FI96299C - Sealing device for continuous unwinder - Google Patents

Description

96299

Continuous unroller sealing device Foganordning för kontinuerlig avrullningsmaskin 5

The invention relates to a continuous unwinding sealing device for connecting a new machine roll to a unwinding machine roll web to a unwinding machine web, the sealing device comprising a sealing roll for pressing the emptying roll web to a new machine roll and said sealing device, and the roll is attached to a lever device articulated from an articulation point between the axes of said rollers such that the web travel before sealing and the web travel in sealing are such that the length of the web in sealing and said rolls in the home position is substantially the same.

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Off-machine coating machines use a continuous unroller, in which a new machine roll introduced to the unroller is connected to the tail of a machine roll which is emptied at full speed. The sealing method is basically the same on modern high-speed coating machines, regardless of the machine manufacturer. At the end of the web of the new machine roll, a seam is prepared with 20 double-sided adhesive tapes, which are fastened to the surface of the roll with fastening tape pieces. The surface speed of the new machine roll is accelerated to the same as the running speed of the machine, after which the web of the emptying machine roll is pressed onto the above seam with a roller or brush. The old web is cut with a blade above the seam.

25 Sealing of the open roller has become problematic at current travel speeds (1200 - 1600 m / min). For this reason, the running speed of the coating machine is often reduced during sealing. The main reasons for the sealing problem are the airflows at high speeds and the high speed of the sealing roller required. At a high speed close to the so-called sealing roll and the machine roll. a vacuum is created in the sealing gap, which may be pulsating when the new machine roll is non-wheeled. The vacuum tends to partially pull the old web into the seam even before sealing, and causes the old web to flutter. In addition, the vacuum tends to detach the tape seam from the surface of the new machine roll, 2 96299 whereby the new machine roll "explodes" before sealing. In order to control the flow of the web, folding is required at the sealing roll, which in turn requires the web to be stretched when the sealing roll is quickly struck on the surface of a new machine roll. The aim is to keep the tension peak caused by the impact of the roll in the sealing small by using a small sealing gap-5 (8 - 12 mm), which causes a strong vacuum effect. The already used bending angle causes a problematic tension peak in the track. Higher driving speeds would require an even larger bending angle.

Thus, in the sealing devices of the continuous unwinder, the main problems are the high speed of the impact of the sealing roll 10, the large bending angle of the web and the vacuum formed in the sealing gap. The vacuum causes harmful flutter and the possibility of the tape used for sealing coming off is very high. When a large sealing gap is used, the risk of the web breaking is increased. Similarly, when a large bending angle is used, the risk of breaking the web increases. When the sealing gap is reduced, the result is an increase in vacuum and the resulting side effects. When the sealing gap is enlarged, the tension peak on the web, i.e. the risk of the web breaking, increases.

A sealing device with a soft rubber surface, usually 35 mm thick, is now commonly used as a sealing device for a continuous unwinder. The core material 20 of the sealing roll is generally steel, but may also be some other material, such as carbon fiber.

FI patent application 942869 discloses a sealing device for a continuous unroller, by means of which a new machine roll to be introduced into the unroller is connected to the web of a machine roll which is emptied at full speed. The sealing device comprises a sealing roll with which the web of the emptying machine roll is pressed onto the seam in the new machine roll and at least one other roll. The sealing roll and the second roll are attached to a lever device articulated from an articulation point between the axes of the rolls such that the web travel before sealing and the web travel in sealing are such that the length of the web in sealing and said rolls is in the basic position.

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There is a problem with the sealing device of a continuous open winder due to the high driving speeds currently used from 1200 to 1600 m / min. The problem is the short adhesion time of the sealing tape used in the sealing. With the high driving speeds currently used, and especially with surface-glued paper grades, it is very close to the situation 5 that the adhesion in the sealing nip does not have enough time to take place. This problem can be illustrated by the following example.

The length of the sealing nip between the machine roll and the rubberized sealing roll is of the order of about 25 mm. If the track speed is 1500 m / min, the track travel time through the nip is only 10 1 ms. Today, a line load of about 2500 to 4500 N / m is generally used as the line load of the sealing roll, which gives a sealing pressure of 100 to 180 kP. The strength of the sealing roll cannot be increased because the surface layers of the machine roll can break during sealing.

The object of the invention is to provide an improvement on the currently known sealing devices of the continuous unwinder 15. It is a more detailed object of the invention to provide a sealing device for a continuous unwinder which avoids the numerous disadvantages of prior art solutions.

The sealing device of the continuous unwinder according to the invention is characterized in that the support wire 20 is adapted to pass through the sealing roll and said second roll to form a wire nip, whereby the gluing time available for sealing increases many times.

According to the basic idea of the invention, the support wire is arranged to pass through the sealing roll 25 and the auxiliary roll, whereby in addition to the roll nip, a wire nip is formed. In this case, the adhesion time of the sealing is multiplied compared to the situation where the sealing roll and the new machine roll only form a roll nip. In addition, in the solution according to the invention, the adhesion of the sealing tape takes place even at a low gluing pressure, because the adhesion time is sufficiently long. Thus, the invention has been found to increase the gluing time 30 by extending the distance during which the sealing tape is under pressure.

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In the sealing device according to the invention, the elongation of the web when the sealing roller strikes is eliminated by using two moving rollers. Since the elongation of the web as the rollers move is compensated, a large sealing gap, such as 100 mm, can be used, so that no disturbing vacuum is created in the sealing gap. As a result, the flutter 5 of the web is reduced and the risk of the new machine roll breaking down is reduced. In the solution according to the invention, the folding angle with the sealing roller can be increased, whereby the web travel is more controlled. The solution according to the invention also does not have the risk of premature adhesion of the web to the sealing tape.

In a preferred embodiment of the invention, the two rollers of the sealing device are attached to a lever articulated from an articulation point between the axes of the rollers. The position of the articulation point is selected depending on the bending angles of the sealing roll and the web guide roll, i.e. the auxiliary roll, so that the length of the web in the sealing and the rolls in the basic position is substantially the same. In large machines with large roll diameters, lightweight composite rolls can be used, so that the mass of the sealing roll mechanism does not become disturbingly large.

The invention will be explained in detail with reference to a preferred embodiment of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figures 1A, 1B and 1C show a side view of a sealing mechanism known from the prior art.

Figure 2 shows a side view of a sealing device according to FI patent application 942869.

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Figure 3 shows a side view of a preferred embodiment of a sealing device according to the invention.

In Figures 1A, 1B and 1C, the emptying roll is denoted by reference numeral 11 and the sealing roll by reference numeral 12. The new roll is denoted by reference numeral 13 and its direction of rotation by arrow A. The tape seam is denoted by reference numeral 14.

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In the prior art solution, the new machine roll 13 is accelerated to the running speed and the old web P is brought close to the surface of the new machine roll 13. The web P is then pressed onto the surface of the machine roll 13 by a sealing roll 12. The old web P is cut with a cutting blade 15 above the seam 14. The prior art sealing machine according to Figures 1A-1C has the disadvantages described above.

The sealing device according to Fig. 2 comprises, in addition to the sealing roll 12a, at least one second roll 12b, which is an auxiliary roll and at the same time a web guide roll. The rollers 12a and 12b are attached to a lever 16 articulated from a pivot point 10 17 between the axes of the rollers 12a and 12b. The distance of the pivot point 17 from the axis of the roll 12a is denoted by a reference stop Sj and the distance from the axis S2 of the roll 12b. The passage of the web P before sealing is marked with the letter Wj and the passage of the web P during sealing with the putty W2. After the sealing device, the web P passes forward through the guide roll 18. The actuator of the sealing device is denoted by the reference number 19. The actuator 19 imparts a sufficiently rapid impact on the sealing roller 12a. The speed can be limited to the desired value by a viscosity damper 20.

The position of the hinge point 17, i.e. the distances S1 and S2, are selected depending on the bending angles of the sealing roll 12a and the auxiliary roll 12b so that the length of the web in the sealing and the rollers 12a and 12b in the basic position is substantially the same. In Fig. 2, the travel of the web before the sealing 20 Wj, i.e. the distance from the point P1 to the point P2, is substantially the same as the travel of the web P in the sealing W2. Pj denotes the point of detachment of the web P from the roll 11 to be unwound, and P2 denotes the point of arrival of the web P on the guide roll 18.

In the embodiment according to Fig. 2, a compressed air bellows 25 is used as the actuator 19, which is provided with e.g. a hydraulic damper 20. Especially in large machines, e.g. large coating machines with large roll diameters, lightweight composite rolls 12a and 12b can be used as rolls. high. The web guide roll, i.e. the auxiliary roll 12b, does not necessarily have to be a composite roll, but can be e.g. a steel roll.

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In the solution according to Figure 2, it has thus been realized to increase the sealing gap from the currently used gap size by about 8 to 12 mm up to, for example, up to or even 100 mm. Furthermore, in the solution according to Figure 2, it has been possible to increase the angle of refraction without any adverse effect.

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In the solution according to Figure 3, according to the basic idea of the invention, the support wire 21 is arranged to pass through the sealing roll 12a and the auxiliary roll 12b, whereby in addition to the roll nip, a wire nip 1 is formed. Of course, in the embodiment according to Fig. 3, the support wire 21 also passes through the guide roll 18.

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In the embodiment according to Figure 3, the adhesion time of the seal is multiplied compared to the situation according to Figure 2. In addition, the adhesion of the sealing tape takes place even at low bonding pressures, because the adhesion time is sufficiently long. Thus, the invention has realized to increase the gluing time by extending the distance during which the sealing tape is under pressure.

The embodiment according to Figure 3 can be illustrated by the following practical example.

The length of the roll nip Lt is usually of the order of 20 to 30 mm. Correspondingly, the length of the wire nip L2 is generally of the order of 200 to 1000 mm. If, for example, the length of the roll nip Lj is 25 mm and the nip pressure is 100 kP, the residence time is 1 ms. If the length of the wire nip L2 is 600 mm and the pressure is 5 kP, the residence time is 24 ms. This is calculated with a wire tension of 6000 N / m, a machine roll diameter of 2.5 m and a running speed of 1500 m / min. It is immediately apparent from the example that, thanks to the solution according to the invention, the adhesion time of the sealing tape can be increased many times, i.e. in this example 24 times.

Only a preferred embodiment of the invention has been described above, and it will be clear to a person skilled in the art that numerous modifications can be made to it within the scope of the inventive idea set out in the appended claims.

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Claims (2)

1. Continuous unrolling machine, with which a new machine roll (13) is introduced into the joint, the full roll is connected to the web (P) 5. the machine roll (11) which pours to be emptied, the joint comprising a joining roller (12) , with which the web of the machine roll (11) which is inclined to be emptied is pressed onto the joint (14) of the new machine roll (13), and which joint device comprises at least one other roll (12b) and in which the joint device the joint roll (12a) and said second rolls (12b) are fixed to a lever assembly (16) which is guided from a pivot point (17) between the axes of said rollers (12a, 12b) in such a way that the web (P) of the web (P and the course of the web (P) at the joint (W2) is such that the length of the web (P) at the joint, and while said rollers (12a, 12b) are in the basic position, is essentially the same, characterized in that the supporting wire (21) ) is arranged to run through the seam roller (12a) and said second roll (12b) to form a wire type (L2), the bonding time available at the joint increasing multiply. Sealing device according to claim 1, characterized in that the length of the wire type (L2) is 200 - 2000 mm. 20