Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/135—Nozzles
  • B41J2/165—Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
  • B41J2/16517—Cleaning of print head nozzles
  • B41J2/16552—Cleaning of print head nozzles using cleaning fluids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/135—Nozzles
  • B41J2/165—Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
  • B41J2/16517—Cleaning of print head nozzles
  • B41J2/1652—Cleaning of print head nozzles by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum at the outside of the print head

Definitions

• the present invention refers to an equipment and method for cleaning inkjet printing heads that are used for the industrial decoration of different articles.
• the industrial decoration is focused on ceramic pieces and other products in which the surfaces to be decorated are extensive, using inks that due to their chemical composition tend to seal the print heads with relative frequency.
• the objective of the invention is to achieve optimum cleaning of the printheads with a high degree of efficiency and low cost.
• the solution that is applied consists in disconnecting the ink inlet tubes and applying a normally organic solvent liquid with a syringe that, when passing through and leaving the injection zone, where piezoelectric devices are located, drag the ink or bodies that generate the seal.
• the invention proposes an equipment and method for cleaning inkjet printing heads, where the temperature of the solvent used in cleaning is controlled, also controlling the solvent pressure and the pressure of an air fluid that participates in cleaning in combination with the solvent. Cleaning times are also controlled depending on the type of head and ink used by the print head and also on the degree of shutter.
• the equipment of the invention is intended to clean, by means of a solvent, internal spaces of the ink print heads that are normally traversed by the flow of ink during its injection, highlighting that the path of at least one pressurized fluid that crosses the internal spaces of the heads does it in two directions of circulation, thus achieving a more effective cleaning.
• a main tray inside which an ink print head is housed for cleaning, a lower part of the ink print head being injected continuously in a liquid solvent contained within the main tray.
• a level control device that regulates the optimum height as an overflow of the liquid solvent contained within the main tray, liquid solvent that covers the bottom of the printhead.
• An address switch that selects the direction of circulation of a solvent fluid, selected from a gaseous fluid and a liquid solvent; where that fluid circulates through internal spaces of the ink print head by means of a first fluid inlet / outlet passage in a first direction of circulation and by means of a second fluid inlet / outlet passage in a second direction of circulation.
• a first pipe connects the first step with an ink print head inlet.
• a second pipe connects the second passage with the passage device where the ink print head is embedded.
• 1 device of the invention further comprises:
• a main new solvent boiler that feeds a first working solvent boiler through a conduit in which a second new solvent filter and a new solvent filling valve are intercalated.
• a second working boiler of working solvent A second working boiler of working solvent.
• a return switch that integrates outputs in which two conduits converge that connect with the work tanks, first and second; counting the return switch with a first input that connects to the direction switch through a conduit, and a second output that connects to a first working solvent filter that connects to the direction switch.
• a return valve that integrates two outlets in which two conduits converge that are directed to the two work boilers, first and second, that return valve integrating an inlet that connects to the level tank through a conduit.
• the equipment of the invention comprises a rejection tank that connects to the drain valve through a conduit.
• the equipment of the invention further comprises:
• a compressed air pressure / vacuum switch in which two pipes that start from the work tanks, first and second, converge.
• a vacuum generator that is linked to the pressure / vacuum switch through a pipe.
• a control valve in which three conduits related to: the main boiler, the pressure / vacuum switch and a gaseous fluid filter that connect to a compressed air intake outlet converge.
• the equipment of the invention also comprises an ultrasound device located inside the main tray to undo and detach the particles that form the seal inside the ink print head, also comprising a solvent recirculation return device to the print head of ink and which is attached to the level device.
• the pressure control valve, pressure / vacuum switch and vacuum generator that are part of a pressure / depression air circuit, these elements generate pressure variations within the boilers to boost / suck the liquid solvent contained within the boilers; generating a pressure difference between the inlet / outlet of the ink print head, according to the direction of circulation of the liquid solvent inside the ink head.
• the equipment of the invention further comprises a seal between the ink print head and the passage device during cleaning, where the seal between both elements is materialized by an elastic seal having an upper base, a lower base and the minus a through slot around which at least one perimeter lip is located that protrudes above the upper base of the elastic joint.
• the elastic seal is supported by the passage device, while each perimeter lip of the elastic seal sits against a lower face of the ink print head, where the counterposed effort between the ink print head and the passage device during the Cleaning generates a bend in each perimeter lip towards the interior space of the through groove.
• the elastic joint is fitted within a recess of the passage device, selected from a minor recess where it adjusts a minor elastic joint that has a single through groove, and a larger recess where it adjusts a major elastic joint that has several through grooves. It should be noted that each of the perimeter lips has an angular profile.
• the bottom of the minor recess is interrupted by a central opening bordered by a perimeter rib that fits against the inner face of the through groove of the minor elastic joint.
• the bottom of the major recess is interrupted by several central openings bordered by perimeter ribs that fit against respective internal faces of the through grooves of the major elastic joint.
• each through groove is bordered by a single perimeter lip where one of its branches is an extension of the inner face of that through groove, while the other even branch has a convergent inclination above the upper face of the elastic seal.
• each through groove is bordered by several perimeter lips, where one of its branches is perpendicular to the upper base of the elastic joint, while the other even branch has a convergent inclination above the upper face of the elastic joint.
• one of the perimeter lips it has a branch that is an extension of the internal face of the through groove.
• the method for cleaning inkjet printing heads carried out by the equipment described in any one of the preceding claims comprises the following steps:
• the ultrasonic device is activated to undo and descale the dirt inside the ink print head.
• the solvent that runs through the cleaning circuit and draws the particles that come off the ink print head is filtered to less than 1 meter to prevent those particles from re-entering the ink print head and to save solvent consumption .
• the level tank receives the surplus of liquid solvent evacuated from the main cuvette through the level control device
• Figure 1. Shows a schematic view of the equipment for cleaning inkjet printing heads, object of the invention.
• Figure 2. Represents an exploded perspective view showing an ink print head and a passage device and also a smaller elastic seal that has a single through slot.
• Figure 3. Represents a sectional view where it essentially shows the smaller elastic seal fitted within a smaller recess of the passage device.
• Figure 4.- Shows an exploded perspective view showing a multiple ink printhead associated with a passage device in combination with a larger elastic seal.
• Figure 5. Represents a view similar to that shown in Figure 2 where a multiple ink print head and a passage device in combination with a larger elastic seal having several through slots are shown.
• Figure 6. It shows a sectional view during head cleaning where the inward fold of a pair of perimeter lips of the elastic seal is highlighted when they rest on a lower face of the ink print head.
• the inkjet printing head cleaning equipment comprises a supporting structure 21 that supports a main tray 25, which is filled with a liquid solvent to a height sufficient to cover a lower injection part of an ink print head 16 to be cleaned housed inside the main tray 25, lower injection part where piezoelectric devices are located that They are responsible for regulating and applying inkjet and which are not represented in the figures.
• a level 17 control device is provided inside the main cuvette 25, so that the surplus of liquid solvent that is inside the main cuvette is evacuated by the level 17 control device to a level 13 reservoir to prevent the ink print head 16 from getting wet and that solvent mixed with a pressure recirculating solvent that runs inside the ink print head 16 in Two directions of circulation to achieve a better and more effective cleaning.
• Said control device 17 basically comprises a level control tube.
• the level 13 tank is associated with a drain valve 14 that derives part of the solvent from the level 13 tank to a rejection tank 24.
• two solvent intakes reach a first outlet through a first inlet / outlet passage 19a and a second outlet through a second inlet / outlet passage 19b.
• the first step 19a connects with the ink inlet of the ink print head 16, while the second step connects with a passage device 18 where the ink print head 16 is embedded in correspondence with the exit holes in the area bottom where the ink comes out, so that the solvent circulates inside the ink print head 16, in a first direction of circulation from its outlet holes to the inlet of the ink print head 16 passing first through the device step 18 to lead to the first step 19a, and in a second direction of circulation from the entrance to the exit holes of the ink print head 16 passing through the passage device 18 to flow into the second step 19b.
• the two input / output steps, first 19a and second 19b, are associated with a direction switch 19 to select the direction of solvent flow.
• the equipment of the invention also includes a main boiler 4 containing clean solvent, and of which two working boilers are supplied as needed: one first 7 and the second 8.
• the connection between the main tank 4 and the two boilers 7 and 8 provides a huge reduction in solvent consumption that is usually used in cleaning the ink print head 16, so that the solvent is recirculated through a circuit with various conduits and elements described below.
• the tank of level 13 is also associated with the working boilers, first 7 and second 8, by medication of conduits that connect with such boilers 7-8 with interposition of a return valve 9.
• first 7 and second 8 start other ducts that converge in a pressure / vacuum switch 5 associated in turn with a vacuum generator 6 and also with a control valve 3 of the air pressure both in both boilers 7-8 as in the main boiler 4.
• the air pressure control valve 3 is associated with a filter of regulation 2 of the compressed air and this in turn connects with an inlet 1 of compressed air.
• first 7 and second 8 start other conduits that converge in an arrival / return switch 20, from which a first conduit that flows into the direction switch 19 starts with interposition of a first solvent filter 11 of work and a second conduit that ends directly in the direction switch 19.
• the circuit of the equipment of the invention also has a conduit that goes from the main boiler 4 to the first working boiler 7, a second filter 10 of new solvent and a filling valve 12 of new solvent being interposed in that conduit, through from which this new solvent passes to the first working boiler 7.
• the equipment of the invention also has a solvent recirculation return device 17a to the ink print head 16 and which is fixed to the level 17 control device.
• Both the main cuvette 25 and the rest of the device elements are supported by the supporting structure 2, also supporting a pneumatic and hydraulic control panel 22 also an electrical control panel 23.
• an ultrasonic device 15 is located inside the main tray 25 to undo and detach the particles that form the seal inside the ink print head.
• the solvent in the work tanks, first 7 and second 8 passes through the first working filter 11 through the arrival / return switch 20 to always ensure an expected quality.
• E 1 solvent surplus of the main cuvette 25 can be returned to the working boilers, first 7 and second 8, a through the level tank 13 and return valve 9 and can also optionally be returned to the rejection tank 24 through the level tank 13 and valve; Drain 14.
• the liquid solvent 16 can be injected into the ink print head with the selection of the flow direction of the fluids to clean the ink print head 16.
• the filters, first 11 and second 10 they are intended to retain the particles that are released from the jams and thus reuse the cleaning liquid solvent to avoid high consumption.
• the filtering that is done is less than 1 miera.
• the ultrasonic device 15 has the function of undoing and detaching the particles that form the jam in the inside the ink print head 15.
• short cycles of activation of the ultrasonic device 15 are made to prevent the temperature from rising to more than 45 degrees. These cycles are carried out intermittently for the entire duration of the cleaning. This prevents the solvent from overheating.
• the return device 17a is a connection to the level 17 control tube that is used to connect the recirculation output of some ink printheads 16.
• ink printheads 16 carry recirculation, whereby in this case the recirculation outlet is connected to the level 17 control device which in turn sends all this remaining solvent to the reservoir 13.
• the pressurized air fluid serves to generate pressure inside the boilers and boost the solvent. In this way we avoid the use of discharge pumps, which need a lot of maintenance. Thus, in the present invention we move the liquid solvent by air pressure.
• first 7 and second 8 we do it by giving air pressure through the pressure control valve 3 and sending that flow of liquid solvent to the boilers work, first 7 or second 8, through the second filter 10 of new solvent.
• a first pipe (26) connects the first passage (19a) with an inlet of the ink print head (16); while a second pipe (27) connects the second passage (19b) with the passage device (18) where the ink print head (16) is embedded.
• a completely sealed special seal is provided between the ink print head 16 and the passage device 16 comprising an elastic joint 28-28 'of parallelepiped configuration that it has an upper base 29, a lower base 30 and at least one through slot 31 that reaches both bases 29-30.
• an elastic joint 28-28 'of parallelepiped configuration that it has an upper base 29, a lower base 30 and at least one through slot 31 that reaches both bases 29-30.
• it is a smaller elastic joint 28 that has in correspondence with its upper base 29 and around the through groove 31, at least one perimeter lip 32 that contacts against a face bottom 16a of the ink print head 16, so that the ink outlet holes flow into that bottom face 16a in an area delimited by the perimeter lip 32.
• the elastic seal 28-28 ' supports at its horizontal base 30 on a horizontal plane, the perimeter lip 32 having an angular profile, one of its branches is vertical as a continuation of an internal lateral face of the through groove 31 of the elastic seal 28-28 ', while the other branch of that angular profile is inclined and convergent upwards.
• the elastic seal 28-28 integrates two perimeter lips 32: an inner one corresponding to that described above and a second perimeter lip equal to and adjacent to the first.
• the minor elastic seal 28 is fitted within a minor recess 33 of the passage device 18.
• the bottom of this minor recess 33 is interrupted by a central opening 34 bordered by a perimeter rib 35 that fits against the inner face of the through slot 31.
• FIG. 5 and 6 there is shown a larger elastic seal 28 'that has several through slots 31 to be applied to a multiple ink print head 16.
• the major elastic seal 28 ' has a perimeter lip 32 around each through groove 31 as shown more clearly in Figure 5, although as it is evident, several perimeter lips 32 may be incorporated around each through groove 31.
• the major elastic seal 28 ' fits into a larger recess 33' of the passage device 18, so that the bottom of this major recess 33 'is affected by several central openings 34 bordered by respective perimeter ribs 35 which are adjusted with the internal faces of the through slots 31.

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• Ink Jet (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51299253

Family Applications (1)

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Citations (5)

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• 2013
  • 2013-02-08 ES ES201330156A patent/ES2492090B1/es not_active Expired - Fee Related
  • 2013-10-29 EP EP13874401.6A patent/EP2955027B1/en active Active
  • 2013-10-29 CN CN201380003762.0A patent/CN104321198B/zh active Active
  • 2013-10-29 WO PCT/ES2013/070751 patent/WO2014122336A1/es active Application Filing
  • 2013-10-29 TR TR2019/01126T patent/TR201901126T4/tr unknown
  • 2013-10-29 BR BR112015019025-1A patent/BR112015019025B1/pt active IP Right Grant
  • 2013-10-29 ES ES13874401T patent/ES2709055T3/es active Active
  • 2013-10-29 PL PL13874401T patent/PL2955027T3/pl unknown
• 2014
  • 2014-04-21 IN IN873KON2014 patent/IN2014KN00873A/en unknown

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