WO2011035130A1 - Press-side fluid injection without pumping - Google Patents

Press-side fluid injection without pumping Download PDF

Info

Publication number
WO2011035130A1
WO2011035130A1 PCT/US2010/049293 US2010049293W WO2011035130A1 WO 2011035130 A1 WO2011035130 A1 WO 2011035130A1 US 2010049293 W US2010049293 W US 2010049293W WO 2011035130 A1 WO2011035130 A1 WO 2011035130A1
Authority
WO
WIPO (PCT)
Prior art keywords
make
fluid
ink
valve
reservoir
Prior art date
Application number
PCT/US2010/049293
Other languages
French (fr)
Inventor
Douglas Gabler
Richard M. Jones
Original Assignee
Sun Chemical Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sun Chemical Corporation filed Critical Sun Chemical Corporation
Publication of WO2011035130A1 publication Critical patent/WO2011035130A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41FPRINTING MACHINES OR PRESSES
    • B41F31/00Inking arrangements or devices
    • B41F31/02Ducts, containers, supply or metering devices
    • B41F31/03Ink agitators

Definitions

  • an injection pump also known as a metering pump or a solvent pump.
  • Commercial units for example, use either air-operated or electrically operated pumps.
  • the pump is controlled by a pump controller, which is, in turn, driven by the output of a sensor in the ink line or sump, where such sensor measures viscosity, pH or other ink property.
  • overhead stirrers are typically used in the ink sump to blend any injected make-up fluid with the ink.
  • This complex apparatus has a large physical size, and a significant cost associated with it. Moreover, because each station on a printing press requires a make-up system, such a make-up pump and mixer needs to be provided for each press color station.
  • make- up fluid can be injected into any type of ink being circulated by an ink pump to a press color station under continuous operation for the purpose of maintaining the ink in a state of constant, or within a certain defined range of, rheology and surface tension.
  • the makeup fluid can be stored in a reservoir, and the output of the reservoir provided with a valve. Downstream of the valve can be a make-up fluid injection nozzle, arranged to inject make-up fluid into an ink line.
  • the make-up fluid flow can be, for example, gravity-assisted, or for example, can be injected into the ink line, or both.
  • a partial vacuum can be created in the ink line, and the make-up fluid injected at a region of negative pressure associated with the partial vacuum.
  • the valve can be a proportional solenoid valve, and can be automatically controlled by a controller, where the controller is driven by a signal coming from a sensor provided in an ink line or sump.
  • the senor can measure the pH, viscosity, water content, impedance or conductivity of the ink, for example, and the controller can be set to open the valve as make-up fluid is needed.
  • a separate make-up fluid pump can be obviated and/or
  • a mechanical ink mixer can be removed, by exploiting the negative pressure in the ink intake line generated by the existing ink pump and the turbulence that follows the sudden increase in pressure following a constriction in the ink feed line.
  • the inventive apparatus thus involves a small and portable device that can be used as an add-on to existing presses, regardless of size, or, for example, can be provided with new presses.
  • a portion of the ink inlet line containing the make-up fluid nozzle can be sold as a removable disposable part. Additionally, for example, such a disposable apparatus could be sold together with a prefilled bag of make-up fluid, as a single disposable kit.
  • Fig. 1 depicts an exemplary gravity-fed, vacuum-assisted, make-up fluid injection system for a pumped ink according to an exemplary embodiment of the present invention
  • Fig. 2 depicts a generic diagram of an exemplary ejector to illustrate the essentials of inline mixing according to an exemplary embodiment of the present invention
  • Fig. 3 depicts an exemplary pump inlet line (horizontal line region) at a lower pressure than a pump outlet (diagonal line region) due to a constriction between them according to an exemplary embodiment of the present invention.
  • conventional injection systems for ink maintenance all include a pump mechanism for the make-up fluid governed by the output of a sensor.
  • This invention replaces this pump with a simple valve and utilizes the draw of the ink feed pump to pull in the make-up fluid as a result of the existing negative pressure provided by the ink pump.
  • commercial injection systems also include mixers to blend the injected liquid with the ink.
  • this invention replaces this mixing operation by injecting the make-up fluid directly into the ink flow where by combination of constrictions followed by expansions, sufficient mixing occurs.
  • the inventive device's simplicity preferably with no moving parts is technically easier to control and maintain, is lower cost, and has a smaller footprint (physical size) than current commercial units.
  • Fluid injection control can be, for example, as simple as a shutoff valve or clamp and a narrow inside diameter needle inserted into the ink feed line in front of the ink pump.
  • the design and use of a simple apparatus for injection of make-up fluid into any type of ink being circulated by an ink pump to a press color station under continuous operation is described for the purpose of maintaining the ink in a constant rheological and surface tension state.
  • the present invention obviates the need for a make-up fluid pump by exploiting a negative pressure in the ink intake line that is generated by the existing ink pump to both incorporate the make-up fluid and cause it to mix with the ink, thus allowing removal of a mechanical ink mixer as well.
  • Described herein is an apparatus for the injection of make-up fluid into a pumped ink during the operation of the press.
  • it can be comprised of an atmospheric pressure make-up liquid reservoir, a connecting tube in which is installed an on/off valve, and a narrow diameter needle that is inserted into the feed line to the ink pump.
  • it can comprise a valve whose rate of delivery from the make-up fluid reservoir is controlled by the output of at least one sensor in either the ink reservoir (sump) or in the ink return line.
  • the invention is based upon the recognition that the negative pressure in the ink feed line ahead (upstream) of the ink pump can draw in a flow of liquid from a narrow diameter delivery line inserted into the ink pump feed line.
  • the flow of one liquid can impart velocity to droplets of a second, and a series of velocity increases by flow constriction followed by velocity drops by flow expansion can serve to mix both flows.
  • Control of ink composition by viscosity or pH feedback to a pump that injects a fluid into a printing ink is widely employed to assure optimum ink rheology.
  • this fluid is most commonly a volatile solvent.
  • single-fluid lithography it is commonly fountain solution in water.
  • This fluid injection function is often combined with an ink pumping station to give a package that is comprised of an ink reservoir (sump), an ink pump, a make-up fluid reservoir, a make-up fluid pump, the make-up fluid pump electronics, a solenoid valve, a sensor, the sensor's electronics, a check valve, and a mixer. All-combined, the unit occupies nearly six square feet of floor space (footprint) which must be repeated as many times as there are ink stations on the press. The cost of such an installation is a considerable investment for the printer or the ink supplier.
  • the present invention addresses the cost and the footprint of such a device by elimination of the make-up fluid pump and/or its electronics and/or the mixer.
  • the opportunity to do so comes from the realization that the ink pump creates a vacuum that can be used to draw liquid through a narrow feed line inserted into the pump intake line. It is even possible that in some circumstances the valve may be a simple on/off function and the make-up flow be controlled by the inside diameter of the make-up fluid feed line inserted into the ink pump intake line.
  • Fig. 1 depicts an example of a gravity-fed, vacuum-assisted, make-up fluid injection system for a pumped ink according to an exemplary embodiment of the present invention.
  • make-up fluid resides in fluid reservoir 100, and a flow meter 1 15 inputs a flow rate to a controller 120, which controls the flow of the make-up fluid out of the reservoir and into the printing press.
  • Controller 120 also receives a signal from a viscosity, pH, conductivity, dielectric, or other sensor (meter), placed upstream from the fluid injection needle (not shown in Fig. 1 , but would be to the left of Fluid Injection needle 140 in the ink intake line, or, for example, in the ink sump).
  • Controller 120 operates a solenoid valve 125, which can be, for example, either simple or proportional.
  • a check valve 130 prevents ink backing up to the valve.
  • a fluid injection needle 140 is placed in the intake line to ink pump 150 which feeds ink to the press.
  • the fluid reservoir is preferably at atmospheric pressure, either from a vent in a hard container or by use of a collapsible container (similar in function to a hospital IV bag).
  • the ink will preferably be at less than atmospheric pressure so that a pressure differential will exist (a partial vacuum). This vacuum will assist fluid flow through a narrow orifice such as a stainless steel tube inserted into the ink intake line. Shear forces can then mix the ink and the makeup fluid either in the pump, and/or in a doctor bladed chamber that feeds the engraved cylinder of a flexographic or gravure press, and/or in a roller train of a lithographic press. If additional mixing is required, this can optionally be achieved by the well known static mixers that separate and blend fluid flows. Such static mixers can, for example, be inserted into the ink feed line after the injector and either before or after the ink pump.
  • Fig. 2 a generic diagram of an exemplary ejector, shows an exemplary embodiment of the present invention where such mixing is accomplished.
  • Fig. 2 illustrates the essentials of (i) the inline mixing that occurs following a draw of make-up fluid 210 from a make-up nozzle 220 due to the negative pressure provided by the flowing ink, (ii) the constriction and rise in pressure that occurs either in the ink pump (peristaltic) or by other constriction in the ink line, and (iii) the pressure drop caused by expansion following the ink pump or by an increase in hose diameter or other means.
  • the constriction can be placed, for example, either ahead, or following, the ink pump.
  • make-up fluid 210 can, for example, be drawn into the ink flow through the make-up fluid nozzle 220.
  • the negative pressure created by the flowing ink thus assists the make-up liquid flow, and thus eliminating the need for a pressure head on the make-up fluid, such as, for example, provided by gravity as in the exemplary embodiment of Fig. 1 .
  • Such sudden rising and lowering of velocity causes turbulence which can mix the fluid by shearing forces, as discussed, for example, in U.S. Patent Nos. 4,860,959 and 4,186,772, and illustrated in Fig. 3.
  • Fig. 3 depicts an exemplary pump inlet line (the region at the left covered in horizontal lines) at a lower pressure than a pump outlet (the region at the right covered in diagonal lines).
  • the constriction 315 imparts a localized increase in the negative pressure in the inlet line (i.e., in the white (non-hatched) region in between the horizontal line and diagonal line regions).
  • a make-up fluid nozzle can be placed anywhere in the lower pressure horizontal line region 310 where a partial vacuum already exists, or, for example, for an even larger vacuum it can be placed in the constricted (non-hatched) region 315. Due to the partial vacuum, the make-up fluid will thus be drawn into the ink flow 350, again without the need for a make-up injection pump or stirrers.
  • an increase in vacuum caused by the constriction can be implemented where the make-up fluid is viscous or an ink pump does not generate enough partial vacuum to draw the make-up fluid without assistance.
  • the partial vacuum can be increased, for example, by increasing the constriction 315, or by placing the injection nozzle into region 315, for example.
  • the make-up nozzle 220 (or the fluid injection needle 140 in Fig. 1 ) can have a diameter that narrows at its distal end, so as to so as to inject the make-up fluid into the ink intake line.
  • a nozzle or needle can have, for example, a diameter somewhat less than, for example, that of the ink intake line itself, as shown, for example, in Figs. 2 and 3.
  • the nozzle can have a distal diameter that is, for example, less than 1 /10 th that of the ink intake line.
  • even smaller distal diameters may be appropriate, such as less than 1 /15 th , or even less than 1/20 th of the diameter of the ink intake line.
  • sizing depends upon a number of factors, and can be optimized for various presses. Such factors can include, for example, the ink pump rate the size of the ink intake line, the viscosity of the ink and the makeup fluid, the vacuum created, and the flow of makeup fluid that is required to compensate a variable evaporation rate.
  • a proportional type solenoid valve (for example, 0% voltage, no flow; 100% voltage, maximum flow; 50% voltage, half flow) can, for example, be included to receive a voltage signal indirectly from a sensor that resides in the ink return line or sump.
  • a voltage signal can be used, for example, to open or close the valve.
  • This signal can be, for example, generated by the sensor's electronics according to the upper and lower limit set points on the sensor, and can, for example, be used by a programmable logic controller (“PLC”), or other such controller, to create the proper voltage for the solenoid.
  • PLC programmable logic controller
  • a flow meter output could optionally be used to ramp up the flow as demand increases.
  • a control algorithm would also specify a flow rate designed to keep up with the loss of make-up fluid, and the controller would thus control both the valve 125 and such a flow meter 1 15, as shown in Fig. 1 .
  • a simple open/closed valve can be employed with an adjustable needle valve located downstream to control the flow rate of the make-up liquid.
  • the flow can be either on or off and the rate can be set by the inside diameter of the make-up fluid line inserted into the ink feed pump intake line.
  • a check valve can complete the unit, preventing ink backflow into the fluid make-up line.
  • a controller can automatically set the flow rate, or, for example, an operator can set and maintain the water flow by use of a manual value.
  • a manual value can be proportional or operate in a simple on/off configuration.
  • the manual valve can be adjustable, on/off, or a pinch valve similar to the type used in IV bags.
  • each line can, for example, have its own fluid, or a single fluid reservoir can service more than one make-up line through a manifold system.
  • the make-up nozzle (or fluid injection needle) empties into an ink line
  • the nozzle given its small diameter, may become clogged with make-up fluid or ink and thus would need to be cleaned prior to another use.
  • Such a cleaning task may be undesirable for printing press operators (multiplied by, for example, six stations) , and the costs of a small section of ink line with a make-up fluid nozzle provided therein is small.
  • a portion of the ink inlet line containing the make-up fluid nozzle can be sold as a removable disposable part. This would be the portion of ink line at the far left of Fig. 2, with the make-up nozzle.
  • such a disposable apparatus could be sold together with a prefilled bag of make-up fluid, as a single disposable kit. Once the make-up fluid is used up, the bag, length of pipe and make-up nozzle can be discarded, and a new kit can be installed in the ink inlet line.
  • the remaining components, such as a sensor, controller, flow meter, etc. can be permanent, for example, and located outside of the disposable line of pipe or tube.

Landscapes

  • Ink Jet (AREA)

Abstract

Systems and methods for the injection of make-up fluid into a printing press without the need of an injection pump are presented In exemplary embodiments of the present invention, make-up fluid can be injected into any type of ink being circulated by an ink pump to a press color station under continuous operation for the purpose of maintaining the ink in a state of constant, or within a certain defined range of, rheology and surface tension In exemplary embodiments of the present invention, the make-up fluid can be stored in a reservoir, and the output of the reservoir provided with a valve Downstream of the valve can be a make-up fluid injection nozzle, arranged to inject make-up fluid into an ink line The make-up fluid flow can be, for example, gravity-assisted, or for example, can be injected into the ink line, or both.

Description

PRESS-SIDE FLUID INJECTION WITHOUT PUMPING
CROSS-REFERENCE TO RELATED APPLICATIONS:
The present application claims priority to U.S. Provisional Patent Application No. 61/243,231 , filed on September 17, 2009, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION:
Conventionally, systems for the controlled injection of fluid to ink flows include an injection pump, also known as a metering pump or a solvent pump. Commercial units, for example, use either air-operated or electrically operated pumps. The pump is controlled by a pump controller, which is, in turn, driven by the output of a sensor in the ink line or sump, where such sensor measures viscosity, pH or other ink property. In addition to the pump, overhead stirrers are typically used in the ink sump to blend any injected make-up fluid with the ink.
This complex apparatus has a large physical size, and a significant cost associated with it. Moreover, because each station on a printing press requires a make-up system, such a make-up pump and mixer needs to be provided for each press color station.
Finally, if an existing press does not have such apparatus, to add the make-up pump and mixer for each of its color stations is a costly, and cumbersome task. However, without it, such an existing press cannot be used with inks that require the controlled injection of make-up fluid on press.
Instead, what is needed in the art is a small footprint, disposable, low-cost method for fluid injection that can be added to any existing press, thus solving the problems of the prior art. SUMMARY OF THE INVENTION:
Systems and methods for the injection of make-up fluid into a printing press without the need of an injection pump or a mechanism for stirring in the injected fluid are presented. In exemplary embodiments of the present invention, make- up fluid can be injected into any type of ink being circulated by an ink pump to a press color station under continuous operation for the purpose of maintaining the ink in a state of constant, or within a certain defined range of, rheology and surface tension. In exemplary embodiments of the present invention, the makeup fluid can be stored in a reservoir, and the output of the reservoir provided with a valve. Downstream of the valve can be a make-up fluid injection nozzle, arranged to inject make-up fluid into an ink line. The make-up fluid flow can be, for example, gravity-assisted, or for example, can be injected into the ink line, or both. In exemplary embodiments of the present invention, a partial vacuum can be created in the ink line, and the make-up fluid injected at a region of negative pressure associated with the partial vacuum. In exemplary embodiments of the present invention, the valve can be a proportional solenoid valve, and can be automatically controlled by a controller, where the controller is driven by a signal coming from a sensor provided in an ink line or sump. In exemplary embodiments of the present invention, the sensor can measure the pH, viscosity, water content, impedance or conductivity of the ink, for example, and the controller can be set to open the valve as make-up fluid is needed. Thus, in exemplary embodiments of the present invention (i) a separate make-up fluid pump can be obviated and/or (ii) a mechanical ink mixer can be removed, by exploiting the negative pressure in the ink intake line generated by the existing ink pump and the turbulence that follows the sudden increase in pressure following a constriction in the ink feed line. The inventive apparatus thus involves a small and portable device that can be used as an add-on to existing presses, regardless of size, or, for example, can be provided with new presses. In exemplary embodiments of the present invention, a portion of the ink inlet line containing the make-up fluid nozzle can be sold as a removable disposable part. Additionally, for example, such a disposable apparatus could be sold together with a prefilled bag of make-up fluid, as a single disposable kit.
BRIEF DESCRIPTION OF THE DRAWINGS:
Fig. 1 depicts an exemplary gravity-fed, vacuum-assisted, make-up fluid injection system for a pumped ink according to an exemplary embodiment of the present invention; Fig. 2 depicts a generic diagram of an exemplary ejector to illustrate the essentials of inline mixing according to an exemplary embodiment of the present invention; and
Fig. 3 depicts an exemplary pump inlet line (horizontal line region) at a lower pressure than a pump outlet (diagonal line region) due to a constriction between them according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION:
As noted, conventional injection systems for ink maintenance all include a pump mechanism for the make-up fluid governed by the output of a sensor. This invention replaces this pump with a simple valve and utilizes the draw of the ink feed pump to pull in the make-up fluid as a result of the existing negative pressure provided by the ink pump. Depending on the position of fluid injection, commercial injection systems also include mixers to blend the injected liquid with the ink. In another exemplary embodiment, this invention replaces this mixing operation by injecting the make-up fluid directly into the ink flow where by combination of constrictions followed by expansions, sufficient mixing occurs. The inventive device's simplicity preferably with no moving parts is technically easier to control and maintain, is lower cost, and has a smaller footprint (physical size) than current commercial units. These advantages become more significant when they are utilized in multiple print stations. Since each ink station requires a make-up system, eliminating the make-up pump and the mixer is a considerable savings in capital and space. Fluid injection control can be, for example, as simple as a shutoff valve or clamp and a narrow inside diameter needle inserted into the ink feed line in front of the ink pump.
Thus, the design and use of a simple apparatus for injection of make-up fluid into any type of ink being circulated by an ink pump to a press color station under continuous operation is described for the purpose of maintaining the ink in a constant rheological and surface tension state. The present invention obviates the need for a make-up fluid pump by exploiting a negative pressure in the ink intake line that is generated by the existing ink pump to both incorporate the make-up fluid and cause it to mix with the ink, thus allowing removal of a mechanical ink mixer as well.
Described herein is an apparatus for the injection of make-up fluid into a pumped ink during the operation of the press. In its simplest form, it can be comprised of an atmospheric pressure make-up liquid reservoir, a connecting tube in which is installed an on/off valve, and a narrow diameter needle that is inserted into the feed line to the ink pump. In its most complex form, it can comprise a valve whose rate of delivery from the make-up fluid reservoir is controlled by the output of at least one sensor in either the ink reservoir (sump) or in the ink return line. The invention is based upon the recognition that the negative pressure in the ink feed line ahead (upstream) of the ink pump can draw in a flow of liquid from a narrow diameter delivery line inserted into the ink pump feed line. Previously, such devices required a sensor-driven make-up fluid pump, either air driven or electrical. The construction of the injector can also provide mixing. By forcing the ink flow following injection through a constriction (converging nozzle) followed by an expansion (diverging diffuser), mixing of the two flows occurs. It is noted that the notion of fluid injectors with no moving parts dates back to 1858 and H. Giffard, as provided in S. L. Kneass, Practice and Theory of the Injector, John Wiley and Sons (originally printed in 1894, reprinted in 2007 by Kessinger). As provided therein, the flow of one liquid can impart velocity to droplets of a second, and a series of velocity increases by flow constriction followed by velocity drops by flow expansion can serve to mix both flows. However, to date, no application of this technology to the delivery of controlled composition ink to a press is known. Control of ink composition by viscosity or pH feedback to a pump that injects a fluid into a printing ink is widely employed to assure optimum ink rheology. In gravure or flexographic printing, this fluid is most commonly a volatile solvent. In single-fluid lithography, it is commonly fountain solution in water. This fluid injection function is often combined with an ink pumping station to give a package that is comprised of an ink reservoir (sump), an ink pump, a make-up fluid reservoir, a make-up fluid pump, the make-up fluid pump electronics, a solenoid valve, a sensor, the sensor's electronics, a check valve, and a mixer. All-combined, the unit occupies nearly six square feet of floor space (footprint) which must be repeated as many times as there are ink stations on the press. The cost of such an installation is a considerable investment for the printer or the ink supplier.
The present invention addresses the cost and the footprint of such a device by elimination of the make-up fluid pump and/or its electronics and/or the mixer. The opportunity to do so comes from the realization that the ink pump creates a vacuum that can be used to draw liquid through a narrow feed line inserted into the pump intake line. It is even possible that in some circumstances the valve may be a simple on/off function and the make-up flow be controlled by the inside diameter of the make-up fluid feed line inserted into the ink pump intake line. Fig. 1 depicts an example of a gravity-fed, vacuum-assisted, make-up fluid injection system for a pumped ink according to an exemplary embodiment of the present invention. With reference thereto, make-up fluid resides in fluid reservoir 100, and a flow meter 1 15 inputs a flow rate to a controller 120, which controls the flow of the make-up fluid out of the reservoir and into the printing press. Controller 120 also receives a signal from a viscosity, pH, conductivity, dielectric, or other sensor (meter), placed upstream from the fluid injection needle (not shown in Fig. 1 , but would be to the left of Fluid Injection needle 140 in the ink intake line, or, for example, in the ink sump). Controller 120 operates a solenoid valve 125, which can be, for example, either simple or proportional. A check valve 130 prevents ink backing up to the valve. A fluid injection needle 140 is placed in the intake line to ink pump 150 which feeds ink to the press.
The fluid reservoir is preferably at atmospheric pressure, either from a vent in a hard container or by use of a collapsible container (similar in function to a hospital IV bag). In the ink pump intake, the ink will preferably be at less than atmospheric pressure so that a pressure differential will exist (a partial vacuum). This vacuum will assist fluid flow through a narrow orifice such as a stainless steel tube inserted into the ink intake line. Shear forces can then mix the ink and the makeup fluid either in the pump, and/or in a doctor bladed chamber that feeds the engraved cylinder of a flexographic or gravure press, and/or in a roller train of a lithographic press. If additional mixing is required, this can optionally be achieved by the well known static mixers that separate and blend fluid flows. Such static mixers can, for example, be inserted into the ink feed line after the injector and either before or after the ink pump.
In exemplary embodiments of the present invention, mixing can also occur due to the principles governing an aspirator, as next described with reference to Fig. 2. Fig. 2, a generic diagram of an exemplary ejector, shows an exemplary embodiment of the present invention where such mixing is accomplished. With reference thereto, Fig. 2 illustrates the essentials of (i) the inline mixing that occurs following a draw of make-up fluid 210 from a make-up nozzle 220 due to the negative pressure provided by the flowing ink, (ii) the constriction and rise in pressure that occurs either in the ink pump (peristaltic) or by other constriction in the ink line, and (iii) the pressure drop caused by expansion following the ink pump or by an increase in hose diameter or other means. In exemplary embodiments of the present invention the constriction can be placed, for example, either ahead, or following, the ink pump.
Continuing with reference to Fig. 2, make-up fluid 210 can, for example, be drawn into the ink flow through the make-up fluid nozzle 220. The negative pressure created by the flowing ink thus assists the make-up liquid flow, and thus eliminating the need for a pressure head on the make-up fluid, such as, for example, provided by gravity as in the exemplary embodiment of Fig. 1 . In exemplary embodiments of the present invention, either as a part of the pumping operation (peristaltic), or inserted into the ink flow following injection, there can be, for example, a constriction where the velocity rises, such as the converging inlet nozzle 240. Following this point the velocity falls at a diverging outlet 270. Such sudden rising and lowering of velocity causes turbulence which can mix the fluid by shearing forces, as discussed, for example, in U.S. Patent Nos. 4,860,959 and 4,186,772, and illustrated in Fig. 3.
Fig. 3 depicts an exemplary pump inlet line (the region at the left covered in horizontal lines) at a lower pressure than a pump outlet (the region at the right covered in diagonal lines). The constriction 315 imparts a localized increase in the negative pressure in the inlet line (i.e., in the white (non-hatched) region in between the horizontal line and diagonal line regions). Thus, there is a pressure decrease 310 leading up to the constriction 315, and a pressure increase 320 following it. Using the partial vacuum created by the constriction shown in Fig. 3, in exemplary embodiments of the present invention a make-up fluid nozzle can be placed anywhere in the lower pressure horizontal line region 310 where a partial vacuum already exists, or, for example, for an even larger vacuum it can be placed in the constricted (non-hatched) region 315. Due to the partial vacuum, the make-up fluid will thus be drawn into the ink flow 350, again without the need for a make-up injection pump or stirrers. In exemplary embodiments of the present invention an increase in vacuum caused by the constriction can be implemented where the make-up fluid is viscous or an ink pump does not generate enough partial vacuum to draw the make-up fluid without assistance. The partial vacuum can be increased, for example, by increasing the constriction 315, or by placing the injection nozzle into region 315, for example.
In exemplary embodiments of the present invention, the make-up nozzle 220 (or the fluid injection needle 140 in Fig. 1 ) can have a diameter that narrows at its distal end, so as to so as to inject the make-up fluid into the ink intake line. So as to further facilitate mixing of the make-up fluid into the ink, such a nozzle or needle can have, for example, a diameter somewhat less than, for example, that of the ink intake line itself, as shown, for example, in Figs. 2 and 3. For example, the nozzle can have a distal diameter that is, for example, less than 1 /10th that of the ink intake line. Or, as may be appropriate, even smaller distal diameters may be appropriate, such as less than 1 /15th, or even less than 1/20th of the diameter of the ink intake line. In general such sizing depends upon a number of factors, and can be optimized for various presses. Such factors can include, for example, the ink pump rate the size of the ink intake line, the viscosity of the ink and the makeup fluid, the vacuum created, and the flow of makeup fluid that is required to compensate a variable evaporation rate.
In exemplary embodiments of the present invention, as shown in Fig. 1 , a proportional type solenoid valve (for example, 0% voltage, no flow; 100% voltage, maximum flow; 50% voltage, half flow) can, for example, be included to receive a voltage signal indirectly from a sensor that resides in the ink return line or sump. Such a voltage signal can be used, for example, to open or close the valve. This signal can be, for example, generated by the sensor's electronics according to the upper and lower limit set points on the sensor, and can, for example, be used by a programmable logic controller ("PLC"), or other such controller, to create the proper voltage for the solenoid.
In exemplary embodiments of the present invention, as a further refinement, a flow meter output could optionally be used to ramp up the flow as demand increases. Thus, in such exemplary embodiments, a control algorithm would also specify a flow rate designed to keep up with the loss of make-up fluid, and the controller would thus control both the valve 125 and such a flow meter 1 15, as shown in Fig. 1 . Alternatively, for example, a simple open/closed valve can be employed with an adjustable needle valve located downstream to control the flow rate of the make-up liquid. And most simply, the flow can be either on or off and the rate can be set by the inside diameter of the make-up fluid line inserted into the ink feed pump intake line. In exemplary embodiments of the present invention, as shown in the embodiment of Fig. 1 , a check valve can complete the unit, preventing ink backflow into the fluid make-up line.
Besides a PLC, in exemplary embodiments of the present invention other types of controllers can be used as well. In exemplary embodiments of the present invention, a controller can automatically set the flow rate, or, for example, an operator can set and maintain the water flow by use of a manual value. In exemplary embodiments of the present invention such an automatic valve can be proportional or operate in a simple on/off configuration. In exemplary embodiments of the present invention the manual valve can be adjustable, on/off, or a pinch valve similar to the type used in IV bags.
In exemplary embodiments of the present invention, each line can, for example, have its own fluid, or a single fluid reservoir can service more than one make-up line through a manifold system. The savings of omitting, for example, six or more pumps and six or more mixers (such as, for example, is needed in a printing press having color stations for CMYK and two spot colors), the convenience of a collapsible container and gravity feed, and the ability to add this system to any current ink pumping station is a considerable advantage vs. current installations, which have larger footprint and may require air lines for operation.
It is noted that where the make-up nozzle (or fluid injection needle) empties into an ink line, after running on-press for a significant time period, the nozzle, given its small diameter, may become clogged with make-up fluid or ink and thus would need to be cleaned prior to another use. Such a cleaning task may be undesirable for printing press operators (multiplied by, for example, six stations) , and the costs of a small section of ink line with a make-up fluid nozzle provided therein is small. Thus, in exemplary embodiments of the present invention, a portion of the ink inlet line containing the make-up fluid nozzle can be sold as a removable disposable part. This would be the portion of ink line at the far left of Fig. 2, with the make-up nozzle. Additionally, for example, such a disposable apparatus could be sold together with a prefilled bag of make-up fluid, as a single disposable kit. Once the make-up fluid is used up, the bag, length of pipe and make-up nozzle can be discarded, and a new kit can be installed in the ink inlet line. The remaining components, such as a sensor, controller, flow meter, etc. can be permanent, for example, and located outside of the disposable line of pipe or tube.
The present invention has been described in detail, including various exemplary embodiments thereof. However, it will be appreciated that those skilled in the art, upon consideration of the present disclosure, may make modifications and/or improvements on this invention that fall within the scope and spirit of the invention

Claims

WHAT IS CLAIMED:
1 . Apparatus for injecting make-up fluid into a printing press, comprising: a make-up fluid reservoir;
a valve connected to the output of the reservoir; and
a make-up fluid injection nozzle downstream of the valve,
wherein the make-up fluid injection nozzle empties into an ink pump intake line of the printing press such that there is a pressure differential between the make-up fluid and the ink.
2. The apparatus of claim 1 , wherein the make-up fluid injection nozzle is arranged so that in operation the make-up fluid mixes into the ink flow.
3. The apparatus of claims 1 or 2, wherein the make-up fluid reservoir is at atmospheric pressure.
4. The apparatus of any of claims 1 -3, wherein the make-up fluid reservoir is at a higher gravitational potential than the make-up fluid injection nozzle.
5. The apparatus of any of claims 1 -4, wherein the make-up fluid is injected into the ink to maintain the ink within a certain defined range of rheology and surface tension.
6. The apparatus of any of claims 1 -5, wherein the make-up fluid injection nozzle has a diameter less than 1/10th of the diameter of the ink line.
7. The apparatus of any of claims 1 -6, wherein the make-up fluid injection nozzle has a diameter that narrows at its distal end.
8. The apparatus of any of claims 1 -7, further comprising:
a sensor provided in an ink return line or sump; and a controller communicably connected to the sensor.
9. The apparatus of claim 8, wherein the sensor provides a signal to the controller representative of a physical property of the ink.
10. The apparatus of claim 9, wherein said physical property is at least one of viscosity, pH, conductivity, dielectric and impedance.
1 1 . The apparatus of any of claims 8-1 1 , wherein the controller controls the valve based upon the signal received from the sensor.
12. The apparatus of any of claims 1 -1 1 , wherein the valve is one of open/close and proportional.
13. The apparatus of claim 12, where in the valve is proportional, and solenoid based.
14. The apparatus of any of claims 1 -13, further comprising a flow meter arranged to measure the flow of make-up fluid.
15. The apparatus of claim 14, wherein the flow meter is communicably connected to the controller, and outputs a signal which the controller additionally uses in controlling the valve.
16. The apparatus of any of claims 1 -15, further comprising a constrictor in the ink intake line of the printing press.
17. The apparatus of claim 16, wherein the constrictor creates a negative pressure region in a portion of the ink intake line, and wherein the make-up fluid nozzle is placed so as to empty into said negative pressure region.
18. A system for injecting make-up fluid into a printing press, comprising: the apparatus of any of claims 1 -17; and
make-up fluid provided in the make-up fluid reservoir.
19. A system for injecting make-up fluid into a printing press, comprising:
N make-up fluid modules, each said module comprising:
an apparatus according to any of claims 1 -17; and
make-up fluid provided in the make-up fluid reservoir, wherein N is the number of ink colors supplied to the printing press.
20. The system of claim 19, wherein a control algorithm is provided for each of the N modules.
21 . The system of claim 20, wherein the control algorithm and the make-up fluid used in a module varies as to each color of ink used.
22. The system of claim 20, wherein the control algorithm and make-up fluid used are the same, or can vary in any possible combination, with the module.
23. A method of providing make-up fluid into an ink on-press, comprising: providing make-up fluid in a reservoir;
providing a valve on the output of the reservoir;
providing a nozzle after the valve that empties into an ink intake line of the press such that there is a pressure differential between the make-up fluid and the ink; and
opening and closing the valve in response to a control algorithm.
24. The method of claim 23, wherein the nozzle is arranged so that in operation the make-up fluid mixes into the ink flow.
25. The method of claims 23 or 24, wherein the make-up fluid reservoir is at atmospheric pressure.
26. The method of any of claims 23-25, wherein the make-up fluid reservoir is at a higher gravitational potential than the nozzle.
27. The method of any of claims 23-26, wherein the make-up fluid is injected into the ink to maintain the ink within a certain defined range of rheology and surface tension.
28. The method of any of claims 23-27, further comprising providing a constrictor in the ink intake line of the press.
29. The method of claim 28, wherein the constrictor creates a negative pressure region in a portion of the ink intake line, and wherein the nozzle is placed so as to empty into said negative pressure region of said ink intake line.
30. A method of providing make-up fluid into an ink on-press, comprising: providing a set of N modules;
providing, in each module:
make-up fluid in a reservoir;
a valve on the output of the reservoir;
a nozzle after the valve,
providing that each nozzle empties into a separate ink intake line of the press such that there is a pressure differential between the make-up fluid and the ink; and
opening and closing the valve in each module in response to a control algorithm.
31 . The method of claim 30, wherein each said nozzle is arranged so that in operation the make-up fluid mixes into the ink flow.
32. The method of any of claims 30-31 , further comprising providing a constrictor in the ink intake line associated with one or more of said modules.
33. The method of claim 32, wherein the constrictor creates a negative pressure region in a portion of an ink intake line into which it is placed, and wherein the nozzle is placed so as to empty into said negative pressure region of said ink intake line.
34. The apparatus of any of claims 1 -17, wherein the make-up fluid injection nozzle and a portion of the ink pump intake line into which the injection nozzle empties are provided as a disposable kit.
35. The apparatus of claim 34, wherein the disposable kit further includes a disposable make-up fluid reservoir.
36. The apparatus of claim 35, wherein the disposable make-up fluid reservoir is pre-filled with make-up fluid.
PCT/US2010/049293 2009-09-17 2010-09-17 Press-side fluid injection without pumping WO2011035130A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US24323109P 2009-09-17 2009-09-17
US61/243,231 2009-09-17

Publications (1)

Publication Number Publication Date
WO2011035130A1 true WO2011035130A1 (en) 2011-03-24

Family

ID=43759024

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2010/049293 WO2011035130A1 (en) 2009-09-17 2010-09-17 Press-side fluid injection without pumping

Country Status (1)

Country Link
WO (1) WO2011035130A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020200519A1 (en) * 2019-04-05 2020-10-08 Bobst Bielefeld Gmbh Ink supply system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1002635A (en) * 1911-03-10 1911-09-05 Wladislaus Bratkowski Apparatus for measuring and regulating the concentration of dye liquors.
US2590538A (en) * 1945-05-30 1952-03-25 Hoe & Co R Inking mechanism for printing machines
US3212217A (en) * 1963-05-28 1965-10-19 Tex Tube Inc Cleaning device
US4796782A (en) * 1985-10-30 1989-01-10 Automation, Inc. Ink monitor system
FR2672401A1 (en) * 1991-02-04 1992-08-07 Filotex Sa Process for regulating the viscosity of an ink or the like and device for the implementation thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1002635A (en) * 1911-03-10 1911-09-05 Wladislaus Bratkowski Apparatus for measuring and regulating the concentration of dye liquors.
US2590538A (en) * 1945-05-30 1952-03-25 Hoe & Co R Inking mechanism for printing machines
US3212217A (en) * 1963-05-28 1965-10-19 Tex Tube Inc Cleaning device
US4796782A (en) * 1985-10-30 1989-01-10 Automation, Inc. Ink monitor system
FR2672401A1 (en) * 1991-02-04 1992-08-07 Filotex Sa Process for regulating the viscosity of an ink or the like and device for the implementation thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020200519A1 (en) * 2019-04-05 2020-10-08 Bobst Bielefeld Gmbh Ink supply system

Similar Documents

Publication Publication Date Title
CA2384414C (en) Inkjet printing device for inks containing a high loading of pigment and inkjet printing process utilizing said device
US9004744B1 (en) Fluid mixer using countercurrent injection
DE60224408T2 (en) FLUID INJECTOR WITH VENTILATION / PROPORTIONING OPENINGS
EP1199097B1 (en) Device for treating an exhaust gas from a diesel engine
EP2178786B1 (en) Fluid dispensing apparatuses and methods thereof
EP1561484A1 (en) Microdosing device
EP2418989A1 (en) Foaming soap dispenser
CN102481780A (en) Ink cleaning method and device for flexographic press
JP7224686B2 (en) Circulator for container liquid mixture
US20070036024A1 (en) Fluid blending and mixing system
WO2011035130A1 (en) Press-side fluid injection without pumping
US9499390B1 (en) Liquid delivery system
EP1306551B1 (en) Method and apparatus for supplying coating material
CN108883381B (en) Apparatus and method for producing a ready-to-use solution from a concentrate
KR950704181A (en) LIQUID DISPENSING APPARATUS
JP3701181B2 (en) Multi-component mixed pressure feeder
JP2003200084A (en) Method and apparatus for feeding coating material
JP3927026B2 (en) Paint feeder
US20160008775A1 (en) A liquid processing mixer
JP2021030473A (en) Viscosity controller
CN216584369U (en) Ejector for wastewater treatment
EP2907661B1 (en) Assembly and method for preparing, applying and withdrawing a dispersion
CN209590624U (en) A kind of device for the metering of release agent spray painting control
EP3861416B1 (en) Liquid ejection device for a vehicle wash facility, and method for operating same
CN220053260U (en) Circulation ink supply device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10817894

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10817894

Country of ref document: EP

Kind code of ref document: A1