Winding paper web

(42) Date of commencement of the patent: 15. 8.1992 (45) Date of issue: 25. 3.1993

<td>(30) Priority:</td><td colspan="2">(73) Patent owner:</td>

<td>11. 4.1984 FI 841448 claims.</td><td rowspan="2">VALMET PAPER MACHINERY INC. SF-00130 HELSINKI (FI).</td><td></td>

<td>(56) Documents:</td><td></td>

<td></td><td>(72) Inventor:</td><td></td>

<td>DE-0S3121039 DE-0S3221929 FI-PS 820383 US-PS 3869095 US-PS4508283</td><td>OINON HAhWU 3RVENPSS (FI).</td><td></td>

(54) DEVICE FOR WINDING A MATERIAL RAIL, IN PARTICULAR A PAPER WEB, ON A SLEEVE

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AT 395 843 (57) The invention relates to a device for winding a material web (P), in particular a paper web, on a sleeve, the device (10) comprising a first carrier roll (11), a second carrier roll (12) and a press roll (13), which exerts a pressure on the material web roll (15), which is wound on a sleeve (14), wherein the first support roller (11) forms a first nip (N p together with the roller (15) and likewise the second support roller (12) forms a second nip (N 2) together with the roller (15) and one or both said carrier rolls (11, 12) are driven, and in which device (10) the support rollers (11, 11) 12) and the press roll (13) are arranged asymmetrically to each other, such that the weight (M) of the roller (15), which is in winding, acting on the second gap (N j) and the material web (P) through the space between the support rollers (11, 12) and through the first gap (N p through on the

Sleeve (14) runs, characterized in that the tension of the wound reel (15) of the amount of that component (F p of the pressing force (F), which acts on the first gap (N p, from the press roll (D) is determined.

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AT395 843B

The present invention relates to a device for winding a material web, in particular a paper web, on a sleeve, the device comprising a first carrier roll, a second carrier roll and a press roll, which exerts a pressure on the web roll, which is wound on a sleeve, the first support roller forming a first nip together with the roller and likewise the second support roller forming a second nip together with the roller and one or both of said support rollers being driven, and in which device the support rolls and the press roll are arranged asymmetrically to each other, so that the weight of the roll, which is in winding, acts on the second gap and the material web runs through the gap between the support rollers and through the first gap on the sleeve.

The biggest disadvantage of a device of this type is the difficult control of the tension of the material web during the winding process. At the beginning of the winding process, it is necessary that the tension of the material web is higher, otherwise the inner part of the roll would be too loose. A loose or soft inner part has the influence that the tightly wound outer shell, which has been generated in a later phase, pressure on the loose inner part, whereby z. B. unwanted so-called wrinkles, arise in the paper web.

It has previously been known, in conjunction with winding, to exert an influence on the strength of a roll carried by two parallel support rolls by distributing the load from the roll under the support rolls. For this purpose, one arranges carrier rolls with just such diameters on different horizontal planes, or one uses also carrier rolls with different diameters. It has also been previously known to obtain a harder winding when winding on a smaller diameter carrier roll than when winding on a larger diameter carrier roll.

With regard to the state of the art, reference is made to the Finnish patent application 820383, in which a method for centerless winding of a material web is specified. By means of the construction in question, one obtains even tension up to a certain roll size, while with larger rolls, the described pinching of the surface continues to be unpleasantly noticeable.

It is already known to relieve the roll on a roll, it being possible to influence the nip pressure at the nip formed by the roll and the roll. In the known arrangement, the support rollers are of the same size and neither of the two support rollers is moved vertically.

The object of the present invention is to improve the presently known device for winding a material web. One achieves the objects of the invention in the device mentioned in the fact that the tension of the winding roller in the amount of that component of the pressing force acting on the first gap, is determined by the press roll.

From claims 2 to 7 show advantageous developments of the main feature of the invention.

It has been understood in the device according to the invention, the support rollers and the press roll in such a manner to each other asymmetrically to arrange, that the weight of the wound reel acts on the second gap, which forms the second support roller with the wound reel. Of course, acts on this second gap, the component of the pressing pressure of the press roll, which is directed against this gap. Further, in the apparatus according to the invention, the tension in the take-up roll is determined solely by the amount of that component of the pressing pressure from the press roll which is directed against the first nip formed by the first support roll with the roll being wound up. As a result of this construction, the web material wound on the reel at the beginning of the winding operation can be held under higher tension to achieve the desired compactness of the inner part of the reel being wound. With progressive winding can be the pressing pressure of the press roll change so that the respective desired voltage is achieved in the outer shell of the roll located in the winding, and that is done by reducing the nip pressure, which is effective in the first gap - optionally down to to zero. It can therefore in the device according to the invention of the roll located in the winding consistently give the desired voltage, which z. B. the danger of the emergence of disadvantageous so-called wrinkles in the wound paper web is eliminated.

The invention will be described in detail with reference to the construction principle of the invention shown in the figure of the accompanying drawing, on which, however, the invention should not be limited exclusively.

The figure in the drawing represents an advantageous embodiment of the invention in a schematic side view.

In the embodiment shown in the figure of the drawing, the device according to the invention has been generally designated by the reference number (10). The apparatus (10) comprises a first carrier roll (11), a second carrier roll (12) and a press roll (13) which presses on the roll (15) which is being wound onto a sleeve (14). The first support roller (11) forms a first gap (Nq together with the roller (15). Likewise, the second carrier roll (12) forms a second gap (N₂) together with the roller (15). At least one of the two support rollers (11, 12) is a driven support roller arranged to rotate the sleeve (14) and the roller (15) thereon in winding. In some advantageous embodiments, both support rollers (11) and (12) are driven separately, and in the

-2AT 395 843 B

Case, it is possible, the support rollers (11) and (12) separately for Strammhalten or Decrease the tension in the surface turns of the roller (15) insert, for example, according to a preselected program. In the figure in the drawing, the arrow (A) indicates the direction of rotation of the larger roller (12). Similarly, the arrow (B) indicates the sense of rotation of the roller (15), which is in winding on the sleeve (14), and the arrow (C) shows that of the smaller support roller (11). The second support roller conveniently has a diameter 1.5 to 4 times larger than the first support roller (11).

According to the basic idea of ​​the invention, the carrier rollers (11, 12) and the press roller (13) are arranged asymmetrically relative to one another in such a way that the weight (M) of the reel (15) being wound up and the component (F₂) of the pressing pressure (F) from the press roll (13) to the second gap (N₂). Secondly, according to the basic idea of ​​the invention, the tension in the roll (15) being wound is determined by the amount of the component (Fj) of the pressing pressure (F) from the press roll (13) facing the first nip (FIG. Np judges. It regulates the pressing pressure in the gap (N ^ by means of an application of the press roll (13). This type of control is quite obvious to the person skilled in the art, and therefore no such, previously known, loading device is shown in the figure of the drawing. The direction of the pressing force (F) from the press roll (13) closes with the direction of the weight (M) of the roll (15) which is applied to the nip (N₂), an angle (a) whose size is advantageously in the range of 20-30 °. It is also possible to arrange the press roll (13) movably on a substantially circular path of increasing diameter of the roll (15), similar to the arrow (D), indicating the inclination of the press roll (13), the roll (15 ) in support of the support rollers (11) and (12), can further increase.

As seen in the figure of the drawing, the web, in the present embodiment, a paper web (P), on the sleeve (14) through the gap between the support rollers (11) and (12) and through the gap (Np through on which latter the static component (M + F₂) of the weight of the roller (15) and the press roll (13) does not act. The smaller carrier roll (11) rotates at a speed (V * p less than the rotational speed (V₁₂) of the larger carrier roll (12). This makes it possible to obtain a controlled tension in the nip (Np by the action of the press roller (13).

Of course, as the diameter of the reel (15) is increased, an increasing nip pressure on the nip (N₂) exercised. This increasing pressure in the nip would have a detrimental effect on the paper web (P) if the paper web (P) were passed through the nip (N₂) would lead. Therefore, as the diameter of the reel (15) being wound increases, the nip pressure acting on the nip (Np) must be correspondingly decreased so that uniform tension is obtained throughout the reeling roll (15).

In some favorable embodiments, the first support roller (11) is arranged to move relative to the support roller (12) as indicated by the arrow (E) in the figure as the roller (15) becomes larger, so that the weight (M ) of the roller (15) exclusively on the second gap (N₂) acts.

In the foregoing, only one advantageous embodiment of the invention has been presented, and it will be apparent to those skilled in the art that numerous modifications thereof are possible within the scope of the inventive concept disclosed in the claims below.