Apparatus and method for cutting a material web

Abstract

The invention relates to an apparatus and method for cutting a material web in a papermaking machine. The apparatus includes a cutting device, an upper holding device and an upper positioning device. The cutting device is fixed above the upper positioning device on the upper holding device such that it can be moved in the cross-machine direction. The apparatus additionally has an air guide box and the air guide box is fixed above the material web, likewise on the upper holding device. Furthermore, the apparatus has a cutting table fixed to a lower holding device via a first and/or a second lower positioning device. The cutting table is movable substantially vertically with respect to the material web via the first lower positioning device and/or movable in the cross-machine direction via the second lower positioning device.

Claims

1. A method for making paper in a paper making machine in which a paper material web can be transported with high speed in a transport direction, said method comprising cutting the paper material web moving with high speed through the papermaking machine, said cutting comprising: moving a cutting device in a cross-machine direction above the paper material web, the cutting device being movably mounted to an upper holding device arranged above the paper material web, the cutting device being movable along the upper holding device over at least a portion of a width of the paper material web; generating with the cutting device a cutting medium that, when applied to the paper material web moving with high speed, cuts the paper material web; stabilizing and preventing speed-induced oscillations in the paper material web during said cutting as the paper material web moves with high speed through the papermaking machine by means of an air guide box fixedly connected to the upper holding device, the air guide box being positioned above the paper material web, the air guide box defining a stabilization surface extending substantially parallel to the paper material web; moving a cutting table in a substantially vertical direction with respect to the paper material web and/or in the cross-machine direction independently of movement of the cutting device, the cutting table being fixed to a lower holding device positioned underneath the paper material web, the lower holding device being separate from the upper holding device along which moves the cutting device, the cutting table being movable via the lower holding device between parking and operating positions separately from the cutting device.

2. A method according to claim 1, further comprising synchronizing the movements of the cutting table and the cutting device in the cross-machine direction.

3. A method according to claim 2, including receiving position signals indicative of position information for the cutting device and/or the cutting table and, on a basis of the position signals, moving at least one of the cutting device and the cutting table to match movements and/or positions of the cutting device and the cutting table in the cross-machine direction.

4. A method according to claim 1, further comprising: aligning and activating the cutting device such that a longitudinal cut edge is produced proximate to an edge of the paper material web; aligning and activating a knock-off medium nozzle arranged downstream from the cutting device, such that an area of the paper material web between the longitudinal cut edge and the edge of the paper material web that is close to the longitudinal cut edge tears off transversely and this area forms the start of an edge strip.

5. A method according to claim 1, further characterized in that during said cutting, a distance between the paper material web and said air guide box is smaller than that between the cutting device and the paper material web.

6. A papermaking machine in which a paper material web can be transported with high speed in a transport direction, said papermaking machine comprising: an apparatus for cutting the paper material web moving with high speed through the papermaking machine, said apparatus including: a) an upper holding device arranged in a cross-machine direction above the material web; b) an upper positioning device movably mounted to said upper holding device, said upper positioning device movable along said upper holding device in the cross-machine direction over at least a portion of a width of the material web; c) a cutting device for cutting the paper material web moving with high speed, said cutting device mounted to said upper positioning device, whereby said cutting device is fixed on said upper holding device and moves with said upper positioning device along said upper holding device over the material web, said cutting device operative to generate a cutting medium that, when applied to the material web, cuts the material web; d) an air guide box mounted to an underside of said upper holding device such that said air guide box is positioned below said upper positioning device and above the paper material web, said air guide box defining a stabilization surface extending substantially parallel to the paper material web, said stabilization surface stabilizing and preventing speed-induced oscillations in a portion of the paper material web passing underneath said air guide box as the paper material web moves with high speed through the papermaking machine; e) a cutting table; f) a lower holding device positioned underneath the paper material web, said lower holding device being separate from said upper holding device on which is fixed said cutting device; g) at least one of a first lower positioning device and a second lower positioning device, said cutting table being fixed to said lower holding device via said at least one of said first lower positioning device and said second lower positioning device, said cutting table being movable substantially vertically with respect to the paper material web via said first lower positioning device and/or being movable in the cross-machine direction via said second lower positioning device; wherein each of said first and second lower positioning devices is operative to move said cutting table independently of said cutting device, such that said cutting table is movable between parking and operating positions separately from said cutting device.

7. A papermaking machine according to claim 6, wherein said air guide box includes a cutout, through which a cutting medium can be led from the cutting device to the paper material web.

8. A papermaking machine according to claim 6, wherein said apparatus further comprises synchronizing means for the synchronization of movements of the cutting device and of said cutting table in the cross-machine direction.

9. A papermaking machine according to claim 8, wherein each of said upper positioning device and said second lower positioning device is adapted to generate respective position signals, said synchronizing means receiving said position signals and, on a basis of said position signals, activating at least one of said upper positioning device and said second lower positioning device to match movements and/or positions of the cutting device and said cutting table in the cross-machine direction.

10. A papermaking machine according to claim 6, wherein said cutting device further comprises at least one knock-off medium nozzle arranged downstream from the cutting device.

11. A papermaking machine according to claim 6, wherein at least one of the upper holding device above the paper material web and the lower holding device underneath the paper material web is fixed in the cross-machine direction with both ends on vertical pillars located beside the papermaking machine.

12. A papermaking machine according to claim 6, wherein a distance between the paper material web and said air guide box is smaller than that between the cutting device and the paper material web.

Description

(1) The invention is now to be illustrated further by way of example by using drawings, in which:

(2) FIG. 1 shows a side view of an apparatus according to the invention having a cutting device and an air guide box which are both fixed to an upper holding device above a paper web,

(3) FIG. 2 shows a plan view of the apparatus according to FIG. 1,

(4) FIG. 3 shows a side view of an apparatus according to the invention, the apparatus additionally having another upper positioning device, a knock-off medium nozzle and a cutout in the air guide box,

(5) FIG. 4 shows a plan view of the apparatus according to FIG. 3,

(6) FIG. 5 shows a plan view of a similar apparatus according to FIG. 4, the cutout being an elongated hole,

(7) FIG. 6 shows a side view of an apparatus according to the invention additionally comprising a cutting table that can be moved vertically,

(8) FIG. 7 shows a perspective illustration of an apparatus according to the invention, additionally comprising synchronizing means,

(9) FIG. 8 shows a perspective view of an apparatus according to the invention together with a machine component of the papermaking installation which no longer collides with the apparatus according to the invention.

(10) FIG. 1 shows a side view of an apparatus 1 according to the invention having a cutting device 20 and an air guide box 40, which are both fixed 10 to an upper holding device 30 above a paper web. The air guide box 40 is welded to the underside of the holding device 30 via a region on the upper side of said air guide box, close to the transverse edge of the air guide box 40. The holding device 30 is a supporting beam which is stretched transversely over the material web. Via an upper positioning device 31, the cutting device 20 is arranged on the vertical transverse side of the supporting beam 30 such that it can be moved. The positioning device 31 has a holder, which reaches into the interior of the supporting beam 30 and can be moved there. The cutting device 20 is screwed firmly to the holder. The material web 10 runs just underneath the stabilization surface of the air guide box 40. Placed downstream is a spool, onto which the material web 10 can be wound after the apparatus 1. Air guide box 40, holding device 30 and the cutting device 20 fixed to the holding device 30 such that it can be moved by the positioning device 31 form a structural unit that can be installed.

(11) During operation of the apparatus 1, the material web 10 is wound onto the spool. It runs through the area of the papermaking machine spanned by the air guide box 40 and is stabilized by the air guide box 40. The cutting device 20 has been fixed directly to the holding device 30 via an upper positioning device 31 and the air guide box 40. The cutting device 20 produces a high-pressure jet of a cutting medium 22 and, just after the end of the air guide box 40, blasts the jet onto the material web 10. There, the cutting medium 22, together with the movement of the material web 10, effects a longitudinal cut edge (not shown here) starting from the cutting point 21. Here, the severing of an edge strip 11 is carried out. This apparatus 1 permits clean cut edges or cuts through cutting the material web 10, despite restricted space. This becomes possible as a result of the combining of the air guide box 40 and a cutting device 20 to form one component having a common holding apparatus 30. Thus, a cut can be carried out close to an air guide box 40 in a space restricted by the air guide box 40.

(12) FIG. 2 shows a plan view of the apparatus 1 according to FIG. 1. In this example, the cutting device 20 can be moved in the cross-machine direction (indicated here by a double arrow) over the entire width of the material web 10 along the supporting beam 30. On the material web 10, which runs in upstream of the air guide box 40, a dotted line indicates the future longitudinal cut edge 12 and the edge strip 11 produced in the future at the web edge 14.

(13) FIG. 3 shows a side view of an apparatus 1 according to the invention, the apparatus additionally having another upper positioning device 31, a knock-off medium nozzle 26 and a cutout 45 in the air guide box 40. In addition, triangular ribs are shown as fixing means 32. The air guide box 40 is screwed to the holding device 30 via the fixing ribs 32 and also directly. The positioning device 31 has, on the vertical side of the holding device 30, an upper and a lower rail 31.1, in which a holder for a cutting device 20 is held such that it can be moved in the transverse direction. A knock-off medium nozzle 26 is additionally mounted on the cutting device 20 via a further holder.

(14) During operation of the apparatus 1, the cutting device 20 blasts a cutting medium 22 through the cutout 45 onto the material web 10. The knock-off medium nozzle 26 is activated and a knock-off medium jet 27 tears the start of the edge strip 11 abruptly off the material web 10.

(15) As a result of the fixing ribs 32, the fixing of the air guide box 40 is still more stable. Since the cutting device 20 is if possible arranged at a transverse end of the air guide box 40, the air guide box 40 is not fixed to the holding device 30 at its center. By means of the fixing ribs 32, therefore, the relatively large area of the air guide box 40 which is further removed from the holding device 30 is better stabilized. By means of the knock-off medium nozzle 26, it is possible to arrange for the cut into the material web 10 by the cutting medium 22 to begin only within the web edge 14. As a result of the knocking off, an additional transverse cut edge or transverse tearing edge is produced, which extends from the web edge 14 as far as the longitudinal cut edge 12.

(16) FIG. 4 shows a plan view of the apparatus 1 according to FIG. 4. This illustration makes it clear that the cutout 45 in this case represents a rectangular cutout 45 in the downstream corner region of the air guide box 40. The knock-off medium nozzle 26 is fixed to the cleaning device 20 via a holder, slightly offset with respect to the cleaning device 20, and can be moved together with the latter in the transverse direction. The apparatus additionally has a plurality of fixing ribs 32, which are distributed uniformly along the supporting beam 30.

(17) During operation of the apparatus 1, the cutting device 20 is moved in the transverse direction together with the knock-off medium nozzle 26 in the region of the cutout 45. From the parking position, which is wholly outside on the supporting beam 30, the cutting device is moved to the position which, in the cross-machine direction, is located at the level of the future longitudinal cut edge 12. After reaching this position, the cutting device 20 is activated, so that the latter blasts a cutting medium 22 onto the material web 10. The point of the first incision into the material web 10 then moves in the transport direction (indicated by the contour arrow) toward the knock-off medium nozzle 26. The latter is then activated as soon as the first incision point passes/has passed the point of impingement of the knock-off medium 27 and a transverse tearing edge is produced by the knock-off medium 27. The air guide box 40 stabilizes the material web 10 during this, and bulges which could result in the transverse direction after running through the air guide box 40 are also not in the area of the cutting device 20, since the latter is located upstream of the transverse edge of the air guide box 40 on account of the cutout 45. The area of the cutout 45, as compared with the stabilization surface of the air guide box 40 in the transverse direction, is so small that bulging of the material web 10 in the area of the cutout 45 does not take place or is not very pronounced.

(18) FIG. 5 shows a plan view of a similar apparatus 1 according to FIG. 4, the cutout being an elongated hole. In addition, two optional (shown dashed) knock-off medium nozzles 26 can be moved together in the cross-machine direction via a carriage 31.2, together with the cutting device 20, by the positioning device 31. Furthermore, there is a second optional cutout 45, which is likewise an elongated hole, it being possible for the knock-off medium 27 to be led through this second cutout 45.

(19) During operation of the apparatus 1, the cutting medium 22 blasts through the elongated cutout 45. If, in addition, there are knock-off medium nozzles 26, these blast the knock-off medium through the second elongated hole 45 that is present, in order to knock the edge strip 11 off the material web 10.

(20) In this way, the material web 10 is stabilized even better, since the air guide box 40 is pierced by cutouts 45 in still smaller areas.

(21) FIG. 6 shows a side view of an apparatus 1 according to the invention additionally comprising a cutting table 23 that can be moved vertically. The cutting table 23 has a surface which can be brought up close to the material web 10. In addition, it has an inclined surface 24 and a discharge channel 25 for the edge strip 11 (indicated dashed). Via a first lower positioning device 51, it can be moved vertically up to the material web 10. The positioning device 51 connects the cutting table 23 to a lower holding apparatus 50. The lower holding device 50 is a supporting beam, which is arranged transversely underneath the material web 10.

(22) During operation of the apparatus 1, the cutting table 23 is brought up from below from a position far below the material web 10 until it is close to the material web 10. During the cutting, the surface of the cutting table 23 supports the material web 10. Air carried along with the material web (dashed arrows) is deflected away from the material web 10 by the inclined surface 24. The edge strip 11 is intercepted and led away via the channel 25 integrated into the cutting table 23. After the cutting operation, the cutting table 23 is moved into a parking position once more, so that the latter does not represent any obstacle to other operations or machine components.

(23) In this way, the cutting table 23 can thus be cleared very flexibly out of the way again when it is not needed. The inclined surface 24 improves the stabilization of the material web 10 by the cutting table 23.

(24) FIG. 7 shows a perspective illustration of an apparatus 1 according to the invention, additionally comprising synchronizing means 60. In this example, the synchronizing means 60 comprise, inter alia, a shaft 60.1 (indicated by a dashed line), which is mounted in both holding devices 30 and 50 such that it can be rotated. In case the holding devices 30 and 50 are displaced with respect to each other, the shaft 60.1 has at least one universal joint in between. Within the holding devices 30 and 50 there are arranged, for example, universal joints, gear mechanisms, or a deflection roller of a rope and pulley system firmly connected to the shaft 60.1 in rotation, none of which is visible, and which transmit the movement of the shaft 60.1 in each case to the positioning devices 31 and 52. The cutting table 23 is arranged on the lower holding device 50 such that it can be moved in the transverse direction via the second lower positioning device 52. The lower second positioning device 52 has a rail/carriage system (52.1, 52.2) and can be actuated via an actuating motor 52.3. The actuating motor 52.3 displaces the carriage 52.2 in the transverse direction on the rails 52.1. In this example, the cutout 45 is a rectangular cutout 45 in the corner region of the air guide box 40. In addition, by means of a round metal 46, the transverse edge of the air guide box 40 in the region of the cutout 45 is lengthened. At the right-hand edge of the graphic, a further apparatus 1 according to the invention is fitted to the upper transverse beam 30 via a further upper positioning device 31, as illustrated as a detail. This is set up for a central cut of the material web 10. Also arranged underneath is a further cutting table (not to be seen), which has no chute 25 however, since no edge strip 11 has to be led away there. It can be moved vertically and in the transverse direction via the lower positioning devices 51 and 52.

(25) During operation of the apparatus 1, the knock-off medium nozzles 26 produce conical jets of the knock-off medium 27 at the start of the cutting process. The edge strip 11 then falls into the chute 25. However, in this image, the cutting table 23 is in the parking position. The actuating motor 52.3 is activated, by which means the cutting table 23 is moved along the lower holding device 50. Via the shaft 60.1, the rotational movement of the actuating motor 52.3 is transmitted to the upper positioning device 31, which means that the carriage 31.2 and therefore also the cutting device 20 are moved synchronously with the cutting table 23.

(26) By means of the synchronizing means 60, the position of the cutting table 23 in the transverse direction is kept in the same position as the cutting device 20. As a result, optimal assistance of the cutting operation by the cutting table 23 is possible. As a result of lengthening the transverse edge of the air guide box 40 via the round metal 46, bulging of the material web 10 after passing through the air guide box 40 is suppressed still further in the area of the cutout 45. By means of the conical jets of the knock-off medium 27, an edge strip 11 can be knocked effectively off the material web.

(27) FIG. 8 shows a perspective illustration of an apparatus 1 according to the invention together with a machine component 80 of the papermaking machine, which then no longer collides with the apparatus 1 according to the invention. In addition, a vertical pillar 70 is shown, to which both the upper holding device 30 and the lower holding device 50 are screwed. The machine component 80 in this case is a C-shaped or U-shaped channel for threading in the material web 10.

(28) During operation of the apparatus 1, the cutting table is moved from the parking position (as shown) around the machine component 80 via a vertical and horizontal movement into the operating position directly underneath the air guide box 40.

(29) In this graphic, advantages of this invention become clear. The fact that the cutting device 20 and the air guide box 40 are fitted to the same holding device 30 means that, in this restricted space in the direct vicinity of the air guide box 40, a cut in the material web 10 can be made by the cutting device 20. In addition, as a result of the mobility of the cutting table 23 and on account of the arrangement of the cutting table 23 separately from the cutting device 20, on the lower holding device 50, high flexibility of the cutting table 23 is made possible. The latter can therefore be moved around machine components 80 from a parking position into an operating position. Therefore, considerable flexibility is achieved despite the restricted space. The vertical pillar 70 in this example would, for example, stop it being possible to move to a parking position at the side of the papermaking machine. By using the apparatus 1 according to the invention, firstly the cutting device 20 can be moved into a suitable parking position and, secondly, the cutting table 23 can be moved into another suitable parking position.

(30) By means of this invention, for the first time an apparatus for cutting a material web has been proposed which can be incorporated in an existing papermaking installation without any obstruction of other machine components by this apparatus, or vice versa, taking place. It is distinguished, inter alia, by the combination of an air guide box and a cutting device, which is additionally space-saving. The joint fitting of these components to an upper holding device permits mounting in the most restricted space in the papermaking machine and, at the same time, the apparatus has the advantage that, on account of the compact combination of cutting device and air guide box, the cutting of the material web is now carried out in an area of the material web close to the air guide box, which stabilizes the material web. A cutout in the air guide box permits further displacement of the cutting point into an area of the material web which is even better stabilized, which means that extremely exact cuts are possible. The flexibility and intelligent use of restricted space in the papermaking machine is additionally or alternatively improved further by a cutting table arranged separately from the cutting device. In this way, the cutting table, which can be moved vertically and/or in the cross-machine direction, can be moved around other machine components. Nevertheless, by means of the cutting table, which can be brought up from below close to the material web and the cutting point, optimal supporting and stabilizing of the material web is carried out. In addition, respectively different parking positions can be defined for the cutting device and the cutting table. Via positioning devices, both the cutting device and the cutting table can be moved flexibly for different cutting contours and cutting types. As a result of synchronizing the movements in the cross-machine direction, perfect coordination of the cutting table and the cutting device with each other is possible, which means that the table supports the cutting operation optimally in any position with respect to the cross-machine direction. The mobility of the cutting table in the vertical direction additionally permits the stabilizing action of the cutting table to be adapted individually via the distance of the cutting table from the material web.

DESIGNATIONS

(31) TABLE-US-00001 1 Apparatus for cutting a material web 10 Material web 11 Edge strip 12 Longitudinal cut edge 14 Web edge 20 Cutting device 21 Cutting point 22 Cutting medium, high-pressure water jet or laser beam 23 Cutting table 24 Inclined surface 25 Chute/discharge channel 26 Knock-off medium nozzle 27 Knock-off medium 30 Upper holding device 31 Upper positioning device 31.1 Rail 31.2 Carriage 32 Fixing means 40 Air guide box 45 Cutout 46 Round metal 50 Lower holding device 51 First lower positioning device 52 Second lower positioning device 52.1 Rail 52.2 Carriage 52.3 Actuating motor 60 Synchronizing means 60.1 Shaft 70 Vertical pillar 80 Machine component