Patent Application
20220203687
This application claims priority from European Patent Application No. 20306712.9 filed on Dec. 30, 2020. The content of this application is incorporated herein by reference in its entirety.
The invention concerns the field of continuous inkjet printers (CU).
It concerns a new cleaning process of CIJ printers.
It also concerns a new architecture (arrangement of the ink circuit) of CIJ printers, in particular the arrangement of the ink circuit, for the purpose of increased flexibility.
Continuous inkjet printers (CU) are well known in the field of industrial coding and labelling of various products, for example to mark barcodes or expiry dates on food items directly on the production line and at fast production rate. This type of printer is also found in some fields of design in which use is made of the graphic printing possibilities of the technology.
There is a need for a process to clean an ink circuit of CIJ printers, so that individual components or parts of its ink circuit can be easily disassembled or removed from the ink circuit, for example when they must be repaired or replaced by other components or parts, while minimizing risks of spillage or dropping, in particular of ink. Such process must be able to be carried out by an operator without any particular training.
One particular problem arises when a component or a part of a known printer, for example a valve, must be replaced. Said part is first disassembled from the printer and stoppers are mounted on the hydraulic conduits from which the part was removed and possibly also on the removed part itself, which is time consuming and costly. Alternatively, non-return valves or check valves can be used in the circuit, but they are also costly. Furthermore, the removed part remains dirty and/or is not dry, which causes important ink and/or solvent spills; for this reason, it is sometimes introduced into an airtight bag to be transported, which is not satisfactory since the removed part often remains dirty and retains a lot of residual fluid.
There is also a need, for environmental reasons, to collect the used components or parts of such machines and to recycle or refurbish or evacuate them to waste stations with minimum spillage and dropping. A process must therefore be found to clean an ink circuit of a CIJ printer, so that, after use, clean individual components or parts of said circuit can be easily recycled and/or refurbished and/or transported to a repair station or to a collecting or waste station.
There is also a need for a process to clean an ink circuit of a CIJ printer, so that clean and dry or nearly dry individual components or parts of said circuit can be easily removed and then transported with minimum risks of ink and/or solvent spillage. There is also a need for an ink circuit of a CIJ printer to implement a new cleaning process according to the above requirements.
There is also a need for an ink circuit architecture of such CIJ printers which minimizes the number of components whilst guaranteeing great flexibility and reliability, ease of cleaning and/or maintenance to allow rapid servicing, minimizing risks of spillage and able to be carried out by an operator without any particular training.
There is also a need for components for such an ink circuit which can be easily cleaned and/or removed from said ink circuit for example when they must be repaired or replaced by other components.
There is a further need for an ink circuit architecture of such CIJ printers which can be modulated or tailored depending on the needs and/or on the kind of printing which must be performed; preferably, such an ink circuit architecture has one or more parts or modules which can be adapted or changed, in particular when manufacturing or building the CIJ printer which comprises said ink circuit architecture.
The invention concerns a method or process for flushing or cleaning an ink circuit of a CIJ printer or at least part of said ink circuit, for example an ink circuit as disclosed below; such a circuit may comprise at least one single-block assembly or module.
In an embodiment, said method comprises flushing or cleaning at least said part of the ink or hydraulic circuit of an ink jet printer, or said ink or hydraulic circuit, with a gas, for example with air. Gas is circulated or flowed, in said circuit or in at least part of it, and removes ink from the part in which it is circulated or flowed.
Thus, there is no residual ink in the circuit or in at least part of it. This avoids the risks of spillage or dropping of ink.
Ink can be recovered, for example in a recovery cartridge or in a tank or in the main ink tank of the ink circuit. Ink can thus be reused and is not wasted.
The invention also concerns a cleaning or flushing method or process for cleaning or flushing at least an ink or hydraulic circuit of a continuous inkjet printer or at least one part of said circuit, said hydraulic circuit comprising for example a solvent tank and an ink tank and hydraulic connection or means for sending ink and/or solvent to a print head.
In an embodiment, said cleaning or flushing process comprises circulating or flowing, for example pumping, a gas or a gas and solvent or clean solvent, through said circuit or at least one part of said hydraulic circuit and possibly recovering dirty fluid from said circuit or from at least one part of said hydraulic circuit, said dirty fluid comprising a mixture of solvent and ink.
Said process may comprise alternatively or simultaneously circulating or flowing, through said at least one part of said hydraulic circuit or through said circuit, for example by pumping said solvent, for example from said solvent reservoir, and said gas, for example between 80% and 95% of solvent and 20% to 5% of gas.
If said hydraulic circuit comprises a solvent pump for pumping solvent and/or a pressure pump for pumping ink from said ink tank, said circulating or flowing of gas or of gas and solvent can implement pumping of gas and/or solvent and can be performed with one or both of said solvent pump and/or said pressure pump. Gas under pressure (at a pressure higher than the atmospheric pressure) can be directly introduced into the circuit, and in particular into a flow of solvent, without pumping said gas.
Said step of circulating or flowing a gas and solvent in an embodiment of a process according to the invention for example comprises alternatively sending or circulating or flowing several volumes of gas and solvent, forming for example a slug flow, and/or forming a mixture of solvent and gas, forming, or not, a diphasic mixture or an emulsion, said flow or mixture or emulsion comprising for example between 80% and 95% of solvent and 20% to 5% of gas. A slug flow comprises several volumes of solvent, two successive such volumes being separated by one volume of gas.
A cleaning process according to the invention may comprise:
An embodiment, in which said flushing or cleaning process comprises circulating or flowing a gas and clean solvent through said circuit or at least one part of said hydraulic circuit, can comprise at least one of:
In a flushing or cleaning process according to the invention, gas, for example compressed gas (at a pressure higher than atmospheric pressure) can be introduced into the ink circuit, for example alternatively or simultaneously to solvent, through a dedicated inlet in the circuit, for example upstream or downstream of one of the pump(s) of the circuit.
Said hydraulic circuit to which the invention applies can comprise a solvent pump for pumping solvent and an ink pump (or a pressure pump) for pumping ink from said ink tank, pumping of gas and solvent according to an embodiment of the invention being performed with one or both of said solvent pump and said ink or pressure pump.
In an embodiment, said hydraulic circuit to which the invention applies comprises at least an ink cartridge and a solvent cartridge, said flushing or cleaning process comprising at least one of:
In a particular embodiment, a flushing or cleaning process according to the invention may comprise a preliminary step of mounting a device in the circuit for introducing a gas, for example compressed gas, into said circuit, said cleaning process comprising circulating or flowing said gas and solvent in or through at least one part of said hydraulic circuit.
A flushing or cleaning process according to the invention may comprise or end with a drying step of said at least one part of a hydraulic circuit or of said circuit. Said drying step for example comprises sending or circulating or flowing a flow of gas, which may be heated, through said hydraulic circuit or through said at least one part of said hydraulic circuit.
In a particular embodiment, said hydraulic circuit comprises at least one removable single-block assembly or removable module or removable component, said flushing or cleaning process comprising cleaning said at least one removable single-block assembly or module or component. A drying step as mentioned above is particularly useful in this case, for example if said single-block assembly or module or component must be disassembled from said circuit: a clean and dry or nearly dry single-block assembly or module or component can be removed from the circuit with minimum risk of ink or solvent spills and thus with a minimum risk to waste ink or solvent. The drying step of a single-block assembly or module or component may achieve removing at least 85% or 90% of the fluid (mostly solvent) from said assembly or module or component.
The invention also concerns a process for maintaining a hydraulic circuit of a continuous inkjet printer, or at least one part of said hydraulic circuit, which may comprise at least one removable single-block assembly (or removable block or removable module), said process comprising:
The invention also concerns a continuous inkjet printer, comprising:
Preferably the controller is controlling, or programmed to control, said hydraulic circuit so as to perform at least one of the following:
Said CIJ printer can comprise a solvent pump for pumping solvent and/or an ink pump (or a pressure pump) for pumping ink.
Said CIJ printer can comprise at least an ink cartridge receiving portion or connection and/or at least a solvent cartridge receiving portion or connection.
Said ink circuit can comprise an inlet for introducing gas, for example compressed gas, into the ink circuit, for example in order to perform a cleaning step or process according to the invention.
Said ink circuit can comprise at least one removable single-block assembly (or removable block or removable module), as disclosed below, said controller controlling said hydraulic circuit to perform a process according to the invention, for example to circulate or flow at least gas, or to alternatively or simultaneously circulate or flow gas and solvent, through at least said removable single-block assembly.
In a continuous inkjet printer according to the invention, said controller may be programmed to control said hydraulic circuit to perform a drying step, for example by sending or circulating of flowing gas, for example heated gas, through the circuit.
Embodiments of a process according to the invention or of a CIJ printer according to the invention can implement at least one removable single-block assembly or removable block or removable module. Such single-block assembly may comprise at least one fluid component like for example at least one pump and/or at least one filter and/or at least one damper and/or at least one valve.
Said at least one removable single-block assembly or removable block or removable module can further comprise means, such as securing or fastening means, for mounting and disassembling said single-block assembly to and from an ink circuit of a CIJ printer.
Said at least one removable single-block assembly or removable block or removable module may comprise a housing having at least one fluid inlet and at least one fluid outlet, and fluid connection means, for example ducts, to allow fluid to flow from said at least one fluid inlet to said at least one fluid component, and then to said at least one fluid outlet.
Several examples of different such removable single-block assemblies (or removable blocks or removable modules) are a “first single-block assembly” (or “first block or module”), a “second single-block assembly” (or “second block or module”), a “third single-block assembly” (or “third block or module”) which are described below. The adjectives “first”, “second”, “third” do not indicate a preferred order or any order of importance, but are merely used for the sake of clarity. Said different single-block assemblies or removable blocks or removable modules can be used independently from each other in a printer.
A first single-block assembly comprises:
In one embodiment said first single-block assembly comprises a hydraulic part of a pump, and coupling means for coupling said hydraulic part and a motor for driving said hydraulic part, said motor being in an ink circuit, outside said first single-block assembly. For example, said coupling means of said first single-block assembly comprises an axis of said pump, said axis traversing said housing.
A second single-block assembly comprises:
A third single-block assembly comprises:
Said third single-block assembly may further comprise at least one filter, said fluid connection means allowing a fluid to flow from said fluid inlet or from one of said at least two fluid inlets to said filter, then to said recovery device, and to said fluid outlet or to one of said at least two fluid outlets.
Said recovery device of said third single-block assembly may comprise at least a second pump or a venturi. Said third single-block assembly may further comprise at least a 3-way valve.
Any of said removable single-block assemblies or removable modules, for example any of said first, second, or third single-block assemblies, can comprise an identifier, for example of the electrical or of the magnetic type.
An electrical identifier can have for example an electrical characteristic having one of at least two or three values; it can have more values, for example if there are:
A magnetic identifier can comprise at least one magnet disposed at one or more specific location(s) or position(s) in the single-block assembly, said specific location(s) or position(s) depending on at least one technical characteristic of the single-block. A magnetic identifier comprising one magnet can have for example at least two or three different positions in the device, each position identifying for example a different type of pump or a different type of filter or a different type of recovery device. It can have more possible positions, for example if there are:
A magnetic identifier can cooperate with means in the circuit, for example a switch, for example a “reed switch”, to identify the removable single-block assembly or the removable module. Several switches can be located at different locations in the ink circuit. Depending on the location of the magnet in the module, which itself depends on one or more technical characteristics of the module, one or the other of the switches is activated when the module is connected to the circuit, which is detected by the printer or its controller. An identification of the module is thus obtained.
An identifier of a module can comprise several magnets disposed at several locations in the module or single-block, each combination of locations depending on at least one technical characteristic of the module or single-block; for example, each combination of locations provides the identification of a different type of pump or a different type of filter or a different type of recovery device and each magnet interacting with means in the circuit, for example a switch, for example a “reed switch”. This multiplies the possible identifications with respect to the identifications with only one magnet.
Any of said removable single-block assemblies or removable modules, for example any of said first, second, or third single-block assemblies can comprise means, preferably magnetic means, for guiding its positioning in a printer or with respect to an ink circuit or to a corresponding interface in the printer. Any removable component or part of the circuit can also be provided with such magnetic guiding means.
In an embodiment, at least one of said removable single-block assemblies or removable modules, for example any of said first, second, or third single-block assemblies, as well as the corresponding part of the printer to which it must be connected, have magnetic means that cooperate to attract each other when said single-block assembly or module approaches the location in the printer where it must be connected so that it is easier for an operator to mount said assembly or module.
For example, each of said at least one single-block assembly and the corresponding connecting part or surface of the printer to which it must be connected has a magnet, both magnets attracting each other. Or one of them has a magnet and the other part has a material having magnetic properties such that both the assembly and the corresponding connecting part of the printer attract each other when the module approaches said connecting part. Other components or parts of the circuit can be mounted on or in the circuit, the mounting being assisted or guided by magnetic means as described above.
Further aspects and embodiments of the above described single-block assemblies or modules or blocks are disclosed in the following parts and in the drawings of this application.
In an embodiment, of a process according to the invention or of a CIJ printer according to the invention, an ink circuit of said continuous inkjet printer comprises one or more of the above described removable single-block assemblies or removable modules, for example one or more of said first, second, or third single-block assemblies. Any of said removable single-block assemblies or removable modules, for example any of said first, second, or third single-block assemblies can be mounted in or on the ink circuit or disassembled or removed from the ink circuit, for example after a flushing or cleaning process according to the invention, independently from the others.
An ink circuit of a continuous inkjet printer to which the invention can apply or an ink circuit of a continuous inkjet printer according to the invention, can comprise:
Said circuit may further comprise means for mounting and disassembling said at least one single-block assembly or module to and from the first part of said ink circuit, for example to and from at least one corresponding receiving interface. A receiving interface may have at least one fluid inlet and/or at least one fluid outlet which correspond(s) to the at least one fluid outlet(s) and/or to the at least one fluid inlet(s) of the single-block assembly or module which must be mounted or assembled with said interface.
If the ink circuit has several different single-block assemblies or modules, each of them can be disassembled or removed from said ink circuit, for example after a flushing or cleaning process according to the invention, independently from the other(s) and can be mounted back (for example after a cleaning or repairing step) or replaced with a different or similar or identical module. For example, a recovery module can be replaced by a recovery module having a different structure and/or one or more different component(s), in particular if a different ink is used in the printer. Another example can be the replacement of a module by a technically updated module, with more advanced technical function(s) or updated component(s).
A different or updated component(s) can be for example a different or more advanced filter (having a different, for example a smaller, mesh size than the previous one) and/or a different pump (having a different, for example a larger, flow rate or power, than the previous one) and/or pumps differing by their technology (a gear pump or a peristaltic pump or a diaphragm pump, which can be adapted to different types of inks) and/or a different pump or venturi (having a different, for example larger, geometry than the previous one).
An ink circuit to which the invention applies, or an ink circuit of a continuous inkjet printer according to the invention, may be compatible with a plurality of the above-described modules, for example with two different third single block assemblies; at least two of said modules, although they may differ from each other by one or more technical features, for example different filters, may be alternatively mounted on said circuit or printer, or on the same corresponding interface of said circuit. Said circuit or interface has connections (at least one fluid inlet and/or at least one fluid outlet) so that said at least two different modules (different modules having different structure(s) and/or one or more different component(s) as explained above) can be alternatively connected to said circuit or printer or to said corresponding interface, the exchange of module occurring for example after a flushing or cleaning process according to the invention.
The invention applies in particular to an ink circuit of a continuous inkjet printer or to a continuous inkjet printer, or a continuous inkjet printer which can comprise, or a continuous inkjet printer according to the invention can comprise:
Such an ink circuit may further comprise a third single-block assembly or module as disclosed above.
As already explained above, any single-block assembly of an ink circuit to which the invention may apply, in particular any of the first, second or third single-block assembly or module, may comprise at least one identifier, for example of the electrical or of the magnetic type. Said identifier may cooperate with corresponding means in the ink circuit to read said identifier.
As already explained, said first single-block assembly may comprise a pump or at least a hydraulic part of a pump, and coupling means for coupling said hydraulic part of a pump and a motor for driving said hydraulic part. Said motor of said first single-block assembly may be in the ink circuit, outside said first single-block assembly, said coupling means coupling said motor and said pump.
Said coupling means of said first single-block assembly may comprise an axis of said pump, said axis traversing said housing.
The means for mounting and disassembling any of said single-block assemblies or any single block assembly of an ink circuit to which the invention applies:
The invention also concerns a process for maintaining a hydraulic circuit of a continuous inkjet printer, comprising a solvent tank or reservoir and a main tank for ink, and at least one removable single-block assembly among:
a flushing or cleaning process, for example according to the invention, flushing or cleaning at least one of said first removable single-block assembly, said second removable single-block assembly and a third removable single-block assembly;
and said process further comprising removing and replacing at least one of said first removable single-block assembly, said second removable single-block assembly and said third removable single-block assembly. Said removed single-block assembly can be replaced with a different or similar or identical module. For example, a recovery module can be replaced by a recovery module having a different structure and/or one or more different component(s), in particular if a different ink is used in the printer. Another example can be the replacement of a module by a technically updated module, with more advanced technical function(s) or updated component(s). A different or updated component(s) can be for example a different or more advanced filter (having a different, for example a smaller, mesh size than the previous one) and/or a different pump (having a different, for example a larger, flow rate or power, than the previous one) and/or pumps differing by their technology (a gear pump or a peristaltic pump or a diaphragm pump, which can be adapted to different types of inks) and/or a different pump or venturi (having a different, for example larger, geometry than the previous one).
An example of circuit, and of components of such a circuit, to which the invention can be applied is given on
Components for such a circuit are shown on
An example of a pump module (or ink pressure pump module) 10 is illustrated on
The pump illustrated on
The ink circuit has a receiving portion or zone or interface to receive the pump module and connect it to the hydraulic circuit of the printer. Said receiving portion or zone or interface has at least one fluid inlet (s) which corresponds to the fluid outlet 16 and at least one fluid outlet which corresponds to the fluid inlet 14 of said first single-block assembly, so that fluid can flow from said interface outlet into said first single-block assembly and then out of said first single-block assembly to said interface inlet.
An example of said receiving interface is described below.
The pump module can be mounted in or on the ink circuit or on said receiving portion or zone or interface; it can be disassembled from said circuit or from said receiving portion or zone or interface of the ink circuit. For example, one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means can be used to mount and remove said module.
This pump module, like any other module in this application, can be provided with an identifier, for example an electric identifier or an RFID identifier or a magnetic identifier, to identify which embodiment is implemented, for example which pump is implemented in the module. Electric identifiers, RFID identifiers and magnetic identifiers are described below.
As seen on
The housing can be provided with slots or openings 22o to facilitate air circulation around the pump.
Any of the embodiments of this module can be provided with one or more member or means 77 to allow mounting and disassembling, as described below in connection with
In another embodiment, it is the remainder or the other part(s) of the machine which may comprise one or more members or pins 772, 773 (each cooperating with a spring), the module 10 being equipped with corresponding holes to cooperate with said members or pins.
In both embodiments the ink circuit has a receiving portion or zone or interface to receive the module, which can be mounted on and disassembled from said receiving portion or zone or interface, for example with one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means. Hole 22h1, 22h2, 22h3 are visible on
An example of a filter module 30 is illustrated on
Another embodiment of the filter module 30′ is illustrated on
The reference numbers are the same as on
The ink circuit has a receiving portion or zone or interface to receive the filter module and connect it to the hydraulic circuit of the printer. Said receiving portion or zone or interface has at least two fluid inlets which correspond to the fluid outlets 38 and 44 and at least two fluid outlets which correspond to the fluid inlets 36 and 42 of said second single-block assembly, so that fluid can flow from said interface outlet(s) into said second single-block assembly and then out of said second single-block assembly to said interface inlet(s). In a simpler embodiment, said module comprises one fluid inlet, one fluid outlet and one filter; the corresponding receiving portion or zone or interface to receive said filter module and connect it to the hydraulic circuit of the printer has one fluid inlet which corresponds to the fluid outlet of said module and one fluid outlet which corresponds to the fluid inlet of said module. An example of said receiving interface is described below. The filter module can be mounted in or on the ink circuit or on said receiving portion or zone or interface; it can be disassembled from said circuit or from said receiving portion or zone or interface of the ink circuit. For example, one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing or fastening means can be used to mount and remove said filter module. Holes 32h1, 32h2, 32h3, 32h4 are visible on
This filter module, like any other module in this application, can be provided with an identifier, for example an electric identifier or an RFID identifier or a magnetic identifier, to identify which embodiment is implemented, for example which filter(s) is/are implemented in the module. Electric identifiers, RFID identifiers and magnetic identifiers are described below.
Preferably the module is provided with means 77 to allow mounting and dismounting of the module 30. These means may allow the defining of axis (or hinge or pivot pin) about which the module is able to pivot. These means may be in the form of retractable members or pins 772, 773 returned by a spring 771.
For example, said means 77 comprise a cylinder, aligned along axis 37 (axis of rotation) and containing said retractable members or pins 772, 773 said spring 771. Spring 771 is located between both pins 772 and 773, and is able to be compressed in said cylinder under their action. Each pin can move between an extended position as in
The members 772 and 773 cooperate with corresponding members (for example holes) on the remainder of the machine.
In another example, it is the remainder of the machine which may comprise one or more members or pins 772, 773 (each cooperating with a spring), the module 30 being equipped with corresponding holes to cooperate with said members or pins. The module can thus be mounted and disassembled from the hydraulic circuit of the printer.
Means 77, 771-773 can also be applied to at least one of the other module(s) 10, 50 described in connection with
2 different examples of a recovery module 50 are illustrated on
In an example, module 50 comprises a housing 52, possibly including a cover 53; said module comprises one or more fluid inlet(s) 55, 59, 61, and one or more fluid outlet(s) 57, 63; inside the housing, a recovery device, for example a venturi 54 (
This module 50, like any other module in this application, can also be provided with an identifier, for example an electric identifier, or an RFID identifier or a magnetic identifier, to identify which embodiment is implemented, for example an embodiment according to
For example, electrodes or contacts of an electric identifier (for example a resistor) can be apparent or accessible through a window of the housing of any module or single block assembly and contact corresponding electrical contacts of the ink circuit or on the interface when the module, for example module 50, is mounted in the circuit or on the interface. Said identifier can be for example a resistance with a first value of resistance for a module according to
Alternatively, any module or module type can have a RFID identifier or tag, storing identification information, the printer having means to read said information stored in said RFID identifier or tag.
Another identifier of any module or module type or single-block assembly in this application, can be of the magnetic type, for example based on an electrical switch, for example a “reed switch”, operated by an applied magnetic field.
For example, a module may comprise several possible locations of one or more magnet(s), each location corresponding to a particular module or single-block and/or to at least one technical characteristic of said module or single-block. Several switches are located at different locations in the ink circuit. Depending on the location of the magnet(s) in the module, one or more of the switches is/are activated, which is detected by the printer or its controller. An identification of the module and/or of its technical characteristic(s) is thus obtained. Alternatively, a plurality of magnets can be located in the ink circuit, one or several of them interacting with one or more electrical switch(es) of the module, for example a “reed switch”, depending on the location of the switch(es), the location of the switch(es) depending on one or more technical characteristics of the module.
In a particular embodiment, an identifier of a module comprises several (N) magnets disposed at several (N or more than N) possible locations in the module, each combination of magnets locations providing the identification of a particular module or single-block and/or of at least one technical characteristic of said module or single-block; for example, each combination of locations identifies a different type of pump or a different type of filter or a different type of recovery device. Each magnet of the combination interacts with means in the circuit, for example a switch, for example a “reed switch”, which interaction is detected by the printer. This multiplies the possible identifications with respect to the identifications with only one magnet.
For example, if a module has 2 possible locations for a magnet:
In this case of 2 possible locations, 3 identifiers can thus be created, identifying 3 different modules or 3 variants of a same module.
Another example concerns the case of a module having 3 possible and different locations for one or more magnets:
In this case of 3 possible locations, 7 identifiers can thus be created, identifying 7 different modules or 7 variants of a same module.
Of course, more identifications are possible with n>3.
Each magnet can interact with mans in the circuit, for example a switch, for example a “reed switch”, disposed at a particular location in the circuit or in the interface to interact with a magnet disposed at a specific location in the module. For example, for 3 locations of 3 different magnets in the module, 3 switches are provided in the circuit, each one being able to interact with one magnet when it is in one specific position in the module. Any module and the ink circuit, or the corresponding interface of the module in the circuit, can be provided with the means to implement at least one of the above-mentioned identifiers. For example, the characteristics of the main filter 40 of the filter module (see
The ink circuit has a receiving portion or zone or interface to receive the recovery module and connect it to the hydraulic circuit of the printer. The recovery module can be mounted in or on the ink circuit or on said receiving portion or zone or interface; it can be disassembled from said circuit or from said receiving portion or zone or interface of the ink circuit. For example, one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means can be used to mount and disassemble and remove said module (see the examples of
Said receiving portion or zone or interface has at least two fluid outlets which correspond to the fluid inlets 55 and 61 (
Preferably, said receiving portion or zone or interface has at least three fluid outlets which correspond to the fluid inlets 55, 59 (
An example of said receiving interface is described below.
Any of the embodiments of this module 50 can be provided with one or more means 77 as described above in connection with
Electrical contacts 51 of an electric identifier can be seen through an opening in cover 53; as explained above, they can be contacted by corresponding contacts of the circuit for identification of the embodiment of the module, the controller of the printer measuring the value of the resistance value through said contacts. In a variant (not represented on the figures), as explained above, an identifier can comprise means, for example one or more electrical switch(es), for example one or more “reed switch(es)”, located in the ink circuit and which can be operated by a magnetic field generated by one or more magnet(s) located in the module.
The ink circuit has a receiving portion or zone or interface to receive the vacuum or recovery module 50, which can be mounted in the ink circuit or disassembled from said receiving portion or zone or interface of the ink circuit, for example with one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means. Holes 52h1, 52h2, 52h3, 52h4,52h′1, 52h′2, 52h′3, 52h′4are shown on
As explained above, each of the modules 10, 30, 50 is maintained in the circuit by appropriate securing means so that each module can be mounted on the corresponding receiving zone or portion or interface of the circuit and disassembled or removed from said zone or portion or interface. This possibility to mount or disassemble any of the modules provides an ink-jet printer with a modular feature: the ink-jet printer can be adapted with different pump modules, and/or different filter module(s), and/or different recovery module(s), for example when manufacturing or building it and/or during use of the printer. For example, a recovery module like the one illustrated on
As explained above, this can be achieved by at least one interface portion(s) or zone(s) or surface(s) which has all fluid inlet(s)/outlet(s) to make it compatible with different modules. Furthermore, one or more of said modules can comprise means 77 to position it along an axis of rotation and to rotate it around said axis. Such means can be combined with the above-described securing means: after the module is fixed with respect to the rotation axis, it is rotated and brought into contact with the corresponding receiving portion or zone or interface of the hydraulic circuit of the printer. In this position it can be locked with the corresponding securing means and used in combination with the hydraulic circuit. When the module must be removed, for example for being changed or repaired or cleaned, it is unlocked, rotated around the axis and then removed from said axis and from the printer.
As can be understood from this figure, each module can be removed from the circuit independently from the other modules and can be mounted back (for example after a cleaning step) or replaced with a similar or identical module. For example the a recovery module according to
In particular, a 3-way valve 70 can be connected to the inlet 14 of the ink pressure pump module 10. Depending on the operation stage of the printer, the fluid to be introduced into the module 10 is selected, with help of the valve 70, among a first fluid (ink supplied though a first duct 71) and a second fluid (air and/or solvent supplied though a second duct 72). The first fluid is thus pumped by pump 24, for example when the printer is printing, and is then sent to the print head through the fluid circuit, and in particular through the filter module 30. The second fluid is pumped by pump 24, for example when the circuit is being cleaned. An example of cleaning process implementing air (or gas) and solvent, is given below.
A damper 74 can be connected on the fluid path to the inlet 36 of the filter module 30 (between fluid outlet 16 of module 10 and fluid inlet 36 of module 30), in order to damp the pressures variations or oscillations of the ink before sending it to the print head, such pressures variations or oscillations being generated by the pump and degrading the print quality. The fluid then flows through filter 34 and is then sent to the print head through part of the fluid circuit (for example through a fluid manifold as illustrated on
A 3-way valve 76 can be connected to the outlet 44 of the filter module 30. Depending on the operation stage of the printer, the fluid flowing out of the filter module 30 can be sent, through the valve 76, either to the print head 100 (possibly through an additional filter 77) or to the main reservoir of the circuit (through the recovery module 50). A sensor 75 can be implemented to measure the pressure and/or the temperature of the fluid flowing out of the filter module 30.
In the illustrated example the fluid flowing out of the filter module 30 through outlet 44 and sent back to the main reservoir of the circuit ink circuit first flows through the recovery module 50, in particular through inlet 55, filter 56, recovery device 54 and outlet 57.
Part of the fluid sent to filter module 30 can also be sent back to the part of the fluidic circuit, for example to a fluid manifold, as illustrated on
The modules 10 and 30 are identical to the modules 10 and 30 of
Module 50 implements a diaphragm pump 54′ and comprises a further fluid inlet and a further fluid outlet with respect to
The fluid flowing out of the filter module 30 and sent back to the main reservoir of the circuit ink circuit first flows through the recovery module 50, in particular through inlet 55, filter 56 and diaphragm pump 54′.
A 3-way valve 66 can be connected to the outlet of filter 56. Depending on the operation stage of the printer, the fluid pumped by pump 54′ can be selected, with help of the valve 66, among the first fluid and the second fluid. It then flows through outlet 57 and to the main reservoir.
Just like for the embodiment of
On both
This figure also shows, under the interface 11, the part of a magnetic pump which remains outside housing 22 (see
The interface 11 can comprise means to interact with an identifier of the pump module. For example, the interface 11 comprises electrical contacts to contact an electric identifier of the pump module 10, as already explained above. In a variant (not represented on the figures), as explained above, an identifier can comprise means, for example one or more electrical switch(es), for example one or more “reed switch(es)”, located in the ink circuit and which can be operated by a magnetic field generated by one or more magnet(s) located in the module.
The holes 22h′1, 22h′2, 22h′3 correspond to the holes 22h1, 22h2, 22h3 of
This figure also shows holes 770, 771 which cooperate with retractable members or pins 772, 773 of means 77 (
The interface 31 can comprise means to interact with an identifier of the filter module. For example, the interface 31 comprises electrical contacts to contact an electric identifier of the filter module 10, or a plurality of electric switches, like “reed” switches, to cooperate with a magnet which is located in the filter module, at different locations depending on the characteristics of the filter module.
Each of said interfaces comprises the appropriate duct(s) to connect its fluid inlet(s) and outlet(s). In particular, when several possible alternative modules can be connected on the same interface, said interface comprises the ducts (fluid inlets and/or outlets) and/or electrical contacts to be compatible with the several modules.
For example, interface 51 has several inlets/outlets in order to be able to connect either the recovery module of
The same applies to the other interfaces which are for connecting any of the other single block assemblies: thus, any interface preferably contains all necessary inlets/outlets and/or electrical contact(s) and/or magnetic means, so that any version or technically updated first, resp. second, resp. third. single block assembly can be connected to interface 11, resp.31, resp.51.
In a variant (not represented on the figures), as explained above, an identifier can comprise means, for example one or more electrical switch(es), for example one or more “reed switch(es)”, located in the ink circuit, for example in the interface, and which can be operated by a magnetic field generated by one or more magnet(s) located in the module.
One or more of the modules, in particular of the above-described modules, and the part of the circuit or the corresponding interface to which it must be connected can be provided with magnetic means to help positioning the module with respect to the ink circuit or to the corresponding interface.
Alternatively:
Module 150 can be for example any of the above-described modules. Other components or parts can be mounted on the circuit by being guided by magnetic means as described above.
The above-mentioned and described modules can be implemented in a fluid circuit as shown on
As illustrated on
An example of a cartridge 82, 84 is shown in
It comprises a portion 120 (this portion is the most rigid, but can however be deformed somewhat when the cartridge is empty) and a semi-rigid, or flexible, portion 140. The rigid portion 120 is provided with a rigid nipple (or mouth, also called “nose” or “nozzle”) 160 that allows for a hydraulic connection to the ink circuit. Initially, the nipple is closed by a capsule of a rubber-type material, for example of EPDM, or other (chemically compatible with the fluids in question), being hermetically crimped or sealed. Upon setting up the cartridge, a hollow needle, linked to the ink circuit, hits the capsules and establishes the hydraulic circuit between the cartridge and the ink circuit. The elastic material of the capsule is chosen to ensure the sealing of the needle-capsule junction.
Another example of cartridge has a storage chamber and a distal end portion which has a cylindrical shape and is closed by a lid.
Examples of cartridge holders 82a, 84a are shown on
The hydraulic module 90 preferably has an ink portion and a solvent portion, the ink portion comprising ink pump 92 for pumping the ink from ink cartridge 82 and the solvent portion comprising pump 94 for pumping the solvent from solvent cartridge 84. It can also comprise a number of 3-way valves 931, 932, 933, 99 to send the appropriate fluid to the appropriate module 10, 30, 50 and/or to the reservoir 80. Ducts 96-98 connect the ink portion and the solvent portion of the hydraulic module 90 with the reservoir 80; ducts 102-104 connect the ink portion and the solvent portion of the hydraulic module 90 with the different modules 10-50 as shown on
Each of the modules 10, 30, 50 is maintained in the circuit by appropriate fastening or securing means, already described above, so that each module can be mounted on the circuit and disassembled or removed from said circuit.
The main reservoir 80 can be of the type comprising two compartments as disclosed in EP 3466697, the upper compartment 801 for storing ink and the lower compartment 802 for storing solvent: - the upper part 801 can be supplied with ink from cartridge 82 through one or more of said valves 931, 932, 933, and one or more of said ducts 96; Ink can be pumped from this upper part by the pump of module 10 through one or more ducts 110;
- the lower part 802 can be supplied with solvent from cartridge 84 through one or more of said valves 99 and one or more of said ducts 97; solvent can be pumped from this lower part by the pump 94 through one or more ducts 98.
A flushing or cleaning process according to the invention can be implemented to clean the above-described circuit, in particular the 3 different modules 10, 30, 50, or to clean only part of it, for example only one of the modules 10, 30, 50, in particular if only one of the modules 10, 30, 50 is to be unplugged or detached from the circuit and repaired or replaced. If such a cleaning process is not performed, ink flows out of any of the modules 10, 30, 50 when it is unplugged or disassembled from the printer, which results in a loss of ink and solvent and, of course, in dropping on the rest or the other part(s) of the system and out of the printer and of the module.
In an embodiment both solvent and ink cartridges 84, 82 are first unplugged from the circuit and ink cartridge 82 is replaced with a recovery cartridge for recovering dirty or cleaning fluid from the circuit. The solvent cartridge 84 being removed, gas, for example air (at atmospheric pressure) can be pumped from means 114c of fluidic connection by activating the pump(s) 94, 24 and the valves of the circuit, in particular valves 931, 932, 933, as if the solvent cartridge was connected to the ink circuit and solvent had to be pumped.
Pump 94 is started, thus pumping air as explained above throughout the whole circuit or through part of it, and in particular through one or more of the modules 10, 30, 50. Ink present in the circuit is thus sent back to the ink tank 80, through appropriate position of each of the valves 99, 933, 70, 76.
In the following steps, ink present in the circuit is sent to the recovery cartridge, through appropriate position of each of the valves 99, 933, 70, 76.
The valves 99 (
A solvent rinsing step can be performed to eliminate any residual ink which could remain in the circuit, or in part of it, for example in one or more of the 3 modules 10, 30, 50. In a preferred embodiment, a drying step can be performed after cleaning by circulating gas in all or part of the circuit, ensuring elimination of substantially all the residual solvent, for example at least 85% or 90% of the residual solvent, present in the circuit. Thus, one or more of the modules 10, 30, 50 can be disassembled from the circuit with reduced risks of ink or solvent spillage.
In the above-described process, solvent thus flows through the same path as the gas.
The above flushing or cleaning steps can be performed for only a part of the circuit, for example for only one of the modules 10, 30, 50. Only cleaning the part or the component of the circuit which must be removed from the circuit saves solvent.
After a flushing or cleaning process as described above has been performed, one or more of the cleaned modules 10, 30, 50 can be disassembled and removed from the printer, and repaired or replaced.
The above process can also be implemented if:
In both cases:
In a variant, the order of gas and solvent can be reversed and steps S5-S7 are replaced by following steps S′5-S′7:
In an example, gas and solvent are alternatively pumped according to steps S5-S7 or S′5-S′7 through only one of the modules 10, 30, 50 because only one module, for example the pump module 10, must be disassembled from the circuit. More generally, gas and solvent can be alternatively pumped according to steps S5-S7 or S′5-S′7 through at least one component or part, for example a valve or a filter or a pump, because said component or part must be replaced. An alternative pumping can be performed by activating one or more valves.
In a preferred embodiment, an initial step of circulating gas in at least part of the circuit allows recovering ink which can be sent to the main tank (ref 80 on
The further steps of the flushing or cleaning process comprise circulating gas and solvent in at least part of the circuit, dirty fluid being recovered in the cartridge for recovering dirty fluid through adapted control of the valves of the circuit.
This creates a gas-solvent mixture, for example a circulation of alternating volumes 401 of gas and of volumes 402 of solvent in a duct 400 (
In a variant of the process illustrated on
As indicated above, a drying step can be performed at the end of the cleaning process, for example by circulating gas in all or part of the circuit, for example compressed gas and/or heated gas. Gas can be heated by circulating it over heating means, for example one or more resistors, for example before being injected into the circuit. A drying step allows disassembling one or more of the modules 10, 30, 50 with a reduced risk of ink or solvent spillage.
The above process can also be implemented if:
In both cases:
In another embodiment, a circuit may comprise removable cartridges but the process may not involve removing said cartridges, steps S1 and S2 not being performed (see example below).
In another embodiment, if a circuit does not comprise removable cartridges (see example below), steps S1 and S2 are also not performed.
This fluid circuit is described in detail in EP 3085541.
It comprises in particular:
A flushing or cleaning process as explained above, in particular in connection with
In particular, cartridges 82 and 84 can be unplugged, cartridge 82 being replaced with a recovery cartridge.
3-way valve 339 can be controlled so that gas, for example air (at atmospheric pressure) and solvent can be alternatively pumped by pumps 341 and 331 and sent to at least part of the circuit, dirty solvent being recovered in the recovery cartridge by controlling 3-way valves 333 and 337 (the valves of the printing head, not illustrated on this figure, being closed, so that no solvent flows towards the printing head).
Thus a gas-solvent mixture is formed, for example a circulation of alternating volumes 401 of gas and of volumes 402 of solvent in a duct 400 (
In a preferred embodiment, an initial step of circulating gas, for example air, in at least part of the circuit allows recovering ink which is sent to the main tank. The further steps of the cleaning process comprise circulating air and solvent in at least part of the circuit, dirty fluid being recovered in the recovery cartridge, through adapted control of the valves of the circuit.
As indicated above, a drying step can be performed at the end of the cleaning process, for example by circulating air in all or in part of the circuit, for example compressed air and/or heated air. Air can be heated by circulating it over heating means, for example one or more resistors, for example before being injected into the circuit. A drying step allows disassembling one or more of fluidic components like one or more valve(s) and/or one or more pump(s) and/or one or more filter(s) or damper(s) with reduced risk of ink or solvent spillage.
It has to be noted that some residual amount of solvent may remain in at least part of the circuit after cleaning and drying but this amount is minor (less than 15% or 10% of the initial volume, this value can even be significantly reduced with compressed air and/or heated air) and does not prevent from disassembling one or more of the above-mentioned fluidic components in good conditions, with a minimum risk of spillage or dropping.
Another cleaning process can be applied to the circuit of
Air, or, more generally, a gas, can be introduced into the ink circuit at specific locations, for example:
Gas can be introduced into the circuit at any of the above locations for example through a side duct laterally connected to the main ducts (or the main duct has a
“T” shape).
Gas can be introduced under a pressure higher than the atmospheric pressure into the flow of cleaning solvent circulating in the ink circuit.
In all the above discussed cases, a gas-solvent mixture is formed, for example a circulation of alternating volumes 401 of gas and of volumes 402 of solvent in a duct 400 (
The alternative pumping of solvent and air generates pressure surges or pulses or bumps of the pump(s) which contribute to an efficient cleaning of the ducts of the circuit.
Dirty solvent can be recovered in a separate tank 390 through an extra valve 391. This dirty solvent can be reused in the main tank 80 when there is a need to dilute ink contained therein, for example by pumping part of said solvent by pump 331, through an extra duct 392 and an extra valve 393.
This other cleaning process, without removing cartridges 82, 84 can be applied to a circuit like illustrated on
Gas is for example introduced upstream of pump 94 through a lateral duct 147. Alternatively, compressed gas can be introduced downstream of a pump, for example with a device as explained in connection with
Dirty solvent can be recovered in a separate tank 390. With respect to
Preferred embodiments of cleaning processes of the circuits of
It comprises a valve 381 and a non-return valve 382 in series, both being mounted in parallel to a non-return valve 383.
A gas, for example from a compressor (not represented on the figure) can be introduced through end 386 and then through valves 381 and 382; the other end 384 of the device, upstream of non-return valve 383 can be connected to the outlet of a pump, for example pump 320 or pump 339 of
Thus gas, for example compressed gas, can be introduced into the circuit, alternatively with solvent or simultaneously to a solvent flow, forming an alternation of gas and solvent or a flow of a mixture, possibly a diphasic mixture, of solvent and gas. The gas can be air.
The device 380 can be permanently in the circuit, for example downstream or at the outlet of a pump 320 (as illustrated on
Alternatively, as illustrated on
This other cleaning method and/or the device of
Any of the above cleaning methods can be applied to the preparation of a new ink jet printer just after manufacturing or building of a new printer. Indeed, the ink circuit of a new printer may contain residual solid particles which can be eliminated by a cleaning process as described above. Solvent containing solid particles is then sent in a waste tank or filtered before being reused in the ink circuit.
Any of the above cleaning methods can also be applied to a circuit not comprising removable cartridges 82, 84, for example a circuit as illustrated on
An example of such circuit is illustrated on
Air, or, more generally, a gas, can be introduced into the ink circuit of
The introduction of gas creates a gas-solvent mixture, for example a circulation of alternating volumes 401 of gas and of volumes 402 of solvent in a duct 400 (
It is preferable to avoid any interference of the gas with the pump 320 or 341; for this reason, a non-return valve can be mounted at the outlet of said pump(s). Thus, a gas can be introduced under a pressure higher than the atmospheric pressure into the flow of cleaning solvent circulating in the ink circuit. This creates a gas-solvent mixture, possibly a diphasic mixture of said gas and said solvent (for example 90% of solvent and 10% gas or between 80% and 95% of solvent and between 20% and 5% of gas) which is efficient to clean the circuit.
The device 380 of
In preferred embodiments of a cleaning process of the circuit of
A circuit like illustrated on
Another embodiment of a flushing or cleaning process according to the invention can be applied to an ink circuit of a CIJ printer, for example an ink circuit according to the invention, in particular according to any of the above-described circuits (
It comprises a step of circulating or flowing gas in at least part of the circuit or in the whole circuit; ink is thus flushed and removed from said part of the circuit or from said circuit and can be recovered, for example in the main tank 80.
Depending on the circuit:
Gas can be introduced into the circuit at any of the above locations for example through a side duct laterally connected to the main duct (or the main duct has a “T” shape) and possibly an additional valve (not represented).
Ink is thus eliminated from the part(s) of the circuit which have been cleaned.
The process can be followed by disassembling or removing from the circuit at least one part which was cleaned according to said above process, for example:
Preferably a flushing or cleaning process to the invention ends with a drying step of the part of the hydraulic or fluid circuit which has been cleaned. For example, the cleaning process can include a final step of pumping gas and sweeping that part of said circuit with said gas.
In particular, if a module, for example like any of the above-described first, second or third module, must be disassembled and removed from the circuit, a cleaning process of the fluid path inside of said module can be performed according to the invention, ending with a drying step of said fluid path. The dry module can then be removed without any fluid dropping from the device.
A “dry” module or a component of a fluid circuit as mentioned in this application or according to the invention also includes any module or a component which has been cleaned and contains less than a maximum volume of fluid.
Indeed, some residual amount of solvent may remain in any of the removable modules 10, 30, 50 after cleaning and drying but this amount is minor and can be trapped in the filter(s) of the module 30, 50 (in particular if the filter comprises absorbent materials) or does not prevent from disassembling the module in good conditions, with a minimum spillage or dripping.
For example, the modules may have an internal fluid volume comprised between 20 cm3 and 150 cm3. Tests were made with the circuit of
A remaining volume of liquid (solvent) of:
Thus, after cleaning and drying, more than 85% or 90% of the initial volume of solvent has been eliminated and less than about 15% or 10% of the initial volume remains in the module or the component. Most of the liquid which remains in module 30 or 50 is trapped in the filter(s) of this module.
A cabinet (also called console or body of the printer) for an ink jet printer comprising a fluid circuit as described in this application is illustrated on
The cabinet can contain three sub-assemblies:
In other words, the body 3 can comprises 2 sub-assemblies: at the top part the electronics, electrical supply and operator interface; and in the lower part an ink circuit supplying the head with ink under pressure and providing a negative pressure for recovery of the ink not used by the head.
As can be seen on
As can be seen on
The 3 modules are accessible from the front side of the printer, so that they can be easily disassembled from the circuit by an operator, independently of each other.
A rear view of the cabinet is illustrated on
The ducts, valves and the other pumps of the circuit are not shown on
The console is hydraulically and electrically connected to a print head (not represented on the figure) by an umbilical.
A gantry, not represented, makes it possible to install the print head facing a printing support 800 (see
Such a printer can be integrated into a packaging machine.
In the drop generator 121 a cavity is supplied with an electrically conductive ink. This ink, held under pressure, by an ink circuit 4 external to the head, escapes from the cavity through at least one nozzle 6 thus forming at least one ink jet.
A periodical stimulation device 123 is associated with the cavity in contact with the ink upstream of the nozzle 6; it transmits to the ink a (pressure) periodical modulation which causes a modulation of velocity and jet radius from the nozzle. When the dimensioning of the elements is suitable, this modulation is amplified in the jet under the effect of surface tension forces responsible for the capillary instability of the jet, up to the jet rupture. This rupture is periodical and is produced at an accurate distance from the nozzle at a so-called «break» point 113 from the jet, which distance depends on the stimulation energy.
In the case where a stimulation device, called an actuator, comprises a piezoelectric ceramic in contact with the ink of the cavity upstream of the nozzle, the stimulation energy is directly related to the amplitude of the electrical signal for driving the ceramics. Other jet stimulation means (thermal, electro-hydrodynamic, acoustic, . . . ), can also be implemented in the frame of this invention. The stimulation using piezoelectric ceramics remains the preferred embodiment due to its efficiency and relative workability.
At its breaking point 113, the jet, which was continuous from the nozzle, is transformed into a train 111 of identical and evenly spaced apart ink drops. The drops are formed at a time frequency identical to the frequency of the stimulation signal; for a giving stimulation energy, any other parameter being otherwise stabilized (in particular ink viscosity), there is an accurate (constant) phase relationship between the periodical stimulation signal and the breaking instant, itself periodical and with a same frequency as the stimulation signal. In other words, to an accurate instant of the period of the stimulation signal corresponds an accurate instant in the separation dynamic of the jet drop.
Without further action (this is the case where drops are not used for printing), the drop train travels along a trajectory 7 collinear to the drop ejection axis (nominal trajectory of the jet) which joins, by a geometric construction of the printing head, the recovery gutter 162. This gutter 162 for recovering non-printed drops uptakes the ink not used which comes back to the ink circuit 4 to be recycled.
For printing, the drops are deflected and deviated from the nominal trajectory 7 of the jet. Consequently, they follow oblique trajectories 9 which meet the support to be printed 800 at different desired impact points. All these trajectories are in a same plane. The placement of the drops on the matrix of impacts of drops to be printed on the support, to form characters, for example, is achieved by combining an individual deflection of drops in the head deflection plane with the relative movement between the head and the support to be printed (generally perpendicular to the deflection plane). In the deviated continuous jet printing technology, the deflection is achieved by electrically charging drops and by passing them into an electric field. In practice, the means for deflecting drops comprise at least one charging electrode 164 for each jet, located in the vicinity of the break point 113 of the jet. It is intended to selectively charge each drop formed at a predetermined electrical charge value which is generally different from one drop to the other. To do this, the ink being held at a fixed potential in the drop generator 121, a voltage slot with a determined value, driven by the control signal, is applied to the charging electrode 164, this value being different at each drop period.
In the control signal of the charging electrode, the voltage application instant is shortly before the jet fractionation to take advantage of the jet electrical continuity and attract a given charge amount, which is a function of the voltage value, at the jet tip. This variable charge voltage affording the deflection is typically between 0 and 300 Volts. The voltage is then held during the fractionation to stabilize the charge until the detached drop is electrically insulated. The voltage remains applied for a certain time after the drop is detached to take break instant issues into account.
The drop deflecting means usually comprise a set of 2 deflection plates 165, located on either side of the drop trajectory upstream of the charging electrode. Both these plates are put to a high fixed relative potential producing an electrical field Ed substantially perpendicular to the drop trajectory, capable of deflecting the electrically charged drops which are engaged between the plates. The deflection amplitude is a function of the charge, the mass and the velocity of these drops.
A CIJ printhead may also comprise several ink-jet cavities for generating several ink jets, each cavity having its own nozzle and activation means or a same cavity may comprise several nozzles to produce several ink-jets. Charging electrodes and deviation electrodes can be associated with each jet as explained above.
The instructions for activating the means 121, 123 for producing ink jets and/or for activating the pumping means, for example of modules 10 or 50, and/or for opening and closing of valves in the path of the different fluids (ink, solvent, gas) and/or for applying the voltage(s) to the charge and/or the deviation electrode(s) can be sent by control means (also called “controller”). It is also these instructions that can make it possible to circulate ink under pressure in the direction of the means 121, 123 then to generate jets as a function of the patterns to be printed on a support 800.
These control means or controller are for example realised in the form of a processor or a microprocessor, or of an electrical or electronic circuit, adequately programmed, for example to implement a cleaning method according to the invention. In particular these control means can be programmed to control one or more pump and/or valve to circulate gas or gas and solvent in the circuit or in at least part of the circuit.
The control means may also be programmed to assure the memorisation of data, for example measurement data of ink levels in one or more reservoirs, and their potential processing.
These control means or controller can also be programmed to read one or more identifier(s) of one or more module(s) or single- block assembl(y)ies according to the invention and to identify said module(s) or single- block assembl(y)ies, which information can be displayed or processed.
Printers according to the invention are industrial printers, for example which have the ability to print on surfaces which are not flat, for example cables or bottles or cans. Another aspect of such printers is that the distance between the printing head and the substrate which must be printed is higher than in conventional desk printers. For example, that distance is at least 5 mm, for example between 10 mm and 30 mm.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20306712.9 | Dec 2020 | EP | regional |
