APPARATUS AND METHOD FOR THE PRODUCTION OF THREE-DIMENSIONAL SCREEN-PRINTED WORKPIECES

Abstract

Apparatus for producing three-dimensional screen-printed workpieces, in particular 3D screen printing machine, with a printing device for the layer-by-layer production of at least one screen-printed workpiece in a plurality of printing operations and with at least one workpiece carrier for at least one screen-printed workpiece, wherein the printing device has at least one printing table plate being formed separately from the workpiece carrier and on which the workpiece carrier can be positioned for carrying out a printing process, an upper printing mechanism with a printing screen and a position detection device for detecting the position of the workpiece carrier, wherein the printing device is configured for fine adjustment and the fine adjustment comprising the position detection of the workpiece carrier by the position detection device and the adjustment of the relative position and/or relative alignment between the workpiece carrier and the printing device dependent on the position detection.

Claims

1. An apparatus (10) for producing three-dimensional screen-printed workpieces with a printing device (12) for the layer-by-layer production of at least one screen-printed workpiece in a plurality of printing operations and with at least one workpiece carrier (14) for the at least one screen-printed workpiece, wherein the printing device (12) comprises at least one printing table plate (16) being formed separately from the at least one workpiece carrier and on which the at least one workpiece carrier (14) can be positioned for carrying out a printing process, an upper printing mechanism (28) with a printing screen and a position detection device for detecting the position of the at least one workpiece carrier (14), wherein the printing device (12) is configured for fine adjustment, and the fine adjustment comprising the position detection of the at least one workpiece carrier (14) by the position detection device and the adjustment of the relative position and/or relative alignment between the at least one workpiece carrier (14) and the printing screen dependent on the position detection.

2. The apparatus (10) according to claim 1, further comprising a positioning and/or handling device (20) for pre-positioning the at least one workpiece carrier (14) on the at least one printing table plate (16) with an accuracy tolerance of +/−500 μm with respect to the position and/or of up to +/−5° with respect to the orientation of the at least one workpiece carrier (14).

3. The apparatus (10) according to claim 1, wherein the at least one workpiece carrier (14) is provided with at least one marking, the at least one marking being detectable electronically by RFID, optically and/or by camera, and/or the at least one workpiece carrier (14) is provided with at least one marking for individual identification and/or individual tracking of the at least one workpiece carrier with an individual marking for tracking, and/or the at least one workpiece carrier (14) is provided with an optically detectable marking, via which the position and/or alignment of the at least one workpiece carrier (14) can be detected, and/or in that the at least one workpiece carrier (14) has a marking which can be detected by a position detection device and/or by a positioning and/or handling device (20) and/or a transport device (18).

4. The apparatus (10) according to claim 1, further comprising an inspection area adjacent to a printing area (24) of the printing device (12) for inspecting the at least one screen-printed workpiece and/or the at least one workpiece carrier (14) and/or for inspecting a relative position and/or relative alignment of the at least one workpiece carrier (14) on the at least one printing table plate (16) and/or for inspecting a relative position and/or relative alignment of the at least one screen-printed workpiece on the at least one workpiece carrier (14) and/or wherein the inspection area is formed as part of the printing device (12) and/or as part of the transport device (30).

5. The apparatus (10) according to claim 1, wherein the printing device (12) has a support arrangement (22) comprising a frame, for the at least one printing table plate (16), and the at least one printing table plate (16) is supported by the support arrangement (22), the at least one printing table plate (16) being immovable relative to the support arrangement (22), or a movability of the at least one printing table plate (16) relative to the support arrangement is limited to a printing area (24) of the printing device (12) and/or a movability of the at least one printing table plate (16) is given only in the printing build-up direction (26).

6. The apparatus (10) according to claim 1, wherein the at least one printing table plate (16) is designed as a sliding plate and/or in that there is movability of the at least one printing table plate (16) relative to the support arrangement (22) beyond the printing area (24) and/or up to an inspection area arranged outside the printing area (24).

7. The apparatus (10) according to claim 1, wherein the upper printing mechanism (28) has a printing and/or flood doctor blade and/or an upper mechanism frame and/or in that the upper printing mechanism (28) and/or the printing screen is movable relative to the at least one printing table plate (16) and/or relative to the support arrangement (22) of the at least one printing table plate (16) and/or a movability of the upper printing mechanism (28) and/or of the printing screen relative to the support arrangement (22) and/or relative to the at least one printing table plate (16) is limited to a printing area (24) of the printing device (12).

8. The apparatus (10) according to claim 1, wherein the printing device (12) is configured for fine adjustment between two successive printing processes for the at least one screen-printed workpiece and/or successive printing layers for the at least one screen-printed workpiece.

9. The apparatus (10) according to claim 1, wherein the fine adjustment comprises the adjustment of the relative position and/or relative alignment between the at least one printing table plate (16) and the upper printing mechanism (28) and/or between the at least one printing table plate (16) and the printing screen and/or that the fine adjustment comprises the adjustment of the relative position and/or relative alignment between the at least one workpiece carrier (14) and the upper printing mechanism (28).

10. The apparatus (10) according to claim 1, wherein the upper printing mechanism (28) and/or the printing screen can be moved, for positional fine adjustment relative to the support arrangement (22), in directions transverse to the print build-up direction (26) and/or relative to the at least one printing table plate (16) and/or that the upper printing mechanism (28) and/or the printing screen can be rotated, for alignment fine adjustment, about an axis of rotation running in the print build-up direction (26) and/or that at least one adjusting device is provided for positional and/or alignment fine adjustment of the upper printing mechanism (28) and/or the printing screen.

11. The apparatus (10) according to claim 1, wherein the at least one printing table plate (16) can be moved, for positional fine adjustment, relative to the support arrangement (22) in directions transverse to the printing build-up direction (26) and/or that the at least one printing table plate (16) can be, for alignment fine adjustment, rotated about an axis of rotation running in the print build-up direction (26) and/or that at least one adjusting device is provided for positional and/or alignment fine adjustment of the at least one printing table plate (16).

12. The apparatus (10) according to claim 1, wherein the upper printing mechanism (28) and/or the printing screen can be moved relative to the support arrangement (22) and/or relative to the at least one printing table plate (16) in a print build-up direction (26) for setting a lift-off height and/or that the at least one printing table plate (16) can be moved relative to the support arrangement (22) and/or relative to the upper printing mechanism (28) and/or relative to the printing screen in a print build-up direction (26) for setting a lift-off height and/or in that at least one adjusting device is provided for adjusting a lift-off height and/or in that an adjusting device is provided for fine adjustment of the lift-off height.

13. The apparatus (10) according to claim 1, further comprising at least one position detection device is provided for a screen-printed workpiece and/or for the at least one printing table plate (16) and/or in that an adjusting device of the at least one printing table plate (16) and/or an adjusting device of the upper printing mechanism (28) and/or of the printing screen is configured to carry out a positional and/or alignment fine adjustment dependent on a position detection by a position detection device.

14. The apparatus (10) according to claim 1, wherein a position detection device is configured to detect the position and/or orientation of the at least one screen printing workpiece and/or of the at least one workpiece carrier (14) in space and/or relative to the at least one printing table plate (16) and/or relative to a support arrangement (22) for the at least one printing table plate (16) and/or relative to an upper printing mechanism (28) and/or printing screen, and/or in that the position detection device is configured to detect the position and/or orientation of the at least one printing table plate (16) relative to the support arrangement.

15. The apparatus (10) according to claim 1, wherein a position detection device is configured to detect the position and/or orientation of the at least one screen-printing workpiece relative to the at least one workpiece carrier (14) arranged underneath it and/or in that a position detection device is configured to carry out a position detection of the at least one workpiece carrier (14) by means of at least one marking on the at least one workpiece carrier (14).

16. The apparatus (10) according to claim 1, wherein a position detection device for position detection is formed within a printing area (24) and/or is arranged within a printing area (24) and/or that a position detection device for position detection is formed outside a printing area (24), within an inspection area arranged outside the printing area (24), and/or that a position detection device is arranged outside the printing area (24) and/or inside the inspection area.

17. The apparatus (10) according to claim 1, wherein a position detection device has at least one camera, in particular a camera arranged below or above the at least one printing table plate (16), and/or in that the position detection device is configured to detect the coverage of at least one opening in the at least one printing table plate (16) by the at least one workpiece carrier (14).

18. A method for producing three-dimensional screen-printed workpieces, in particular with the apparatus (10) claim 1, in which the at least one workpiece carrier (14) for the at least one screen-printed workpiece is provided, in which the at least one screen-printed workpiece is produced layer-by-layer in a printing device (12) in a plurality of printing operations on the at least one workpiece carrier (14), in which the at least one workpiece carrier (14), in order to carry out a printing process, is positioned on the at least one printing table plate (16) of the printing device (12), the at least one printing table plate (16) being formed separately from the at least one workpiece carrier (14), in which between two successive printing processes for at least one screen-printed workpiece a fine adjustment of the printing device (12) is carried out, and the fine adjustment includes a position detection of the at least one workpiece carrier and the adjustment of the relative position and/or relative alignment between the at least one workpiece carrier (14) and a printing screen dependent on the position detection.

19. The apparatus of claim 6, wherein the sliding plate is an interchangeable sliding plate.

20. The apparatus of claim 6, wherein the apparatus comprises two printing table plates (16), the two printing table plates (16) of the printing device (12) being designed as sliding plates

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0138] In the following, the invention is described by way of example on the basis of advantageous embodiments with reference to the accompanying figures. It is shown in:

[0139] FIG. 1a a perspective view of an apparatus according to the invention according to one embodiment,

[0140] FIG. 2a a top view of the apparatus of FIG. 1,

[0141] FIG. 3a a schematic top view of the apparatus of FIG. 1 showing an upper transport plane,

[0142] FIG. 4a a schematic top view of the apparatus of FIG. 1 showing a lower transport plane.

DETAILED DESCRIPTION

[0143] FIG. 1 shows a perspective view of an apparatus 10 for producing three-dimensional screen-printed workpieces according to an embodiment of the invention. FIG. 2 shows a top view of the apparatus 10 of FIG. 1. FIGS. 3 and 4 schematically show a top view of the apparatus 10 with illustration of different transport planes.

[0144] The apparatus 10 comprises a printing device 12 for the layer-by-layer production of at least one screen-printed workpiece in several printing operations. The printing device 12 may be a so-called screen printer. Furthermore, the apparatus 10 comprises a plurality of workpiece carriers 14. The workpiece carriers 14 are designed for at least one screen-printed workpiece, preferably for a plurality of screen-printed workpieces. Accordingly, a single screen-printed workpiece or also a plurality of screen-printed workpieces can be produced layer by layer on a single workpiece carrier 14.

[0145] Furthermore, the printing device 12 has at least one printing table plate 16 formed separately from the workpiece carrier 14. Two or more printing table plates 16 can also be provided in the printing device 12. In the case of two or more printing table plates 16, these can each be designed as an interchangeable sliding table. Also in the case of one printing table plate 16, this may be designed as an interchangeable sliding table.

[0146] The workpiece carrier 14 can be positioned on the printing table plate 16 for carrying out a printing process. Between two successive printing operations, the respective workpiece carrier 14 may be detachable from the printing table plate 16 for drying the screen-printed workpiece. Accordingly, the apparatus 10 may be designed to allow each workpiece carrier 14 to be detachable from the printing table plate 16 between two successive printing operations for drying the screen-printed workpiece thereon. Thus, to produce a single screen-printed workpiece, the respective workpiece carrier 14 is positioned on and removed from the printing table plate 16 several times. The utilization of the printing device 12 can be advantageously improved in this way. In addition, the screen-printed workpiece or the printed material can remain on the respective workpiece carrier 14 between different printing processes, so that the risk of damage is reduced.

[0147] The apparatus 10 may further comprise a transport device 18 for the automated transport of at least one workpiece carrier 14, in particular for a plurality of workpiece carriers 14. The transport device 18 is designed as a transport circuit for the automated transport of the at least one workpiece carrier 14, preferably for a plurality of workpiece carriers 14. In particular, the transport device 18 is designed for automated transport in a circuit between the printing device 12 and at least one position spaced apart from the printing device 12 and/or the printing table plate 16.

[0148] The transport device 18 can be of multi-lane design at least in sections and/or of single-lane design at least in sections, which will be explained in more detail with reference to FIGS. 3 and 4. The transport device 18 is formed at least in sections by a conveyor means, in particular a belt conveyor. Different transport sections of the transport device 18 can run at an angle to one another. Corner transfer units can be provided for this purpose.

[0149] The apparatus 10 may further be equipped with a positioning and/or handling device 20, by means of which a workpiece carrier 14 can be positioned on the printing table plate 16 in an automated and/or defined manner. The positioning and/or handling device 20 can be designed as part of the transport device 18.

[0150] A positioning device 20 can, for example, have a conveyor, in particular a belt conveyor. Such a conveyor means can extend into the printing table plate 16 and/or be recessed into the printing table plate 16 and/or be lowerable and/or raisable relative to the printing table plate 16. In this way, a workpiece carrier 14 can be conveyed up to above the printing table plate 16 and then set down in a suitable manner and raised again and conveyed away.

[0151] A handling device, which is not shown in more detail here, can be a pick-and-place device or a handling robot, for example. In particular, a handling device can contact a workpiece carrier 14 from an area upstream of the printing device 12, lift it and then position it on the printing table plate 16 of the printing device. Following a printing process, the handling device can lift the respective workpiece carrier off the printing table plate 16 again and transport it away from the printing device 12.

[0152] The positioning and/or handling device 20 can also be designed to detect the position of the workpiece carrier 14. For this purpose, a camera system 19 or the like can be provided on the positioning and/or handling device 20, for example, by means of which the workpiece carrier 14 can be detected before contact is made or before it is lifted. By such a position detection of the workpiece carrier 14, in particular the contacting or the lifting by conveyor belts or the gripping of the workpiece carrier 14 by a handling device is simplified or the transport and/or handling safety is increased. Such a position detection of the workpiece carrier 14 can be carried out in particular in an inspection area, which will be discussed below.

[0153] Furthermore, an alignment device can also be provided, by means of which the workpiece carrier 14 can be aligned and/or positioned in a defined manner on the printing table plate 16. The alignment device may preferably be the positioning and/or handling device 20. Likewise, the alignment device can be formed by a mechanical positioning element not shown in more detail here and/or by a stop not shown in more detail here.

[0154] The printing table plate 16 can be designed for temporary fixing of the workpiece carrier 14. For this purpose, the printing table plate 16 can be designed, for example, as a perforated plate, in particular as a perforated plate for vacuum fixing of the workpiece carrier 14.

[0155] The printing device 12 may further comprise a support arrangement 22 for the printing table plate 16. The printing table plate 16 is thus supported by the support arrangement 22. Thereby, the printing table plate 16 may be immovable relative to the support arrangement 22.

[0156] Likewise, a movability of the printing table plate 16 can be provided. A movability of the printing table plate 16 relative to the support arrangement 22 can be limited to a printing area 24 of the printing device 12 and/or be provided for the fine adjustment of the position or alignment of the printing table plate 16. This may be a fine positional adjustment relative to the support arrangement 22 in a direction transverse to the print build-up direction 26 and/or a fine alignment adjustment about an axis of rotation extending in the print build-up direction 26. The print build-up direction 26 or the axis of rotation running in the print build-up direction 26 runs vertically, as shown in FIG. 1.

[0157] Furthermore, it is possible that a movability of the printing table plate 16 relative to the support arrangement 22 extends beyond a printing area 24 of the printing device 12. However, such movability may be limited to at least a housing and/or an enclosure of the printing device 12. In particular, the movability of the printing table plate 16 relative to the support arrangement 22 may be limited to areas outside of a drying device, which will be described in further detail below. Likewise, the movability of the printing table plate 16 relative to the support arrangement 22 may be limited to an inspection area, which will be described in more detail below.

[0158] Further, movability of the printing table plate 16 in the height direction along the print build-up direction 26 may be provided to adjust the lift-off height for subsequent printing operations.

[0159] The printing device 12 may further include an upper printing mechanism 28. The upper printing mechanism 28 may include a printing and or flood doctor blade, which is not shown in more detail here. Likewise, the upper printing mechanism 28 may be equipped with at least one printing screen and/or screen receptacle, which is also not shown in more detail here.

[0160] The upper printing mechanism 28 or a frame of the upper printing mechanism 28 may be immovable relative to the printing table plate 16 and/or relative to the support arrangement 22. On the other hand, a screen receptacle of the upper printing mechanism 28 may be movable relative to a frame of the upper printing mechanism 28 and/or relative to the printing table plate 16 and/or relative to the support arrangement 22. Such movability of the screen receptacle may be limited to a printing area 24 of the printing device 12. A corresponding movability of the screen receptacle may be provided for fine adjustment of position or alignment, respectively. This is particularly advantageous if the printing table plate 16 is arranged immovably relative to the support arrangement 22.

[0161] Likewise, the screen holder together with the printing screen can be moved along the printing build-up direction 26 in order to adjust the lift-off value for subsequent printing processes. A lifting mechanism not shown in more detail can be provided for this purpose. This is advantageous if the printing table plate 16 is arranged immovably along the print build direction 26.

[0162] Furthermore, in order to adjust the lift-off value, it is also possible to provide for movement of the entire upper printing mechanism 28 along the print build-up direction 26. This is also advantageous if the printing table plate 16 is arranged immovably along the print build-up direction 26.

[0163] Likewise, a mobility of the upper printing mechanism 28 relative to the support arrangement 22 and/or relative to the printing table plate 16 may be provided in directions transverse to the print build-up direction 26. Such movability of the entire upper printing mechanism 28 may be limited to a printing area 24 of the printing device 12. A corresponding movability of the upper printing mechanism 28 may be provided for fine adjustment of the position or alignment of the upper printing mechanism. This is again advantageous if the printing table plate 16 is arranged immovably relative to the support arrangement 20 in directions transverse to the print build-up direction 26.

[0164] Furthermore, a position detection device not shown in more detail here can be provided for a screen-printed workpiece and/or for a workpiece carrier 14 and/or for the printing table plate 16. In this case, any actuating devices of the printing table plate 16 and/or any actuating devices of the upper printing mechanism 28 can be set up to carry out a fine adjustment of position and/or alignment dependent on a position detection by the position detection device. In particular, the position detection device may perform position detection within the printing area 24. Likewise, it is possible for the position detection device to perform position detection outside of the printing area 24, for example in an inspection area. Further, multiple position detection devices may be provided. The position detection device may, for example, be formed by a camera system or the like. Such a position detection device can be configured in particular for detecting the position of workpiece carriers 14.

[0165] As can be further seen from FIGS. 1 and 2, the apparatus 10 is equipped with a drying device 30. The drying device 30 may be a drying path. The drying device 30 is arranged downstream of the printing device 12 in the longitudinal direction of the apparatus 10 and may have an active length that is variably adjustable, for example by activating and/or deactivating individual heat generating units, for example convection and/or radiant heat units, which are not shown in detail here.

[0166] In the apparatus 10 according to the present invention, the individual workpiece carriers 14 can be moved through the drying device 30 independently of the printing table plate 16. The printing table plate 16 thus does not experience any temperature load.

[0167] The drying path of the drying device 30 can be designed, in particular, for a continuous drying passage of screen-printed workpieces and/or workpiece carriers 14. In this case, the travel speed for the workpiece carriers 14 can be variably adjustable by the drying device 30.

[0168] A drying device can also be provided in which screen-printed workpieces are dried while stationary. For this purpose, workpiece carriers together with screen-printed workpieces can be moved into the drying device and out of it again in the opposite direction.

[0169] The apparatus 10 may further comprise a buffer storage 32, which may be located downstream of the drying device 30. Further drying or post-drying can take place in the buffer storage 32. The buffer storage can also be used to influence the material flow within the apparatus 10.

[0170] Furthermore, the apparatus 10 can be equipped with a storage device 34, which can be a loading and/or unloading storage device or an input and/or output storage device. Via the storage device 34, individual workpiece carriers 14 can be fed into and discharged from the transport device 18, which is designed as a transport circuit. Temporary intermediate storage of individual workpiece carriers 14 can also take place in the storage device 34. The storage device 34 can be arranged in the material flow between the drying device 30 and the printing device 12.

[0171] The printing device 12, the drying device 30, the buffer storage 32 and/or the storage device 34 can be connected modularly to form an apparatus system. Such an apparatus system may consist of a plurality of apparatuses 10 or of one apparatus 10, which has been expanded and/or reduced by individual devices or stations.

[0172] The printing device 12, the drying device 30, the buffer storage 32 and/or the storage device 34 can be suitably connected by the transport device 18 or integrated into an apparatus system. In particular, an automated transport of workpiece carriers between the printing device 12, the drying device 30, the buffer storage 32 and/or the storage device 34 can be carried out by the transport device 18, in particular along a transport circuit.

[0173] The transport of workpiece carriers 14 by the transport device 18 is now explained with reference to FIGS. 3 and 4, FIG. 3 showing a top view with illustration of an upper level of the transport device 18 and FIG. 4 showing a top view with illustration of a lower level of the transport device 18.

[0174] In particular, the transport device 18 may include a plurality of conveyor belt sections 36 and corner transfer units 38. The conveyor sections 36 can transport individual workpiece carriers 14 between different stations or devices of the apparatus 10.

[0175] As mentioned above, the printing processes take place within the printing device 12. For this purpose, the respective workpiece carriers 14 must be positioned within the printing device 12, in particular on the printing table plate 16 of the printing device 12.

[0176] After printing has been completed, the respective workpiece carrier 14 is positioned out of the printing device 12 into a placement area 40 downstream in the material flow. Placement areas 40 can be provided on both sides of the printing table plate 16. Accordingly, the workpiece carriers 14 can be conveyed away from the printing table plate 16 on both sides. Between the printing table plate 16 and the respective placement area 40, the workpiece carriers can be conveyed by a positioning device 20, which can also be formed by a conveyor belt section and forms part of the transport device 18.

[0177] An aforementioned placement area 40 can in particular also be designed as an inspection area and/or serve as an inspection area.

[0178] The respective workpiece carrier 14 is conveyed from the respective placement area 40 to the drying device 30. The workpiece carrier 14 can be conveyed from the placement area 40a along the conveyor belt section 36a to the drying device 30. Starting from the placement area 40b, the workpiece carriers are conveyed to the corner transfer unit 38a, further along the conveyor belt section 36b to the corner transfer unit 38b and then into the drying device 18. Likewise, the workpiece carriers can be conveyed further from the corner transfer unit 38b to the conveyor belt section 36a and then into the drying unit 30.

[0179] The drying path 42 runs within the drying device 30. The drying path 42 can be of two-lane design, i.e. formed by two conveyor sections 36c and 36d, in order to increase the drying capacity. After passing through the drying path 42, the respective workpiece carrier 14 reaches a buffer storage 32, in which further drying or subsequent drying can take place.

[0180] After the buffer storage 32, further conveying takes place to one of the corner transfer units 38c and 38d, respectively, and further along the conveyor line 36e to the corner transfer unit 38e.

[0181] The storage device 34 is arranged adjacent to the corner transfer unit 38e. Starting from the corner transfer unit 38e, the workpiece carriers are further conveyed along a return path which has the conveyor belt lines 36f and 36g. The conveyor belt lines 36f and 36g can merge into one another along the conveying direction, and the downstream conveyor belt line 36g can have an incline. In particular, the conveyor belt line 36g may be inclined downwardly to allow transfer of workpiece carriers from the upper level of the transport device 30 shown in FIG. 3 to a lower level of the transport device 30 shown in FIG. 4. It is also possible for both conveyor lines 36f and 36g of the return path to have a vertical inclination.

[0182] The workpiece carriers 14 pass through the conveyor belt line 36g to the corner transfer unit 38f shown in FIG. 4. Starting from the corner transfer unit 38f, the workpiece carriers 14 can be conveyed further either to the conveyor belt line 36h or to the conveyor belt line 36i.

[0183] The conveyor belt line 36h leads to the lifting device 44a, which lifts the workpiece carriers 14 to the upper level of the transport device 18. Finally, lifted workpiece carriers 14 can be conveyed further to the placement area 40b, from where loading of the printing table plate 16 by the positioning device 20 can take place.

[0184] The conveyor belt line 36i first leads to the corner transfer unit 38g and from there further along the conveyor belt line 36j to the lifting device 44b, by means of which the workpiece carriers 14 are lifted into the upper level of the transport device 18. Finally, lifted workpiece carriers 14 can be conveyed further to the placement area 40a, from where loading of the printing table plate 16 by the positioning device 20 can take place.

[0185] Instead of the corner transfer unit 38f, the corner transfer unit 38a can also be equipped with a lifting function for direct transport of the workpiece carriers 14 between the two levels of the transport device 18. This can be advantageous, in particular, if the printing device 12 is to be bridged over a distance as short as possible, for example, in order to carry out multiple drying without intermediate printing of the workpiece carrier. However, this can also be accomplished without a lifting function of the corner transfer unit 18a, as can be seen from the arrangement of the conveyor belt line 36.

[0186] The apparatus 10 described above is particularly suitable for the mass production of three-dimensional screen-printed workpieces. In particular, the apparatus 10 enables extensive or complete automation of the screen printing process. The risk of operating errors is reduced and the level of productivity can be significantly increased by means of a apparatus 10 as described above.