EP2897802B1

EP2897802B1 - Enhanced moisture removal systems for printing systems

Info

Publication number: EP2897802B1
Application number: EP13838893.9A
Authority: EP
Inventors: Pedro Benito; Jose Manuel Plaja ROIG; Roque NEBOT; Alfredo GIRBES; Ricardo MENDOZA; Mario Kuehn
Original assignee: Electronics for Imaging Inc
Current assignee: Electronics for Imaging Inc
Priority date: 2012-09-21
Filing date: 2013-09-20
Publication date: 2018-03-07
Anticipated expiration: 2033-09-20
Also published as: EP2897805A4; EP2897802A1; BR112015006431A8; BR112015006429A2; ES2698533T3; BR112015006431A2; CN203740459U; CN203780074U; EP2897801B1; EP2897805B1; ES1135032U; EP2897801A4; BR112015006429B1; EP2897805A2; BR112015006428A2; BR112015006431B1; BR112015006428A8; EP2897802A4; ITMI20130313U1; WO2014047513A3

Description

FIELD OF THE INVENTION

The invention relates to the field of printers. More particularly, the invention relates to enhanced moisture removal structures and systems for modular print bar assemblies in a printing environment.

BACKGROUND OF THE INVENTION

Conveyor belt systems have long been used to transfer objects, such as materials, objects, substrates, and workpieces. In such environments, the transfer belt is suspended between a plurality of rollers, wherein one of the rollers, i.e. a drive roller, is typically connected to a drive mechanism, e.g. a motor, such that rotational movement of the drive mechanism results in rotational movement of the drive roller, which moves the belt with respect to the rollers, providing linear movement.
Printing systems often use conveyor belt systems to transfer workpieces, such as but not limited to flexible substrates, e.g. paper or film, or rigid substrates, e.g. ceramic tiles. In a prior tile printing system, ceramic tiles are arranged upon a conveyor belt, and are moved through a print zone, which typically includes a plurality of print bars, wherein each of the print bars comprise a plurality of print heads that are configured to controllably deliver ink onto the ceramic tiles as they are moved through the print zone.
In printing environments, such as for printing on ceramic tiles, the ceramic tiles are often subjected to water or steam, e.g. from manufacturing, cleaning, or other processing, at elevated temperatures, before entering the printing area. It is often necessary to remove this moisture from the ceramic tiles, to achieve a dry surface, before jetting oil-based ink or other coatings onto the ceramic tiles. While such hot ceramic tiles are transported through a printing system, past one or more print bars, additional moisture is commonly outgassed. As well, ink, dust, dirt, or other undesired particulates might be introduced, as the ceramic tiles travel past the print bars.
EP 2 492 098 A1 describes a machine for printing on tiles having a support structure for a plurality of printing modules including respective heads provided with nozzles for ejecting a printing fluid, and means for advancing the tiles to be printed according to a direction arranged below said printing modules. Each printing module is slidably associated to the support structure according to a given sliding direction, so as to be able to be translated outside from the encumbrance of said advancing means.
US 5,594,477 A describes a priming device for a printbar having an array of print dies employs a vacuum nozzle shorter in width than one print die. At least one wet wiper blade is located adjacent to the vacuum nozzle and is used not only to moisten and wipe the channel outlets of the printbar, but during application of vacuum pressure in priming, the wiper blade serves to block the flow of air into adjacent channels, thereby eliminating cross-talk between groups of channels.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide enhanced moisture removal structures and systems, which are configured to consistently remove moisture across the ceramic tiles, e.g., at one or more points with respect to a printing system.
This object is achieved by the subject matter as defined in the independent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of an exemplary enhanced modular printing system having a conveyor assembly for transporting one or more work pieces in relation to an array of one or more print bars;
Figure 2 is a side view of an exemplary enhanced modular printing system;
Figure 3 is a detailed partial perspective view of an exemplary conveyor assembly associated with an exemplary enhanced modular printing system;
Figure 4 is a plan view of an exemplary enhanced modular printing system, wherein each of a plurality of print bars is alignably affixed in a corresponding print bar bay;
Figure 5 is a plan view of an exemplary enhanced modular printing system, wherein one of a plurality of print bars is located in a released position in relation to its corresponding print bay, and wherein the other print bars are alignably affixed in relation to their corresponding print bays;
Figure 6 is an end view of an exemplary enhanced modular printing system, wherein one of the print bars is located in an aligned and locked position in relation to the chassis;
Figure 7 is an end view of an exemplary enhanced modular printing system, wherein one of the print bars is located in a released position in relation to the chassis;
Figure 8 is a schematic view of an exemplary print bar attachment structure in a released position;
Figure 9 is a schematic view of an exemplary print bar attachment structure in an aligned position;
Figure 10 is a schematic view of an exemplary print bar attachment structure in an aligned and locked position;
Figure 11 is a first perspective view of an exemplary print bar attachment structure;
Figure 12 is a second perspective view of an exemplary print bar attachment structure;
Figure 13 is a third perspective view of an exemplary print bar attachment structure;
Figure 14 is a schematic side view of an enhanced moisture removal system for an exemplary printing system;
Figure 15 is a schematic end view of an enhanced print bar having one or more enhanced moisture removal plenums associated therewith;
Figure 16 is a plan view of an exemplary enhanced modular modular printing system having an enhanced moisture removal system;
Figure 17 is a detailed view of an exemplary enhanced plenum for moisture removal in a printing system; and
Figure 18 is a detailed view of an alternate exemplary enhanced plenum for moisture removal in a printing system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 is a schematic diagram of an exemplary modular printing system 10 having a conveyor assembly 14 for transporting one or more work pieces WP in relation to an array 40 of one or more print bars 42. Figure 2 is a side view 60 of an exemplary enhanced modular printing system 10. Figure 3 is a detailed partial perspective view 80 of an exemplary conveyor assembly 14 associated with an enhanced modular printing system 10.
The exemplary conveyor assembly 14 seen in Figure 1 comprises a transfer belt 18 that extends between a plurality of rollers 16, e.g. 16a, 16b, which are rotatably mounted with respect to a chassis 12. It should be understood that the exemplary enhanced modular printing system 10 seen in Figure 1 provides a simplified view of the printing system 10. For example, the conveyor assembly 14 may further comprise one or more additional rollers, such as a tension roller 52 associated with a tension mechanism 72 (FIG. 2), and/or the rollers 16 and transfer belt 18 may further comprise a belt interlock mechanism 96 (FIG. 3), such as but not limited to a plurality of teeth 96 that intermesh. As well, the enhanced printing system 10 may preferably comprise additional structures and mechanisms to provide improved dimensional tolerances for any of setup, operation, or longevity.
The exemplary conveyor assembly 14 seen in Figure 1 is typically operated upon by a drive mechanism 26, which controllably rotates one of the rollers 16, e.g. 16a, thus producing movement 32 of the transfer belt 32, by which one or more work pieces WP, e.g. ceramic tiles WP, are controllably moved, such as to be operated upon at one or more locations with respect to the system 10. While the exemplary printing system 10 is described herein with respect to one or more work pieces WP, e.g. ceramic tiles WP, it should be understood that the structures and systems described herein may readily be implemented for a printing system 10 associated with other work pieces or substrates, such as but not limited to any of paper, film, textiles, or other articles of manufacture.
The drive mechanism 26 typically comprises a drive motor 142 (FIG. 6) and a coupling mechanism, e.g. a transfer drive 144 (FIG. 6), wherein the drive motor 142 is controllably powered through a controller 20, e.g. a programmable logic controller (PLC). The drive mechanism 26 may preferably comprise one or more enhanced structures, to provide highly accurate and repeatable location and movement.
The enhanced modular print system 10 may preferably include an encoder 28, such as to provide accurate controlled movement 32 of the transfer belt 18 through the drive mechanism 26. The controller 20 typically comprises one or more processors 22, e.g. 22a-22e, and may also comprise storage 24, e.g. memory, such as for but not limited to storage of any of operating parameters, thresholds, operational history, and/or tracking. The controller 20 is typically configured to control all of the movements and operations in the printing system 10, such as but for but not limited to movement of the transfer belt 18 through the drive mechanism 26, and coordinated operations of the print bars 42, e.g. 42a-42h.
As also seen in Figure 1, a display 34 and user interface 36 are also typically connected to the controller 20, such as to provide input from a user USR, e.g. an operator, and/or to provide information to the user USR. As well, the printing system 10 may further comprise a communications link 46, through which the controller 20 may preferably be configured to transmit an output signal 48 and/or receive an input signal 50.
The exemplary enhanced modular printing system 10 seen in Figure 2 and Figure 3 is configured for printing on ceramic tiles WP, and may preferably comprise one or more workpiece guides 98 (FIG. 3), upstream of one or more of the print bars 42, such as at the entrance area 86 (FIG. 3) of the transfer belt 18. Ceramic tiles WP that are placed on the transfer belt 18 may not initially be located with a great degree of accuracy, and/or may be twisted, i.e. rotated. The workpiece guides 98 ensure that tiles WP are in the proper location on the transfer belt 18, e.g. in the middle, and that the tiles WP are acceptably straight, e.g. within an acceptable threshold.
The exemplary enhanced modular printer system 10 seen in Figure 2 and Figure 3 may preferably comprise an enhanced tension adjustment mechanism 72 for the transfer belt 18. For example, such as during any of initial setup, belt replacement, or other service, a threaded, i.e. guide screw mechanism 102 (FIG. 4) may be rotatably moved, such as to provide a fine adjustment of linear distance between the rollers 16, e.g. 16a,16b, to obtain a desired tension in the transfer belt 18, such as recommended by the manufacturer of the transfer belt 18.
Similarly, for adjustment of parallelism between the rollers 16, the tension mechanism 72 may preferably comprise a pair of guide screws 102, e.g. 102a, 102b, on opposing sides of at least one of the rollers 16, e.g. 16a or 16b. One or both of the guide screws 102, e.g. 102a and/or 102b, may preferably be adjustable, to achieve parallelism between the roller 16 and transfer belt 18, i.e. to achieve 90 degrees between the axis of the roller 16 and the longitudinal axis of the transfer belt 18.
In some embodiments, a guide screw set 102 associated with a first roller 16, e.g. 16a, may be considered a main or primary guide mechanism 102, which may be adjustable for parallelism, when the corresponding roller 16 is free for adjustment of any of parallelism or tension, i.e. not locked down, such as when the position of the opposing roller 16, e.g. 16b, is maintained. Similarly, the opposite roller 16, e.g. 16b, may be adjustable for any of parallelism or tension, i.e. not locked down, such as when the position of the opposing roller 16, e.g. 16a, is maintained. The operator USR can then determine when the roller 16 is aligned with the workpiece guide 98, which assures that the transfer belt 18 is parallel to the opposing roller 16 and properly aligned with the transfer belt 18.
Once the transfer belt 18 is adjusted to be parallel, with adequate tension, the guide screw mechanism 102 is tightened, and the workpiece guide 98 is put back in place. Upon completion, the operator USR may start up the enhanced modular printing system 10 in a test mode, such as to confirm that the guide is not getting hot, e.g. from excessive friction. If not, the enhanced modular printing system 10 may be put into or returned to service. If the temperature of the workpiece guide 98 increases excessively during testing, the operator or service personnel USR may repeat one or more of the procedures as necessary, and retest.
When the transfer belt 18 and rollers 16 are considered to be both parallel and properly tensioned, the operator USR may preferably mark 112 (FIG. 5) both the transfer belt 18 and the workpiece guide 98, and then rotabably move, i.e. advance, the transfer belt 18 from one part of the system to another part of the system, e.g. at opposite ends 86,88, at which time the location of the mark 112 may be determined and compared to the expected location, by which a difference is calculated, e.g. in millimeters. The calculated difference provides an indication as to whether there is any slip in the transfer belt 18, i.e. to confirm that there is no problem with the set up during operation.
After setup, the owner or operator USR, does not typically need to reset the tolerance, as the rollers 16 and transfer belt 18 are dimensionally stable, such as for the expected lifetime of the transfer belt 18, e.g. which may have a useful lifetime in operation of up to or greater than about two years.
An exemplary printing operation is also seen in the in Figure 2, wherein a print job 66, such as received from a remote terminal, e.g. an artist or designer, arrives at a main computer 62, which may be associated with the controller 20. In some system embodiments, the print job 66 comprises a tagged image file format (TIFF) print job 66.
The main computer 62 then typically produces, i.e. RIPs, a raster image file from the received print file 66, through which the main computer 62 makes appropriate separations 64, which are assigned to one or more channels 68, e.g. 68a-68h, as necessary to print the image. Each of the channels 68, e.g. 68a-68h, are sent to a corresponding slave computer or processor 70, e.g. 70a-70h, associated with each print bar 42, e.g. 42a-42h, for printing respective colors or other coatings on the workpieces WP. The slave computers or processors 70 may be independent of or integrated with corresponding print bars 42. The different print bars 42, e.g. 42a-42h, are controlled by the respective slave computers 70, wherein each slave computer 70, e.g. 70a, operates in conjunction with a respective print bar 42, e.g. 42a, i.e. one channel for each slave computer 70.
While the main computer 62 is making the RIP, the printing system 10 is typically configured to work with the graphics that are loaded into the slaves 70. When each of the slave computers 70 has the information for their respective print bar 42, the slave computer 70 connects, e.g. through an HPC card, to each of the print heads 82 (FIG. 3, FIG. 6, FIG. 15). In some printing system embodiments 10, each print head 82 has a dedicated HPC card, for local processing.
The controller 20 may preferably be configured, such as through the programmed processors 20, e.g. 22a-22e, to provide integral printer management capabilities, and/or to optimize the printer's capabilities across its options. The controller 20 and processors 22 may preferably be remotely updatable,, such as through the communications link 46, which enables the worker USR to handle all the elements fast and intuitively.
The enhanced modular printing system 10 may preferably comprise additional features, such as any of a tone adjustment system (TAS), calculated linearization capabilities, and/or calculate ink consumption capabilities. The tone adjustment system (TAS) may preferably be based on an intuitive interface, such as displayed 36, which guides the user USR through the process of study and application of changes in tone or intensity, to apply to a model. This feature enables adjustments or variations on existing models in the enhanced modular printing system 10, without use of external additional software, or extensive knowledge in color management.
The electronic design of the enhanced modular printing system 10 may preferably be based on the modular distribution of components, thus facilitating future upgrades and allowing full accessibility. The electronic system of the enhanced modular printing system 10 delivers high performance, by using the main computer 62 to upload image files 66, and slave computers 70 that manage the printing of the files 66. The result is increased graphical variability and nonstop manufacturing. The enhanced electronics design makes it possible to choose from various printing options, and simultaneously use different print heads 82 in the same printing system 10, e.g. some for decoration and others to apply effects, such as but not limited to three-dimensional (3D) effects.
Figure 3 is a detailed partial perspective view 80 of an exemplary conveyor assembly 14 associated with an enhanced modular printing system 10, wherein the transfer belt moves in a direction of travel 32 with respect to an X axis, 92x, a Y axis 92y, and a Z axis 92z. The exemplary print bars 42 seen in Figure 3 are fixedly locked with respect to the chassis 12, such as through attachment structures 150 (FIG. 6-15), such as comprising a fixed portion 162 (FIG. 7) and a movable portion 164 (FIG. 7), which are configured to be alignable and lockable with respect to each other, and may be located on one or both sides 152a, 152b (FIG. 6, FIG. 7) of the chassis 12, such as through but not limited to fixed attachment plates 99.
Figure 4 is a plan view 100 of an exemplary enhanced modular printing system 10, wherein each of the print bars 42 are in an aligned and locked position 103a in relation to the chassis 12. Figure 5 is a plan view 120 of an exemplary enhanced modular printing system 10, wherein one of the print bars 42, e.g. 42d, is located in a released position 103c in relation to the chassis 12, such as with respect to a print bar bay 124, and wherein the other print bars 42 are alignably affixed 103a in relation their respective print bar bays associated with the chassis 12. The plurality of print bars 42, e.g. 42a-42h, seen in Figure 4 and Figure 5 comprise separate, i.e. independent, modular print bars 42.
Figure 6 is an end view 140 of an exemplary enhanced modular printing system 10, wherein one of the print bars 42 is located in an aligned and locked position 103a in relation to the chassis 12. Figure 7 is an end view 160 of an exemplary enhanced modular printing system 10, wherein one of the print bars 42, e.g. 42d (FIG. 5), is located in a released position 103c in relation to the chassis 12. When a print bar 42 is located in a released position 103c, the released print bar 42 can be fully accessed, such as to carry out both daily operations and/or preventive maintenance work, such as with a maintenance system 156. As well, the printer 10 may preferably continue to operate, while specific tasks are performed on one or more of the print bars 42. As seen in Figure 6 and Figure 7, each of the print bars 42 may comprise a print bar frame 154.
The enhanced print bar 42 seen in Figure 6 and Figure 7 thus provides sliding movement for removal and installation, to provide easy access for both the print head frame 154 and for the head maintenance system 156 associated with each print bar 42. As well, enhanced modular printing system 10 has separate print bars 42 for different ink colors or other coatings 90, such that each color or coating corresponds to a separate print head frame, head maintenance tray, and vacuum anti-steam system 302 (FIG. 14).
Some exemplary embodiments of the enhanced modular printing system 10 comprise a Model C3 multipurpose digital ceramic decoration printer, e.g. CRETAPRINTER® or a CRETACOMPACT®, available through EFI Cretaprint, Inc., of Foster City, CA, USA, which are currently configured to hold up to eight print bars 42, e.g. 42a-42h, for decoration and special finishing purposes. Such modular printer systems 10 are highly configurable, and provide accurate transport of workpieces WP, e.g. up to 0.3 mm accuracy, in colors that are separated up to 2800mm.
Embodiments of the enhanced modular printing system 10 that are configured to hold a plurality of print bars 42 may preferably provide a large number of configuration options, to best meet the requirements of the user USR. For example, the user USR may readily configure the enhanced modular printing systems 10 based on any of

number of decoration bars 42;
number of special application bars 42;
printing width 104 (FIG. 4);
printing features suitable to any of resolution, speed, and ink discharge requirements; and/or
print direction.

In some embodiments of the enhanced modular printing system 10, the user USR can initially select a configuration that best fits their current production requirements, and then, as needed or desired, the user USR can expand the system 10, such as by adding and/or replacing print bars 42, and/or by adding to a specified printing width 104.
For example, in some CRETAPRINTER® system embodiments 10, the printing width 104 may be increased in multiples of 70mm up to a maximum of 1120 mm, while in some CRETACOMPACT® system embodiments 10, the printing width 104 may be increased in multiples of 70mm up to a maximum of 700 mm.
Once a configuration has been chosen, this can be enlarged (or decreased as desired or needed), both in printing width 104 and in number of bars 42, such as shown:

3 print bars 42, e.g. for ceramic trichromie printing;
4 print bars 42, 42, e.g. for ceramic for ceramic quatrichromie printing;
6 print bars 42, e.g. for ceramic hexachromie printing; and/or
8 print bars 42, e.g. for ceramic double quadrichromie printing.

In this manner, a ceramics manufacturer USR can select a configuration that best fits their current production requirements, and can then optimize the modular printing system 10 as their needs change, thus maximizing the value of their initial investment.
In some embodiments of enhanced modular printing system 10, the user USR may preferably print from four to eight colors, each with an associated print bar 42, to decorate ceramic tiles WP. Within a given enhanced modular print system 10, the print heads 82 may preferably be provided by one or more manufacturers, e.g. Toshiba, Xaar, Fuji/Dimatix, and/or Konica/Minolta. While different print bars 42 may include print heads 82 from different manufacturers, the print heads 82 within a print bar 42, e.g. 42a, are typically configured with a plurality of heads 82 from the same manufacturer, wherein the print heads 82 are configured as a set from a chosen manufacturer within the corresponding print bar 42.
In some exemplary system embodiments 10, the user USR may preferably designate any from zero to three print bars 42 for the generation of applications other than decorating. In current system embodiments, print heads 82 for applications other than decorating comprise Fuji-Dimatix printheads, available through Fuji Photo Film Co., Ltd. Corp, of Tokyo, Japan.
In some embodiments, the enhanced modular printing system 10 may preferably be configured, such as with electronics and software, to operate with different print heads 82 in the same system 100. For example, one or more of the print bars 42 may be configured with print heads 42, e.g. 42a-42f, for printing, while one or more of the other print bars 42, e.g. 42g-42h, may be configured with print heads 82 having a stronger ink discharge, e.g. to apply special finishes, such as but not limited to undercoatings, glazes, clear or tinted translucent coatings, and/or protective finishes. Some embodiments of the enhanced modular printing system 10 may preferably be configured to apply at least two different glazes on the same ceramic tile WP, such as to achieve different effects, depending where the different glazes are applied.
The enhanced modular printing system 10 may therefore be configured or reconfigured to meet any of the current or future needs of a manufacturing plant. For example, the compact modular chassis 12 allows the enhanced system 10 be quickly and easily installed on site, and also readily allows subsequent updates, as needed or desired. Thus, the user USR can readily maintain and/or update the enhanced modular printing system 10. For embodiments of enhanced modular printing systems 10 that are configured for printing on ceramics WP, the systems 10 may readily be configured to apply a wide variety of ceramic decorations and special effects, while fitting within the physical space of a manufacturing plant.
Some embodiments of the enhanced modular printing system 10 may comprise one or more symmetric components, such as but not limited to the chassis 12, the print bars 42, and/or associated electrical boards, such as to be readily configured for any required belt direction 32, wherein the work pieces WP, e.g. ceramic tiles 42 may move 32 either direction, e.g. with regard to the X axis 92x. For example, in the enhanced modular printing system 10 seen in Figure 4, the transfer belt 32 may be configured to move 32 the ceramic tiles WP from the right to the left hand side, or alternately, from the left to the right hand side, such as needed or desired by the user USR.
Some embodiments of the enhanced modular printing system 10 may preferably be configured to protect the print heads 82 associated with one or more of the print bars 42. For example, the exemplary print bar 42 seen in Figure 15 further comprises a height sensor 332, e.g. a dual-laser sensor 332 at the entrance of the print bar 42, which is configured to detect both the position and the thickness of each workpiece WP. The height sensor 332 is configured to send a signal to a mechanism 336 that is configured to move at least a portion of the print bar 42 vertically 338. The configuration may preferably be used for any of:

protecting a print bar 42, when it is not delivering ink; or
moving at least a portion of the print bar 42 vertically to adjust the print bar 42 to the sensed height of a workpiece WP.

During such operations, print bars 42 that are not currently used for the application of any decoration or special effect may preferably be configured to remain above and protected.
Figure 6 also shows an exemplary drive mechanism 26, end roller 16 and conveyor assembly 14 for an exemplary ceramic tile printing system 10. The partial cutaway view of the transfer belt 18 seen in Figure 3 reveals that the conveyor assembly 14 typically comprises a transfer belt support 94 located between the rollers 16, such as to support the weight of one or more workpieces WP, e.g. ceramic tiles WP.
In some embodiments of the enhanced printing system 10, the drive motor 142 is preferably chosen to reduce or eliminate electrical noise, e.g. radio frequency (RF) noise, which may otherwise interfere with the operation of the electronics associated with the enhanced printing system 10. For example, the drive motor 142 may preferably comprise a brushless motor 142, to provide accurate continuous operation. As well, the encoder 28 (FIG. 1) may preferably be chosen to provide accurate continuous operation of the drive motor 142, while reducing or eliminating RF noise.
The drive motor 142 may preferably be specified for a wide variety of applications, such as to provide stepped, i.e. start and stop, motion, or continuous motion. For example, in the exemplary enhanced modular printing system 10 disclosed herein, such as for printing on ceramic tiles WP, the drive mechanism 26 is typically required to transport a large number of ceramic tiles WP, which are commonly large and heavy. A current embodiment of the enhanced modular printing system 10 is configured to move ceramic tiles WP at a constant velocity, wherein the maximum speed of the transport belt 18 is about five meters per minute. As such, the drive mechanism 26, comprising the drive motor 142 and transfer drive 144, are rated to controllably bring transfer belt 18 and workpieces 18 up to speed, maintain a constant speed throughout a rated duty cycle, e.g. up to full 100 percent capacity, and bring the system 10 to a stop.
In addition to the rated power for the drive motor 142 and transfer drive 144 to bring up a line to constant speed and maintain that speed, it should be understood that the system 10 and combined mass of a large number of ceramic tiles WP, e.g. up to approximately 500 kilograms at a time, typically results in significant inertia, with which the drive mechanism 26, transfer belt 18, and other components associated with the conveyor assembly 14 are configured to handle, such as for starting, constant operation, and stopping.
In addition to the performance requirements for the drive mechanism 26, the transfer belt 18 is also configured to be adequately strong under all operation conditions, while avoiding deformation or flexing. Similarly, all other hardware associated with the enhanced modular printing system 10 is configured to meet all of the operation requirements.
While the exemplary enhanced modular printing system 10 disclosed herein may preferably be configured to operate with a constant belt velocity, it should be understood the enhanced modular printing system 10 may suitably be configured for other types of operations, such as for systems that may require stepped operation, wherein the drive motor 142 may preferably be configured to be powered on and off. In such applications, the drive motor 142 may preferably be controlled with pulse width modulation (PWM).
Some embodiments of the enhanced modular printing system 10 are powered through an uninterruptable power supply (UPS), wherein the enhanced modular printing system 10 buffers the outside current, such as for any of the controller 20, sensors, print bar electronics, associated computers, memories, or other sensitive electronics. The operation of the drive mechanism 26 is controlled through the controller 20, such as for any of start up, operation, and shutdown of the conveyor assembly 14.
The use of the uninterruptable power supply (UPS) helps to avoid variations in the peaks of tension, and maintains the power at a consistent level. The printing system 10 can therefore move at a constant rate, independent of incoming power fluctuations, wherein the printing system 10 can match the electronics and print heads 82. As well, such as at a customer facility, upon loss of incoming power, the UPS may preferably be configured to provide sufficient time, such as to switch off the machine production, e.g. to avoid problems with the electronics, the computers, and heads.
Print Bar Attachment Systems and Associated Structures. Figure 8 is a schematic view 180 of an exemplary print bar attachment structure 150 in a released position 183c, corresponding to a released position 103c of a print bar 42 with respect to a print bar bay 124. Figure 9 is a schematic view 200 of an exemplary print bar attachment structure 150 in an aligned position 183b, corresponding to an aligned position 103b of a print bar 42 with respect to a print bar bay 124. Figure 10 is a schematic view 220 of an exemplary print bar attachment structure 150 in an aligned and locked position 183a, corresponding to a locked position 103a of a print bar 42 with respect to a print bar bay 124.
The exemplary print bar 42 seen in Figure 8 comprises one or more alignment pins 184 having a conical profile 185, wherein the alignment pins 184 extend axially from the print bar 42, i.e. orthogonal to the longitudinal axis, e.g. orthogonal to the X axis 92x, of the transfer belt 18. The exemplary alignment pins 184 seen in Figure 8 are affixed to and extend from a print bar attachment plate 186. The exemplary print bar 42 seen in Figure 8 is transversely movable 202 (FIG. 9), 208 (FIG. 9) in relation to the chassis 12, e.g. parallel to a Y axis 92y, such as through movement of one or more slide mechanisms 122, which may preferably be mounted to a print bar frame 154 associated with each corresponding print bar 42. A lock mechanism 194 is also mounted to the print bar 42, and comprises a pin mechanism 198 and an actuator 196, e.g. a pneumatic actuator 196 or an electric actuator 196, wherein the pin mechanism 198 is movable 224 (FIG. 10) between an unlocked position and a locked position, in response to movement 262 (FIG. 12) of the actuator 196. The exemplary actuator 196 seen in Figure 8 is pivotably attached to the print bar 42, such as through a pivot mount 198. The fixed portion 162 of the exemplary attachment structure 150 seen in Figure 8 comprises a latch mechanism 192 that is fixedly attached with respect to the chassis 12, wherein the latch mechanism 192 is configured to receive at least a portion of the pin mechanism 198.
As seen in Figure 9, the print bar 42 is slidably movable 202 with respect to the chassis 12. The conical profile 185 of the alignment pins 184 aids in alignment between the alignment pins 184 and the alignment holes 182 having associated axes 282 (FIG. 13), such that the alignment pins 184 are configured to readily move into the corresponding alignment holes 182. While the conical profile 185 shown in Figure 8 illustrates an exemplary profile 185 that may be used to align the alignment pins 184 and the alignment holes 182, it should be under stood that other profiles 185, e.g. conical or rounded profiles 185, may preferably be used to ensure accuracy and repeatability of the sliding movement of the print bars 42 with respect to a corresponding print bay 124.
Once the alignment pins 184 enter the alignment holes 182, the print bar 42 is configured to arrive at an aligned and lockable position 103b, wherein the print bar 42 is accurately positioned within a corresponding print bay 124, such as with with respect to an X axis 92x, a Y axis 92y, and a Z axis 92x. The exemplary aligned and lockable position 103b seen in Figure 9 corresponds to a position in which a portion of the print bar 42, e.g. the print bar attachment plate 186, contacts a fixed portion of the printing system 10, e.g. a fixed attachment plate 99.
When the print bar 42 is in the aligned and lockable position 183b with respect to the chassis 12, the pin mechanism 198 is lockable with respect to the latch mechanism 192. For example, the exemplary actuator 196 seen in Figure 10 is configured, such as in response to manual or automated control 22, to controllably move the pin mechanism 198 in relation to the latch mechanism 192, to accurately lock the print bar 42 to a corresponding print bay 42.
Similarly, from a locked position 183a, the exemplary actuator 196 seen in Figure 10 is configured, such as in response to manual or automated control 22, to controllably move the pin mechanism 198 in relation to the latch mechanism 192, to unlock the print bar 42 with respect to its corresponding print bay 42, whereby the print bar 42 may be moved 208 (FIG. 9), toward a released position 183c (FIG. 8).
Figure 11 is a first perspective view of 240 an exemplary locking mechanism 150. Figure 12 is a second perspective view 260 of an exemplary locking mechanism 150. Figure 13 is a third perspective view 280 of an exemplary locking mechanism 150. As registration of the print bars 42, e.g. 42a-42h, with respect to the printing system 10 and to the other print bars 42 is critical, the attachment mechanisms 150 are configured to accurately lock down the print bars 42 in their respective print bays 124, while simultaneously providing access to the print bars 42, as needed or desired. Each of the print bars 42 may preferably have at least two alignment and locking mechanisms 150, such as on opposing sides 152a,152b of the chassis 12, wherein the print bars 42 are accurately constrained on across the transfer belt 18, to provide accurate registration for the print heads 82 with respect to the printing system 10.
The alignment and locking mechanisms 150 therefore allow the print bars 42 to easily be removed, serviced, and returned to service. Once alignably installed with respect to the printing system, 10, the locking mechanisms 150 may readily be actuated, such as pneumatically or electrically, to accurately lock the print bars 42 into their respective print bays 124, so that the print bars 42 can be placed back into service, while inherently retaining the print quality the print bars 42.
Enhanced Moisture Removal Systems and Structures. Figure 14 is a schematic side view 300 of an enhanced moisture removal system 302 for an exemplary printing system, such as for but not limited to an enhanced modular printing system 10. The exemplary enhanced moisture removal system 302 seen in Figure 14 may be positioned upstream and/or downstream of one or more of the print bars 42. Some embodiments of the enhanced moisture removal system 302 may be affixed with respect to the chassis 12, such that the corresponding print bar 42 may be moved, e.g. 202, 208 (FIG. 9) independently from the plenum. In other embodiments of the enhanced moisture removal system 302, at least a portion of the enhanced moisture removal system 302, e.g. the plenum 304 may be affixed to or otherwise integrated with a corresponding print bar 42.
The exemplary enhanced moisture removal system 302 seen in Figure 14 comprises an enhanced vacuum plenum 304 that typically extends transversely across the printing width 104 (FIG. 4) of a transfer belt 18. The plenum 304 extends to a header 312 that is connected to a vacuum conduit 316, which is configured to be connected to a vacuum source 320, such as through a vacuum manifold 318 that may preferably be connected to a plurality of moisture removal structures 302. The exemplary enhanced moisture removal system 302 seen in Figure 14 may further comprise a damper 314, such as to trim the amount of vacuum applied to the enhanced vacuum plenum 304. As well, the exemplary enhanced moisture removal system 302 may further comprise a shroud or mounting structure 311 that surrounds at least a portion of the enhanced vacuum plenum 304.
The enhanced moisture removal system 302 is configured to draw moisture G (FIG. 15) away from the print zone, e.g. 85 (FIG. 3) for one or more print bars 42 associated with a printing system, such as for an enhanced modular printing system 10 that is configured to print on ceramic tiles WP. Such ceramic tiles WP enter the printing system 10 at elevated temperatures, e.g. about 150 degrees Celsius. The ceramic tiles WP are commonly processed with water and/or steam, such that as the tiles enter the printing system 10, there is commonly residual moisture G that, if not removed, can be problematic for subsequent printing operations, e.g. the jetted delivery 84 of oil-based ink 90. As well, moisture G may continue to be outgassed from the ceramic tiles WP as they are transported on the transfer belt 18, which can cause subsequent problems.
To alleviate such moisture G and other contamination that may be present, the enhanced moisture removal system 302 may preferably be placed before and/or after each of the print bars 42, to draw away moisture G, as well as any other airborne contaminants, such as but not limited to any of dust or ink particulates.
The enhanced vacuum plenum 304 may preferably be configured to optimize the removal of moisture G and/or other contaminants. For example, the exemplary enhanced vacuum plenum 304 seen in Figure 14 may preferably be shaped to provide a desired, i.e. consistent, pressure differential in the region 306 that corresponds to the printing width 104 of the enhanced modular printing system 10, e.g. such as from a near end 308a to a far end 308p. As seen in Figure 14, the plenum 304 comprises a profile 310, e.g. 310a-310p, that decreases as it extends away from the header 312, wherein the cross section 310a at the near end 308a is larger than the cross section 310p at the far end 308p of the plenum 304.
It should be understood that the size and shape of the enhanced vacuum plenum 304 seen in Figure 14 is exemplary in nature, and that the specific size and shape of the enhanced vacuum plenum 304 may preferably be chosen to provide adequate moisture removal across the printing width 104 of the transfer belt 18. As well, the specific size and shape of the vacuum inlets 366, e.g. 366a-366f (FIG. 17) at different points on the lower suction surface 322 may preferably be chosen to enhance the removal of moisture from the workpieces WP.
Figure 15 is a schematic end view 330 of an enhanced print bar 42 having one or more enhanced moisture removal plenums 304, e.g. 304a,304b, associated therewith. In the exemplary printing system 10 seen in Figure 15, the transfer belt 18 is configured to transport a plurality of workpieces WP past one or more print bars 42, wherein the transport belt 18 has a characteristic direction of travel 32. As seen in Figure 15, a workpiece WP entering the print zone of the print bar 42 may have residual moisture G on or around the workpiece WP. A first moisture removal plenum 304a, positioned upstream of the print bar 42, is configured to remove moisture G before ink delivery 84 (FIG. 3) from the print heads 82. A second removal plenum 304b, positioned downstream of the print bar 42, is configured to remove moisture G and/or other contaminants after ink delivery 84 from the print heads 82, such as before arrival of the workpiece 42 at one or more subsequent print bars 42.
The enhanced moisture removal systems 302, having enhanced vacuum plenums 304, are therefore configured to efficiently remove moisture G in printing environments, such as for ceramic printing systems 10 that are configured to transport ceramic tiles WP past one or more print bars 42, wherein the print heads 82 are able to controllably deliver 84 ink 90, e.g. oil-based ink 90, or other coatings, onto the dry ceramic tiles WP. While some enhanced moisture removal systems 302 may comprises both pre and post print bar plenums 302a, 302b, some preferred embodiments 302 may preferably comprise a single plenum 302, either before or after each of the print bars 42, such that the printing system 10 may be more compactly packaged.
Figure 16 is a plan view of an exemplary enhanced modular printing system 10 having an enhanced moisture removal system 302. The enhanced modular printing system 10 seen ion Figure 16 comprises a plurality of print bars 42, e.g. six print bars 42a-42f, and further comprises a moisture removal plenum 304 located upstream of each of the respective print bars 42, such that a single plenum 302 is provided between each of the neighboring print bars 42. Each of the moisture removal plenums 302 are connected, e.g. 312, 316 (FIG. 14) to provide conduits to remove moisture G, such as into a common manifold 318 that is connected to a vacuum source 320, whereby moisture G and other contaminants may effectively be removed from the printing environment 10. As described above, the moisture removal plenums 304 may preferably be configured to shaped to provide a desired, i.e. consistent, pressure differential in the region 322, to adequately remove the moisture G and other impurities.
Figure 17 is a detailed view 360 of an exemplary enhanced plenum 304 for moisture removal in a printing system, such as for but not limited to an enhanced modular printing system 10. The exemplary enhanced moisture removal plenum 304 seen in Figure 17 has a characteristic cross section 310 as it extends from the far end 308p to the near end 308a, wherein the shape of the enhanced plenum 304 is shaped to provide a desired, i.e. consistent, pressure differential in the suction region 322, to adequately remove the moisture G and other impurities across the printing width 104 of the transfer belt 18. For example, the height 362p of the enhanced vacuum plenum 304 at the far end 308p is less than the height 362a of the enhanced vacuum plenum 304 at the near end 308a. Similarly, the width 364 of the enhanced vacuum plenum 304 may be configured across the suction region 322. While the exemplary enhanced moisture removal plenum 304 seen in Figure 17 is generally shown as a planar duct, e.g. having a rectangular cross section at one or more points across the suction region 322, it should be understood that other cross sections may be provided, such as having but not limited to having other polygonal or curved surfaces and/or cross sections. As also seen in Figure 17, the size and shape of one or more vacuum inlet ports 366, e.g. 366a-366f, may preferably be configured to provide a desired, i.e. consistent, pressure differential in the suction region 322.
Figure 18 is a detailed view 380 of an alternate exemplary embodiment of enhanced vacuum plenum 304 that is configured for the efficient removal of moisture G and/or other contaminants in a printing system, such as for but not limited to an enhanced modular printing system 10. While the exemplary enhanced vacuum plenum 304 seen in Figure 17 provides a header 312 at one end 308a of the plenum 304, the exemplary enhanced vacuum plenum 304 seen in Figure 18 provides a header 312 between the ends 308a,308p of the plenum 304, such as for but not limited to connection to a vacuum manifold 318 that is located above the enhanced modular printing system 10. The exemplary enhanced vacuum plenum 304 seen in Figure 18 is also shaped to provide a desired, i.e. consistent, pressure differential in the suction region 322, to adequately remove the moisture G and other impurities across the printing width 104 of the transfer belt 18, wherein the shape is based at least in part upon the location of the plenum header 312. Similarly, the width 364 of the enhanced vacuum plenum 304 may be configured across the suction region 322. While the exemplary enhanced moisture removal plenum 304 seen in Figure 18 is generally shown as a planar duct, e.g. having a rectangular cross section at one or more points across the suction region 322, it should be understood that other cross sections may preferably be provided, such as having but not limited to having other polygonal or curved surfaces and/or cross sections. Furthermore, as also seen in Figure 18, the size and shape of one or more vacuum inlet ports 366 may preferably be configured to provide a desired, i.e. consistent, pressure differential in the suction region 322.
In addition to allowing the print heads 82 to deliver 84 ink or other coatings 90 onto dry ceramic tiles WP, the enhanced vacuum plenum 304 also prevents steam build-up and condensation in the print heads, and within other portions of the print bars 42.
Accordingly, although the invention has been described in detail with reference to a particular preferred embodiment, persons possessing ordinary skill in the art to which this invention pertains will appreciate that various modifications and enhancements may be made without departing from the spirit and scope of the claims that follow.

Claims

A moisture removal system (302) for a ceramic tile printing system having one or more print bars (42), a chassis (12) having a first end, a second end opposite the first end, a first side, and a second side opposite the first side, wherein the first side and the second side extend from the first end to the second end, a conveyor assembly (14) mounted to the chassis and extending between the first end and the second end, wherein the conveyor assembly comprises a first roller (16) at the first end, a second roller (16) at the second end, a transfer belt (18) extending between the first roller and the second roller for moving workpieces with respect to the print bars (42), and a drive mechanism (26) linked to any of the first roller or the second roller, wherein the moisture removal system comprises:
a vacuum source (320);

a vacuum manifold (318) connected to the vacuum source (320);

at least one vacuum plenum (304) corresponding to each of the print bars (42) and extending transversely over the transfer belt (18) from a near end (308a) to a far end (308p),

wherein each of the vacuum plenums (304) comprise an inlet (366) defined at the far end proximate the transfer belt (18), an outlet conduit (312, 316) that is connected to the vacuum manifold (318), and a plenum passage (322) extending from the inlet to the outlet,

wherein each of the vacuum plenums (304) comprises a plurality of cross sections between the near and the far end,

wherein the plurality of cross sections are any of polygonal or curved to provide a consistent pressure differential across a portion of the width of the transport belt (18) to draw moisture away from a ceramic tile print zone.
The vacuum system of Claim 1, wherein each of the vacuum plenums (304) corresponding to each of the print bars (42) is located between the corresponding print bar (42) and the first end of the chassis.
The vacuum system of Claim 1, wherein each of the vacuum plenums (304) corresponding to each of the print bars (42) is located between the corresponding print bar (42) and the second end of the chassis.
The vacuum system of Claim 1, wherein the at least one vacuum plenum (304) corresponding to each of the print bars (42) comprises two vacuum plenums (304a, 304b), wherein the first of the two vacuum plenums (304a) is located between the corresponding print bar (42) and the first end of the chassis, and wherein the second of the two vacuum plenums (304b) is located between the corresponding print bar (42) and the second end of the chassis.
The vacuum system of Claim 1, further comprising:
any of a shroud or mounting structure corresponding to each of the vacuum plenums (304), wherein each of the shroud (311) or mounting structure surrounds at least a portion of a corresponding vacuum plenum (304).
The vacuum system of Claim 1, wherein a single plenum (304) corresponds to each of the print bars (42), wherein the printing system may be compactly packaged.
The vacuum system of Claim 1, wherein the shape of each of the vacuum plenums (304) is configured to prevent steam build-up and condensation.
The vacuum system of Claim 1, further comprising:
a damper valve (314) corresponding to each of the vacuum plenums (304), wherein the damper valves (314) are controllable to adjust the vacuum applied through the corresponding vacuum plenums (304).
A plenum (304) for removing moisture from one or more ceramic tiles in a printing system having one or more print bars (42), a chassis (12) having a first end, a second end opposite the first end, a first side, and a second side opposite the first side, wherein the first side and the second side extend from the first end to the second end, a conveyor assembly (14) mounted to the chassis and extending between the first end and the second end, wherein the conveyor assembly comprises a first roller (16) at the first end, a second roller (16) at the second end, a transfer belt (18) extending between the first roller and the second roller for moving workpieces with respect to the print bars, and a drive mechanism (26) linked to any of the first roller or the second roller, wherein the plenum comprises:
a plenum body (310) that extends transversely across the transfer belt (18) from a near end to a far end, the plenum body having a lower surface proximate the transfer belt (18);

one or more inlets (366) defined on the lower surface of the plenum body;

an outlet (312, 316) defined in the plenum body that is configured to be connected to a vacuum system (320); and

a plenum passage (322) that extends from the inlets to the outlet;

wherein each of the vacuum plenums (304) comprises a plurality of cross sections between the near and the far end,

wherein the plurality of cross sections are any of polygonal or curved to provide a consistent pressure differential across a portion of the width of the transport belt (18) to draw moisture away from a ceramic tile print zone.
The plenum of Claim 9, wherein the plenum (304) is located between a corresponding print bar (42) and the first end of the chassis.
The plenum of Claim 9, wherein the plenum (304) is located between a corresponding print bar (42) and the second end of the chassis.
The plenum of Claim 9, wherein the shape of the plenum (304) is configured to prevent steam build-up and condensation.