EP0523528A1 - Device for winding a continuous web - Google Patents

Abstract

A device for winding a continuous web is described, in which a contact roller presses the web against the reel and in which it has been made possible to adjust, preferably to lower, the reel hardness over wide ranges, regardless of the set web tension, which is achieved by driving the contact roller by means of a motor towards the winding tube, which is also motor-driven. <IMAGE>

Description

The invention relates to a device for winding up a running material web, which is wound onto a winding tube until a certain winding diameter is reached, a contact roller pressing the material web against the winding tube.

Such, mostly fully automatic, devices are known from numerous publications, for example from US Pat. No. 3,918,654, EP 0 395 830 and German application file number P 41 07 127. The material web can be, for example, a paper web, a film web or one with a web magnetic coating provided plastic sheet. In the devices described, the task is to separate the material web wound on a winding tube with a separating knife after reaching a certain winding diameter and to wind the new material web beginning that has been formed onto an empty winding tube while the full package is being removed and replaced by an empty winding tube. For this purpose, the almost completely wound winding tube leaves its winding position. A new sleeve to be wound takes its place. The running web is cut between the new and wound winding tube and lies against the new tube, whereupon the process just mentioned begins again.

It is also of particular importance, during and after the casting, when conveying and winding up sensitive material webs such as magnetic tapes, that neither the magnetic layer nor the back of the film is damaged or scratched. For example, DE-OS 39 36 286 describes a suction roller for conveying a material web, in which one is made of porous sintered metal existing surface-treated roller body with a specific pore distribution across the width is used to convey the material web. The German application P 40 03 927 describes a hollow roller suction device for conveying a material web, in which sealing wedges are attached laterally below the material web to reduce the suction vacuum.

wobei x = ln (1/Ra) ist und wobei die Bahn mit einer Kontaktwalze an den Wickel angepreßt wird.The applicant of EP 0 064 291 has found that when a polyester web is wound up without damage such as folds and kinks, the relationship between the winding hardness H and the roughness value Ra of the web should exist even after a long storage period

$\text{H ≧ 0.67x³ - 10.61x² + 55.54x - 1.16}$

where x = ln (1 / Ra) and the web is pressed against the roll with a contact roller.

Investigations by the applicant of the present invention have shown that, in particular, the tape tension determines the winding hardness during winding and thus the quality of the material web. As can be seen from FIG. 1, the winding hardness can be adjusted, inter alia, by the pressure of the rollers (7, 9) on the winding and by the tape tension caused by the oscillating roller (5). If the tape tension is too low, the web tends to move sideways, but if the tape tension and pressing forces are too high, the material web can be damaged, or introduced particles or deformations impact on adjacent winding layers and the product is unusable.

The object of the invention was to achieve a uniform and preferably the lowest possible winding hardness of the wound web with the highest possible strip tension. In addition, a wrinkle-free smooth winding pattern should be achieved even with a large winding diameter.

According to the invention the object was achieved with a winding device with the features mentioned in the characterizing part of claim 1. Further details of the invention emerge from the subclaims, the description and the drawings.

Figuren 1 und 2

Querschnitte durch zwei Ausführungsformen der erfindungsgemäßen Wickelvorrichtung

Figur 3

eine Draufsicht auf einen Teil der Anordnung gemäß Figur 2

Figur 4

einen Teil gemäß der Anordnung von Figur 2

Figur 5

die auf die Kontaktwalze wirkenden Antriebskräfte.

In the following, the invention is explained in more detail with reference to the figures, which show

Figures 1 and 2

Cross sections through two embodiments of the winding device according to the invention

Figure 3

3 shows a plan view of part of the arrangement according to FIG. 2

Figure 4

a part according to the arrangement of Figure 2

Figure 5

the driving forces acting on the contact roller.

Figure 1 shows the principle of the winding device according to the present invention. A material web (2) coming from a coating device (not shown) passes through deflection rollers (4, 6), between which a pendulum roller (dancer roller) (5) is attached, which applies the required strip tension. Then the web runs to the winding device to be described, consisting of the driven winding tube (14) onto which the winding is wound, to which a contact roller (7) is pressed. To support the desired effect, a pressure roller (9) can be pressed onto the contact roller (7), which brings the contact roller to the speed of the material web. The essence of the invention now consists in that the contact roller (7) as well as the winding tube (14) can be driven by a motor; Further statements are made below about the level of the driving forces.

Figure 2 shows another arrangement that is possible within the scope of the invention. The material web (2) passes through a cooling roller (3) and a pendulum roller (5), between which there are deflection rollers or pressure rollers (1, 4, 6). The web then runs over a further deflection roller (8) between a pressure roller (9) and an outer driven contact roller (7) onto the winding tube (14), with an additional inner dragged contact roller (7) lying opposite the outer driven contact roller (7). 12) is located.

Figure 3 shows a top view of the drive of the contact roller (7). It consists of a motor (10), for example a direct current motor, which drives the contact roller (7) via a belt drive (11) and a pneumatic coupling (13), which in turn acts on the winding (14).

The outer contact roller (7) has the task of ensuring the transfer of the material web (2) to the winding (14). By pressing the roller (7), the air layer wrapped between the individual layers of film is reduced, the winding becomes harder.

It has proven to be particularly favorable if the point of application of the driven contact roller is chosen at the point where the material web (2) runs onto the winding (14). However, the point of contact of the contact roller can also be arranged after the location of the web running onto the roll, even then the advantages according to the invention are retained.

The winder drive supplies the energy for driving the towed roller (12) via the material web and the frictional connection to the winding.

The inner contact roller (12) is particularly intended for operation in a so-called turret winder, in which the winding is not in contact with the outer contact roller (7) during turning. However, the roller (12) can rest against the winding (14) during the entire winding process.

The tape tension directly on the reel results in the dragged contact roller from the resulting tape tension, which is applied by means of the force of the pendulum roller (5), minus the tensile losses due to the frictional forces on contact and deflection rollers.

The tape tension acting on the reel and the pressure of the contact rollers determine the hardness of the reel at a selected speed. In order to achieve low winding hardnesses, the nominal strip tension is usually set quite low at 30-50 N according to the prior art.

ist also die um den Kontaktwalzenmoment reduzierte Bandzugskraft. Sie soll entgegen der Bandlaufrichtung wirken. Durch das Antriebsmoment der Kontaktwalze (7) senkt sich das Moment des Motors des Wicklerantriebs (14). Wird dieses Verhältnis zwischen beiden Momenten so eingestellt, daß das Antriebsmoment des Motors (10) zu groß ist, so wird F_res = 0 oder eine Richtungsänderung (F_res < 0) resultiert, was zu einer Schlaufe im Wickel (Figur 4) führt; das Produkt ist dann natürlich unbrauchbar. Ist umgekehrt F_KW zu klein, so wird die resultierende Kraft im wesentlichen durch den Bandzug bestimmt, der wie oben genannt, relativ hoch eingestellt wird, und die Wickelhärte wird in zu geringem Maße reduziert. Wird die Kontaktwalze durch den Motor gebremst, ändert F_KW das Vorzeichen und die Wickelhärte nimmt sogar zu.FIG. 5 shows the force relationships during operation of the driven contact roller. The belt tensile force F _BZ acts counter to the web running direction, while the force F _KW acting through the driven contact roller exists in the direction of the belt running. The resulting force ${\text{F}}_{\text{res}}{\text{= F}}_{\text{BZ}}{\text{- F}}_{\text{KW}}$

is the strip tension reduced by the contact roller torque. It should act against the direction of the tape. The torque of the motor of the winder drive (14) is reduced by the drive torque of the contact roller (7). If this ratio between the two moments is set so that the drive torque of the motor (10) is too large, F _res = 0 or a change in direction (F _res <0) results, which leads to a loop in the winding (FIG. 4); the product is then of course unusable. Conversely, if F _{KW is} too small, the resulting force is essentially determined by the strip tension, which, as mentioned above, is set relatively high and the winding hardness is reduced too little. If the contact roller is braked by the motor, F _KW changes the sign and the winding hardness even increases.

From what has been said above, it can be seen that by driving the contact roller it is possible to set the strip tension between the winding and cooling roller or another drive as well as the contact roller and winding largely independently of one another, i.e. a high strip tension before the web comes onto the winding and one to realize slight tension after the contact roller. The belt tension after the cooling or other drive roller is adjusted by the pendulum roller, the tension after the contact roller (7) results from the moment applied by the roller through the motor (10) and the belt tension. The belt tension is increased by braking the contact roller motor (10), and the tape tension is reduced by driving the contact roller.

example

In the case of a magnetic tape web approximately 4500 m long and 65 cm wide, consisting of a 10 μm thick polyethylene terephthalate film on which a 4 μm thick magnetic layer was cast, a strip tension of 92 N was set before the reel (14), which was constant over the length of the film was. The pressure of the driven contact roller was 600 N, the machine speed of the running material web was 200 m / min. The pressure roller (9) pressed at 1.5 bar onto the contact roller (7). Without the driven contact roller, the winding hardness was about 125 units of measurement at the specified strip tension of 92 N, while with the driven contact roller the winding hardness was to be lowered far below 40 units of measurement without the risk of loop formation.

During turning operation, the contact roller (7) does not rest on the winding (14) as described. When starting up a coating device like in turning operation, the torque to be set for the winding process would be too high. For these operating conditions, it must be reduced so that only the frictional moments of the drive system are compensated for or the drive is separated from the roller by a clutch (13).

Claims (7)

Device for winding a running material web (2), which is wound onto a winding tube (14) with a specific tape tension F _BZ until a specific winding diameter is reached, at least one contact roller (7, 12) pressing the material web against the winding tube, characterized in that the winding tube (14) and at least one contact roller (7, 12) can be driven by a motor. Apparatus according to claim 1, characterized in that the point of application of the driven contact roller (7) takes place at the location of the point of contact of the material web (2) on the winding (14). Device according to claim 1, characterized in that the point of application of the driven contact roller (7) follows the location of the point of contact of the material web (2) on the winding (14). Device according to Claims 1 to 3, characterized in that a pressure roller (9) presses the material web (2) against the contact roller (7). Apparatus according to claim 1, characterized in that the driving force F _{KW of} the contact roller and the belt tensile force F _BZ are selected so that a resultant force acting on the belt reel (14) ${\text{F}}_{\text{res}}{\text{= F}}_{\text{BZ}}{\text{- F}}_{\text{HFC}}$

against the winding direction. Apparatus according to claim 1, characterized in that the contact roller (7) is driven by a motor (10), a power transmission (11) and a clutch (13). Apparatus according to claim 1, characterized in that the driving torque of the contact roller is reduced when the material web is started or when a turret winder is operated or is switched off by a clutch (13) which can be activated.

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