Apparatus and method for removing ink from an ink-covered side of a printed band of flexible material

Abstract

An apparatus (1) for removing ink from an ink-covered side of a printed band (10) of flexible material, the apparatus (1) comprises - a band infeed (3); - a band outfeed (5); - a number of guide rollers (20) and at least one smear unit (30) defining a band path (4) from the band infeed (3) to the band outfeed (5), - at least one liquid application section (40) upstream to the at least one smear unit (30), the at least one liquid application section (40) comprising one or more liquid ap- plicators (41) for providing a liquid to an ink-covered side (12); - at least one scraper (50) downstream to the at least one smear unit (30), the least one scraper (50) adapted for engaging the ink-covered side (12) during use for removal of ink; wherein the at least one smear unit (30) comprising a smear surface (32) for smearing ink and liquid together, and the band path (4) is such that the band (10), during use, at least engages a circle arc (34) of the smear unit (30), the circle arc being at least 15 degrees, and wherein the smear surface (32) of the at least one smear unit (30) being configured, during use, to displace with a displacement velocity different than a band velocity.

Description

[0001] APPARATUS AND METHOD FOR REMOVING INK FROM AN INK-COVERED SIDE OF A PRINTED BAND OF FLEXIBLE MATERIAL

[0002] Field of the Invention

[0003] The present invention relates to an apparatus and a method for removing ink from an ink-covered side of a printed band of flexible material, thereby enabling reuse of the band of flexible material.

[0004] Background of the Invention

[0005] In the printing industry there is a growing focus on reusing bands of flexible material for printing.

[0006] EP 3 241 687 suggests a system wherein the band of flexible material is immersed in a cleaning liquid, wherein several pairs of rollers are pressed together with the band in-between for the purpose of removing ink while being submerged. This solution requires a large amount of liquid and both sides of the band is treated with the cleaning liquid which is not needed as only one side has ink and this increases the risk of residues of cleaning liquid which will have a negative affect on the next printing action of the band of flexible material.

[0007] Thus, there is a need for an apparatus capable of cleaning the band of flexible material without submersing the entire band into a cleaning liquid.

[0008] Object of the Invention

[0009] One objective of the present disclosure is to achieve an improved apparatus and process for removing ink from an ink-covered side of a printed band of flexible material, wherein the process is able to efficiently remove all ink from the ink-covered side.

[0010] A further objective of the present disclosure is to achieve a compact apparatus for removing ink from the ink-covered side of the printed band.

[0011] A further objective of the present disclosure is to achieve an apparatus wherein the use of cleaning liquids is more efficient so that less cleaning liquids are required.

[0012] Description of the Invention

[0013] One objective of the invention is achieved by an apparatus removing ink from an ink- covered side of a printed band of flexible material, the apparatus comprises

[0014] - a band infeed; - a band outfeed;

[0015] - a number of guide rollers and at least one smear unit defining a band path from the band infeed to the band outfeed,

[0016] - at least one liquid application section upstream to the at least one smear unit, the at least one liquid application section comprising one or more liquid applicators for providing a liquid to an ink-covered side;

[0017] - at least one scraper downstream to the at least one smear unit, the least one scraper adapted for engaging the ink-covered side during use for removal of ink; wherein the at least one smear unit comprising a smear surface for smearing ink and liquid together, and the band path is such that the band, during use, at least engages a circle arc of the smear unit, the circle arc being at least 15 degrees, and wherein the smear surface of the at least one smear unit being configured, during use, to displace with a displacement velocity different than a band velocity.

[0018] The printed band of flexible material comprises an ink-covered side and the apparatus is provided to remove and / or clean the ink from the ink-covered side. The printed band further comprises a back side opposite to the ink-covered side. In most cases, the back side is clean and / or free from ink, however the apparatus could clean both sides by performing a treatment on each side band by flipping the band after the side is cleaned.

[0019] The upstream direction is defined in the direction from the outfeed to the infeed and the downstream direction is defined in the direction from the infeed to the outfeed.

[0020] The band velocity is the speed at which the printed band moves through the apparatus. The printed band may be pulled by mechanical means arranged external to the apparatus and / or internal of the apparatus. The mechanical means may be motor driven rollers, and / or some of the guide rollers may be motor driven, and / or the mechanical means may be one or more nip rollers arranged internally or externally of the apparatus.

[0021] A number of guide rollers are arranged and configured to turn the printed band of flexible material so that the ink-covered side faces the one or more liquid application sections; the smear unit; and the scraper. Hence, the guide rollers may be placed in-between the liquid application sections, smear units, and / or the scraper, e.g. in an alternating manner. The guide rollers engage a side of the printed band along a circular arc. The guide rollers are required to enable a compact design of the apparatus, as otherwise the band path would have to follow a straight line. E.g., by arranging guide rollers in-between the liquid application sections, smear units, and / or the scraper, the same articles may be arranged in a stacked manner, e.g., along a vertical line.

[0022] Furthermore, the one or more guide rollers are arranged to ensure that the band at least engages a smear surface of the smear unit along a circle arc.

[0023] The one or more liquid application sections may be a nozzle section comprising an array of nozzles for providing a spray of liquid to the ink-covered side of the printed band. The spray of liquid may comprise water, and / or a cleaning solvent and / or solution, and / or a disinfectant, and / or a mixture thereof. One or more different types of liquid may be sprayed by different nozzle sections.

[0024] One effect of spraying a liquid from the one or more nozzles onto the ink-covered side of the band in the nozzle section is that the process of removing ink from the printed band is improved.

[0025] The one or more liquid application sections may comprise one or an array of liquid applicators, wherein the liquid applicators may be rollers and / or brushes configured for providing an application of liquid to the ink-covered side of the printed band. The applied liquid may comprise water, and / or a cleaning solvent and / or solution, and / or a disinfectant, and / or a mixture thereof. One or more different types of liquid may be applied by different liquid application sections.

[0026] One effect of applying a liquid from the one or more liquid applicators onto the ink- covered side of the band in the liquid application section is that the process of removing ink from the printed band is improved.

[0027] Furthermore, after the ink-covered side of the band has been sprayed with the liquid or have liquid applied to the ink-covered side, it is moved downstream to a smear unit which smears the liquid across the ink-covered side and thus mixes the liquid with the ink evenly across the band. This will greatly improve the removal of ink by a downstream scraper.

[0028] The smear surface may be chosen amongst a fibre surface, and / or a filament surface, and / or a brush surface, and / or a silicone surface, and / or a foam sheet. As the smear unit moves of displaces the smear surface engaging the ink-covered side of the band, the smear unit may absorb a part of the ink, part of the liquid, and / or a mixture of ink and liquid. A further advantage is achieved as the liquid absorbed by the smear unit may be reapplied from the smear unit to the ink-covered side at another location on the band, thus further ensuring that the liquid is properly applied to the ink- covered side of the band.

[0029] As the smear surface moves and the printed band downstream to the smear unit no longer engages the smear unit, the ink absorbed by the smear unit may be passively drip of the smear unit. A later embodiment discloses an active way of removing ink absorbed by the smear unit.

[0030] The one or more smear units are configured to displace the smear surface at a displacement velocity different from the band velocity, i.e. , a slower or faster velocity. In one aspect, the different smear units may displace the smear surface at a common displacement velocity or at different displacement velocities. In a further aspect, the one or more smear units may displace the smear surface in a direction opposite to the downstream direction, i.e., the opposite direction which the band moves towards.

[0031] One effect of displacing the one or more smear surfaces of the one or more smear units at a different displacement velocity than the band velocity and / or a different direction than the printed band direction is that the smearing effect of the smear unit is improved by improving the friction between the smear unit and the ink-covered side which causes greater smearing of ink and liquid, i.e., mixing of ink and liquid.

[0032] In an embodiment, the smear unit is a smear roller with a smear surface. The smear surface being attached to the cylindrical smear roller. In that embodiment, as the smear roller rotates and engages the ink-covered side of the band, the smear roller may absorb a part of the ink, the liquid and / or a mixture of ink and liquid. A further advantage is achieved as the liquid absorbed by the smear roller may be reapplied from the smear roller to the ink-covered side at another location on the band, thus further ensuring that the liquid is properly applied to the ink-covered side of the band. As the smear roller rotates and the printed band downstream to the smear roller no longer engages the smear roller, the ink absorbed by the smear roller may be drip from the smear roller. The one or more smear rollers are configured to rotate at a rotation velocity different from the band velocity, i.e., a slower or faster velocity. In one aspect, the different smear rollers may rotate at the same rotation velocity or a different rotation velocity. In a further aspect, the one or more smear rollers may be rotated in a direction opposite to the downstream direction, i.e., the opposite direction which the band moves towards.

[0033] One effect of rotating the one or more smear rollers at a different rotation velocity than the band velocity and / or a different direction than the printed band direction is that the smearing effect of the smear roller is improved by improving the friction between the smear roller and the ink-covered side which causes greater smearing of ink and liquid, i.e. mixing of ink and liquid.

[0034] The smear surface of the smear unit may be a fibre surface, and / or filaments, and / or brush surface, and / or silicone surface, and / or a foam sheet.

[0035] In one aspect, the scraper may be adapted as a rubber or plastic wiper which engages the printed band and scrapes off ink, liquid, and / or a mixture. The material of the scraper is configured to provide the scraping effect while not damaging the printed band.

[0036] In one further aspect the scraper may be arranged at an angle relative to the downstream direction of the band path, so that ink and liquid being removed by the scraper will drift off one or both edges of the printed band.

[0037] In one aspect of the apparatus, an upstream guide roller, and a downstream guide roller, may be arranged in relation to a smear unit to define the band path such that the printed band, during use, at least engages a circle arc of the smear unit. The greater the surface between the smear unit and the band the greater the effect and hence a smaller number of smear units with a greater circle arc are needed.

[0038] The apparatus may be configured with a number of different or similar sections, among other these are but not limited to:

[0039] - liquid application sections comprising one or more liquid applicators and / or nozzles, or one or more liquid applicators and / or nozzles and one or more guide rollers;

[0040] - a nozzle section comprising one or more nozzles, or one or mor nozzles and one or more guide rollers;

[0041] - smearing sections comprising at least one smear unit and one or more guide rollers; - scraping sections comprising at least one scraper and one or more guide rollers;

[0042] - guiding sections comprising at least one guide roller and configured for guiding the printed band in a desired direction and / or into a desired orientation.

[0043] In an embodiment, the apparatus comprises three pairs of a liquid application sections upstream to a smearing section. This is followed by a scraping section, where the ink is removed by the scraper. However, sometimes there are still residues of the liquid which liquid will affect the quality of the next printing performed by the printing band. Therefore, there may be a liquid application section upstream to a smearing section, wherein the liquid application section provides water to the band. This is followed by scraping section. The embodiment may have several guiding sections. In this example, there were three pairs before the scraping section and one pair after said scraping section however there could be any number of pairs without changing the spirit of the invention.

[0044] The number of scraper sections and liquid application sections does not depend on the number of smearing sections, and the number of scraper sections and liquid application sections can be any number greater than one independently of the number of smearing sections. The skilled person would be able to choose the correct number.

[0045] In one aspect of the invention, the apparatus may comprise a cleaning section comprising a nozzle section comprising one or more nozzles; followed by an upstream guide roller, the smear unit, and finally, a downstream guide roller. In a further aspect of the invention, the apparatus is adapted with a number of the cleaning section in succession, preferably three. The apparatus can become more compact by the upstream guide roller of the second and third cleaning section in succession being the downstream guide roller of the previous cleaning section so that only four guide rollers are required for the three smear units. When the printed band has passed through the three cleaning sections, the ink is removed from the ink-covered side. This is also shown in the figures.

[0046] Furthermore, following the three cleaning sections, a scraping section may be arranged to ensure that any remaining liquid and / or ink is removed from the printed band.

[0047] In a further embodiment of the apparatus, the circle arc being equal to or greater than 60 degrees, or equal to or greater than 90 degrees, or equal to or greater than 120 degrees, or preferably equal to or greater than 160 degrees, or equal to or greater than 180 degrees, or between 60 to 330 degrees, or between 90 degrees to 300 degrees, or preferably between 160 to 270 degrees. The smearing effect per smearing unit will increase with the circle arc.

[0048] In an aspect, wherein an upstream guide roller and a downstream guide roller to the smear unit define a line, wherein the smear unit being positioned to displace the band path from said line.

[0049] Thus, to achieve a circle arc of, e.g., 160 to 180 degrees, the path of the printed band from the upstream guide roller to the smear unit may be substantially parallel to the path of the printed band from the smear unit to the downstream guide roller.

[0050] In an embodiment, the smear unit may be chosen amongst

[0051] - a smear roller with the smear surface; or

[0052] - an arc-shaped surface and an endless smear band moving along the arcshaped surface during use, the endless smear band comprising the smear surface; or

[0053] - an arc-shaped surface and a smear band moving along the arc-shaped surface during use, the endless smear band comprising the endless smear band comprising the smear surface or

[0054] - at least two rollers with an endless smear band, wherein the endless smear band comprising the smear surface.

[0055] The smear roller with the smear surface is preferred as it is the simplest solution which requires the least volume as can be seen in the figures.

[0056] The smear unit may have an arc-shaped surface and an endless smear band, or a smear band being displaced over the arc-shaped surface, wherein the band and the smear surface engage along at least part of the arc-shaped surface.

[0057] The smear unit may have at least two rollers with an endless smear band in-between, wherein the band and the smear surface engage along at least part of one of the rollers.

[0058] In a further aspect of the apparatus, the diameter of the one or more smear units and / or the guide rollers may be adapted to achieve a desired circle arc. In one aspect of the apparatus, different smearing sections may be adapted with different angles of the circle arc.

[0059] One effect of making the circle arc where the printed band engages the smear unit as large as possible is that the friction between the smear unit and the printed band is increased, hence the smearing effect is increased. Thus, the liquid applied and / or sprayed from the liquid application section and / or the nozzle section is more evenly distributed across the printed band and ink is efficiently removed and / or cleaned from the ink-covered side.

[0060] In a further embodiment of the apparatus, an upstream guide roller and a downstream guide roller to the smear unit define a line, wherein the smear unit being positioned to displace the band path from the line.

[0061] In a further embodiment of the apparatus, the apparatus comprises one or more drip trays below

[0062] - a part of the band path between the smear unit and a guide roller arranged upstream to the smear unit; and / or

[0063] - the at least one scraper.

[0064] The one or more drip trays are configured to collect excess spray from the nozzles and / or ink and liquid dripping from the one or more smear units, the printed band, the liquid applicators, and / or the one or more scrapers.

[0065] The excess liquid and ink are collected in the drip trays may be guided to a tank. The excess liquid and ink may be filtered and / or further processed in order to re-use the liquid so that the water and / or cleaning solution may be separated from the ink and then reused. Hence, one advantageous effect may be that the invention is more environmentally friendly and cost efficient due to the reuse of the liquid.

[0066] A further effect of the drip trays is that the any articles of the apparatus and / or the printed band placed below the drip trays are protected from excess spray from the nozzles and / or ink and liquid dripping from the one or more smear units, the printed band, the liquid applicators, and / or the one or more scrapers arranged above the drip trays. Hence, a cleaned part of the printed band is protected from being contaminated by excess liquid or ink. In a further embodiment of the apparatus, the apparatus further comprises at least one counter-pressure roller engaging at least a part of the smear unit, the counter-pressure roller being configured for removing excess ink and liquid. In this embodiment, the velocity of the band must be different than zero in order to move the smear surface to the counter-pressure roller.

[0067] The counter-pressure roller is configured to only remove excess ink and liquid from the smear unit, as removing too much liquid would be disadvantageous to the smearing and cleaning process as disclosed herein. The pressure between the band and smear unit may cause unwanted axial displacement along the smear unit, which can cause the ink and liquid to be pressed out into the mechanical parts of the apparatus which is detrimental to the functioning of the apparatus. Furthermore, the axial movement can in some cases cause the ink and liquid to the other side of the band without ink thereby contaminating the band. However, these two negative effects are prevented or at least reduced by the counter pressure roller.

[0068] The counter-pressure roller may be arranged on a horizontal plane arranged substantially parallel to a horizontal plane of the smear unit.

[0069] Furthermore, the counter-pressure roller may be arranged in-between the smear unit and a guide roller arranged upstream to the smear unit.

[0070] Hence, the counter-pressure roller may be arranged above the drip tray so that excess ink and liquid dripping from the counter-pressure roller is collected by the drip tray. The counter-pressure roller is arranged in relation to the smear unit so that it does not engage the printed band.

[0071] The counter-pressure roller may be configured to engage one or more widthwise parts of the smear unit, wherein the widthwise part is an area along the longitudinal extent of the smear unit. The widthwise parts cover at least a widthwise area centered below both edges of the printed band, wherein the widthwise area extends outwards from both edges. Thereby, the ink and liquid are less likely able to travel to the other side of the band. In this case, the length of the counter-pressure roller is greater than the band width.

[0072] The counter-pressure roller may be two counter-pressure rollers arranged to engage each of the two sections of the smear unit which engages the two edges of the printed band, thereby axial displacement of ink and liquid is prevented by the two counterpressure rollers. The two counter-pressure rollers may be displaceable along the smear unit to adapt different printing band with different widths.

[0073] In one aspect, the counter-pressure roller engages the smear unit in one single area which is wider than the width of the printed band.

[0074] The counter-pressure roller or the two counter-pressure rollers work especially well with the smear unit being a smear roller as the counter-pressure roller or the two counter-pressure rollers can easily create pressure against the smear roller.

[0075] One advantage of providing the counter-pressure roller is that the smear unit does not become oversaturated with excess ink or liquid. As oversaturation may cause excess ink or liquid to spill onto the back side of the printed band.

[0076] In a further embodiment of the apparatus, the apparatus further comprises a motor for controlling the rotation velocity of the smear roller and / or a brake for reducing the rotation velocity of the smear roller relative to the band velocity of the printed band, during use.

[0077] In a further embodiment of the apparatus, the apparatus further comprises a motor for controlling the displacement velocity of the smear surface of smear unit and / or a brake for reducing the velocity of the smear surface of smear unit relative to the band velocity of the printed band, during use.

[0078] In one aspect, the motor may be an electric motor, e.g. an induction motor, a brushless motor, permanent magnet motor, a stepper motor, a servo motor, etc.; a hydraulic; a combustion engine; or a pneumatic motor.

[0079] The apparatus may comprise a motor arranged at each smear roller or multiple smear rollers may be connected to one motor through an axle and gearing system. In the same sense, the brake may be arranged at each smear roller or a single brake may be arranged on an axle and gearing system connected to each smear roller.

[0080] The motor may be configured to rotate the smear roller in a clockwise direction and / or a counter-clockwise direction. Furthermore, the motor may be configured to displace the smear surface in an upstream direction and / or a downstream direction. In another aspect of the apparatus, the one or more smear rollers may be rotated by the band velocity rotating the smear rollers due to the friction between the printed band and the smear surface of the smear roller. In this aspect, the smear rollers may be provided with brakes for reducing the rotation velocity of the smear roller to a velocity below the band velocity of the printed band so that the friction between the smear surface and the ink-covered side of the printed band is improved and thereby improving the smearing and cleaning effect.

[0081] In another aspect of the apparatus, the one or more smear surfaces may be displaced by the band velocity displacing the smear surfaces due to the friction between the printed band and the smear surface of the smear unit. In this aspect, the smear units may be provided with brakes for reducing the displacement velocity of the smear surface to a velocity below the band velocity of the printed band, so that the friction between the smear surface and the ink-covered side of the printed band is improved and thereby improving the smearing and cleaning effect.

[0082] The one or more brakes may be actuated by electronic, hydraulic, pneumatic, or mechanical means. The brake may be provided as a brake pad engaging a part of the smear roller, an axle extending from the smear roller or a brake disc.

[0083] A further objective of the invention is achieved by a method for removing ink from an ink-covered side of a printed band of flexible material, the method comprising steps of:

[0084] - driving the printed band at a first velocity,

[0085] - applying a liquid to the ink-covered side,

[0086] - smearing the liquid together with the ink using a smear surface moving at a second velocity,

[0087] - removing the liquid and the ink by scraping the ink-covered side, wherein the second velocity is different than the first velocity.

[0088] In one aspect of the method for removing ink from the ink-covered side of the printed band of flexible material may be carried out using the apparatus of the present invention as disclosed herein. In this aspect, the first velocity may be the band velocity and the second velocity may be the rotation velocity and / or the displacement velocity.

[0089] In a further embodiment of the method, the liquid comprises water, and / or a solvent, and / or a disinfectant. The liquid applied onto the ink-covered side of the printed band is applied to remove the ink from the printed band by cleaning and / or rinsing off the ink, this process is carried out by the liquid being smeared together with the ink and / or by being scraped off from the ink-covered side.

[0090] In a further embodiment of the method, the method comprises a step of applying a pressure to the smear surface for removal of excess ink and liquid.

[0091] As the smear surface smears the liquid together with the ink on the ink-covered side of the printed band, a part of the liquid and / or the ink may be absorbed into the smear surface. One advantage of the smear surface absorption is that ink is removed from the ink-covered side and the liquid may be applied and smeared onto another part of the printed band.

[0092] However, a disadvantage of the smear surface absorption is that the smear surface may become oversaturated with ink and / or liquid, and thus the ink and / or liquid may spill onto an opposite side of the printed band relative to the ink-covered side.

[0093] This disadvantage is overcome by applying a pressure to the smear surface for removing excess ink and liquid.

[0094] Description of the Drawing

[0095] Various examples are described hereinafter with reference to the figures. The reference numbers refer to the elements throughout. The elements will, thus, not be described in detail with respect to the description of each figure. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. In addition, an illustrated example need not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not illustrated, or if not explicitly described.

[0096] Exemplary embodiments of the invention are described in the figures, whereon:

[0097] Fig. 1a illustrates one embodiment of an apparatus with a printed band feeding through an apparatus from an infeed spool and to an outfeed spool, Fig. 1b illustrates a 3D view of one embodiment of an apparatus and adjoining machinery,

[0098] Fig. 2 illustrates one embodiment of an apparatus,

[0099] Fig. 3 illustrates a close-up view of one embodiment of a part of an apparatus, Fig. 4 illustrates a perspective view of one embodiment of a smear unit, a counterpressure roller and a nozzle section,

[0100] Fig. 5 illustrates one embodiment of a method for removing ink from an ink-covered side of a printed band.

[0101] Detailed Description of the Invention

[0102] Exemplary examples will now be described more fully hereinafter with reference to the accompanying drawings. In this regard, the present examples may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the examples are merely described below, by referring to the figures, to explain aspects.

[0103] Throughout the specification, when an element is referred to as being “connected” to another element, the element is “directly connected” to the other element, “electrically connected”, “fluidic connected” or “communicatively connected” to the other element with one or more intervening elements interposed there between.

[0104] The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. As used herein, the terms “comprises” “comprising” “includes” and / or “including” when used in this specification specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0105] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined in the present specification. Figure 1a illustrates one embodiment of an apparatus 1 wherein the apparatus is provided with a band infeed 3 in one side and a band outfeed 5 in the opposite side of the apparatus 1 . A printed band 10 is being fed from an infeed spool 82 to the band infeed 3 through the apparatus 1 in a downstream direction and then out of the band outfeed 5 and onto an outfeed spool 84. Mechanical means may be arranged inside the apparatus, wherein the mechanical means are configured for displacing the printed band 10 in the downstream direction. The mechanical means may be motor driven rollers and / or one or more guide rollers may be motor driven and / or the mechanical means may be one or more nip rollers arranged internally or externally of the apparatus.

[0106] The infeed spool 82 and the outfeed spool 84 are simply adjoining machinery 80 which the apparatus 1 of the present invention may be connected to, this may be any machinery capable of feeding a printed band 10 requiring cleaning to the apparatus 1 and receiving a cleaned printed band 10 from the band outfeed 5. The adjoining machinery 80 may be provided with mechanical means configured for displacing the printed band 10 in the downstream direction.

[0107] Figure 1b illustrates a three-dimensional view of one embodiment of an apparatus 1 and adjoining machinery 80.

[0108] Figure 2 illustrates one embodiment of an apparatus 1 wherein a printed band 10 is provided at a band infeed 3 of the apparatus 1 . The printed band 10 arrives at the band infeed 3 after being guided there by a number of guide rollers 20 arranged on the outer side of the apparatus 1 .

[0109] On the inside of the apparatus 1 , the printed band 10 is guided by a number of guide rollers 20 arranged downstream to the band infeed 3, so that the ink-covered side 12 of the printed band 10 faces a liquid application section 40. The liquid application section 40 may comprise an array of liquid applicators 41 configured to provide a liquid to the ink-covered side 12.

[0110] After the liquid application section 40 an upstream guide roller 22 is arranged and configured to turn the ink-covered side 12 facing downward, so that the ink-covered side 12 engages a smear surface 32 of a smear unit 30 arranged to the left of the upstream guide roller 22. The smear unit 30 is a smear roller 31 with a smear surface 32. The upstream guide roller 22 is arranged upstream to the smear unit 20 relative to the moving direction of the printed band 10, wherein the downstream direction is in the direction from the band infeed 3 to the band outfeed 5.

[0111] Downstream to the smear unit 30 a downstream guide roller 24 is arranged to the right side of the smear unit 30. The arrangement of the upstream guide roller 22 and the downstream guide roller 24 ensures that a contact area where the ink-covered side 12 engages with the smear surface 32 is in the shape of a circle arc 34. Downstream to the downstream guide roller 24, another smear unit 30 is arranged, therefore the downstream guide roller 24 may also be considered as an upstream guide roller 24, relative to the second smear unit 30.

[0112] A number of upstream guide rollers 22, smear units 30, downstream guide rollers 24 and liquid application sections 40 are arranged along the band path 4 of the printed band 10 inside the apparatus 1. When the printed band 10 has passed through these articles, a majority of the ink has been cleared from the ink-covered side 12.

[0113] Following these articles, a scraper 50 is arranged between two guide rollers 20 to engage the printed band 10 on the ink-covered side 12 and ensure that any remaining ink is scraped off the printed band 10.

[0114] Below the scraper 50, the liquid application section 40 and / or a distance between the upstream guide roller 22 and the smear unit 30, one or more drip trays 60 are arranged. The drip trays 60 are configured to collect the excess ink and / or liquid which drips off, is smeared off or scraped off the printed band during use of the apparatus 1.

[0115] Downstream to the scraper 50 another liquid application section 40 is arranged together with a smear unit 30 between an upstream guide roller 22 and a downstream guide roller 24 and followed by a final scraper 50. The final liquid application section 40, smear unit 30 and scraper 50 are provided to ensure that the printed band 10 is completely clean from any ink and / or liquid. The final liquid application section 40 may be configured to only provide a liquid application only comprising water, so that no cleaning solvents or disinfectants are left on the printed band 10.

[0116] Following the final scraper 50, the printed band 10 is guided by a number of guide rollers 20 to the band outfeed 5, where the printed band 10 leaves the apparatus 1. Figure 3 illustrates a close-up view of one embodiment of a part of an apparatus 1 comprising two cleaning sections 2 in succession inside the apparatus 1.

[0117] The cleaning sections 2 each comprise one or more nozzles 43 arranged in a nozzle section 42 followed by an upstream guide roller 22, the smear unit 30, a downstream guide roller 24 and finally a drip tray 60. Because the two cleaning sections 2 are arranged in succession, the downstream guide roller 24 of the first cleaning section may be used as the upstream guide roller 22 of the second cleaning section. The smear unit 30 is a smear roller 31 with a smear surface 32.

[0118] Each upstream guide roller 22 and downstream guide roller 24 may be arranged on a line 26 and each smear unit 30 may be arranged away from the line 26, so that the band path 4 instead follows a second line substantially parallel to the line 26. Thus, ensuring that the band path 4 follows a circle arc around a part of the smear unit 30.

[0119] Furthermore, the smear unit 30 of the cleaning section 2 may be configured with a counter-pressure roller 70 configured to engage a smear surface of the smear unit 30 to remove excess ink and / or fluid from the smear unit 30. The counter-pressure roller 70 is arranged between the smear unit 30 and the upstream guide roller 22.

[0120] Following the second cleaning section, a scraper section 6 is arranged on the band path 4 wherein the scraper section 6 comprises an upstream guide roller 24 followed by the scraper 50 and finally a second guide roller 20 downstream to the scraper 50.

[0121] The apparatus 1 of the present invention may be configured with any number of cleaning sections 2 and scraper sections 6 in succession or alternating order.

[0122] Figure 4 illustrates a perspective view of one embodiment of a smear unit 30, a counterpressure roller 70 and a nozzle section 42. The printed band 10 and its band path 4 is being guided around an upstream guide roller 22, so that the ink-covered side 12 of the printed band 10 faces towards the nozzle section 42, so that the nozzles 43 can spray a liquid onto the ink-covered side 12.

[0123] Downstream to the upstream guide roller 22, the smear unit 30 is arranged so that the ink-covered side 12 engages a smear surface 32 of the smear unit 30. The smear unit 30 is connected to a motor 38 through an axle and gearing system. The motor 38 is configured to rotate the smear unit 30 at a rotation velocity different from a band velocity. The band velocity is the velocity which the printed band 10 moves at through the apparatus.

[0124] Between the smear unit 30 and the upstream guide roller 22, a counter-pressure roller 70 is arranged so that the counter-pressure roller 70 engages the smear unit 30. The counter-pressure roller 70 is provided as two small rollers in this embodiment, however in another embodiment, the counter-pressure roller 70 may be provided as one contiguous roller.

[0125] The counter-pressure roller 70 is configured to at least engage the smear unit along a widthwise area substantially parallel to the longitudinal extent of the smear unit 30, wherein the widthwise area is arranged vertically below both edges of the printed band 10 and where the widthwise area extends a distance in either direction substantially parallel to the longitudinal extent of the smear unit 30.

[0126] As such, when the counter-pressure roller 70 engages the smear unit along the specific widthwise area, the counter-pressure roller 70 ensures that excess ink and / or liquid absorbed by the smear unit 30 does not spill over the edges of the printed band 10 so that an opposite side to the ink-covered side 12 becomes soaked with ink and / or liquid. Thus, the counter-pressure roller 70 ensures that some ink and / or liquid is drained from the smear unit 30 before the smear unit 30 becomes oversaturated.

[0127] Figure 5 illustrates one embodiment of a method for removing ink from an ink-covered side of a printed band, the method comprises the steps of:

[0128] - driving 110 the printed band at a first velocity,

[0129] - applying 120 a liquid to the ink-covered side 12,

[0130] - smearing 130 the liquid together with the ink using a smear surface 32 moving at a second velocity,

[0131] - removing 140 the liquid and the ink by scraping the ink-covered side 12, wherein the second velocity is different than the first velocity.

[0132] The method 100 may furthermore comprise a step of applying 150 a pressure to the smear surface for removal of excess ink and liquid.

Claims

CLAIMS1. An apparatus (1) for removing ink from an ink-covered side of a printed band (10) of flexible material, the apparatus (1) comprises- a band infeed (3);- a band outfeed (5);- a number of guide rollers (20) and at least one smear unit (30) defining a band path (4) from the band infeed (3) to the band outfeed (5),- at least one liquid application section (40) upstream to the at least one smear unit (30), the at least one liquid application section (40) comprising one or more liquid applicators (41) for providing a liquid to an ink-covered side (12);- at least one scraper (50) downstream to the at least one smear unit (30), the least one scraper (50) adapted for engaging the ink-covered side (12) during use for removal of ink; wherein the at least one smear unit (30) comprising a smear surface (32) for smearing ink and liquid together, and the band path (4) is such that the band (10), during use, at least engages a circle arc (34) of the smear unit (30), the circle arc being at least 15 degrees, and wherein the smear surface (32) of the at least one smear unit (30) being configured, during use, to displace with a displacement velocity different than a band velocity.

2. An apparatus (1) according to claim 1 , wherein the circle arc (34) being equal to or greater than 60 degrees, or equal to or greater than 90 degrees, or equal to or greater than 120 degrees, or preferably equal to or greater than 160 degrees, or equal to or greater than 180 degrees, or between 60 to 330 degrees, or between 90 degrees to 300 degrees, or preferably between 160 to 270 degrees.

3. An apparatus (1) according to claim 1 or 2, wherein an upstream guide roller (20,22) and a downstream guide roller (20,24) to the smear unit (30) define a line (26), wherein the smear unit (30) being positioned to displace the band path (4) from said line (26).

4. An apparatus (1) according to any of claims 1 to 3, wherein the smear unit (30) chosen amongst- a smear roller (31) with the smear surface (32); or- an arc-shaped surface and an endless smear band moving along the arc-shaped surface during use, the endless smear band comprising the smear surface (32); or- an arc-shaped surface and a smear band moving along the arc-shaped surface during use, the endless smear band comprising the smear surface (32); or- at least two rollers with an endless smear band, wherein the endless smear band comprising the smear surface (32).

5. An apparatus (1) according to any of claims 1 to 4, wherein the apparatus comprises one or more drip trays (60) below- a part of the band path (4) between the smear unit (30) and a guide roller (20) arranged upstream to the smear unit (30); and / or- the at least one scraper (50).

6. An apparatus (1) according to any of claims 1 to 5, wherein the apparatus (1) further comprises at least one counter-pressure roller (70) engaging at least a part of the smear unit (30), the counter-pressure roller (70) being configured for removing excess ink and liquid from the smear unit (30).

7. An apparatus (1) according to any of claims 1 to 6, wherein the apparatus (1) further comprises a motor (38) for controlling the displacement velocity of the smear unit (30) and / or a brake for reducing the displacement velocity of the smear unit (30) relative to the band velocity of the printed band (10), during use.

8. A method (100) for removing ink from an ink-covered side of a printed band (10) of flexible material, the method (100) comprising steps of:- driving (110) the printed band (10) at a first velocity,- applying (120) a liquid to the ink-covered side (12),- smearing (130) the liquid together with the ink using a smear surface (32) moving at a second velocity,- removing (140) the liquid and the ink by scraping the ink-covered side (12), wherein the second velocity is different than the first velocity.

9. A method (100) according to claim 8, wherein the liquid comprises water, and / or a solvent, and / or a disinfectant.

10. A method (100) according to claim 8 or 9, wherein the method comprises a step of applying (150) a pressure to the smear surface (32) for removal of excess ink and liquid.

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