Winding device for rolling up the material web

Abstract

The present invention relates to a winding device for winding up a material web (101, 201) running along a running direction, the winding device having at least one knife (103, 203) for dividing the material web into a plurality of sub-material webs (106, 107, 108, 109; 206, 207, 208, 209; 305, 306, 307, 308) along the running direction and having a folding device (301, 302, 303) for folding the edges of the sub-material webs. In order to provide a winding device capable of winding up a material web with folded edges as wrinkle-free as possible, a folding element (309, 310, 311, 312) is provided for each edge of the sub-material web. The at least one knife (103, 203) can be moved transversely to the running direction by a first oscillating device. The second oscillating device can be used to move the folding element for the left edge of the partial material web as viewed in the running direction transversely to the running direction. The third oscillating device can be used to move the folding element for the right edge of the partial material web as viewed in the running direction transversely to the running direction. The first, second, and third oscillating devices can be controlled by a control unit in such a way that the folded edges of the partial material web can be rolled up in an offset manner.

Description

Technical Field

[0001] The invention relates to a winding device for winding a material web running in a running direction, the winding device comprising at least one knife for dividing the material web in the web direction into a plurality of partial material webs and a folding device for folding edges of the partial material webs. Background Art

[0002] Stretch film is used to bind and package individual items, such as bags stacked on pallets. The items are wrapped with stretch film, connecting them to one another via the self-adhesive film. It has been shown that the edges of the stretch film are often the starting point for film breakage during wrapping and packaging. Damage to the edges or edges of a stretch film roll can render it unusable. This damage can occur, for example, if a wound roll of stretch film is transported improperly or dropped to the ground.

[0003] It is known that by folding or folding the edges before winding onto the roll, the stretch film becomes more resistant to damage and subsequently less likely to tear. However, folding the edges can also lead to edge accumulation when the film roll is wound with straight edges, which can also render the film roll unusable. Therefore, when folding the edges, the edges of the film need to be wound onto the roll with an offset relative to each other. This can be achieved, for example, by lateral oscillation of the winding shaft.

[0004] No. 8,221,298 B2 discloses a device for producing non-folded edges of plastic films, wherein a folding element is arranged behind each knife and wherein each folding element produces two folded edges.

[0005] WO 2015 / 055726 A1 discloses a winding device for winding a continuous material web, the winding device comprising at least one knife for dividing the material web into a plurality of sub-material webs along the web direction and a folding device for folding over the edges of the sub-material webs. The winding device includes an oscillating device that can move the at least one knife transversely to the web direction.

[0006] EP 2952459 B1 discloses a device and a method for producing a certain number of rolled-up film rolls, wherein the film is reinforced in its edge region by folding. The lateral end sections of two adjacent film sections are folded over by means of two adjacent folding elements.

[0007] In known winding devices, the folding unit is arranged directly behind the blade and is mechanically coupled to it. To fold the edges, a folding unit is used that folds over two opposite edges of adjacent film webs together. It has been observed that this can cause wrinkles in the film, which can impair its functionality. Summary of the Invention

[0008] Starting from this, the object of the present invention is to provide a winding device which is able to wind up a material web having folded-over edges as wrinkle-free as possible.

[0009] According to the present invention, a folding element is provided for each edge of the sub-material web. A first oscillating device can be used to move the at least one knife transversely to the direction of travel. A second oscillating device can be used to move the folding element for the left edge of the sub-material web as viewed in the direction of travel transversely to the direction of travel. A third oscillating device can be used to move the folding element for the right edge of the sub-material web as viewed in the direction of travel transversely to the direction of travel. A control unit can control the first, second, and third oscillating devices in such a way that the folded edges of the sub-material web can be rolled up in an offset manner.

[0010] Compared to known winding devices, the winding device according to the present invention allows the width of the folded edge to be adjusted. The width of the folded edge can be kept constant by the control unit in a corresponding manner despite varying machine parameters. This ensures that the same number of film layers can always be wound during one cycle of the oscillating blade, effectively reducing the occurrence of wrinkles in the film.

[0011] According to a preferred embodiment, it is provided that the first oscillating device, the second oscillating device and the third oscillating device are each formed by an eccentric driven by a motor.

[0012] According to another preferred embodiment, it is provided that the frequencies of the first oscillating device, the second oscillating device and the third oscillating device can be adjusted separately by the control unit.

[0013] According to another preferred embodiment, it is provided that the strokes of the first oscillating device, the second oscillating device and the third oscillating device can be adjusted separately by the control unit.

[0014] According to a further preferred embodiment, it is provided that the thickness distribution of the wound-up roll is measured and transmitted to the control unit.

[0015] According to a further preferred embodiment, it is provided that the web speed of the material web is measured and transmitted to the control unit.

[0016] According to a further preferred embodiment, it is provided that the material web is a stretch film produced on a cast film line or on a blown film line. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further details and advantages of the invention are described with the aid of the accompanying drawings.

[0018] Figure 1 shows a schematic diagram of a knife beam according to a first embodiment of the present invention;

[0019] Figure 2 shows a schematic diagram of a knife beam according to a second embodiment of the present invention;

[0020] Figure 3 shows a top view of the folding device according to the present invention; and

[0021] Figure 4 Shown in accordance with Figure 3 perspective view of the. DETAILED DESCRIPTION

[0022] Figure 1 The material web 101 is a stretch film produced on a cast film system.

[0023] After its production, the stretch film 101 is transported in direction 102 and from there reaches a knife beam 103. Knife beam 103 is moved back and forth in direction 104 by an oscillating device and has a total of five cutting knives 105. At the edges, scraps 111 and 112 are produced on the left and right, respectively, which can be further processed for other uses.

[0024] Behind the blade beam 103, S-shaped strips 106, 107, 108 and 109 are produced and, more precisely, are formed as in Figure 1 The strips are produced in the same shape as shown in FIG. The edges of the S-shape do not have to be absolutely uniform. The amplitude and frequency of the movement of the oscillating device can also be irregular. In addition, it is also conceivable that each knife 105 is controlled individually and thus performs different movements.

[0025] Figure 2 The schematic diagram of the blade beam according to the second embodiment of the present invention is shown. The material web 201 is again a stretch film produced on a cast film system.

[0026] After the stretch film 201 is produced, it is transported along direction 202 and arrives at the knife beam 203. The knife beam 203 is moved back and forth along direction 204 by an oscillating device and has a total of three cutting knives 205. Since the outermost edges on the left and right sides are not cut, the same as in the embodiment of the present invention, the stretch film 201 is transported along direction 202 and arrives at the knife beam 203. The knife beam 203 is moved back and forth along direction 204 by an oscillating device and has a total of three cutting knives 205. Figure 1 Compared with the embodiment of the present invention, no scrap is generated.

[0027] Behind the blade beam 203, S-shaped strips 206, 207, 208 and 209 are produced and, more precisely, are formed as in Figure 2 The same shape as shown in FIG produces the strips. The edges of the S-shape do not have to be absolutely uniform. The amplitude and frequency of the movement of the oscillating device can also be irregular. In addition, it is also conceivable that each knife 205 is controlled individually and thus performs different movements.

[0028] The outermost strips 206 and 209 have straight and S-shaped edges, respectively, and are further processed in this shape for a particular application.

[0029] Figure 3 The folding device according to the present invention is shown in a top view. The folding device is arranged in the running direction as shown in FIG. Figure 1 Or follow Figure 2 The folding device is formed by a crossbar 301, to which a first guide rail 302 and a second guide rail 303 are attached. Four sub-material webs 305, 306, 307, and 308, which were previously separated from the material web running over the entire width at the knife beam 103 or 203, run in the running direction 304.

[0030] The folding device is designed such that a folding element is provided for each edge of the partial material webs 305, 306, 307, and 308. The folding elements 309, 310, 311, and 312 are movably guided on the first guide rail 302, thereby folding the left edges of the partial material webs 305, 306, 307, and 308, as viewed in the running direction 304. Similarly, the folding elements 313, 314, 315, and 316 are movably guided on the second guide rail 303, thereby folding the right edges of the partial material webs 305, 306, 307, and 308, as viewed in the running direction 304.

[0031] The folding elements 309 , 310 , 311 and 312 are connected to a transmission rod 318 , which is driven by an eccentric motor 317 . In a corresponding manner, the folding elements 313 , 314 , 315 and 316 are connected to a transmission rod 320 , which is driven by an eccentric motor 319 .

[0032] The first oscillating device has been referred to according to Figure 1 The knife beam 103 or refer to Figure 2 The blade beam 203 is described above. Furthermore, the eccentric motor 317 represents a second oscillating device, with which the bending elements 309, 310, 311, and 312 for the left edge of the partial material web, as viewed in the running direction 304, can be moved transversely to the running direction. Similarly, the eccentric motor 319 represents a third oscillating device, with which the bending elements 313, 314, 315, and 316 for the right edge of the partial material web, as viewed in the running direction 304, can be moved transversely to the running direction 304.

[0033] The operating principle of the second oscillating device is described below. The corresponding description also applies to the third oscillating device. The rotational motion of the eccentric motor 317 is converted into a linear motion of the deflecting elements 309, 310, 311, and 312 transverse to the direction of travel 304. The eccentric motor 317 does not rotate continuously, but rather performs alternating partial rotations within predetermined angular segments. This allows the stroke of the deflecting elements 309, 310, 311, and 312 to be adjusted using the aperture angle of the angular segments. Furthermore, the frequency of the alternating partial rotations corresponds to the frequency of the motion of the deflecting elements 309, 310, 311, and 312. If the reciprocating linear motion of the deflecting elements 309, 310, 311, and 312 and the deflecting elements 313, 314, 315, and 316 is performed with an offset relative to one another, the width of the deflected edge can be adjusted.

[0034] The frequencies and strokes of the three oscillating units are coordinated with one another by a control unit such that the folded edges of the partial material webs can be rolled up in an offset manner, thereby avoiding the aforementioned edge accumulation.

[0035] Figure 4 Shown in accordance with Figure 3 Identical parts are provided with the same reference numerals, so that reference is made in this respect to the drawings according to Figure 3 In addition, in accordance with Figure 4 As can be seen from the diagram of FIG, each folding element has a controllable lifting cylinder, which is shown in FIG. Figure 4In the figure, only the lifting cylinders of the folding elements 313 are designated by reference numeral 401. These lifting cylinders allow the folding elements to be pivoted inward or outward relative to the web path. This reduces the setup time for a new order, for example, by enabling the operator to simultaneously pivot multiple folding elements inward using appropriate machine commands. Furthermore, in the event of a disturbance, consequential losses can be avoided by pivoting the folding elements out of the web path when a disturbance is detected.

Claims

1. A winding device for winding up the material web running in the running direction, having at least one knife for dividing the material web into a plurality of sub-material webs along the running direction, A plurality of bending elements for bending the edges of the partial material web are provided, wherein a bending element is provided for each edge of the partial material web, having a first oscillating device, with which the at least one knife can be moved transversely to the direction of travel, a second oscillating device, with which a folding element for the left edge of the partial material web, viewed in the running direction, can be moved transversely to the running direction, A third oscillating device is provided, with which a folding element for the right edge of the partial material web, viewed in the running direction, can be moved transversely to the running direction, and A control unit is provided for controlling the first, second and third oscillating devices in such a way that the folded edges of the partial material webs can be rolled up in an offset manner.

2. The winding device according to claim 1, wherein the first oscillating device, the second oscillating device and the third oscillating device are each composed of an eccentric wheel driven by a motor. 3 . The winding device according to claim 1 , wherein the width of the folded-over edge can be adjusted by the control unit.

4. The winding device according to claim 1 or 2, wherein the frequencies of the first oscillating device, the second oscillating device and the third oscillating device can be adjusted separately by the control unit. 5 . The winding device according to claim 1 , wherein the strokes of the first oscillating device, the second oscillating device, and the third oscillating device can be adjusted separately by the control unit.

6. Winding device according to claim 1 or 2, wherein the thickness distribution of the wound-up log is measured and transmitted to the control unit.

7. The winding device according to claim 1 or 2, wherein the web speed of the material web is measured and transmitted to the control unit.

8. The winding device according to claim 1 or 2, wherein the material web is a stretch film produced on a cast film line or on a blown film line.

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