FI89683C - ADJUSTMENT OF ORGANIZATION OF BANNING MATERIALS - Google Patents

Description

89683! Method and apparatus for adjusting the coating width of web material I Förfarande och anordning för regiering av bestrykningsbredden av banmaterial 5

The invention relates to a method for adjusting the coating width of a web material in a coating film press, in which a web to be coated, such as a paper or board web i or the like, is passed through a nip formed by the press rolls. said films are transferred to the track in the roll nip and the part of the film exceeding the track width is scraped from the surface of the rolls with edge scrapers before the roll nip.

The invention also relates to a device for adjusting the coating width in a coating material film-15 press comprising a nip formed by rolls through which a web to be coated, such as a paper or board web or the like, is passed. tracked to move to the web, as well as edge scrapers on either side of the web to scrape the portion of the films over the web width from the surface of the rolls 20 before the roll nip.

The web material such as paper, board, and the like is generally coated with a film-type press-type device comprising opposing press rolls that form a nip with each other through which the web to be coated is arranged to pass. The coating agent is applied to the surface of the press rolls by a suitable coating device, such as a short residence type coating device, and from the surface of the rollers by a coating agent. ·: They pass into the web material as it passes through the nip formed by the rollers. Coating equipment. the width of the coating film to be applied to the surface of the rolls is usually limited by the edge seals in the coating device itself. Normally, the width of the film determined by the coating device 30 is slightly larger than the width of the web material, because otherwise the edges of the web material would remain uncoated. Because the width of the film is ‘- greater than the width of the web material itself, the coating film causes spattering upon contact with the nip formed by the rollers 3 9 68 3 2. With the ever-increasing speeds of machines nowadays, splashing of the coating material has become even more problematic. As a result, in devices of the type described above, the so-called edge scrapers that scrape off the coating film 5 from the surface of the roll over the width of the web material. However, when the speed of the machines is increased, the track does not always stay in the same place in the transverse direction, but the track starts to "live", i.e. to move back and forth in the transverse direction. As a result, there is a need to adjust the edge scrapers in the transverse direction of the track. In the prior art devices, the adjustment of the edge scrapers has been very complicated and cumbersome and has generally been carried out only manually. Thus, the current equipment has not been able to eliminate the harmful splashing of the coating material.

It is an object of the present invention to provide a method and apparatus which provide a significant improvement over the prior art solutions and which substantially completely prevent the splashing of the coating material. To achieve this, the method according to the invention is mainly characterized in that the method measures the position of the track edges before the roll nip and transmits a control signal corresponding to the measurement information to the scraper adjusters to move the scrapers substantially to the position required by the track edges to scrape off excess coating material from the roll surface.

The device according to the invention is in turn mainly characterized in that the device comprises sensors measuring the position of the track edges before the roll nip and that the scrapers are transversely displaceable and are provided with adjusting devices adapted to move off the surface of the rollers before it gets into the nip.

The most significant advantage of the invention over the prior art solutions is precisely that the splashing of the coating material on the press nip can be avoided. Another essential advantage is that the use of the invention makes the life of the press rolls longer than 3,889,683 previously, because when using the invention the edge scraper is not always against the roll at the same point, but the scraper moves all the time. Film press rolls are usually rolls with a soft surface, so if the edge scraper stays in the same place in the transverse direction at all times, the edge scraper blade makes a groove on the surface of the soft roll. In the invention 5, this groove formation is avoided. Other advantages and features of the invention will become apparent from the following detailed description of the invention.

The invention will now be described in detail with reference to the figures of the accompanying drawing.

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Figure 1 is a fully schematic side view of a film press, such as a size press, or the like, in which the method and apparatus of the invention are applied.

Fig. 2 is an enlarged detail of Fig. 1, showing in particular the coating unit and the edge scraper arranged in connection therewith.

Figure 3 is a schematic and mainly machine direction view of the second roll of the film press and the application bar and the edge scraper arranged in connection therewith.

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Thus, Fig. 1 schematically shows an adhesive press or a similar film press comprising the press rolls 1 and 2 so that the first roll 1 and the second roll 2 together form a nip N through which the web material to be coated, such as a paper or board web or the like W, is passed. In the solution according to Figure 1, the path 25 W is guided to the nip N through the guide and folding rollers 3,4. In the press, a first coating film F is applied to the surface of the first roll 1 by a coating unit 10 and a second coating film 10 is applied to the surface of the second roll 2 by a coating unit 10a, respectively. The coating material films are transferred from the surface of the rollers 1 and 2 to the web material W to be coated passing through the nip in the roll nip N.

The application beam 11 of the coating unit 10 is pivotally mounted on the press body 5 by a transverse articulation shaft 6 of the machine. The application beam 11 is further supported on the press body 5 by a load cylinder 7 by means of which the application beam 11 can be pivoted relative to the articulation shaft 6. Fig. 1 further shows measuring sensors 40 on both sides of the track W 5, which measure the position of the track edge before the track moves to the nip N. The reference numeral 41 denotes a control line for transmitting control pulses corresponding to the measurement information of the sensor 40 to the press scrapers 1 and 2 not presented.

Fig. 2 shows in more detail the coating unit 10 of the first roll 1 of the press, which in the example shown is a so-called short residence coating unit. In the coating unit 10 according to Fig. 2, a coating agent such as an adhesive, a pigment coating or the like is fed to the application zone 23 bounded by the coating member 21, the dam blade 22 and the edge seals of the coating unit 10 (not shown). In the embodiment according to Fig. 2, the coating member 21 is loaded against the surface of the roll 1 for coatings, but instead of a blade, a rod coater can also be used as a coating member in the coating unit. There is a gap between the dam blade 22 and the surface of the roll 1, through which the overflow of coating material from the application zone 23 into the collection basin (not shown) is tracked. The coating member 21 is mounted and attached to the blade holder 24 in a conventional manner 20. Behind the coating member 21, a profile strip 25 is traced, which rests directly on the rear surface of the coating member 21. In the embodiment of Figure 2, the profile strip 25 is fixed, but a conventional load hose or similar structure can also be used instead. Attached to the applicator beam 11 are adjusting spindles 26, which are numbered at regular intervals in the cross-machine direction. For each adjusting spindle 26, spindle motors 27 are mounted on the applicator beam 11. In the exemplary embodiment of Fig. 2, the adjusting spindles 26 are fixed to the profile strip 25 by pulling and / or pushing said adjusting spindles 26 so as to bend the profile strip 25 as desired. By thus bending the profile strip 25, the coating member 21 and thus the coating material film 30 to be applied to the surface of the roll 1 can be profiled in a manner known per se.

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Fig. 2 also schematically shows an edge scraper 30 arranged in connection with the coating unit 10, which is normally arranged in the direction of rotation of the roll 1 after the coating unit 10. The edge scraper 30 is normally provided with a scraper blade 31 resting on the surface of the roll 1 and loaded, and the edge scraper 30 is mounted on its own frame structures 5, such as a frame guide 32, which may be known or at least connected to an application beam 11. Figure 2 shows only one edge scraper 30. it is of course clear that said edge scrapers 30 are located on both sides of the track W in the region of each end of the roll 1.

Figure 3 shows a mainly machine direction view of a device arrangement according to the invention. Figure 3 shows an arrangement in the region of the second end of the first roll of the film press. Reference number 1 is used for said roll, and reference number 11 denotes an application bar. According to Fig. 3, while the machine is running, the coating unit applies a coating film F to the surface of the roll 1, which in the nip 15 (not shown) between the press rolls passes through the nip through the nip W. The edge seals of the coating unit (not shown) determine the width of the film F the edge F of the film F coming to the roll 1 is denoted by G. The edge of the track W is correspondingly denoted by E. According to Fig. 3, the width of the film F is larger than the width W of the track. Thus, an area of the reference mark a 20 of film F remains on the surface of the roll 1, which does not adhere to the web W, but which should therefore be allowed to be scraped off the surface of the roll 1. Figure 3 shows the area a to be scraped as a rather narrow zone, but in several cases it is quite large in width. As already described above, the edge E of the track W does not remain at the same point in the transverse direction of the machine at all times during the run, but the track W can "live" during the run for various reasons. Therefore, there is a need to have the position of the edge scrapers 30 adjusted accordingly in the cross-machine direction.

In the invention, the adjustment of the edge scrapers 30 is implemented as already stated in connection with Fig. 1, before the track W enters the nip N, the position 30 of the track edge E on both sides of the track is measured with measuring sensors 40, which are e.g. infrared sensors. According to Fig. 3, the edge scrapers 30 are displaceably mounted in the transverse direction «9683 6, e.g. on trusses 32 or the like, and further the edge scrapers 30 are provided with an adjusting device 33, e.g. a stepper motor, with which the edge scraper 30 can be adjusted transversely. Thus, during the operation of the machine, the measuring sensors 40 provide a control pulse corresponding to the measurement information along the control line 41 to the edge scraper 30 adjusting device 33 on the same side 5 to move the edge scraper 30 to the position corresponding to the edge E of the track. The arrangement according to the invention thus makes it possible to keep the edge scraper 30 at all times substantially at the position required by the edge E of the track W, whereby splashing in the roll nip N can be eliminated. In the event of possible rapid changes in the track width, a control signal is obtained quickly enough for a change of position. The edge scrapers 30 thus move in the transverse direction of the machine as the machine is constantly running as required by changes in track width.

The invention has been described above by way of example with reference to the examples shown in the figures of the accompanying drawing. However, the invention is not limited to the examples shown in the figures, but the various embodiments of the invention may vary within the scope of the inventive idea defined in the appended claims.

Claims (7)

A method of controlling the coating width of the web material in a coating press film, wherein the web (W) to be coated, such as a paper or cardboard web or equivalent, is set to run through a nip (N) formed by the press rolls ( 1,2), extending over the surface of the rollers (1,2) in the press films (F) of coating material at least partially over a width greater than the web width with coating units (10, 10a) in such manner, said films ( F) is transferred to the web (W) in the roll nip (N) and the portion that likes to be cut across the web width of the film (F) is scraped from the surface of the rollers (1,2) with edge cutters (30) before the roll nip (N). characterized in that, in the method, the position on the edges (E) is measured by the web (W) before the roll nip (N) and the control signal corresponding to the measurement data is conveyed to the control devices (33) for the edge blades (30) for transfer of the edge blades (30). in a position that is essentially assumed by edge the web (W) on the web (W) to scrape off extra coating material from the surface of the rollers (1,2) before it enters the nip (N). Method according to claim 1, characterized in that the edge blades (30) of each roller (1,2) of the press, which are on the same side of the web (W), are controlled in the transverse direction in substantially the same position according to a control pulse obtained from the same 20 sensors (40). Method according to claim 1 or 2, characterized in that the position on the edges (E) of the web (W) is measured with light cells, advantageously infrared light cells. Apparatus for carrying out the method according to any preceding claim for controlling the width of the coating in a coating press film comprising a nip (N) formed by rollers (1,2), through which the nip web (W) is to be coated. such as a paper or cardboard web or the like, set to run, which rolls (1,2) are provided with coating units (10, 10a) for spreading films (F) of coating material over the surface of the rollers (1.2). ), from which said films (F) have been arranged in the roll nip (N) to be transferred to the web (W) and with edge cutters (30) on both sides of the web (W) to scrape off that part of the film (F) extending beyond the web width away from the surface of the rolls (1,2) before the roll nip (N), characterized in that the device comprises sensors (40) measuring the position on the edges (E) of the web (W) before the roll nip (N). ) and that the edge blades (30) can be transmitted in the transverse direction of the machine and are provided with control means (33) arranged to move the edge blades (30) in the transverse direction of the machine during the threading of the machine to a position required by control signals given by the measuring sensors (40) to scrape off excess coating material from the surface of the rollers (1). , 2) before it gets into the nip (N). Device according to claim 4, characterized in that the edge blades (30) are mounted in a transferable manner in transverse lines (32) in the machine. Device according to claim 4 or 5, characterized in that said control devices (33) comprise stepper motors. 15 Device according to any of claims 4-6, characterized in that said measuring sensor (40) comprises light cells, advantageously infrared light cells.