); - the third slide comprises an air connection to allow the feeding of compressed air that then exits the air outlet openings, thereby enabling the third slide to be slidable on the first rail (23); - the first rail (23) runs continuously or is divided into two rail sections for the first and the third slides (24), said rail sections being are spaced apart.

5. Film winding system (1) according to any one of the previous claims, characterised by the following features: - the first adjustment device (10) comprises: a) a first and a second radial air bearing (13); or b) a first and a second hydrostatic bearing; - the contact roller (6) comprises first and second journals (15) in the area of the first and the second end face (14), said journals (15) being supported in the first and second radial air bearings (13) or hydrostatic bearings.

6. Film winding system (1) according to any one of the previous claims, characterised by the following feature: - the first adjustment device (10) also comprises a linear motor (12) that is configured to move the contact roller (6) via the slide system towards the first winding station (4) or away from the first winding station (4); or - the first adjustment device (10) comprises an electric motor that is configured to rotate the adjusting spindle, thereby enabling the contact roller (6) to be moveable towards the first winding station (4) or away from the first winding station (4), in particular characterised by the following feature: - a control device is provided that is configured to control the linear motor (12) or the electric motor of the first adjustment device (10) in such a way that the contact roller (6) rests on the film bale (5) at a predetermined contact pressure.

7. Film winding system (1) according to any one of the previous claims, characterised by the following features: - a first deflection roller (9) is provided; - the first deflection roller (9) is located in the direction of travel of the film web (2) before the compensating roller (8), in particular characterised by one or both of the following features: - a distance between the first deflection roller (9) and the contact roller (6) is less than a distance between the compensating roller (8) and the contact roller (6); and / or - the first deflection roller (9) is mounted rotatably by means of radial air bearings (20) or hydrostatic bearings.

8. Film winding system (1) according to any one of the previous claims, characterised by the following features: - a second deflection roller (21) is provided; - the second deflection roller (21) is located in the direction of travel of the film web (2) after the compensating roller (8) and before the contact roller (6), in particular characterised by the following feature: - the second deflection roller (21) is mounted rotatably by means of radial air bearings (22) or hydrostatic bearings.

9. Film winding system (1) according to any one of the previous claims, characterised by the following features: - a contact roller frame (30) is provided; - the slide system of the first adjustment device (10) or the adjusting spindle is located on the contact roller frame (30) so that the contact roller (6) is moveable relative to the contact roller frame (30); or the contact roller frame (30) is located on the slide system or the adjusting spindle of the first adjustment device (10), wherein the contact roller (6) is located on the contact roller frame (30) so that the contact roller (6) and the contact roller frame (30) are moveable collectively, in particular characterised by the following feature: - the first deflection roller (9) and the second deflection roller (21) and / or the compensating roller (8) are located on the contact roller frame (30).

10. Film winding system (1) according to any one of the claims 1 to 8, characterised by the following feature: - a base adjustment device (33) is provided that comprises a base frame (32) and an air-bearing slide system or a hydrostatic-bearing slide system or an adjusting spindle (34); - the contact roller (6) and the compensating roller (8) and the first deflection roller (9) and / or the second deflection roller (21) are located on the base frame (32) ; - the base adjustment device (33) is configured to move the contact roller (6), the compensating roller (8), the first deflection roller (9) and / or the second deflection roller (21) towards the winding station (4) or away from the winding station (4).

11. Film winding system (1) according to any one of the previous claims, characterised by the following features: - a second adjustment device (16) is provided and configured to move the compensating roller (8) towards the contact roller (6) or away from the contact roller (6), thereby enabling the setting of a specific film tension; - the second adjustment device (16) comprises an air-bearing slide system (17) or a hydrostatic-bearing slide system or an adjusting spindle, in particular characterised by the following features: - the air-bearing slide system (17) of the second adjustment device (16) comprises a first rail and at least a first slide that is located on the first rail; - the first slide comprises air outlet openings that are directed in the direction of the first rail; - the first slide comprises an air connection to allow the feeding of compressed air that then exits the air outlet openings, thereby enabling the first slide to be slidable on the first rail.

12. Film winding system (1) according to claim 11, characterised by the following feature: - the second adjustment device (16) comprises a linear motor (18) that is configured to move the compensating roller (8) via the air-bearing slide system (17) or the hydrostatic-bearing slide system towards the contact roller (6) or away from the contact roller (6); or - the second adjustment device (16) comprises an electric motor that is configured to rotate the adjusting spindle, thereby enabling the compensating roller (8) to be moveable towards the first winding station (4) or away from the first winding station (4), in particular characterised by the following feature: - a control device is provided that is configured to control the linear motor (18) or the electric motor of the second adjustment device (16) in such a way that a predetermined film tension is appliable via the compensating roller (8).

13. Film winding system (1) according to any one of the previous claims, characterised by the following features: - the compensating roller (8) is mounted rotatably by means of radial air bearings (19) or hydrostatic bearings, and / or characterised by the following features: - the first winding station (4) comprises a base body (4a), wherein the base body (4a) of the first winding station (4) is rotationally displaceable and wherein the film web (2) is windable around the base body (4a); - a second winding station (7) comprising a base body (7a), wherein the base body (7a) of the second winding station (7) is rotationally displaceable and wherein the film web (2) is windable around the base body (7a); - the first winding station (4) is configured to be pivoted from the winding position, in which it is arranged adjacent to the contact roller (6), into an unloading position, wherein the wound film bale (5) is removable from the first winding station (4) in the unloading position, wherein the second winding station (7) is configured to be pivoted at the same time from the unloading position into the winding position; - a cutting device is provided; - a cutting device is configured to cut the film web (2) across its width when the first winding station (4) is pivoted in the direction of the unloading position, wherein the second winding station (7) is configured to be pivoted further into the winding position in such a way that the base body (7a) of the second winding station (7) immediately comes into contact with the new beginning of the film web (2) now formed; and / or characterised by the following features: - at least one discharge device is provided; - the discharge device is located in the area of the film web (2) and is configured to discharge electrical charge on the film web (2) and / or film bale (5).

14. Assembly (100) comprising a film stretching unit (110) and a film winding system (1) according to any one of the previous claims, characterised by the following features: - a plastic melt is feedable at the entry area (111) of the film stretching unit (110); - the film stretching unit (110) comprises different zones (110a, 110b, 110c, 110d and 110e) in which the plastic melt is heated and / or the film web (2) is stretched; - an exit area (112) of the film stretching unit (110) is connected to the film entry area (3) of the film winding system (1).

15. Use of the assembly according to claim 14 to produce and wind a battery separator film.