GB2217190A

GB2217190A - A cleaning device for removing deposits from rollers

Info

Publication number: GB2217190A
Application number: GB8905476A
Authority: GB
Inventors: Helmet Anstotz; Peter Mehn; Gunter Schrors
Original assignee: Eduard Kuesters Maschinenfabrik GmbH and Co KG
Current assignee: Eduard Kuesters Maschinenfabrik GmbH and Co KG
Priority date: 1988-03-25
Filing date: 1989-03-10
Publication date: 1989-10-25
Anticipated expiration: 2009-03-10
Also published as: JPH0214775A; GB8905476D0; FI891358A; DE3810085A1; FI891358A0; GB2217190B

Description

i A_ ri r) 'd PATENTS ACT 1977 Agents Ref: P5599GB-NHF/SJW/jio

DESCRIPTION OF INVENTION

A cleaning device.

THE PRESENT INVENTION relates to a cleaning device and more particularly to a cleaning device for a roller, such as is used in a paper, textile or similar processing plant.

During the processing of paper or similar materials, a coating may be applied to a web of the paper or material at a position upstream of a roller over which the material passes. If the coating is not dry when the material passes over the roller then deposits in the form of rings or blobs of ink, paint, dye or the like tend to be left on the roller, particularly at positions near the edge of the web.

In order to remove such deposits it has been previously proposed to provide a cleaning device for rollers of this type and one such cleaning device as known from DE-PS 34 28 388. This prior cleaning device comprises a scraper extending along the length of the roller and a steamspraying pipe which extends over the same length and which may be actuated in zones along its length. If rings of ink, paint, dye or the like occur on the roller they are moistened by actuating the appropriate zones of the steamstraying pipe, whereupon the scraper is subsequently engaged against the roller surface and removes the dissolved or softened ring of ink or the like.

In practice the previously proposed cleaning devices do not. completely remove the ring of ink or the like and also tend to leave a considerable amount of moisture on the surface of the roller, this being something which is often - 2 undesirable.

DE-OS 36 41 954 discloses a similar type of cleaning device except that the spray pipe in this particular disclosure is not actuated in zones.

The use of rotating cylindrical brushes for cleaning roller surfaces is known per se from DE-PS 110 811. DE-AS 14 61 123 also discloses brushes which engage rollers, although in this case the brushes are provided mainly for the purpose of preventing a torn paper web from winding around the rollers of a calender. DE-PS 172 036 distloses a rotating brush which cooperates with a 'throw-off' device, the device being used for sampling purposes. In this case the brush is dipped into a liquid dye and engages the throwoff device, which is in the form of a stationary bracket, whereupon liquid dye is thrown off the brush and is sprayed onto a passing web.

The present invention seeks to provide an improved cleaning device which provides more efficient cleaning of a roller and which leaves the roller in a dryer condition than previously proposed cleaning devices.

According to the present invention there is provided a cleaning device for removing deposits such as rings of ink or the like from the surface of a roller forming part of a paper, textile or similar processing plant, the cleaning device comprising means for moistening any deposits on the roller surface and a rotatable brush capable of being brought into engagement with the roller surface in order to remove the moistened deposits from the surface of the rotating roller, the cleaning device being further provided with an element with which the bristles of the brush engage such that material which is carried by the bristles, subsequent to having been kemoved from the surface of roller, is removed from the bristles.

i It has been found that a cylindrical brush can remove the softened material forming the ink rings or the like more efficiently, that is to say after fewer rotations of the roller, than. a scraper, which has only a single edge and which engages any one point on the roller surface only once per revolution of the roller. In contrast, the brush has a number of "scraper edges", constituted by the free ends of the bristles of the brush, the scraper edges being staggered in the peripheral direction and acting at a giving point on the roller surface during each revolution. The device which removes material from the brush, which material was previously entrained by the roller surface, also serves to remove any entrained moisture, so that the roller surface is left in a dryer condition.

Preferably the axis of rotation of the brush is substantially parallel to the axis of rotation of the roller and the brush is in the form of a cylindrical brush.

Conveniently the element with which the bristles of the brush engage comprises a brush strip mounted upon the cleaning device. A brush strip is particularly effective for removing the material carried by the bristles of the brush. Advantageously the brush strip has bristles which extend substantially radially with respect to the brush, the bristles of the brush strip engaging the periphery of the bristles of the brush.

0 Preferably the device is further provided with a nozzle for dispensing water in a direction towards the brush such that water falls upon the bristles of the brush after they have wiped the roller surface. A water dispensing nozzle assists in removing material from the bristles of the brush.

Conveniently the water nozzle directs water tangentially towards the brush at a position adjacent said element.

i Advantageously a second element is provided, with which the bristles of the brush engage, the second element serving to remove moisture from the bristles of the brush before the bristles wipe the roller surface. Thus the second element assists in drying the bristles of the brush. Preferably said second element comprises a second brush strip.

Preferably a nozzle is.provided for directing air onto the bristles of the brush after the bristles have moved past said first mentioned element. An air dispensing nozzle may be provided in addition to or as an alternative to the second element in order to help dry the bristles of the brush.

Conveniently the air nozzle directs air tangentially towards the rotating brush at a position adjacent said second element.

Preferably the means for moistening deposits on the roller surface comprises a nozzle directed towards the surface of the roller for dispensing a moistening medium onto the roller surface. The nozzle may dispense steam or a liquid, e.g. water or a water/solvent mixture, onto the deposits on the roller surface. However, if a water nozzle is provided for directihg water onto the brush, then this water supply may be controlled to effect moistening of the deposits.

Conveniently the device has a width substantially equal to the width of a region adjacent one end of the roller in which rings of ink or the like are likely to be deposited upon the roller surface. This avoids the device being of unnecessary length since the deposits are usually only found in the same relatively narrow zones of the roller surface.

The device may be movabie, in a reciprocating manner, across the width of the roller. This enables the device to 4 a 1 be moved from a zone adjacent one end of the roller surface to the zone adj ' acent the other end where deposits may be found. However, the necessary drive would be relatively expensive and cleaning can only be effected in one zone at any one time.

It is therefore preferred that the device is fixed in position relative to the longitudinal direction of the roller. A cleaning device may be provided adjacent each end of the roller.

Conveniently the device is provided with a casing, the casing defining a single opening through which the brush may engage the rolller surface when the casing has been moved to a position immediately adjacent the roller.

In previous "open" cleaning devices, such as are shown in DE-PS 3428388 and DE-OS 3641954 there is a risk that moisture and material removed from the roller surface will be spread outside the cleaning device. A substantially enclosed casing avoids this problem. Material can be withdrawn from the casing in a manner which is known, per se, from DE-AS 1461123.

Preferably the device is provided with means for monitoring the condition of the roller surface so as to detect the presence of any deposits on the roller surface, the monitoring means serving to actuate the cleaning device upon detecting deposits on the roller surface.

The present invention also provides a cleaning device for removing deposits such as rings of ink or the like from the surface of a roller forming part of a paper, textile or i similar processing plant, the cleaning device being provided with means for monitoring the. condition of the roller surface so as to detect the presence of any deposits on the roller surface, the monitoring means serving to actuate the cleaning device upon detecting deposits on the roller surface.

The monitoring means may comprise an optical sensor, in the form of a reflected-light scanner.

The sensor may be movable, in a reciprocating manner, so as to scan the surface of the roller in the region in which rings of ink or the like are likely to be deposited upon the roller surface.

Preferably the monitoring means serve to actuate the cleaning device f-or a predetermined period of time upon the detection of deposits on the roller surface.

The invention further provides a roller for a paper, textile or similar processing plant, when provided with a cleaning device in accordance with any one of the preceding claims.

In order that the present invention may be more readily understood and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a schematic side view of a cleaning device in accordance with the present invention; and FIGURE 2 is a plan view of a roller provided with two cleaning devices as shown in Figure 1.

Referring to the accon.panying drawings, a roller 1 is rotatably mounted by way of trunnions 2, for rotation in the direction of arrow 3. A web of material such as a paper web (not shown in the drawings) is coated on one side with a coating material which is subsequently dried before the web of material Passes over the roller 1. However, it is often the case that the coating applied near the edge of the web is somewhat thicker than the coating applied to the central region of the web and as a result the coating near the edges of the web cannot be fully dried by the drying device provided. If the coated side of the web passes over the roller then some of the still damp coating substance, such as ink, paint or the like, will stick to the outer surface of the roller.

In Figure 2 of the drawings the edge of a web of material is denoted by the dotted line 4 and a ring of ink or the like which has been deposited upon the outer surface of the roller is denoted by the reference numeral 5.

The edges 4 of the web 1 are not always located at exactly the same position upon the roller, there being a range of displacement of the web upon the roller, with the rings of ink or the like 5 being deposited upon the roller within that range of displacement.

A respective cleaning device 10, 101 (see Figure 2) is provided at each end of the roller 1 adjacent the position in which the edge of a web of material will normally be located.

The cleaning devices 10, 101 are fixed in position relative to the longitudinal direction of the roller 1, i.e. in the transverse direction of a web which passes over the roller, each cleaning device having a width corresponding approximately to the zone at the end of the roller 1 in which rings of ink or the like 5 are likely to be deposited upon the roller. Alternatively a single device may be 4 provided which is movable across the width of the roller such that it may engage the roller surface adjacent either end of the roller.

Each cleaning device 10, 101 comprises a easing 6 which is movable towards and away from the surface of the roller'l in a substantially radial direction, as indicated by arrow 7 (see Figure 1). Thus each device may be selectively moved into engagement with the roller surface. A cylindrical brush 8 is rotatably mounted in the easing 6, for rotation in the direction of arrow 9, i.e. in the opposite direction to the direction in which the roller 1 rotates. The brush 8 is rotatable about an axis 11 which is parallel to the axis of the roller 1. Means are provided for rotating the brush 8.

The length of the cylindrical brush 8 is approximately equal to the length of zones 12 at each end of the roller where rings of ink or the like 5 are likely to be deposited. Thus, even though the easing 6 is fixed relative to the longitudinal direction of the roller, when the cleaning device is moved to engage the surface of the roller 1, it is ensured that the brush 8 will engage any rings of ink or the like 5 deposited on the end zones of the roller surface. The brush 8 engages the roller surface at a line of engagement 13.

A first brush strip 14 is mounted within the casing 6 at a point such that the bristles of the brush 8 engage the brush strip 14 after they have "wiped" the surface of the roller 1. The brush strip 14 is of the same length as the cylindrical brush 8 and has bristles which extend radially with respect to the brush 8. The brush strip 14 serves to remove material from the bristles of the brush 8. The point of engagement between the bristles of the brush 8 and the first brush strip 14 is denoted by reference numeral 15. A water nozzle 16 is mounted upon the casing 6 so as to direct In - 9 a jet of water 17 onto the point of engagement 15 between the bristles of the brush 8 and the brush strip 14, the jet of water 17 flowing in a direction opposite to the direction of rotation 9 of the brush 8 at the point of engagement 15. The jet of water 17 extends over the full length of the brush 8. The arrangement of the water jet 17 and the brush strip 14 facilitate the removal of matter adhering to the bristles of the brush 8 subsequent to having been removed from the surface of the roller 1 at the line of engagement 13. As the bristles of the brush 8 engage the brush strip 14 this matter is, in effect, thrown off the bristles of the brush 8, since the bristles are initially deformed as they engage the brush strip and subsequently return to their original condition with rapid motion which throws any matter off the bristles.

A second brush strip 18 is mounted in the easing 6 at a position such that the bristles of the brush 8 will engage the brush strip 18 subsequent to having engaged the brush strip 14. The bristles of the brush 8 engage the brush strip 18 at a point of engagement 19. The second -brush strip 18 serves primarily to remove any water left on the bristles of the brush 8. An air nozzle 20 directs a jet of air 21 towards the point of engagement 19 in order to facilitate drying the bristles of the brush 8. This particular arrangement ensures that the bristles of the brush 8 have a relatively low moisture content when acting upon the surface of the roller 1 at the line of engagement 13, thereby ensuring that the roller 1 remains fairly dry. Appropriate regulation of the air stream from the nozzle 20 enables the moisture content of the bristles of the brush 8 at the point of engagement 13 with the roller surface to be controlled to a certain degree.

The specific embodiment disclosed in the drawings also comprises a further nozzle 22 mounted in the easing 6, the nozzle 22 directing a jet of water 23 against the surface of - the roller 1 at a position immediately prior to the line of engagement 13 of the brush 8 with the surface, thereby moistening any rings of ink or the like which have been deposited on the roller surface, prior to the surface being wiped by the bri stles of the brush 8.

The easing 6 is provided with an appropriate opening through which the bristles of the brush 8 extend in order to engage the surface of the roller but is otherwise fully enclosed such that neither moisture nor material removed from the surface of the roller 1 can be sprayed into the enviroment. Any material removed from the surface of the roller 1 and any water in the easing 6 is withdrawn through an outlet 25 in the easing.

By way of example the brush 8 may be provided with polyamide bristles having a diameter of approximately 0.3 to 0.5 mm. The length of the brush 8 may be approximately 90 mm and the diameter of the brush may be of the order of 150 to 170 mm. The bristles of the brush strips 14, 18 may have a length of approximately 25 to 30 mm and be somewhat stiffer than the bristles of the brush 8, having a diameter of the order of 0.7 to 0.8 mm. If the roller 1 rotates at speeds in the range of 600 to 800 rpm, the brush 8 may rotate at speeds in the range of 50 to 200 rpm.

It has previously been necessary for the operator of a system incorporating rollers of the type presently under consideration to constantly monitor the system in order to cheek whether any rings of ink or the like have been deposited on the surface of the roller.

In order to relieve the operator from this task, the present invention incorporates an automated arrangement for detecting the presence of rings of ink or the like on the surface of the roller 1 arrd for actuating the cleaning device in response to a signal generated upon detection of i k 1 il - matter deposited on the surface of the roller.

When rings of ink or the like are deposited upon the roller surface they are relatively dull in colour and differ markedly in reflectivity from the smooth adjacent roller surface. The roller surface is monitored by means of optical sensors in the form of reflected-light scanners 26 which direct a beam of light 27 onto the.roller surface and measure the intensity of the reflected light.

As mentioned above the rings of ink or the like are not always deposited at exactly the same position on the roller surface but may be deposited anywhere within the zones 12 adjacent each end of the roller, the zones having a width of approximately 100 mm and corresponding to the positions at which the edge of a web being treated may be positioned. Thus, care must be taken to ensure that the monitoring device responds appropriately if a ring of ink or the like is deposited at any position within the zone 12. To this end the scanners 26 are movable in the longitudinal direction of the roller 1 within the zones 12 adjacent each end of the roller where the rings of ink or the like are likely to be deposited. A suitable drive is provided for moving the scanners in a reciprocating manner. As an alternative, a group of reflected-light scanners or similar devices may be disposed in a side by side arrangement within the zone 12 so that the individual scanners cover the entire region in which rings of ink or the like may be deposited. However, this particular arrangement would be fairly expensive.

In use the scanners 26 constantly monitor the surface of the roller in the end regions where rings of ink or the like may be deposited and if light from a scanner 26 falls upon a ring of ink or the like 5, as shown at the left hand end of the roller 1 in Figurd 2 of the drawings, the amount of reflected light drops which causes the scanner to 1 1 k generate a signal which is transmitted via a line 28 to a control means 29 which actuates an adjusting device 30 which supplies water to the nozzles 16 and 22 via lines 31, 32 and air to the nozzle 20 via__a line 33. The adjusting device 30 also actuates a drive 34 which moves the cleaning device easing 6 towards the roller 1 such that the brush 8 engages the surface of the roller. The cylindrical brush 8 rotates such that the bristles of the brush remove deposits from the surface of the roller 1. The cleaning device is operated for a predetermined, fixed period of time before the device is moved away from the roller such that the brush no longer engages the roller surface. The cleaning device 10, 101 may, for example, by operated for a fixed period of time of between 10 and 30 seconds. The precise duration of the cleaning operation will depend on the specific embodiment of the cleaning device in individual cases and the application of the roller and can be determined empirically.

In Figure 2 of the drawings the left hand cleaning device 10 is shown in the operative position in which the brush 8 engages the roller surface in order to remove a ring of ink or the like 5, whilst the right hand cleaning device 101 remains in the inoperative position remote from the surface of the roller, since no ring of ink or the like has been detected at this end of the roller by the scanner 26.

If the ring of ink or the like has not been removed from the surface of the roller after a cleaning operation then this fact will be detected by the scanner 26 and the cleaning device will be actuated for a second time, or as many times as is required until the deposit has been removed from the roller surface.

It will be appreciated from the above description that the cleaning device is only operated when a ring of ink or the like has been detected on.the surface of the roller and thus the cleaning device is not used unnecessarily.

1,11 1 It is to be appreciated that the monitoring device incorporating optical sensors such as the scanners 26 may be provided for use with cleaning devices other than the device specifically disclosed in the present application.

It will be appreciated that various modifications and alterations may be made to the above-described embodiment without departing from the scope of the present invention.

t

Claims

7 1. A cleaning device for removing deposits such as rings of ink or the like from the surface of a roller forming part of a paper, textile or similar processing plant, the cleaning device comprising means for moistening any deposi?ts on the roller surface and a rotatable brush capable of being brought into engagement with the roller surface in order to remove the moistened deposits from the surface of the rotating roller, the cleaning device being further provided with an element with which the bristles of the brush engage such that material which is carried by the bristles, subsequent to having been removed from the surface of roller, is removed from the bristles.

2. A cleaning device according to Claim 1 wherein the axis of rotation of the brush is substantially parallel to the axis of rotation of the roller.

3. A cleaning device according to Claim 1 or Claim 2 wherein the brush is in the form of a cylindrical brush.

4. A cleaning device according to any one of Claims 1 to 3 wherein the element with which the bristles of the brush engage comprises a brush strip mounted upon the cleaning device.

5. A cleaning device according to Claim 4 wherein the brush strip has bristles which extend substantially radially with respect to the brush, the bristles of the brush strip engaging the periphery of the bristles of the brush.

6. A cleaning device according to any one of the preceding Claims wherein the device is further provided with a nozzle for dispensing water in a direction towards the brush such that water falls upon the bristles of the brush after they have wiped the roller surface.

j i t 4 k 7. A cleaning device according to Claim 6 wherein the water nozzle directs water tangentially towards the brush at a position adjacent said element.

8. A cleaning device according to any one of the preceding claims wherein a second element is provided, with which the bristles of the brush engage, the second element serving to remove moisture from the bristles of the brush before the bristles wipe the roller surface.

9. A cleaning device according to Claim 8 wherein said second element comprises a second brush strip.

10. A cleaning device according to any one of the preceding claims wherein a nozzle is provided for directing air onto the bristles of the brush after the bristles have moved past said first mentioned element.

11. A cleaning device according to Claim 10, as dependant upon Claim 8, wherein the air nozzle directs air tangentially towards the rotating brush at a position adjacent said second element.

12. A cleaning device according to any one of the preceding claims wherein the means for moistening deposits on the roller surface comprises a nozzle directed towards the surface of the roller for dispensing a moistening medium onto the roller surface.

13. A cleaning device according to any one of the preceding claims wherein the device has a width substantially equal to the width of a region adjacent one end of the roller in which rings of ink or the like are likely to be deposited upon the roller surface.

14. A cleaning device accor ding to Claim 13 wherein the device is movable, in a reciprocating manner, across the width of the roller.

15. A cleaning device according to Claim 13 wherein the device is fixed in position relative to the longitudinal direction of the roller.

16. A cleaning device according to any one of the preceding claims wherein the device is provided with a easing, the easing defining a single opening through which the brush may engage the roller surface when the easing has been moved t.o a position immediately adjacent the roller.

17. A cleaning device according to any one of the preceding claims wherein the device is provided with means for monitoring the condition of the roller surface so as to detect the presence of any deposits on the roller surface, the monitoring means serving to actuate the cleaning device upon detecting deposits on the roller surface.

18. A c-leaning device for removing deposits such as rings of ink or the like from the surface of a roller forming part of a paper, textile or similar processing plant, the cleaning device being provided with means for monitoring the condition of the roller surface so as to detect the presence of any deposits on the roller surface, the monitoring means serving to actuate the cleaning device upon detecting deposits on the roller surface.

19. A cleaning device according to Claim 17 or 18 wherein the monitoring means comprises an optical sensor.

20. A cleaning device according to Claim 19 wherein the optical sensor is in the form of a reflected-light scanner.

21. A cleaning device according to Claim 19 or 20 wherein the sensor is movable, in a eciprocating manner, so as to scan the surface of the roller in the region in which rings t k 1 1 of ink or the like are likely to be deposited upon the roller surface.

22. A cleaning device according to any one of Claims 17 to 21 wherein the monitoring means serve to actuate the cleaning device for a predetermined period of time upon the detection of deposits on the roller surface.

23. A roller for a paper, textile or similar processing plant, when provided with a cleaning device in accordance with any one of the preceding claims.

24. A cleaning device substantially as herein describedg with reference to and as shown in the accompanying drawings.

25. A roller substantially as herein described with reference to and as shown in the accompanying drawings.

26. Any novel feature or combination of features disclosed herein.

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