Apparatus and method for processing a relief master with reduced cleaning - Patents.com

Abstract

An apparatus for treating a relief master (P), such as a printing master, with a liquid (L), comprising: a processing compartment (400) having a processing means (450) configured to treat the relief master with the liquid and remove debris from the relief master; and a liquid collection system (900) configured to receive the liquid and the removed debris from the processing means (450), wherein the liquid collection system is configured to separate debris having dimensions greater than a predetermined minimum dimension from the liquid and to allow at least some of the debris to at least partially dissolve in the liquid, at least when the liquid is in a quiescent state after or before treatment of the relief master by the processing means.

Description

[Technical field]

[0001] The field of the invention relates to apparatus and methods for treating a relief master, particularly a relief master such as a printing master, with a liquid. Certain embodiments relate to apparatus and methods for treating a relief master with a solvent to remove uncured material and generate a relief structure. [Background technology]

[0002] Washer devices for printing plate precursors are known. Typically, a transport bar is used to move the printing plate precursor through such a washer device using a transport system. The washer further uses liquid to partially remove material from the original, and in most cases brushes are used to increase efficiency. These brushes are wetted with liquid using pumps and / or other delivery devices to constantly wet the brushes with liquid. To protect the pump from damage by foreign objects (e.g. screws, particles, bristles, etc.), sieve-like protective means are used to hold such material. These sieve-like protective means need to be cleaned frequently, for example weekly, to avoid clogging. Summary of the Invention

[0003] It is an object of embodiments of the present invention to provide an apparatus and method that reduces cleaning requirements and associated clogging problems.

[0004] According to a first aspect of the invention, there is provided an apparatus for treating a relief master, such as a printing master, with a liquid. The apparatus comprises a processing compartment and a liquid collection system. The processing compartment has a processing means configured to treat the relief master with a liquid and to remove debris from the relief master. The liquid collection system is configured to receive the liquid and the debris removed from the processing means, to separate debris having a dimension larger than a predetermined minimum dimension from the liquid, and to allow at least a portion of said debris to at least partially dissolve in the liquid, at least when the liquid is in a quiescent state after or before the treatment of the relief master by the processing means.

[0005] The debris separated from the liquid in the liquid collection system is primarily debris removed from the relief master, e.g. cured and / or uncured particles, residues, film parts or flock, but can also include any other undesirable parts, such as screws or nuts or bristles, that accidentally came loose and were carried away by the liquid. Typically, however, only the debris removed from the relief master, or only a portion of it, dissolves in the liquid. It has been found that by configuring the liquid collection system such that the debris is at least partially soluble in the liquid, the frequency of cleaning can be significantly reduced.

[0006] In prior art systems, the removed debris tends to be captured in the sieving means and dry out when the apparatus is not in operation. By configuring the liquid collection system to allow at least some of the debris to at least partially dissolve in the liquid not only during operation of the processing means, but also at least when the liquid is in a quiescent state after or before processing of the relief master by the processing means, the amount of debris that can cause clogging can be significantly reduced.

[0007] It should be noted that the inoperative state of the device or processing means refers to a state in which liquid is present in the device but no liquid is circulating through the processing compartment.

[0008] According to a preferred embodiment, the liquid collection system is configured to keep the majority of the separated debris, preferably at least 80% of the separated debris, more preferably at least 90% of the separated debris, wet with liquid, both when the processing means is operating and when it is not operating. By keeping the majority of the separated debris wet, the risk of the debris drying out and causing clogging can be reduced or avoided, even when the processing means is not operating.

[0009] According to an exemplary embodiment, the liquid collection system is configured to maintain a majority of the separated debris, preferably at least 80% of the separated debris, more preferably at least 90% of the separated debris, submerged in liquid both when the processing means is operating and when it is not operating.

[0010] Preferably, the liquid collection system is part of a liquid circulation system configured to circulate the collected liquid back to the processing means. The liquid or a part thereof may be directly recycled to the processing compartment without being cleaned or otherwise treated, and / or the liquid or a part thereof coming from the liquid collection system may be sent to a separate device to be cleaned or otherwise treated, for example in a distillation apparatus, before being returned to the processing compartment. In addition to the distilled or cleaned liquid part of the liquid, components may be added to adjust their concentration to a desired level.

[0011] In a preferred embodiment, the liquid collection system comprises a sieving means. Preferably, the sieving means is at least partially immersed in the liquid even when the liquid is at rest. Surprisingly, it has been found that the frequency of cleaning can be dramatically reduced when the sieving means is immersed in the liquid. However, it is also possible to use non-immersed sieving means that are configured to ensure that the majority of the separated debris is removed from the sieving means and immersed in the liquid.

[0012] Preferably, the liquid collection system comprises a container for storing the sieved liquid, and the sieving means is arranged in the container, whereby the sieving means is immersed at least when the liquid is in a quiescent state after or before treatment of the relief master by the processing means. Preferably, the container is a large capacity container capable of storing more than 20 litres, more preferably more than 30 litres, such as more than 50 litres or even more than 100 litres.

[0013] In a possible embodiment, the sieving means comprises a sieving surface oriented at at least 30° to the horizontal, preferably vertically, in this way debris stopped by the sieving means will tend to move downwards, avoiding the sieving means and reducing the risk of clogging.

[0014] In an exemplary embodiment, the sieving means comprises one or more of a wire mesh, a grid, a plate having a plurality of holes, and is made of a material that is stable in the liquid.

[0015] Preferably the sieving means has openings with dimensions smaller than 5mm, preferably in the range of 0.1mm to 3mm, more preferably 0.5mm to 2mm. More specifically, preferably the sieving means is sized to stop any debris which may cause damage to pumps or other components of the liquid circulation system.

[0016] In a preferred embodiment, the sieving means is integrated into the basket. In this way, a compact sieving means can be obtained. For example, the peripheral wall may form the sieving means and / or the bottom may form the sieving means. In particular, if the bottom forms the sieving means, preferably at least the bottom is immersed in the liquid in a stationary state. Preferably, the basket is removably placed in a container that holds a certain amount of liquid, and at least the bottom is immersed in the liquid.

[0017] In another possible embodiment, the basket is provided with a closed bottom tray configured to hold a quantity of liquid even in a stationary state of the liquid, and a peripheral portion forming a sieve means. In such an embodiment, even when the liquid is not circulating in the machine, some of the debris stopped by the sieve means falls downwards into the closed bottom and thus into the liquid contained in the tray, so that these debris can dissolve in the liquid. In this way, a relatively small amount of liquid in the tray is sufficient to ensure that the debris is at least partially dissolved and that the sieve means does not have to be submerged.

[0018] Preferably, the sieve means is removable, in this way it may be removed for cleaning, although this is usually not required very often.

[0019] Preferably, the sieving means is made of metal, alloy, plastic, glass, ceramic, paper, natural fibers or combinations thereof. Preferably, the sieving means is made of woven or non-woven forms of fibers, filaments or wires.

[0020] Preferably, the liquid collection system, and in particular the sieve means, is configured so as not to absorb or adsorb debris, in this way debris is avoided from becoming trapped in the liquid collection system.

[0021] Preferably the sieving means is arranged to retain fragments having a maximum dimension greater than 5mm, preferably greater than 3mm, more preferably greater than 2mm.

[0022] In an exemplary embodiment, the processing means comprises one or more pre-cleaning members and one or more main cleaning members downstream of the pre-cleaning members, and the sieving means comprises a first sieving means for receiving the liquid used by the pre-cleaning members and a second sieving means for receiving the liquid used by the main cleaning members. In this way, two liquid circulation flows can be differentiated into a first flow for performing a pre-cleaning step and a second flow for performing a main cleaning step. The first sieving means and / or the second sieving means may be at least partially immersed in the liquid. Preferably, at least the first sieving means is at least partially immersed in the liquid both during and after the treatment. Typically, during the pre-cleaning, many debris such as particles and film parts from the laser ablation mask and photopolymer residues are removed from the relief master, and by having the sieving means at least partially immersed for this flow, the cleaning frequency of the sieving means can be reduced.

[0023] The first sieving means may be disposed in the first storage vessel. The second sieving means may be disposed in the second storage vessel. Preferably, the second storage vessel is larger than the first storage vessel. The first vessel may have a volume of more than 20 liters, or even more than 30 liters, for example between 35 liters and 100 liters. The second vessel may have a volume of more than 50 liters, or more than 100 liters, or even more than 200 liters, for example between 200 and 600 liters.

[0024] Preferably, the liquid collection system is further configured to convey the liquid that has passed through the first sieving means to an outlet and to recycle the liquid that has passed through the second sieving means directly to the processing means. In this way, the liquid used for pre-washing, which typically contains dissolved material from the relief master, may be processed outside the apparatus before being reused. For example, the liquid used for pre-washing may be conveyed to a distillation apparatus to remove polymeric material.

[0025] According to an exemplary embodiment, the apparatus further comprises liquid conveying means configured to generate a pre-wash flow of at least 0.3 liters per minute, preferably at least 0.6 liters per minute through the first sieving means and a main wash flow of at least 10 liters per minute, preferably at least 30 liters per minute through the second sieving means.

[0026] Preferably, the processing means further comprises one or more cleaning members downstream of the one or more main washing members. The processing compartment may then be provided with an inlet for fresh liquid arranged so that fresh liquid is used by the one or more cleaning members.

[0027] In an exemplary embodiment, the apparatus further comprises a transport system configured to move the relief master through the processing compartment. Preferably, the transport system comprises at least one transport bar provided with a coupling portion configured to be coupled to the relief master, the transport system being configured to transport the transport bar through the processing compartment.

[0028] Preferably, the carrier bar is provided with at least one penetrating element, more preferably with a plurality of penetrating elements. The shape of the at least one penetrating element may be selected from the group including, for example, a rod, a blade, a needle, having a circular, elliptical, triangular, rectangular or multi-angled cross section, or a combination thereof. The at least one penetrating element may be made of a metal or an alloy.

[0029] Preferably, the length of the carrier bar is from 100 mm to 10,000 mm, more preferably from 200 mm to 5,000 mm, and most preferably from 500 mm to 3,000 mm.

[0030] In a preferred embodiment, the transport system is substantially symmetrical about a central axis of the apparatus and has first and second transport mechanisms for coupling to the first and second outer ends of the transport bar, respectively. Although such a symmetrical arrangement is typically preferred, it should be noted that a driven transport mechanism may be provided at the first outer end of the transport bar and a simple guide mechanism may be provided at the second outer end of the transport bar.

[0031] Preferably, the conveying system comprises a lead screw, preferably a pair of lead screws, or a chain or belt, preferably a pair of chains or belts, such lead screws or chains or belts extending in the direction of movement on one side of the processing section or on both sides of the processing section.

[0032] According to a preferred embodiment, the apparatus comprises a plate bonding station and / or a separation station configured for bonding and / or separating the relief master to and / or from the carrier bar. The plate bonding station may be configured to engage at least one penetrating element in an area near the edge of the relief master. More preferably, each penetrating element has a sharp tip or edge capable of producing a penetrating action in the material of the relief master, and the plate bonding station is configured to cause the at least one penetrating element to at least partially penetrate or penetrate a non-perforated area near the edge of the relief master. In this way, the penetrating element is pressed into the material of the printing plate without generating waste. It is noted, however, that the invention also encompasses the use of a pre-perforated relief master bonded to the carrier bar in the plate bonding station.

[0033] Preferably, the transport system is configured to move at least two transport bars in a closed loop through the apparatus. Two, three or more transport bars may be transported simultaneously through the apparatus. For example, one of the at least two transport bars may be transported through the processing compartment, while another one is transported back to the plate bonding station.

[0034] The treatment means may include rollers, brushes, spray nozzles, pipes, tables placed under the rollers or brushes, and combinations thereof. Preferably, the liquid application means is a roller or a cylindrical brush. The brush may be, for example, a moving (rotating or oscillating) brush (flat or cylindrical).

[0035] Preferably, the liquid application means comprises a shaft and a liquid application tool, such as bristles arranged on the shaft, intended to contact the relief master, and the liquid ejector extends below the carrier bar and below the shaft of the liquid application means at a distance from the liquid application tool. In this way, the liquid ejector allows good ejection of any liquid on the carrier bar, while not interfering with the processing by the liquid application tool.

[0036] Furthermore, the device can comprise a protection system for preventing contamination of the transport system by liquid. The protection system is configured to guide and drain the liquid such that the transport system is protected from wetting by the liquid of the processing compartment. Preferably, the protection system comprises a liquid drain extending longitudinally below the outer end of the transport bar next to the transport system. The liquid drain is provided with an upwardly extending part on the side facing the transport system. In this way, the upwardly extending part stops the liquid flowing over the liquid drain towards the transport system. The other side of the liquid drain, which is furthest from the transport system, can extend horizontally or downwardly so as to be able to drain the liquid into a reservoir below the liquid drain. However, it is also possible that the liquid drain only consists of an upwardly extending part, for example an upwardly inclined part, which only guides the liquid into the reservoir.

[0037] Preferably, the carrier bar is provided with an upwardly extending portion at its outer end. In such an embodiment, the upwardly extending portion of the liquid ejector extends between the carrier system and the upwardly extending portion of the carrier bar. In this way, liquid present on the carrier bar is stopped by the upwardly extending portion of the carrier bar and can flow laterally from the carrier bar onto the liquid ejector, where the fluid is ejected into the reservoir as explained above.

[0038] Preferably, the processing compartment comprises a wall portion having a lower edge directly above the outer end of the transport bar as the transport bar moves through the processing compartment. More preferably, the wall portion extends adjacent to the upwardly extending portion of the transport bar such that the upper edge of the upwardly extending portion of the transport bar is higher than the lower edge of the wall portion. Also preferably, the liquid drain extends below the lower edge of the wall portion. In this way, any splashes or drops of liquid on the wall portion of the processing compartment can slide along the wall portion onto the drain or the transport bar, whereby they are drained and prevented from wetting the transport system. The wall portion may comprise an opening configured to allow a component of the liquid application means, such as a shaft, to pass through the wall portion. The wall portion is typically an upright wall portion, preferably a vertical wall portion.

[0039] The apparatus may further comprise additional components selected from the group including pumps, filters, sensors (temperature, solids, density, pressure, etc.), gears, motors, spray systems, a control unit configured to control one or more of these components, and combinations thereof.

[0040] 20. The apparatus of claim 1, further comprising a control unit configured to control the components.

[0041] According to another aspect of the invention, there is provided a method for treating a relief master (P) with a liquid, comprising the steps of: treating the relief master with a liquid to remove debris from the relief master; A method is provided that includes the steps of collecting the liquid and the removed debris, separating the debris having a dimension greater than a predetermined minimum dimension from the liquid, and retaining the debris in the liquid at least after processing to allow at least a portion of the debris to at least partially dissolve in the liquid.

[0042] Preferably, a majority of the separated pieces, preferably at least 80% of the separated pieces, more preferably at least 90% of the separated pieces, are maintained wet with the liquid both during and after processing. More preferably, a majority of the separated pieces, preferably at least 80% of the separated pieces, more preferably at least 90% of the separated pieces, are maintained submerged in the liquid both during and after processing.

[0043] According to an exemplary embodiment, a sieving means is used to perform the separation step, and the separated debris is not absorbed or adsorbed on the sieving means, in such a way that the risk of debris adhering to the sieving means is reduced or avoided.

[0044] Preferably, the sieving means is arranged in a container for storing the sieved liquid, whereby the sieving means is immersed at least when the liquid is in a quiescent state after or before processing of the relief master.

[0045] In an exemplary embodiment, the processing step includes a pre-cleaning step followed by a main cleaning step, for example during the pre-cleaning step carbon and polymer debris can be removed and during the main cleaning step preferably carbon-free debris can be removed, said debris preferably having an average size smaller than the average size of the debris removed during the pre-cleaning step.

[0046] In an exemplary embodiment, the liquid used during the pre-washing step is sent through a first sieving means that is at least partially immersed in the liquid during and after the pre-washing step. The first sieving means may be disposed in a first storage vessel. Optionally, the liquid used during the main washing step is sent through a second sieving means that may be at least partially immersed in the liquid during and after the main washing step. The second sieving means may be disposed in a second storage vessel. The liquid used during the pre-washing step may be conveyed to an outlet, and the liquid used in the main washing step may be directly recirculated through the optional second sieving means and used in the processing step.

[0047] Optionally, the processing step further comprises a cleaning step after the main washing step using fresh liquid, which may be liquid collected at the outlet and cleaned in a separate device.

[0048] In a preferred embodiment, the method further comprises the steps of coupling the relief master to a carrier bar and moving the carrier bar with the coupled relief master during the processing step.

[0049] Preferably, the treatment during the treating step is selected from the group including washing, brushing, rinsing, spraying, optionally combined with any one of the following: developing, heating, cooling, removal of material, treatment with gas or liquid, treatment with electromagnetic waves, and combinations thereof.

[0050] The method may further comprise the step of performing a post-treatment on the relief master, said post-treatment being selected from the group comprising washing, brushing, rinsing, spraying, drying, irradiating, developing, heating, cooling, removing material, treatment with a gas or liquid, sanding, cutting, treatment with electromagnetic waves, and combinations thereof. Also, the method may further comprise the step of performing a pre-treatment on the relief master, said pre-treatment being selected from the group comprising cutting, ablation, exposure to electromagnetic radiation, and combinations thereof.

[0051] Preferably, the method further comprises the step of separating the carrier bar from the processed relief master in a plate separation station of the processing device. Preferably, the carrier bar is moved in a closed loop from the plate bonding station through the processing compartment to the plate separation station and back to the plate bonding station. Preferably, at least two carrier bars are transported simultaneously in the processing compartment. In other words, one or more carrier bars can be automatically circulated in the device. An operator can bring the relief master to be processed to the plate bonding station, then bonding, processing and separation are performed automatically, after which the carrier bar is automatically returned to the plate bonding station. In such a way, an operator does not have to separate or return the carrier bar. This reduces the number of manual interactions required.

[0052] The accompanying drawings are used to illustrate presently preferred, non-limiting, exemplary embodiments of the apparatus and method of the present invention. The above and other advantages of the features and objects of the present invention will become more apparent when read in conjunction with the accompanying drawings, and the invention will be better understood from the following detailed description. [Brief description of the drawings]

[0053] [Figure 1] FIG. 1 is a schematic perspective view of an exemplary embodiment of an apparatus for processing a relief master; [Diagram 2] FIG. 1 is a schematic side view of an exemplary embodiment of an apparatus for processing a relief master. [Diagram 3] FIG. 3 is a detailed schematic diagram of the first sieve means of the embodiment of FIG. 2; [Figure 4] FIG. 3 is a detailed schematic diagram of the second sieve means of the embodiment of FIG. 2; [Diagram 5] FIG. 13 is a detailed schematic diagram of another exemplary embodiment of a sieving means; [Figure 6] 1 is a schematic perspective view of an exemplary embodiment of a carrier bar; [Figure 7] FIG. 2 is a detailed perspective view of a portion of an exemplary embodiment of a plate bonding station; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] 1 shows diagrammatically an apparatus 1000 for treating a relief master, such as a printing plate master P. The apparatus is, for example, a cleaning apparatus for cleaning the relief master with a liquid. However, other treatments are also possible, such as brushing, rinsing, spraying, drying, irradiating, developing, heating, cooling, removing material of the relief master, treating the relief master with a gas or liquid, sanding the relief master, cutting the relief master, treating the relief master with electromagnetic waves, or combinations thereof.

[0055] The device 1000 comprises a transport system 210, 220, 230 with at least one, preferably at least two and even more preferably at least three transport bars 100 intended to be coupled to a relief master. For example, as shown in FIG. 1, four transport bars 100 can be provided in the transport system 210, 220, 230. The transport bar 100 is coupled to the leading edge 3 of the relief master P and preferably extends longer than the entire length of the leading edge 3 so that the ends of the transport bar 100 can be coupled to a transport mechanism of the transport system 210, 220. It is noted that it is also possible to couple several relief masters to the transport bar 100. Preferably, the length of the transport bar 100 is between 100 mm and 1000 mm, more preferably between 1000 mm and 4000 mm.

[0056] The apparatus 1000 comprises a plate bonding station 300 configured to bond a relief master P to the carrier bar 100, a processing section 400 configured to process the relief master P while the carrier bar 100 with the bonded relief master P is moved through the processing section 400, and a plate separation station 500 configured to separate the processed relief master P from the carrier bar 100. Preferably, the transport systems 210, 220, 230 are configured to automatically move each carrier bar 100 from the plate bonding station 300 through the processing station 400 to the plate separation station 500 after being bonded to the relief master P in the plate bonding station 300 and automatically return from the plate separation station 500 to the plate bonding station 300 after being separated from the processed relief master P, such that the carrier bars 100 move in a closed loop through the apparatus 1000. In the illustrated example of FIG. 1, four carrier bars 100 circulate through the apparatus 1000. However, the present invention also encompasses an embodiment in which the transport bar is manually returned from the plate separating station 500 to the plate combining station 300 .

[0057] In a preferred embodiment, each carrier bar 100 is provided with a number of penetrating elements 110 (here in the form of pins or rods) and the plate bonding station 300 is configured to engage the number of penetrating elements 110 in a region near the leading edge 3 of the relief master P. In FIG. 1, the relief master P has a leading edge 3, a trailing edge 4, both perpendicular to the forward transport direction Tf of the relief master P through the apparatus 1000, and two side edges 1, 2 parallel to the forward transport direction Tf. The region near the leading edge 3 of the relief master P is coupled to the number of penetrating elements 110 of the carrier bar 100. FIG. 6 shows a more detailed exemplary embodiment of the carrier bar 100. The number of penetrating elements 110 preferably have sharp tips and the plate bonding station 300 is preferably configured to cause the number of penetrating elements 110 to at least partially penetrate or pass through the non-perforated region near the leading edge 3 of the relief master P. However, it should be noted that according to another exemplary embodiment, the apparatus 1000 of Fig. 1 may be used with a transport bar 100 provided with a plurality of piercing elements 110 that do not have sharp tips. For example, before bringing the relief master P to the plate bonding station 300, an area near the leading edge 3 of the relief master P may be pre-drilled, whereby the plurality of piercing elements 110 can be placed through pre-drilled holes in the area near the leading edge 3.

[0058] The processing section 400 has an entrance side 410 and an exit side 420. The carrier bar 100 with the relief master P coupled thereto is moved from the entrance side 410 to the exit side 420 through the processing section 400, the carrier bar 100 moving in a forward transport direction Tf. Between the exit side 420 of the processing section 400 and the plate separation station 500, a plate release zone 600 is provided. The relief master P is fully withdrawn from the processing section 400 into the plate release zone 600 by the transport system before being separated from the carrier bar 100 in the separation station 500. In such a way, the relief master P can be released into the plate release zone 600 when it is separated from the carrier bar 100. At the bottom of the plate release zone 600, a removal means may be provided that is configured to remove the processed relief master P after it is separated from the carrier bar 100 in the plate separation station 500. In the illustrated embodiment, the removing means 700 is a trolley configured to receive the processed relief master P into the plate release zone 600 and to be moved from the plate release zone 600 so as to facilitate the transfer of the relief master from the plate release zone. For example, if the apparatus 1000 is a washer, an operator can transfer the cleaned relief master P to a dryer for drying the cleaned relief master. In other non-illustrated embodiments, the removing means 700 can be a carrier, a robot, a moving belt, at least one rotating drum, etc. Such a device can also be configured to transfer the processed relief master P from the plate release zone 600 after it has been separated at the plate separation station 500.

[0059] In the embodiment of Fig. 1, the transport system comprises a forward transport mechanism comprising a first transport mechanism 210 on one side of the apparatus 1000 and a second transport mechanism 220 on the other side of the apparatus 1000. The transport mechanisms 210, 220 are configured to transport the transport bar 100 with the relief master P coupled thereto in a forward transport direction Tf at least from the entrance side 410 to the exit side 420 of the processing compartment 400, and optionally from the exit side 420 to the plate separation station 500. For that purpose a first outer end 101 of the transport bar 100 is coupled to the first forward transport mechanism 210 and a second outer end 102 of the transport bar 100 is coupled to the second forward transport mechanism 220. As shown in Fig. 7, the transport system 210 may comprise a bar coupling means 215 configured to couple the transport bar 100, more specifically the first outer end 101 and the second outer end 102 of the transport bar, to the first and second forward transport mechanisms 210, 220. Although only the first outer end 101 and the first transport mechanism are shown in Fig. 7, it is understood that the second outer end 102 and the second transport mechanism 220 may be embodied in a similar manner. The bar coupling means 215 may be configured, for example, to push or move the transport bar 100 towards the first and second forward transport mechanisms in order to couple the outer ends 101 and 102 of the transport bar 100 to the forward transport mechanisms 210, 220. In the embodiment of FIG. 1, the processing section 400 has first and second opposing sides 430, 440 extending in a forward transport direction Tf, and the first and second forward transport mechanisms 210, 220 extend on the first and second opposing sides 430, 440 of the processing section 400, respectively.

[0060] The transport system further comprises a rear transport mechanism 230 configured to transport the transport bar 100 from the plate separating station 500 back to the plate combining station 300. In the illustrated embodiment of FIG. 1, the rear transport mechanism 230 is located at the upper side of the apparatus 1000. However, in other embodiments, the rear transport mechanism 230 can be located in a lower part of the apparatus 1000 below the front transport mechanisms 210, 220. The rear transport mechanism 230 can comprise any one of the following: one or more belts, one or more chains, one or more lead screws, linear motors, or combinations thereof. In FIG. 1, the rear transport mechanism 230 is located centrally above the processing compartment 400. However, the rear transport mechanism 230 can also be realized with first and second rearward transport mechanisms located on either side of the processing compartment 400 above or below the first and second front transport mechanisms 210, 220. Alternatively, the rear transport mechanism may be arranged at a side of the processing section, and optionally the transport bar may be rotated and transported rearward in a vertical position. However, in order to reduce the footprint of the apparatus, the rear transport mechanism is preferably arranged above or below the first and second front transport mechanisms 210, 220. As shown in FIG. 1, the rear transport mechanism 230 is arranged partially above the processing section 400, and the transport system further comprises an upper transport mechanism 250 configured to move the separated transport bar 100 in the plate separating station 500 upwards towards the rear transport mechanism 230. For example, the upper transport mechanism 250 can move the transport bar 100 in an upward direction Tu, typically vertically, towards the rear transport mechanism 230, and the rear transport mechanism moves the transport bar 100 in a rear transport direction Tb opposite to the forward transport direction Tf back to the plate bonding station 300. The upper transport mechanism 250 may comprise any one or more of a magnetic means, an electromagnetic means, a clamping means, a vacuum means, a linear motor, a chain, a belt, a lead screw, a piston, or combinations thereof. In other embodiments where the rear transport mechanism 230 is located below the front transport mechanism, a lower transport mechanism may be provided.The downward transport mechanism may comprise any one or more of magnetic means, electromagnetic means, clamping means, vacuum means, linear motors, chains, belts, lead screws, pistons or combinations thereof, or may simply be caused by gravity.

[0061] Fig. 6 shows a more detailed exemplary embodiment of the carrier bar 100. The carrier bar 100 is provided with a first connecting portion 121 and a second connecting portion 122 at the first outer end 101 and the second outer end 102. In this case, the connecting portions 121, 122 consist of connecting means used in combination with a lead screw. The carrier bar 100 is provided with a penetrating element 110. The carrier bar 100 is equipped with a channel 120 that allows an alignment pin to pass through the carrier bar 100 from below the carrier bar.

[0062] 6, in an exemplary embodiment, the first forward transport mechanism 210 comprises a first lead screw, and the first coupling portion 121 is configured to be coupled to the first lead screw 210. Similarly, the second forward transport mechanism 220 may be provided with a second lead screw that may be coupled to a second coupling portion 122. In other embodiments, the first and / or second forward transport mechanisms 210, 220 may comprise other transport means, such as chains or belts, and the first and second coupling portions 121, 122 may be adapted accordingly.

[0063] 2, 3 and 4 show in detail an exemplary embodiment of an apparatus 1000 for treating a relief master P with a liquid L. The apparatus 100 comprises a processing section 400 with a processing means 450 comprising a number of liquid application rollers 450a, 450b, 450c. A transport system (not shown in FIG. 2) similar to that shown in FIG. 1 can be used to move a transport bar (not shown) with a relief master P bonded thereto through the processing section 400 in a direction Tf. The processing means 450 is configured to treat the relief master P with the liquid L and to remove debris from the relief master P. The apparatus further comprises a liquid collection system 900 configured to receive the liquid and the debris S from the processing means 450. Although only two debris S are shown diagrammatically, a person skilled in the art will understand that there are many more debris. The liquid collection system 900 is further configured to separate debris S having dimensions larger than a predetermined minimum dimension from the liquid L. The debris S may for example comprise cured and / or uncured particles, residues, film parts, flocks, gelled debris, etc., but also any other undesired parts such as screws or nuts or bristles. The liquid collection system 900 is further configured to allow at least a part of said debris S to be at least partially dissolved in the liquid L during processing, but also when the liquid L is in a quiescent state after or before the processing of the relief master P by the processing means 450, i.e. when the processing means 450 is in operation or not. The screws do not dissolve, but in particular the uncured particles, the polymer particles and other debris removed from the relief master can. Preferably, as shown in FIG. 2, the liquid collection system 900 is configured to keep most of the separated debris S immersed in the liquid L, both when the processing means 450 is in operation or not.

[0064] The processing means 450 includes one or more pre-cleaning members 450a, one or more main cleaning members 450b downstream of the pre-cleaning members 450a, and one or more cleaning members 450c downstream of the main cleaning members 450b. It should be noted that in other embodiments of the present invention, only the pre-cleaning members 450a and / or the main cleaning members 450b may be provided.

[0065] The liquid collection system 900 comprises a first sieving means 910 removably arranged in a first container 901 for receiving the liquid used by the pre-cleaning member 450a and a second sieving means 920 removably arranged in a second container 902 for receiving the liquid used by the main cleaning member 450b. In other embodiments, only one sieving means or more than two sieving means may be provided. In the example of FIG. 2, both the first sieving means 910 and the second sieving means are at least partially immersed in the liquid. However, in other embodiments, only the first sieving means or only the second sieving means may be at least partially immersed in the liquid both during and after the treatment. In yet another embodiment, the sieving means are not immersed in the quiescent state of the liquid, as will be further explained in connection with the example of FIG. 5. The first container 901 may have a volume larger than 20 liters, or even larger than 30 liters, for example between 35 liters and 100 liters. The second vessel 902 may have a volume greater than 50 liters, or greater than 100 liters, or even greater than 200 liters, for example between 200 and 600 liters.

[0066] The liquid collection system 900 is further configured to transport liquid L that has passed through the first sieving means 910 into the first container 901 to the outlet 930 and to recirculate liquid that has passed through the second sieving means 920 into the second container 902 directly to the processing means 450 (see arrow R).

[0067] The apparatus further comprises liquid conveying means (not shown), such as a pump or suction means, which is configured to cause a first flow of at least 0.3 litres per minute, preferably at least 0.6 litres per minute through the first sieving means, and a second flow of at least 10 litres per minute, preferably at least 30 litres per minute through the second sieving means. Thus, the pre-wash uses a much slower first flow compared to the faster second flow used for the main wash.

[0068] Preferably, the liquid collection system 900 is part of a liquid circulation system configured to circulate the collected liquid back to the treatment means 450. In the example of Fig. 2, the liquid used for the pre-wash is recycled directly to the treatment means 450 without being cleaned or otherwise treated, whereas the liquid used for the main wash is sent to a separate device 2100, for example a distillation device, to be cleaned or otherwise treated before being returned as fresh liquid Ln to an inlet 940 of the treatment compartment 400. This inlet 940 is arranged such that the fresh liquid Ln is used by one or more cleaning members 450c.

[0069] As shown in Figure 3, the first sieving means 910 is incorporated into a basket having a closed bottom portion 913 and peripheral portions 911, 912 forming the sieving means 910. In an alternative embodiment, the bottom portion 913 may be a sieving surface. The peripheral sieving portions 911, 912 are oriented at an angle of at least 30° to the horizontal, preferably substantially vertical as shown in Figure 3. In this way, all the debris S intercepted by the sieves 911, 912 can fall into the liquid L.

[0070] 4, a second sieve means 920 is also incorporated into the basket, but now the basket has a sieve bottom portion 923 and closed peripheral portions 921, 922. The peripheral portions 911, 912 are oriented at an angle of at least 30° to the horizontal. In this way, all the debris S intercepted by the peripheral portions 921, 922 can fall into the liquid L.

[0071] Figure 5 shows a variant of the embodiment of figure 3. In figure 5, the sieve means 910 is incorporated into a basket having a closed bottom tray 913 arranged to hold a certain amount of liquid and peripheral parts 911, 912 forming the sieve means 910. The peripheral sieve parts 911, 912 are oriented at an angle of at least 30° to the horizontal, preferably substantially vertical as shown in figure 3. In this way, all the debris S stopped by the sieves 911, 912 can fall into the bottom tray 913. In this way, the sieve parts 911 and 912 do not have to be immersed in the liquid L, but allow all the debris S to dissolve in the liquid L in the bottom tray 913.

[0072] The sieving means 910, 920 may comprise any one or more of a wire mesh, a grid of a liquid stable material, a plate with a plurality of holes. The sieving means 910, 920 may have openings with dimensions smaller than 5 mm, preferably in the range of 0.1 mm to 3 mm, more preferably 0.5 mm to 2 mm.

[0073] Preferably, the sieving means 910, 920 are removable. In the embodiments of Figures 2, 3, 4 and 5, the sieving means are integrated into a basket, which is removable. In this way, the basket can be removed for cleaning.

[0074] Preferably, the sieving means 910, 920 are made of metal, alloy, plastic, glass, ceramic, natural fibers or combinations thereof. Preferably, the sieving means are made from woven or non-woven forms of fibers, filaments or wires, preferably from materials configured not to absorb or adsorb debris S. Preferably, the sieving means 910, 920 are configured to retain debris having a maximum dimension greater than 5 mm, preferably greater than 3 mm, more preferably greater than 2 mm.

[0075] In the embodiment of Figure 1, the processing section 400 of Figure 2 may be implemented. A plurality of liquid application rollers 450a, 450b, 450c may be arranged with their axes parallel to the transport bar 100. The first and second transport mechanisms 210, 220 extend perpendicular to the axis A of the liquid application rollers 450a, 450b, 450c on first and second sides of the liquid application rollers, respectively.

[0076] A relief master usually comprises a support layer made of a first material and an additional layer made of a second material different from said first material. The support layer may be a flexible metal, a natural or artificial polymer, paper or a combination thereof. Preferably, the support layer is a flexible metal or polymer film or sheet. In the case of a flexible metal, the support layer may comprise a thin film, a sieve-like structure, a mesh-like structure, a woven or non-woven structure, or a combination thereof. Steel, copper, nickel or aluminum sheets are preferred and may be about 50 to 1000 μm thick. In the case of a polymer film, the film is dimensionally stable but bendable and may be made, for example, of polyalkylenes, polyesters, polyethylene terephthalates, polybutylene terephthalates, polyamides and polycarbonates, polymers reinforced with woven, non-woven or layered fibers (e.g. glass fibers, carbon fibers, polymer fibers), or a combination thereof. Preferably, polyethylene and polyester foils are used, the thickness of which may be in the range of about 100 to 300 μm, preferably in the range of 100 to 200 μm.

[0077] The relief master can support at least one additional layer. For example, the additional layer can be any one of a directly engravable layer (e.g. by a laser), a solvent or water developable layer, a thermally developable layer, a photosensitive layer, or a combination of a photosensitive layer and a mask layer. Optionally, one or more further additional layers can be provided on top of the additional layer. Such one or more further additional layers can comprise a cover layer on top of all other layers, which cover layer is removed before the imageable layer is imaged. The one or more additional layers can comprise a relief layer and an antihalation layer between the support layer and the relief layer or on the side of the support layer opposite the relief layer. The one or more additional layers can comprise a relief layer, an imageable layer, and one or more barrier layers between the relief layer and the imageable layer that prevent diffusion of oxygen. One or more adhesive layers can be arranged between the different layers mentioned above that ensure proper adhesion of the different layers.

[0078] In a preferred embodiment, the relief master comprises a support layer made of a polymeric material polyester and an additional layer made of a directly engravable material such as a resin material. An optional layer may then be a laser ablation layer. In an exemplary embodiment, the relief master may include at least a dimensionally stable support layer, a relief layer and an imageable mask layer. Optionally, further layers may be present. A cover layer may be present on top of all other layers, which is removed before the imageable mask layer is imaged. An antihalation layer may be present between the support layer and the relief layer, or the antihalation layer may be arranged on the side of the support layer opposite the relief layer. One or more barrier layers may be present between the relief layer and the imageable mask layer, preventing the diffusion of oxygen. One or more adhesive layers may be arranged between the different layers mentioned above, ensuring proper adhesion of the different layers. One or more layers may be removable by treatment with a liquid. The liquids used may be the same or different for the different layers. Preferably, the liquids used are different.

[0079] In a preferred embodiment, the relief master comprises a photosensitive layer and a mask layer. The mask layer can be ablated or change transparency during processing, forming a mask with transparent and opaque areas. Preferably, the mask layer and / or the barrier layer are removed in a pre-cleaning section of the apparatus, as they may contain materials that may cause problems during further process steps or during use of the final relief. Under the transparent areas of the mask, the photosensitive layer undergoes a change in solubility and / or flowability during irradiation. This change is used to generate the relief in one or more subsequent steps by removing parts of the photosensitive layer. The change in solubility and / or flowability may be achieved by photoinduced polymerization and / or crosslinking, making the irradiated areas less soluble. In other cases, the electromagnetic radiation can cause the breaking of bonds or the cleavage of protective groups, making the irradiated areas more soluble. Preferably, a process using photoinduced crosslinking and / or polymerization is used.

[0080] The liquids that may be used in the embodiments of the present invention include, inter alia, water, aqueous solutions, solvents and combinations thereof. The nature of the liquid used is guided by the nature of the master used. If the layer to be removed is soluble, emulsifiable or dispersible in water or aqueous solutions, water or aqueous solutions may be used. If the layer is soluble, emulsifiable or dispersible in organic solvents or mixtures, organic solvents or mixtures may be used. In the case of organically developable masters, different organic solvents or mixtures thereof may be used.

[0081] The liquid may be water or an aqueous solution that may contain other components such as salts, acids, bases, emulsifiers, dispersing aids, viscosity modifiers, surfactants, or combinations thereof. Salts, acids, and bases may be used to control the pH of the liquid. Emulsifiers and dispersing aids may be used to enhance the liquid's ability to uptake materials and stabilize such emulsions and dispersions. The aqueous solution may contain organic solvents such as alcohols, esters, ethers, or hydrocarbons, or combinations thereof.

[0082] The liquid may be an organic solvent or a mixture thereof. For example, developers may be used which contain naphthenes or aromatic petroleum fractions in a mixture with alcohols, such as benzyl alcohol, cyclohexanol, or aliphatic alcohols having 5 to 10 carbon atoms, and optionally also further components, such as cycloaliphatic hydrocarbons, terpenoid hydrocarbons, substituted benzenes such as diisopropylbenzene, esters having 5 to 12 carbon atoms, or glycol ethers or water. Suitable cleaners are disclosed, for example, in EP-A-332070 or EP-A-433374. Furthermore, the solvents and solvent mixtures may contain other components, such as salts, acids, bases, emulsifiers, dispersing aids, viscosity modifiers, antistatic agents, water, surfactants or combinations thereof. Preferably, the liquids containing organic solvents must have a high flash point, preferably above 60°C. For safety reasons, as well as to reduce the cost and complexity of the associated equipment, the temperature when using organic solvents must be 5°C to 15°C lower than the flash point of the cleaner mixture used.

[0083] While the principles of the present invention have been described above with reference to specific embodiments, it should be understood that this description is made purely by way of example and not as a limitation on the scope of protection determined by the appended claims.

Claims

1. 1. An apparatus for treating a relief master (P), such as a printing master, with a liquid (L), comprising: a processing compartment (400) having a processing means (450) configured to process a relief master with a liquid and to remove debris from said relief master; and a liquid collection system (900) comprising a container (901, 902) configured to receive liquid and removed debris from said processing means (450) and sieving means (910, 920) arranged in said container, said liquid collection system configured to separate debris having a dimension greater than a predetermined minimum dimension from said liquid and to allow at least a portion of the separated debris to at least partially dissolve in said liquid, at least when said liquid is in a quiescent state after or before processing of the relief master by said processing means.

2. 2. The apparatus of claim 1, wherein the liquid collection system (900) is configured to keep a majority of the separated debris wet with the liquid both when the processing means is operating and when the processing means is not operating.

3. 3. The apparatus of claim 1 or 2, wherein the liquid collection system (900) is configured to maintain a majority of the separated debris submerged in the liquid both when the processing means is operating and when the processing means is not operating.

4. The apparatus of any one of claims 1 to 3, wherein the liquid collection system (900) is part of a liquid circulation system (2000) configured to circulate the collected liquid back to the processing means (450).

5. Apparatus according to any one of the preceding claims, wherein said sieving means (910, 920) is at least partially immersed in said liquid.

6. An apparatus as described in any one of claims 1 to 5, wherein the sieving means is disposed within the container (901, 902) so that the sieving means is immersed at least when the liquid is in a quiescent state after or before processing of the relief master by the processing means.

7. Apparatus according to any one of the preceding claims, wherein the sieving means (910) comprises sieving surfaces (911, 912) oriented at an angle of at least 30° to the horizontal, preferably vertically.

8. 8. The apparatus according to any one of the preceding claims, wherein the sieving means (910, 920) comprises one or more of a wire mesh, a grid, a plate with a plurality of holes, and wherein the sieving means is made of a material that is stable in the liquid.

9. Apparatus according to any one of the preceding claims, wherein said sieving means (910, 920) have openings with a size smaller than 5 mm, preferably in the range of 0.1 mm to 3 mm, more preferably 0.5 mm to 2 mm.

10. Apparatus according to any one of the preceding claims, wherein said sieving means (910, 920) are integrated into a basket.

11. 11. The apparatus of claim 10, wherein said basket has a closed bottom tray configured to hold a volume of liquid and a peripheral portion forming said sieving means.

12. Apparatus according to any one of the preceding claims, wherein said sieving means (910, 920) are removable.

13. Apparatus according to any one of the preceding claims, wherein said sieving means (910, 920) are made of metal, alloy, plastic, glass, ceramic, natural fibres or combinations thereof.

14. The apparatus of any one of claims 1 to 13, wherein the liquid collection system (900) is configured not to absorb or adsorb the debris.

15. Apparatus according to any one of the preceding claims, wherein the sieving means (910, 920) is configured to retain fragments having a maximum dimension greater than 5mm, preferably greater than 3mm, more preferably greater than 2mm.

16. Apparatus according to any one of claims 1 to 15, wherein the treatment means (450) comprises one or more pre-cleaning members (450a) and one or more main cleaning members (450b) downstream of the pre-cleaning members, and the sieving means comprises a first sieving means (910) for receiving liquid used by the pre-cleaning members (450a) and a second sieving means (920) for receiving liquid used by the main cleaning members (450b).

17. 17. Apparatus according to claim 16, wherein the first and / or the second sieving means are at least partially immersed in the liquid, preferably at least the first sieving means is at least partially immersed in the liquid both during and after treatment.

18. 18. The apparatus of claim 16 or 17, wherein the liquid collection system is further configured to convey liquid that has passed through the first sieving means (910) to an outlet and to recirculate liquid that has passed through the second sieving means (920) directly to the processing means (450).

19. 19. Apparatus according to claim 18, further comprising liquid conveying means configured to produce a flow of at least 0.3 litres per minute, preferably at least 0.6 litres per minute through said first sieving means and a flow of at least 10 litres per minute, preferably at least 30 litres per minute through said second sieving means.

20. 19. Apparatus according to claim 16, 17 or 18, wherein the treatment means (450) further comprises one or more cleaning members (450c) downstream of the one or more main washing members.

21. 21. Apparatus according to claim 20, wherein the processing compartment (400) is provided with an inlet for fresh liquid (Ln) arranged for said fresh liquid to be used by the one or more cleaning members (450c).

22. Apparatus according to any one of the preceding claims, further comprising a transport system (210) configured to move the relief master through the processing compartment.

23. 23. The apparatus according to claim 22, wherein the transport system comprises at least one transport bar (100) provided with a coupling portion (121) configured to be coupled to the relief plate master, the transport system being configured to transport the transport bar through the processing compartment.

24. 24. Apparatus according to claim 23, wherein the connecting portion (121) of the carrier bar comprises at least one penetrating element (110), preferably a plurality of penetrating elements.

25. Apparatus according to any one of claims 22 to 24, wherein the conveying system (210) comprises any one of one or more lead screws, preferably pairs of lead screws, one or more chains or belts, preferably pairs of chains or belts.

26. A method for treating a relief master (P) with a liquid, comprising the steps of: treating the relief master with a liquid to remove debris from the relief master; collecting the liquid and the removed debris in a container (901, 902), separating debris having a dimension greater than a predetermined minimum dimension from said liquid using a sieving means (910, 920) disposed within said container, and allowing at least a portion of said separated debris to at least partially dissolve in said liquid after at least said processing.

27. 27. The method of claim 26, wherein a majority of the separated pieces remain wet with the liquid both during and after processing.

28. 28. The method of claim 26 or 27, wherein the majority of the separated pieces are maintained submerged in the liquid both during and after processing.

29. A method according to any one of claims 26 to 28, wherein the separated fragments are not absorbed or adsorbed by the sieving means.

30. The method according to any one of claims 26 to 29, wherein the sieving means is arranged in the container (901, 902) for storing sieved liquid, whereby the sieving means is immersed at least when the liquid is in a quiescent state after or before the processing of the relief master.

31. A method according to any one of claims 26 to 30, wherein the treating step comprises a pre-wash step followed by a main wash step.

32. 32. The method of claim 31 , wherein the liquid used during said pre-washing step is passed through a first sieve means which is at least partially submerged in said liquid during and after said pre-washing step.

33. 33. The method according to claim 31 or 32, wherein the liquid used during the pre-wash step is conveyed to an outlet and the liquid used in the main wash step is recycled and used in the treating step.

34. 34. The method of claim 31, 32 or 33, wherein the treating step further comprises a cleaning step after the main washing step using fresh liquid (Ln).

35. The method according to any one of claims 26 to 34, further comprising the steps of coupling the relief master to a carrier bar and moving the carrier bar with the coupled relief master during the processing step.

36. 36. The method according to any one of claims 26 to 35, wherein the treatment during the treating step is selected from the group comprising washing, brushing, rinsing, spraying, developing, heating, cooling, removal of material, treatment with gas or liquid, treatment with electromagnetic waves, and combinations thereof.

37. 37. The method according to any one of claims 26 to 36, further comprising the step of performing a post-treatment on the relief master, said post-treatment being selected from the group comprising washing, brushing, rinsing, spraying, drying, irradiating, developing, heating, cooling, removing material, treating with gas or liquid, sanding, cutting, treating with electromagnetic waves, and combinations thereof.

38. 38. The method according to any one of claims 26 to 37, further comprising the step of performing a pre-treatment on the relief master, the pre-treatment being selected from the group comprising cutting, ablation, exposure to electromagnetic radiation, and combinations thereof.

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