3d-printed sleeve for printing plate

Abstract

A sleeve (200) for use with a printing plate (100), said sleeve being 3D printed and comprising: a cylindrical inner layer (220) configured to be mounted on an adapter sleeve (300) and / or on a printing mandrel (400), a cylindrical outer layer (210), and at least a first infill layer (230) between the outer layer and the inner layer.

Description

[0001] 3D-PRINTED SLEEVE FOR PRINTING PLATE

[0002] FIELD

[0003] The field of the invention relates to a sleeve, such as a printing sleeve for mounting a printing plate, preferably a flexographic printing plate, or an adaptor sleeve for mounting a printing sleeve, and to methods for producing such sleeves.

[0004] BACKGROUND

[0005] Flexographic printing is a printing process, where a printing ink is transferred from the raised portions of the printing plate onto a substrate. Flexographic printing uses flexible printing plates allowing printing on many different types of substrates (paper, cardboard, films). Alongside offset printing and gravure printing, flexographic printing is one of the most important printing processes in the packaging industry.

[0006] With the flexographic printing machines, a distinction is made between multi-cylinder and centralcylinder printing machines. In the case of a central-cylinder printing machine, the individual printing units are arranged around a central cylinder over which the substrate web is passed. In the case of multi-cylinder printing machines, the individual printing units are arranged in series. The printing units consist of a cylinder assembly with a mandrel and a printing sleeve, an engraved roll for inking the printing form, and an ink trough from which the printing ink goes onto the engraved roll.

[0007] At its most simple, the cylinder assembly consists of a mandrel onto which the flexographic printing plate is adhered. A great advantage of flexographic printing over other printing processes is its format variability. Through the use of mandrels with different diameters, it is possible for different formats to be printed. A term used by the skilled person is that of the repeat length. The repeat length corresponds to the printed length on one complete rotation of the cylinder assembly. Changing over the heavy steel cylinders, however, takes time. Accordingly, flexographic printing machines are nowadays available with which the repeat length can be altered more simply by means of adaptor sleeves. The adaptor sleeve is arranged onto the mandrel. The wall thicknesses of customary adaptor sleeves typically range from 7 mm to 300 mm. A printing sleeve is arranged on the adaptor sleeve, said printing sleeve carrying the printing plate, usually pre -mounted. Adaptor sleeves and printing sleeves are nowadays generally also referred to as sleeves. Sleeves are often manufactured of plastic. They are significantly lighter than corresponding steel cylinders, and can therefore be changed over much more easily in the printing machine.

[0008] The construction of a sleeve is usually as follows (from inside to outside): a multilayered inner layer comprising a thin inner layer of GRP material (GRP = glass-fiber reinforced plastic), a thin compressible layer and an outer layer of GRP material; an intermediate layer of variable thickness; and an outer layer. The layered structure of the inner layer allows the sleeve to be expanded by means of compressed air. This inner layer customarily has a thickness of typically 1 mm up to 4 mm. The intermediate layer may be a polyurethane foam layer with a thickness of several mm to several cm. The function of this layer is to build up the layer thickness, or to produce the desired repeat length. The outer layer may be a thin GRP layer, to ensure the mechanical and chemical stability of the sleeve.

[0009] Since such a sleeve is made of several very different materials recycling is difficult. The layers must be separated in order to have single component materials. Separation of the layers is tedious and imperfect. Therefore the sleeves are mostly dumped on a landfill or burned. Hence there is a need for a sleeve which is easier to recycle and preferably made of one material.

[0010] In order to ensure that an adaptor sleeve is easily engaged, the mandrel may have air bores which emit a flow of compressed air. As a result of the compressed air, an air cushion is built up, thereby expanding the internal diameter of the adaptor sleeve, and the adaptor sleeve glides over the mandrel. If the supply of air is halted, the adaptor sleeve clamps to the mandrel and is fixed firmly on it. To allow the printing sleeve to be pulled onto the adaptor sleeve, the adaptor sleeve likewise customarily contains an air conduction system. In the prior art there are two known systems here. Either the compressed air is guided directly from the mandrel (bridge system), or there is a separate air connection to one of the end faces of the adaptor sleeve (Airo system).

[0011] SUMMARY

[0012] An object of embodiments of the invention is to provide an improved recyclable and lightweight sleeve with good mechanical stability.

[0013] According to a first aspect of the invention there is provided a sleeve for use with a printing plate. The term sleeve mentioned in this application concerns a printing sleeve and / or an adaptor sleeve. The sleeve is 3D printed and comprises a cylindrical inner layer configured to be mounted on an adapter sleeve and / or on a printing mandrel, a cylindrical outer layer, and at least a first infill layer between the outer layer and the inner layer.

[0014] Thus, the outer layer, the at least one infill layer and the inner layer can be printed in one piece providing a sleeve which can be easily recycled. Printing the sleeve also simplifies the production of the sleeve, because fewer machines, processes and materials are needed. Further, by providing at least one infill layer, the required mechanical properties can be provided to the sleeve whilst reducing the weight of the sleeve.

[0015] Preferably, the first infill layer comprises a plurality of discrete elements, wherein a set of said plurality of discrete elements is located at a distance of each other seen in an axial direction and / or a circumferential direction of the sleeve, wherein each discrete element is surrounded by a void space. Such discrete elements can provide the required stability to bridge the gap between the outer layer and the inner layer, whilst at the same time having a reduced weight.

[0016] Preferably, each discrete element extends substantially in a radial direction of the sleeve or in a direction between 0° and 40° from the radial direction, more preferably between 0° and 20° from the radial direction, even more preferably within 10° from the radial direction. Preferably, the discrete elements are pillar-like structures and / or wall-like structures. Preferably, the plurality of discrete elements comprises more than 50 discrete elements, more preferably more than 100 discrete elements, even more preferably more than 150 discrete elements. The discrete elements may be placed according to any pattern, for example such that axial channels and / or circumferential channels and / or spiral channels are formed between the discrete elements.

[0017] Preferably, the discrete elements may be arranged according to a regular pattern. Such regular patterns could be for example a hexagonal, a cubic, a checkerboard or a wavy pattern or combinations thereof. With a cubic pattern is meant, that the discrete elements are arranged at the corners of a quadrate, with a hexagonal pattern it is meant that the discrete elements are arranged at the corners of a hexagon, etc.

[0018] Preferably, the pattern may be arranged in a way that a periodicity direction of the pattern is oriented parallel to the cylinder axis or inclined to the cylinder axis (resulting in a spiraling pattern). The angle between the axial direction of the sleeve and the direction of a periodicity direction of a pattern may be preferably in the range of 0° to 70°, more preferably 0° to 50°. A periodicity direction of a pattern is a direction wherein the centers of neighboring discrete elements are arranged on a line. In that manner a robust, sufficiently rigid lightweight first infill layer can be obtained.

[0019] Preferably the discrete elements are arranged to form a plurality of rings, each ring comprising multiple discrete elements arranged circumferentially at a distance of each other, wherein preferably discrete elements of adjacent rings are rotated around the axial direction of the sleeve with respect to each other, so that seen in the axial direction the discrete elements are not aligned.. The rotation angle for each of the rings with respect to an adjacent ring can be the same or different, for example between 0 and 45 degrees, preferably between 0 and 15 degrees.

[0020] In an exemplary embodiment, each discrete element has a cross section perpendicular on a radial direction of the sleeve, and said cross section is smaller in a middle portion of the discrete element than in end portions of the discrete element.

[0021] Each discrete element has a cross section perpendicular on a radial direction of the sleeve, and said cross section may have for example any one of the following shapes: circle, polygon, such as square or pentagon or hexagon or octagon, oval or combinations thereof. Optionally, the shape may vary in the radial direction.

[0022] In an embodiment, the first infill layer comprises a plurality of wall elements. Preferably, each wall element extends substantially in a radial direction of the sleeve or in a direction between 0° and 40° from the radial direction, more preferably between 0° and 20° from the radial direction, even more preferably within 10° from the radial direction.

[0023] In another embodiment the first infill layer comprises a plurality of wall elements extending radially and axially, wherein the wall elements have preferably a substantially constant thickness, and thus the distance between adjacent wall elements gradually increases seen in an outward radial direction. Preferably, the distance between adjacent wall elements at an inner portion of the first infill layer is smaller than the distance between adjacent wall elements at an outer portion of the first infill layer. Preferably, the distance between adjacent wall elements at the inner portion of the first infill layer is in the range of 0 to 10 mm, preferably in the range of 0 to 5 mm. Preferably, the distance between adjacent wall elements at the outer portion of the first infill layer is in the range of 1 to 30 mm, more preferably 1 to 20 mm, e.g. in the range 1 mm to 10 mm. Preferably, the angle between the axial direction of the sleeve and a length direction (not the radial direction) of the wall elements is in the range of 0° to 70°, more preferably 0° to 50°. Optionally, the plurality of wall elements may be interconnected. This may further improve the rigidity of the infill layer.

[0024] Optionally, the plurality of interconnected wall elements delimits a plurality of cavities. Each cavity has a cross section perpendicular on a radial direction of the sleeve, and said cross section may have any one of the following shapes: circle, polygon, such as square or pentagon or hexagon or octagon, oval or combinations thereof. Preferably the cavities may have one or more of the following shapes: ellipsoids such as spheres, a polyhedron such as a tetrahedron, a hexahedron or an octahedron, a cone. Preferably, the plurality of cavities comprises more than 50 cavities, preferably more than 100 cavities, more preferably more than 150 cavities. The cavities have a volume in the range of 0,001 cm3to 100 cm3, preferably 0,01 to 80 cm3, more preferably 0,05 to 40 cm3. Preferably, the cavities comprise a volume larger than 0,001, more preferably 0,01 and even more preferably 0,05 cm3.

[0025] Preferably, the sleeve further comprises an intermediate cylindrical layer and a second infill layer between the intermediate layer and the inner layer, wherein the first infill layer is located between the outer layer and the intermediate layer. Preferably, the second infill layer is more compressible than the first infill layer. In this way the inner layer can be pressed slightly inward facilitating the mounting of the sleeve.

[0026] Preferably, the second infill layer comprises a plurality of walls extending in an axial direction between the inner layer and the intermediate layer. This can provide flexibility and compressibility in the radial direction to the inner layer. For example, the thickness of the walls of the second infill layer may be in the range of 0,1 mm to 10 mm, preferably 0,1 mm to 5 mm. The walls of the second infill layer may comprise an angle alpha between the wall and the tangent of the surface of the inner layer in the range of 0° to 60°, preferably in the range of 5° to 40°, wherein the smaller angle is measured.

[0027] Optionally, the second infill layer comprises a plurality of tubular bodies having an axis extending in an axial direction of the sleeve. The plurality of tubular bodies may be located at a distance of each other seen in a circumferential direction of the sleeve.

[0028] Preferably the thickness of the walls of the tubular bodies are in the range of 0,1 mm to 10 mm, preferably 0, 1 mm to 5 mm. The tubular shaped bodies may have an outer diameter in the range of 1 mm to 30 mm, preferably 2 mm to 10 mm. In one embodiment the tubular bodies comprise an angle beta between the walls of the tubular bodies and the tangent of the surface of the inner layer in the range of 0° to 60°, preferably in the range of 5° to 40°, wherein the smaller angle is measured.

[0029] Optionally, the sleeve further comprises a further cylindrical intermediate layer and a third infill layer between the outer layer and the further cylindrical intermediate layer, wherein the first infill layer is located between the cylindrical intermediate layer and the further cylindrical intermediate layer. Preferably, the third infill layer is more compressible than the first infill layer. In this way also the outer layer can be made slightly compressible which may be advantageous for certain applications. More generally any number of infill layers and intermediate cylindrical layers may be provided in the sleeve.

[0030] The sleeve may be printed according to building layers, wherein each building layer is any one of the following: a layer built on a surface perpendicular to the axis of the sleeve, a layer built on a planes tilted with respect to the axis of the sleeve, a layer built on a cylindrical surface having an axis corresponding to the axis of the sleeve. Building layers perpendicular to the axis of the sleeve as shown in Figure 21 A are preferred. Preferably, each building layer has a thickness which is more than 0.2 mm, preferably more than 0.25 mm. This will reduced the printing time needed to print a sleeve.

[0031] Any suitable 3D printing method may be used for printing the sleeve, for example Fused filament fabrication (FFF) also known as fused deposition modeling (FDM) or other additive manufacturing methods may be used. Also, Powder Bed Fusion (PBF) techniques, such as Selective Laser Sintering (SLS) or Multi Jet Fusion (MJF), may be used. Preferably, Fused Filament Fabrication (FFF) also known as Fused Deposition Modeling (FDM) is used.

[0032] Preferably, the entire sleeve is printed in the same material, preferably a thermoplastic material. This is advantageous for recyclability and manufacturing purposes. However, it is also possible to print the sleeve in different materials. For example, the outer layer and / or the first infill layer and / or the inner layer may be printed in different materials. Optionally, the outer layer has an outer surface having a structured surface, e.g. a textured outer surface. This may facilitate the taping of printing plate on the outer layer.

[0033] Optionally, the outer layer has a milled outer surface and / or the inner layer has a milled inner surface.

[0034] Preferably, the inner and / or the outer layer and / or the infill layer is electrically conductive, wherein optionally the inner and the outer layer are electrically connected to each other. For example, carbon structures, such as carbon fibers or nanotubes, may be added in the sleeve. For example, the sleeve may be printed in a PLA or PTG material filled with short carbon fibers. Also, a mix of a conductive polymer with a 3D printable material may be used. Alternatively or in addition, a conductive paint / coating may be used. Also, copper pipes or filaments may be used to enhance the conductivity.

[0035] Preferably, the material in which the sleeve is printed is a thermoplastic polymer, wherein preferably the material comprises any one of the following: polyamide such as PA6, thermoplastic polymers such as a cross-linked material (e.g. a two-component system that is cured during printing), for example polyurethane (two component-polyure thanes), epoxies, polyesters, etc. Also, a linear polyester may be used. Also, additives may be used in the material to establish for example electrical conductivity. Other additives may be biobased or recycled additives or glass (for example hollow spheres in view of reduction of weight).

[0036] Preferably, the sleeve is made of a material having any one or more of the following properties: an E-Modulus (ISO 527) between 400 - 10000 MPa, preferably 1000-4000 MPa, more preferably 2000- 3000 MPa, an elongation at break (ISO 527) bigger than 10%, preferably bigger than 50%, a heat resistance (ISO 75) bigger than 80 degrees Celsius, preferably bigger than 100 degrees Celsius, a water absorption (ISO 62) less than 10%, preferably less than 5%, a chemical resistance to ethanol, propanol, acetone, water.

[0037] Preferably, the infill layer is filled with a gas, a fluid or a solid material or combinations thereof. In such embodiments, preferably the end faces are of the sleeve are closed or provided with a closable inlet / outlet.

[0038] Preferably, a thickness of the first infill layer is between 5 and 600 mm. Preferably, a thickness of the second infill layer is between 2 and 50 mm. Preferably, a thickness of the inner layer is between 0.5 and 4 mm. Optionally, the first infill layer is provided with one or more gas channels and the outer layer comprises channels between the one or more gas channels and an outer surface of the outer layer, wherein the sleeve has closed end faces provided with one or more gas inlets. For example, gas passages may also be provided in void space of the first infill layer and an outer surface of the outer layer. The gas inlets may be arranged on the end plate or the gas inlets may be arranged on the inner surface of the inner layer. The gas outlets can be arranged for example on the outer surface of the outer layer or may also be part of a porous material of the outer layer as described for example in the patent application WO2017194440 Al. The distribution of the gas may also occur via the void space, which surrounds discrete elements and / or via specifically designed channels.

[0039] In an exemplary embodiment, the material used for printing at least the inner layer has a hardness between 25 and 90 Shore A of ISO 7619-1:2010, preferably between 25 and 80 Shore A of ISO 7619-1:2010, wherein optionally the same material is used for the second infill layer, and optionally also for the outer layer and the first infill layer.

[0040] In an exemplary embodiment, the material used for printing the outer layer and the first infill layer has a Shore D hardness between 70 and 95, and the material used for printing the inner layer, and optionally the second infill layer if present, has a hardness between 25 and 90 Shore A of ISO 7619- 1:2010, preferably between 25 and 80 Shore A of ISO 7619-1:2010.

[0041] Preferably, a percentage of the volume of the sleeve which is filled with printed material is between 20% and 90%, preferably between 25% and 70%, more preferably between 30% and 50%. The volume of the sleeve is defined as the volume between an inner surface of the inner layer and an outer surface of the outer layer. For example for a sleeve, if the percentage of the volume is 100 % no hollow areas in the printed sleeve are present. For example, if percentage of the volume is less than 100 % printed material there are hollow areas in the printed sleeve. For example if the sleeve is printed with the same material, a percentage of the volume of 50 %, also means that the mass of the sleeve is also 50 % compared to the sleeve with 100 % printed material.

[0042] Preferably, at least a portion of the sleeve is made with an infill percentage of 100 percent or less, preferably less than 90 percent. The printed material is the material used for manufacturing the printed sleeve. For example in the fused deposition modeling (FDM) process, infill is the percentage of filling in a 3D model. This means that an object with 0% infill is completely hollow on the inside, whereas an object with 100% infill is completely solid on the inside. Optionally, the sleeve may be provided with a recess in which an RFID and / or a magnetic element is arranged, wherein the magnetic element is used to faster locate the RFID. The magnetic element could also be used to determine a certain position, e.g. “zero-position”, of the sleeve. The RFID may contain information about the sleeve, e.g. an identification code, serial number, job parameters, productions parameters, printing parameters, sleeve parameters, runtime information, etc.

[0043] Preferably, the roughness Rz (ISO 1302) of an outer surface of the outer layer and / or an inner surface of the inner layer is in the range of 1 pm to 100 pm, preferably in the range of 5 pm to 50 pm. A certain roughness of the layers allows gasses (e.g. air) to escape for easier mounting or demounting of the sleeve or easier mounting or demounting of a printing plate on the sleeve.

[0044] Preferably the surface of the outer layer may have grooves or indentations which are connected to an area which is not covered by an attached printing plate to allow gasses (e.g. air) to escape. Advantageously, the grooves or indentations allow for easier mounting or demounting of a printing plate on the sleeve. Such a sleeve with a rough surface or with grooves is described in the PCT application PCT / EP2024 / 068715 and incorporated by reference.

[0045] Other preferred embodiments are disclosed in the dependent claims.

[0046] A further aspect of the invention concerns the use of the sleeve according to any of the embodiments described above in a printing device.

[0047] A further aspect of the invention concerns an assembly comprising the sleeve according to any of the previous embodiments, a printing mandrel and optionally a further cylinder, for example an adaptor sleeve if the sleeve is a printing sleeve or a printing sleeve if the sleeve is an adaptor sleeve.

[0048] BRIEF DESCRIPTION OF THE FIGURES

[0049] The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of the exposure unit of the present invention. The above and other advantages of the features and objects of the invention will become more apparent and the invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which:

[0050] Figure 1 illustrates installing a printing plate on a printing sleeve and mounting the printing sleeve with the printing plate directly on a mandrel. Figure 2 illustrates installing a printing plate on a printing sleeve and mounting the printing sleeve on an adaptor sleeve before being installed on a mandrel.

[0051] Figure 3A shows a side view of a mandrel.

[0052] Figure 3B shows a cross-sectional view of the mandrel of figure 3A along section line AA.

[0053] Figure 4 shows a cross-sectional side view of the mandrel of figure 3B and a printing sleeve with a printing plate.

[0054] Figure 5 shows a cross-sectional side view of the mandrel of figure 3B and a printing sleeve with a printing plate wherein an adaptor sleeve is installed between the printing sleeve and the mandrel. Figure 6 A shows a perspective view of an embodiment of a sleeve, wherein a portion of the outer layer and the first infill layer has been removed to visualize the first infill layer.

[0055] Figure 6B shows a perspective view of the embodiment of Figure 6A, wherein a portion of the outer layer, the first infill layer and the intermediate cylindrical layer has been removed to visualize the second infill layer.

[0056] Figure 6C is a detailed view of the first infill layer of Figure 6A and Figure 6D is a detailed view of the second infill layer of Figure 6A.

[0057] Figure 6E shows an outer end of the sleeve of Figure 6A illustrating a recess 291 configured to match with an adapter or mandrel on which the sleeve is to be fixed. The 3D printing is performed such that this recess 291 is formed.

[0058] Figure 6F is a sectional view of the sleeve of Figure 6E illustrating that an end part 290 of the sleeve may be shaped to match with an adapter or mandrel on which the sleeve is to be fixed. Note that this end part 290 could also be a closed end face with an air inlet and that air passages may be provided between the void space of the first infill layer 230 and an outer surface of the outer layer 210.

[0059] Figure 6G shows an outer end of the sleeve of Figure 6A with an end plate 292.

[0060] Figure 6H shows a cross-sectional side view of the sleeve of Figure 6G.

[0061] Figure 61 shows an outer end of the sleeve of Figure 6A with an end plate 292.

[0062] Figure 6J shows a cross-sectional side view of the sleeve of Figure 61.

[0063] Figure 6K shows the sleeve of Figure 6A with gas inlets on the end plate and gas outlets.

[0064] Figure 6L shows the sleeve of Figure 6A with gas inlets at the surface of the inner layer and gas outlets.

[0065] Figure 6M shows the sleeve of Figure 6A with gas inlets and gas outlets, wherein the gas outlets are art of a porous material.

[0066] Figure 6N shows a cross-sectional side view of the sleeve of Figure 6K comprising gas channels.

[0067] Figure 7 shows a perspective view of another embodiment of a sleeve, wherein a portion of the outer layer has been removed to visualize the first infill layer. Here the discrete elements 231 of the first infill layer 230 are prism shaped. Figure 8 shows a perspective view of another embodiment of a sleeve, wherein a portion of the outer layer has been removed to visualize the first infill layer. Here the discrete elements 231 of the first infill layer 230 are cylinder shaped.

[0068] Figure 8 A shows the sleeve of Figure 8, wherein rings 801, 802, 803 are rotated with respect to each other.

[0069] Figure 8B shows a perspective view of the embodiment of Figure 8A.

[0070] Figures 9-12 show perspective views of other embodiments of a sleeve, wherein a portion of the outer layer has been removed to visualize the first infill layer. Here the first infill layer 230 comprises a plurality of wall elements 232 creating cavities 233.

[0071] Figure 13 shows a perspective view of another embodiment of a sleeve, wherein a portion of the outer layer has been removed to visualize the first infill layer. Here the first infill layer 230 comprises a plurality of wall elements 232 extending radially and parallel to each other in a wavy pattern.

[0072] Figure 13A shows the sleeve of Figure 13, wherein the wall elements 232 are tilted with respect to the axial direction of the sleeve.

[0073] Figures 14A and 15 A show perspective views of other embodiments of a sleeve, wherein a portion of the outer layer has been removed to visualize the first infill layer. Here the first infill layer 230 comprises a plurality of wall elements 232 extending radially and axially. Figures 14B and 15B show a cross section of a portion of the sleeve of Figures 14A and 15 A, respectively.

[0074] Figure 14C shows the sleeve of Figure 14A, wherein the wall elements 232 are tilted with respect to the axial direction of the sleeve.

[0075] Figure 14D shows a perspective view of Figure 14C, wherein the angle between the axial direction of the sleeve and the direction of the wall elements 232 is defined.

[0076] Figures 16A and 16B show a perspective view and a cross section of another embodiment of a second infill layer of a sleeve, respectively, wherein the first infill layer and outer layer are not shown. Figures 17-20 show cross sections of other embodiments of a second infill layer of a sleeve.

[0077] Figures 21 A and 21B illustrate possible building layers for 3D printing a sleeve.

[0078] Figures 22 and 23 illustrate the building layers in some embodiments of the sleeve.

[0079] DETAILED DESCRIPTION OF EMBODIMENTS

[0080] Figure 1 shows a printing plate 100 and a double-sided tape 150. The figure further shows a sleeve 200. Printing plate 100 can be installed on an outer surface of the sleeve 200 as shown. The sleeve 200 is mounted on a printing mandrel 400 as shown in Figure 1 or on an adaptor sleeve 300 as shown in Figure 2. Printing plate 100 can be affixed on the sleeve 200 via any suitable attachment, preferably via an adhesive double-sided tape 150. The adhesive double-sided tape preferably has substantially the same size as the bottom of the printing plate 150. In addition or instead of the double-sided tape, the sleeve 200 and / or the printing plate 100 may be provided with adhesive means, such as an adhesive layer (not shown).

[0081] The sleeve 200 with the printing plate 100 can be installed on an outer surface of the adaptor sleeve 300 as shown in Figure 2 or directly on an outer surface of the mandrel 400 as shown in Figure 1. Installing the sleeve 200 is preferably occasioned by providing a gas cushion, such as an air cushion, between the inner surface of the sleeve 200 and the outer surface of the adaptor sleeve 300 or the outer surface the mandrel 400. The gas cushion facilitates the installation of the sleeve 200 on the mandrel 400 or on the adaptor sleeve 300. As shown in figure 1 , the mandrel 400 may have a gas inlet 401 and one or more gas outlets 402 at the circumferential surface of the mandrel to provide the gas cushion between the sleeve 200 and the mandrel 400 (see e.g. figure 4). If an adaptor sleeve 300 is used, the adaptor sleeve 300 is preferably provided with one or more gas guides. To provide the gas cushion, air or another gas can be used which can be supplied via inlet 401 of the mandrel 400.

[0082] The installation and affixing of the printing plate 100 to the sleeve 200 is typically performed in a mounting station (not shown) to provide easy access. Afterwards, the sleeve 200 mounted on a printing mandrel 400 to form assembly 600 is brought and installed into a printing apparatus (not shown). Printing plate 100 can be provided with any printing pattern to transfer ink therewith. Figure 1 further shows assembly 600 in the lower left corner. The assembly 600 includes the printing plate 100, the sleeve 200 and the mandrel 400.

[0083] As illustrated in Figure 2, an adaptor sleeve 300 may be arranged in between the sleeve 200 and the mandrel 400. The sleeve 200 is mounted on adaptor sleeve 300 before being installed on mandrel 400. Afterwards, an assembly 700 is formed including the printing plate 100 affixed on the sleeve 200, adaptor sleeve 300 and mandrel 400. This assembly 700 is then suitable for installation in a printing apparatus.

[0084] Figure 3A shows a side view of a mandrel 400 with an outer surface 410 and mounting flanges. Figure 3B shows a cross-sectional view along section line AA of Figure 3A. The mandrel 400 typically has a cylindrical body serving as the main structure of the mandrel 400. The body can be manufactured from steel or aluminum. Mandrel 400 further has mounting flanges 412a, 412b located at a first end and second end of the mandrel 400. The mounting flanges 412a, 412b provide secure mounting points to install the mandrel 400 in a printing apparatus (e.g. a printing press). The mandrel 400 and / or the flanges 412 may include any fastening mechanisms to ensure proper alignment and fixation. The mandrel 400 may have a gas inlet 401 configured to receive gas from an external gas supply (not shown). The gas may be pushed through an opening 402 in the body of the mandrel 400 to the outer surface 410 of the mandrel via one or more gas outlets 401.

[0085] Figure 4 shows a cross-sectional side view of the mandrel of Figure 3B and a sleeve 200 with a printing plate 100. The printing plate 100 is preferably affixed to the sleeve 200 by aid of tape 150. The sleeve 200 has an inner surface configured to be mounted on the mandrel 400. By supplying a gas cushion (not shown), e.g. via air outlet 402 of the mandrel 400, the sleeve 200 can be easily mounted on the mandrel 400 by sliding the sleeve 200 over the outer surface of the mandrel 400. When the gas cushion is removed, the sleeve 200 is fixed on the mandrel 400.

[0086] Figure 5 illustrates a similar configuration but with an adaptor sleeve 300 having one or more gas guides 350 arranged between the mandrel 400 and the sleeve 200. The gas guide 350 acts as a passage with an inlet 301 and outlet 302. Inlet 301 is arranged to receive gas from outlet 402 of the mandrel 400. Outlet 302 provides the gas cushion at the outer surface 310 of the adaptor sleeve 300. In this manner the sleeve 200 may slide easily over the outer surface of the adaptor sleeve 300.

[0087] Figures 6-23 illustrate embodiments of 3D printed sleeves as explained above.

[0088] Figures 6A-6F illustrate an embodiment of a sleeve 200 for use with a printing plate (not shown). The sleeve is a 3D printed sleeve and comprises a cylindrical inner layer 220, a cylindrical outer layer 210, and at least a first infill layer 230 between the outer layer 210 and the inner layer 220. The cylindrical inner layer 220 is configured to be mounted on an adapter sleeve (not shown) and / or on a printing mandrel (not shown). Figure 6E illustrates a recess 291 configured to match with an adapter or mandrel on which the sleeve is to be fixed. The 3D printing is performed such that this recess 291 is formed. Further, Figure 6F illustrates that an end part 290 of the sleeve may be shaped to match with an adapter or mandrel on which the sleeve is to be fixed. Note that this end part 290 could also be a closed end face with a gas inlet and that gas passages may be provided between the void space of the first infill layer 230 and an outer surface of the outer layer 210. The end part 290 could also extend over the whole end face of the sleeve, having the same diameter than the outer diameter of the sleeve. Fig. 6G and Fig. 6H shows the sleeve of figures 6A-6F with an end plate 292, which closes openings 289 at the two sides of the sleeve. It is possible that the end plate 292 is printed with the same or a different material as the sleeve or it could be mounted separately (see Fig. 61 and 6J) and then be made of another material, e.g. metal, plastic, compressible material. For example, a metal end plate 293 (see for example Fig. 6J) would enhance the stability of the sleeve. Fig. 6K, 6L, 6M show the sleeve of Fig. 6G with a gas inlet 296 and gas outlets 295, so that gas passages may be provided between the void space of the first infill layer 230 and an outer surface of the outer layer 210. In Fig. 6K the gas inlet 296 is arranged on the end plate 292, whereas in Fig. 6L the gas inlets 296 are arranged on the inner surface 299 of the inner layer 220. The gas outlets 295 can be arranged on the outer surface 298 of the outer layer 210 (see for example Fig. 6L). The gas outlets 295 may also be part of a porous material 297 of the outer layer 210 (see for example Fig. 6M), as described for example in patent application WO2017194440 Al which is included herein by reference. The distribution of gas can occur via the void space, which surrounds each discrete element 231 and / or via specifically designed channels 301 (see Fig. 6N).

[0089] The first infill layer 230 comprises a plurality of discrete elements 231 located at a distance of each other seen in an axial direction of the sleeve 200, wherein each discrete element 231 is surrounded by a void space. Each discrete element 231 extends substantially in a radial direction of the sleeve. The discrete elements 231 could also be oriented at an angle within a range from 50 to 90°, preferably between 70 to 90°, where 90° is perpendicular to the sleeve axis. The discrete elements 231 are pillar-like structures. As illustrated, preferably the plurality of discrete elements comprises more than 50 discrete elements, more preferably more than 100 discrete elements, even more preferably more than 150 discrete elements. The discrete elements may be arranged according to a regular pattern. Such patterns could be for example hexagonal, cubic, checkerboard pattern.

[0090] In another embodiment the pattern may be arranged in a way that a periodicity direction of the pattern is oriented parallel to the cylinder axis or inclined to the cylinder axis (resulting in a spiraling pattern). The angle between the axial direction of the sleeve and the periodicity direction of the pattern may be preferably in the range of 0° to 70°, more preferably 0° to 50°. A periodicity direction of a pattern is a direction wherein the centers of neighboring discrete elements are arranged on a line.

[0091] By using discrete element, a robust, sufficiently rigid lightweight first infill layer 230 can be obtained.

[0092] As illustrated, a discrete element 231 has a cross section perpendicular on a radial direction of the sleeve and said cross section may be smaller in a middle portion 231b of the discrete element 231 than in end portions 231a, 231c of the discrete element 231. The cross section has the shape of a polygon, such as square. Alternatively, the cross section could be circular or elliptic. In the embodiment of Figures 6A-6F, the discrete elements 231 are solid elements but they could also be hollow elements or a combination of hollow and solid elements. Preferably the cross section of the hollow elements may be similar or the same as the cross section of the solid elements, such a polygon shaped, circular, elliptic or combinations thereof.

[0093] The sleeve 200 further comprises an intermediate cylindrical layer 240 and a second infill layer 250 between the intermediate layer 240 and the inner layer 220. The first infill layer 230 is located between the outer layer 210 and the intermediate layer 240. Preferably, the second infill layer 250 is more compressible than the first infill layer 230.

[0094] As shown in Figure 6D or 14B, the second infill layer 250 may comprise a plurality of walls 251 extending in an axial direction between the inner layer 220 and the intermediate layer 240. This can provide the required flexibility and compressibility in the radial direction to the inner layer 220. The thickness of the walls 251 is in the range of 0,1 mm to 10 mm, preferably 0,1 mm to 5 mm. The walls 251 may be oriented at an angle alpha between the wall 251 and the tangent of the inner layer in the range of 0° to 60°, preferably in the range of 5° to 40°, wherein the smaller angle is measured.

[0095] Figures 7 and 8 illustrate other embodiments of a sleeve 200, wherein the same or similar components have been indicated with the same reference numerals. In the embodiment of Figure 7, the discrete elements 231 of the first infill layer 230 are prism shaped and arranged in a hexagonal pattern. In the embodiment of Figure 8, the discrete elements 231 of the first infill layer 230 are cylinder shaped and arranged in a square pattern. Such embodiments provide a very stable sleeve.

[0096] In another embodiment shown in Fig. 8 A, 8B rings 801, 802, 803 with discrete elements 231 are rotated with respect to each other. The rotation angle for each of the rings 801, 802, 803 with respect to an adjacent ring can be the same of different, for example between 0 and 45 degrees, preferably between 0 and 15 degrees.

[0097] Figures 9-12 show yet other embodiments of a sleeve 200, wherein the same or similar components have been indicated with the same reference numerals. In those embodiments the first infill layer 230 comprises a plurality of wall elements 232 creating cavities 233. Each wall element 232 extends substantially in a radial direction of the sleeve in order to provide the necessary rigidity in the radial direction. Optionally, the wall elements 232 could also extend in a direction within 10° from the radial direction. Preferably and as illustrated, the plurality of wall elements 232 are interconnected. For example, in the embodiments of Figures 9 and 10, the wall elements 232 form a substantially square grid pattern. In the embodiment of Figure 11, the wall elements 232 form a honeycomb pattern. In the embodiment of Figures 9-11, the wall elements 232 have flat sections and have a constant thickness. Preferably, the thickness of the wall elements 232 is in the range of 0,1 mm to 10 mm, preferably in the range 0,1 mm to 5 mm. In the embodiment of Figure 12, the wall elements 232 have curved sections and do not have a constant thickness. Preferably, the smallest thickness of the curved sections is in the range of 0, 1 mm to 5 mm. The plurality of interconnected wall elements 232 delimits a plurality of cavities 233. A cavity 233 has a cross section perpendicular on a radial direction of the sleeve, and said cross section has any one of the following shapes: circle (Figure 12), polygon, such as square (Figures 9 and 10) or pentagon or hexagon (Figure 11) or octagon, oval or combinations thereof. Preferably, the plurality of cavities comprises more than 50 cavities, preferably more than 100 cavities, more preferably more than 150 cavities. Preferably, the largest diameter of the cavities 233 is in the range of 1 mm to 40 mm, preferably in the range of 2 mm 15 mm.

[0098] Figure 13 illustrates another embodiment of a sleeve 200. Here the first infill layer 230 comprises a plurality of wall elements 232 extending radially and parallel to each other in a wavy pattern. In such an embodiment, preferably the wall elements 232 have a substantially constant thickness. The thickness of the wall elements 232 is in the range of 0,1 mm to 10 mm, preferably in the range of 0,1 mm to 5 mm.

[0099] In another embodiment, the wavy pattern, the wall elements 232 could also extend in a spiral shape around the axis of the sleeve (see Fig. 13 A). The angle between the axial direction of the sleeve and the direction of the wavy pattern is larger than zero, preferably in the range of 0° to 70°, more preferably 0° to 50°. For example, if the wavy pattern is a sinusoidal curve, the angle would be defined between the axial direction of the sleeve and the “zero”-line of the sinusoidal curve.

[0100] Figures 14A-B and 15A-B show further embodiments of a sleeve 200. Here the first infill layer 230 comprises a plurality of wall elements 232 extending radially and axially. In the embodiment of Figures 14A-B, the wall elements 232 have a substantially constant thickness, and thus the distance between adjacent wall elements 232 gradually increases seen in an outward radial direction. The distance between the wall elements 232 at an inner portion of the first infill layer is in the range of 0 to 10 mm, preferably in the range of 0 to 5 mm. The distance between the wall elements 232 at an outer portion of the first infill layer is in the range of 1 to 20 mm, preferably in the range 1 mm to 10 mm. Preferably, the angle between the axial direction of the sleeve 1401 and the length direction 1402 of the wall elements 232 is in the range of 0° to 70°, more preferably 0° to 50° (for example in Fig. 14C and 14D). In the embodiment of Figures 15A-B, the distance between the wall elements 232 is constant, and the wall elements 232 have a thickness which gradually increases seen in an outward radial direction. The thickness of the wall elements 232 at the inner portion of the layer have a thickness in the range of range of 0,1 mm to 10 mm, preferably in the range of 0,1 mm to 5 mm. The thickness of the wall elements 232 at the outer portion of the layer have a thickness in the range of range of 0,5 mm to 30 mm, preferably in the range of 0,5 mm to 10 mm.

[0101] Figures 16A and 16B show an embodiment of an inner layer 220 with a second infill layer 250 and intermediate layer 240 of a sleeve, respectively, wherein the first infill layer 230 and outer layer 210 which surround the intermediate layer 240 are not shown. Such second infill layer 250 may be combined with any inner layer 220, first infill layer 230 and outer layer 210 as discussed in this disclosure. Preferably, the second infill layer 250 is more compressible than the first infill layer. In the embodiment of Figures 16A and 16B, the second infill layer 250 comprises a plurality of tubular bodies 254 having an axis extending in an axial direction of the sleeve. In this embodiment, the tubular bodies have a circular cross section. The thickness of the walls of the tubular bodies 254 is in the range of 0,1 mm to 10 mm, preferably 0,1 mm to 5 mm. The tubular shaped bodies 254 have an outer diameter in the range of 1 mm to 30 mm, preferably 2 mm to 10 mm.

[0102] In yet other embodiments the tubular bodies 254 may extend in axial direction according to wavy lines or could extend in a spiral shape. The angle between the axial direction of the sleeve and the axial direction of the tubular bodies 254 may be in the range of 0° to 70°, preferably 0° to 50°.

[0103] Figures 17-20 show cross sections of other embodiments of an inner layer 220 with a second infill layer 250 and an intermediate layer 240, wherein the first infill layer 230 and outer layer 210 of the sleeve which surround the intermediate layer 240 are not shown. As can been seen, the tubular bodies 254 may have any cross section, such as hexagonal (Figure 17), substantially square (Figure 18), substantially rhomboid (Figure 19), irregular (Figure 20). Optionally, as illustrated in Figures 17 and 19, adjacent tubular bodies 254 are located at a distance of each other seen in a circumferential direction of the sleeve. The tubular bodies may touch each other as illustrated in Figure 18 whereby the stability in radial direction is increased. In another embodiment the tubular bodies 254 comprise an angle beta (see Figure 19) between the walls of the tubular bodies 254 and the tangent of the surface of the inner layer in the range of 0° to 60°, preferably in the range of 5° to 40°, wherein the smaller angle is measured.

[0104] Although not illustrated, the sleeve 200 may further comprise a further cylindrical intermediate layer 240’ and a third infill layer 250’ between the outer layer 210 and the further cylindrical intermediate layer 240’, wherein the first infill layer 230 is located between the intermediate layer 240 and the further intermediate layer 240’. Preferably, the third infill layer 250’ is more compressible than the first infill layer 230. In this way also the outer layer 210 can be made slightly compressible which may be advantageous for certain applications. More generally any number of infill layers 250, 250’ and intermediate cylindrical layers 240, 240’ may be provided in the sleeve 200.

[0105] The sleeve 200 of the above-described embodiments may have any one or more of the following features.

[0106] Preferably, a thickness of the inner layer 220 is between 0.5 and 4 mm, preferably between 1 mm and 2 mm. Preferably, a thickness of the first infill layer 230 is between 5 and 600 mm, preferably between 5 mm to 100 mm, more preferably between 5 mm to 20 mm. Preferably, a thickness of the second / third infill layer 250, 250’ is between 0,5 and 50 mm, more preferably between 1 and 10 mm, even more preferably between 1 mm and 5mm.

[0107] Preferably, the outer layer 210 has an outer surface having a structured surface, e.g. a textured outer surface. Preferably, the outer layer 210 has a milled outer surface and / or the inner layer 220 has a milled inner surface. Preferably, the roughness Rz (ISO 1302) of the outer and / or inner surface is in the range of 1 pm to 100 pm, preferably in the range of 5 pm to 50pm. The outer surface may have grooves or indentations which are connected to the an area which is not covered by the attached plate to allow gasses (e.g. air) to escape.

[0108] Preferably, the inner layer 220 and / or the outer layer 210 and / or the intermediate layer 240, 240’ and / or the infill layer 230, 250, 250’ is electrically conductive, wherein optionally the inner layer 220 and the outer layer 210 are electrically connected to each other. In order to achieve electrical conductivity the materials used may be electrically conductive polymers or polymers filled with electrically conductive particles and / or fibers. Electrically conductive particles may be carbon black, metal particles (e.g. copper, silver, nickel, gold etc.), conductive fibers may be silver nano wires or carbon fibers or combinations thereof. Preferably, the entire sleeve 200 is printed in the same material, preferably a thermoplastic material. Preferably, the material in which the sleeve 200 is printed is a thermoplastic polymer, wherein preferably the material comprises any one of the following: polyamide such as PA6, PA11, PA12, Nylon 6, thermoplastic polymers such as a cross-linked material (two-component system that cures), for example polyurethane (two component-polyurethanes), epoxies, polyesters (PET), polystyrene, copolymers of polystyrene (e.g. HIPS), polyvinylchoride (PVC), polyetherimid (PEI), polyphenylenether (PPE) polyetheretherketones (PEEK), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polycaprolactones, poly(meth)acrylates (PMMA), polylactic acid (PLA), high- density polyethylene (HDPE), acrylonitrile styrene acrylate copolymers (ASA), PC / ABS, polypropylene, polyethylene terephthalate (PETG), polyphenylsulfone (PPSU) etc.. These materials may be combined and may contain additives (stabilizers, dyes, antistatic agents, rheology modifiers, surface modifiers, etc.) and fillers (metals, glasses, alloys, polymers, pigments, minerals) and / or fibers (glass fibers, metal fibers, nano wires, carbon fibers, nano tubes, polymer fibers, natural fibers) to adjust the properties.

[0109] Preferably, the sleeve is made of a material having any one or more of the following properties: an E-Modulus (ISO 527) between 400 - 10000 MPa, preferably 1000-4000 MPa, more preferably 2000- 3000 MPa, an elongation at break (ISO 527) bigger than 10%, preferably bigger than 50%, a heat resistance (ISO 75) bigger than 80 degrees Celsius, preferably bigger than 100 degrees Celsius, a water absorption (ISO 62) less than 10%, preferably less than 5%, a chemical resistance to ethanol, propanol, acetone, water.

[0110] Preferably, the material used for printing at least the inner layer 220 has a hardness between 25 and 90 Shore A of ISO 7619-1:2010, preferably between 25 and 80 Shore A of ISO 7619-1:2010, wherein optionally the same material is used for the second infill layer 250, and optionally also for the outer layer 210 and the first infill layer 230.

[0111] Optionally, the material used for printing the outer layer 210 and the first infill layer 230 has a Shore D hardness between 70 and 95, and the material used for printing the inner layer 220, and optionally the second infill layer 250 if present, has a hardness between 25 and 90 Shore A of ISO 7619-1 :2010, preferably between 25 and 80 Shore A of ISO 7619-1:2010.

[0112] Optionally, the infill layer 230, 250 is filled with a gas, a fluid or a solid material or combinations thereof. Preferably, the first infill layer 230 is provided with one or more air channels and the outer layer 210 comprises channels between the one or more air channels and an outer surface of the outer layer 210, wherein the sleeve has closed end faces provided with one or more air inlets.

[0113] Preferably, a percentage of the volume of the sleeve 200 which is filled with the printed material is between 20% and 90%, preferably between 25% and 70%, more preferably between 30% and 50%.

[0114] The sleeve 200 according to any of the above described embodiments is printed according to building layers, wherein each building layer may be any one of the following: a layer built on a surface perpendicular to the axis of the sleeve, a layer built on a planes tilted with respect to the axis of the sleeve, a layer built on a cylindrical surface having an axis corresponding to the axis of the sleeve. Figures 21A and 21B illustrate possible building layers for 3D printing a sleeve. In the embodiment of Figure 21A, the building layers extend perpendicular to the axis of the sleeve, whilst in the embodiment of Figure 21B, the building layers are tilted with respect to the axis of the sleeve. Preferably, a building layer has a thickness which is more than 0.1 mm, preferably more than 0.2 mm, more preferably more than 0.25 mm. In some cases a thickness of 1 to 3 mm is also possible. The tilting angle of the building layer can be in the range of 0 to 89°, preferably in the range of 20 to 80°, more preferably 20 to 60°, in some cases it can be preferred between 30 - 50°. For example the tilting angle in the embodiment of Fig. 21B is 50°.

[0115] The methods preferably used to generate the sleeve 200 are Fused filament fabrication (FFF) also known as fused deposition modeling (FDM). Preferably, the diameter of the filaments used in the method are in the range of 0, 1 mm to 5 mm, more preferably in the range of 1 to 3 mm. In some cases equipment may be used which is able to change the nozzle diameter which allows to form layers with different thickness and / or features with different width. These can be used to generate walls 254, 251 , 232, or layers 240, 220 with different width or thickness in one go.

[0116] Figures 22 and 23 illustrate the building layers in some embodiments of the sleeve 200. Here, the building layers are tilted with respect to the axis of the sleeve. The tilting angle of the embodiments of Fig. 22 and 23 is 45°, but other angles are possible.

[0117] Whilst the principles of the invention have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.

Claims

CLAIMS1. A sleeve (200) for use with a printing plate (100), said sleeve being 3D printed and comprising: a cylindrical inner layer (220) configured to be mounted on an adapter sleeve (300) and / or on a printing mandrel (400), a cylindrical outer layer (210), and at least a first infill layer (230) between the outer layer and the inner layer.

2. The sleeve of claim 1, wherein the first infill layer comprises a plurality of discrete elements (231), wherein a set of said plurality of discrete elements is located at a distance of each other seen in an axial direction and / or a circumferential direction of the sleeve, wherein each discrete element is surrounded by a void space.

3. The sleeve of the previous claim, wherein each discrete element extends substantially in a radial direction of the sleeve or in a direction between 0° and 40° from the radial direction, more preferably between 0° and 20° from the radial direction, even more preferably within 10° from the radial direction.

4. The sleeve of claim 2 or 3, wherein the discrete elements (231) are pillar-like structures and / or wall-like structures.

5. The sleeve of any one of the claims 2-4, wherein the plurality of discrete elements comprises more than 50 discrete elements, preferably more than 100 discrete elements, more preferably more than 150 discrete elements.

6. The sleeve of any one of the claims 2-5, wherein the discrete elements are arranged according to a regular pattern.

7. The sleeve according to claim 6, wherein the pattern is arranged in a way that a periodicity direction of the pattern is oriented parallel to the cylinder axis or inclined to the cylinder axis.

8. The sleeve of any one of the claims 2-7, wherein the discrete elements are arranged to form a plurality of rings, each ring comprising multiple discrete elements arrangedcircumferentially at a distance of each other, wherein discrete elements of adjacent rings are rotated around the axial direction of the sleeve with respect to each other, so that seen in the axial direction the discrete elements are not aligned.

9. The sleeve of any one of the claims 2-8, wherein each discrete element (231) has a cross section perpendicular on a radial direction of the sleeve, and said cross section is smaller in a middle portion (231b) of the discrete element than in end portions (231a, 231c) of the discrete element.

10. The sleeve of any of the claims 2-9, wherein each discrete element has a cross section perpendicular on a radial direction of the sleeve, and said cross section has any one of the following shapes: circle, polygon, such as square or pentagon or hexagon or octagon, oval or combinations thereof.

11. The sleeve of any of the claims 2-10, wherein the discrete elements are solid elements or hollow elements.

12. The sleeve of claim 1 , wherein the first infill layer comprises a plurality of wall elements (232).

13. The sleeve of the previous claim, wherein each wall element extends substantially in a radial direction of the sleeve or in a direction between 0° and 40° from the radial direction, more preferably between 0° and 20° from the radial direction, even more preferably within 10° from the radial direction.

14. The sleeve of any one of the claims 12-13, wherein the plurality of wall elements (232) extends radially and axially, wherein each wall element has a substantially constant thickness and / or wherein a distance between adjacent wall elements (232) at an inner portion of the first infill layer layer is smaller than a distance between adjacent wall elements (232) at an outer portion of the first infill layer and / or the angle between the axial direction of the sleeve (1401) and a length direction (1402) of the wall elements (232) is in the range of 0° to 70°, more preferably 0° to 50°.

15. The sleeve of any one of the claims 12-14, wherein the plurality of wall elements is interconnected.

16. The sleeve of the previous claim, wherein the plurality of interconnected wall elements (232) delimits a plurality of cavities (233).

17. The sleeve of the previous claim, wherein each cavity (233) has a cross section perpendicular on a radial direction of the sleeve, and said cross section has any one of the following shapes: circle, polygon, such as square or pentagon or hexagon or octagon, oval or combinations thereof.

18. The sleeve of claim 16 or 17, wherein the plurality of cavities comprises more than 50 cavities, preferably more than 100 cavities, more preferably more than 150 cavities.

19. The sleeve of any one of the previous claims, further comprising an intermediate cylindrical layer (240) and a second infill layer (250) between the intermediate layer and the inner layer (220), wherein the first infill layer (230) is located between the outer layer (210) and the intermediate layer (240).

20. The sleeve of the previous claim, wherein the second infill layer is more compressible than the first infill layer.

21. The sleeve of the previous claim, wherein the second infill layer comprises a plurality of walls (251) extending in an axial direction between the inner layer and the intermediate layer.

22. The sleeve of claim 21 , wherein the thickness of the walls (251) of the second infill layer is in the range of 0,1 mm to 10 mm, preferably 0,1 mm to 5 mm and / or wherein an angle alpha between the walls (251) and the tangent of the inner layer is in the range of 0° to 60°, preferably in the range of 5° to 40°,.

23. The sleeve of any one of the claims 19-22, wherein the second infill layer comprises a plurality of tubular bodies (254) having an axis extending in an axial direction of the sleeve.

24. The sleeve of the previous claim, wherein the plurality of tubular bodies (254) is located at a distance of each other seen in a circumferential direction of the sleeve.

25. The sleeve of any one of the claims 19-24, further comprising a further cylindrical intermediate layer and a third infill layer between the outer layer and the further cylindrical intermediate layer, wherein the first infill layer is located between the cylindrical intermediate layer and the further cylindrical intermediate layer.

26. The sleeve of the previous claim, wherein the third infill layer is more compressible than the first infill layer.

27. The sleeve of any one of the previous claims, wherein the sleeve is printed according to building layers, wherein each building layer is any one of the following: a layer built on a surface perpendicular to the axis of the sleeve, a layer built on a planes tilted with respect to the axis of the sleeve, a layer built on a cylindrical surface having an axis corresponding to the axis of the sleeve.

28. The sleeve of the previous claim, wherein each building layer has a thickness which is more than 0.1 mm, preferably more than 0.2 mm, more preferably more than 0.25 mm.

29. The sleeve of any one of the previous claims, wherein a thickness of the inner layer is between 0.5 and 4 mm.

30. The sleeve of any one of the previous claims, wherein the entire sleeve is printed in the same material, preferably a thermoplastic material.

31. The sleeve of any one of the previous claims, wherein the outer layer has an outer surface having a structured surface, e.g. a textured outer surface.

32. The sleeve of any one of the previous claims, wherein the outer layer has a milled outer surface and / or wherein the inner layer has a milled inner surface.

33. The sleeve of any of the previous claims, wherein the inner and / or the outer layer and / or the infill layer is electrically conductive, wherein optionally the inner and the outer layer are electrically connected to each other.

34. The sleeve of any of the previous claims, wherein the material in which the sleeve is printed is a thermoplastic polymer, wherein preferably the material comprises any one of the following: polyamide such as PA6, thermoplastic polymers such as a cross-linked material (two-component system that cures), for example polyurethane (two component- polyure thanes), epoxies, polyesters, etc.

35. The sleeve of any one of the previous claims, wherein the sleeve is made of a material having any one or more of the following properties: an E-Modulus (ISO 527) between 400 - 10000 MPa, preferably 1000-4000 MPa, more preferably 2000-3000 MPa, an elongation at break (ISO 527) bigger than 10%, preferably bigger than 50%, a heat resistance (ISO 75) bigger than 80 degrees Celsius, preferably bigger than 100 degrees Celsius, a water absorption (ISO 62) less than 10%, preferably less than 5%, a chemical resistance to ethanol, propanol, acetone, water.

36. The sleeve of any one of the previous claims, wherein the infill layer is filled with a gas, a fluid or a solid material or combinations thereof.

37. The sleeve of any of the previous claims, wherein a thickness of the first infill layer is between 5 and 600 mm.

38. The sleeve of any of the previous claims, wherein a thickness of the second infill layer is between 2 and 50 mm.

39. The sleeve of any one of the previous claims, wherein the first infill layer is provided with one or more gas channels and the outer layer comprises channels between the one or more gas channels and an outer surface of the outer layer, wherein the sleeve has closed end faces provided with one or more gas inlets.

40. The sleeve of any one of the previous claims, wherein the material used for printing at least the inner layer has a hardness between 25 and 90 Shore A of ISO 7619-1:2010, wherein optionally the same material is used for the second infill layer, and optionally also for the outer layer and the first infill layer41. The sleeve of any of the claims 1-39, wherein the material used for printing the outer layer and the first infill layer has a Shore D hardness between 70 and 95, and whereinthe material used for printing the inner layer, and optionally the second infill layer if present, has a hardness between 25 and 90 Shore A of ISO 7619-1:2010.

42. The sleeve of any one of the previous claims, wherein a percentage of the volume of the sleeve which is filled is between 20% and 90%, preferably between 25% and 70%, more preferably between 30% and 50%.

43. The sleeve of any one of the previous claims, where the sleeve is printed with an infill percentage of 100 percent or less, preferably less than 90 percent.

44. The sleeve of any one of the previous claims, wherein a roughness Rz (ISO 1302) of an outer surface of the outer layer and / or an inner surface of the inner layer is in the range of 1 pm to 100 pm, preferably in the range of 5 pm to 50 pm, and / or wherein an outer surface of the outer layer is provided with grooves or indentations which are connected to the an area which is not intended to be covered by a mounted printing plate to allow gasses to escape.

45. Use of the sleeve of any one of the previous claims in a printing device.

46. An assembly comprising the sleeve of any of the claims 1 - 44, a printing mandrel and / or a further cylinder, for example an adaptor sleeve.

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