SYSTEM AND METHOD FOR PREVENTING OR MINIMIZING PRINT DEFECTS IN A PRINTING PROCESS - Patent application

Abstract

The present disclosure provides a system for printing. The present disclosure further provides a method for preventing or minimizing print defects in a printing process.

Description

[Technical field]

[0001] The present disclosure relates to systems and methods for preventing or minimizing print defects. [Background technology]

[0002] The following references are considered to be relevant as background to the subject matter of this disclosure: [1] Piotr Warszynski et al., "Chara .cteristics of polyelectrolyte multilayers: Effect of PEI anchoring layer and posttreatment after deposition," Journal of Colloid and Interface Science, Volume 305, Issue 1,1 January 2007, pages 46-56.

[0003] The following patent applications / publications to the present applicant provide potentially relevant background material and are all incorporated herein by reference in their entirety: [2] WO 2017 / 208246 (publication of PCT / IL2017 / 050616 filed on June 1, 2017); [3] WO 2019 / 111223 (publication of PCT / IB2018 / 059761 filed on December 7, 2018); [4] WO 2015 / 036812 (publication of PCT / IB2013 / 002571 filed on 12 September 2013); [5] WO 2015 / 036865 (publication of PCT / IB2014 / 002395 filed on 11 September 2014); [6] WO 2013 / 132439 (publication of PCT / IB2013 / 051755 filed on 5 March 2013); [7] WO 2013 / 132418 (publication of PCT / IB2013 / 051716 filed on 5 March 2013); [8] WO 2013 / 132345 (publication of PCT / IB2013 / 000840 filed on 5 March 2013); [9] WO 2013 / 132339 (publication of PCT / IB2013 / 000757 filed on 5 March 2013);

[10] WO 2017 / 208152 (publication of PCT / IB2017 / 053177 filed on 30 May 2017);

[11] WO 2019 / 012456 (publication of PCT / IB2018 / 055126 filed on 11 July 2018);

[12] WO 2020 / 003088 (publication of PCT / IB2019 / 055288 filed on 24 June 2019);

[13] U.S. Patent No. 9,914,316;

[14] U.S. Patent No. 9,186,884;

[15] WO 2013 / 132424 (publication of PCT / IB2013 / 051727 filed on 5 March 2013);

[16] U.S. Patent Application Publication No. 2015 / 0054865; and

[17] U.S. Provisional Application No. 62 / 787,984, U.S. Provisional Application No. 62 / 790,890, U.S. Provisional Application No. 62,825,568 and corresponding International Application No. PCT / IB2020 / 050001.

[0004] The acknowledgment of the aforementioned references herein is not to be inferred as meaning that they are in any way relevant to the patentability of the subject matter of the present disclosure. Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have developed a system and method for preventing and / or minimizing print defects associated with the undesired depletion of at least one component used in a printing process that is found to be critical to the quality of a printed image and whose depletion significantly impacts the quality of the printed image. [Means for solving the problem]

[0006] Specifically, the inventors of the present invention have utilized a system for a printing process, e.g., an indirect printing process, in which a release surface of an intermediate transfer member (ITM) is pretreated (e.g., coated) with a treatment formulation (e.g., an aqueous treatment formulation) before an ink image is applied thereto. The treatment formulation is applied to the surface of the ITM to form a thin wet treatment layer thereon, which is passed through a drying process on the ITM release surface to leave a thin substantially dry treatment film on the ITM release surface. Then, thereafter, droplets of an aqueous ink, comprising at least one organic polymer resin and at least one colorant in an aqueous carrier, are applied (e.g., in an inkjet manner) onto the thin substantially dried treatment film to form an ink image thereon. The formed ink image is then passed through a drying process to leave a substantially dry ink image residue on the substantially dried treatment film. The substantially dried ink image, together with the thin substantially dried treatment film, is then transferred from the ITM surface to a final printing substrate (e.g., a foil base, a paper base, or a plastic base).

[0007] Examples of such printing processes and systems are disclosed in the aforementioned patent applications / publications to the applicant (e.g., WO 2013 / 132418, and WO 2017 / 208152), the contents of which are incorporated herein by reference.

[0008] During the printing process, the inks and processing formulations need to be replenished due to their consumption in the printing process and for printing purposes.

[0009] The inventors of the present invention have found that the quality of the ink images produced in the above-described printing process may degrade as the printing process progresses. Sometimes, the quality of the printed image may degrade at various stages in the printing process, and sometimes even very early in the printing process, implying that the degradation in print quality may not be related to the number of print cycles performed.

[0010] Furthermore, the inventors of the present invention have found that the degradation in the quality of the printed image, which may sometimes be reflected in the graininess of the image, is surprisingly highly dependent on the presence of at least one component in the processing formulation: in the absence of said component, the printed image is of very poor quality.

[0011] The inventors have further found that the decrease in print quality may not be related to the physical properties of the treatment formulation (e.g., viscosity and surface tension), nor to the age (freshness) of the treatment formulation, nor to its temperature.

[0012] Furthermore, the present inventors have surprisingly found that, at times, the replenishment requirements for the treatment formulation exceed the amount expected based on the calculated amount of treatment formulation per printing substrate.

[0013] The inventors of the present invention have surprisingly found that components important for image print quality (and therefore for the performance of the printing process) can be depleted during the printing process, or even when active printing is not in progress. It is noted that the depletion of said components is not due to their consumption for printing purposes in the printing process, but rather is the result of an undesired reaction with contaminants that have unintentionally reached the reservoir holding the formulation (e.g., processing formulation) containing said components. In particular, the contaminants can originate from the ink formulation used in the printing process. The inventors have found that the contaminants have a significant adverse effect on the quality of the formulation containing said components.

[0014] The aforementioned specific components that are important to image print quality and whose deficiency adversely affects print quality are referred to herein as "depletable chemical agents" or any linguistic variants thereof, such as "depleted chemical agents," "chemically depleted agents," etc.

[0015] To avoid and / or prevent or minimize degradation in the quality of printed images, the present inventors have developed novel systems and processes which are detailed herein.

[0016] Specifically, the inventors have found that it is not necessary to replenish the entire treatment formulation (all of its components, including the carrier) to counteract the decline in print quality associated with poor quality of the treatment formulation used in the indirect printing process. The performance of the treatment formulation can be restored by simply adding depleted chemicals to it. This has advantages in terms of both cost reduction and waste reduction, making the disclosed system and process even more environmentally friendly.

[0017] The systems and methods of the present invention also beneficially ensure print quality consistency.

[0018] Thus, in one of its aspects, the present invention provides a system for printing, comprising: a liquid reservoir configured to hold a formulation, the formulation comprising a first amount (e.g., by weight, volume, concentration) of at least one depletable chemical (in a liquid carrier, e.g., a liquid carrier containing water), said first amount being substantially equal to or greater than a predetermined threshold, said formulation optionally further comprising at least one additional component; a refill reservoir configured to hold a second quantity (e.g., weight, volume, concentration) of the at least one depletable chemical, optionally in at least one liquid carrier (e.g., water containing the same or a different carrier as the liquid carrier of the formulation contained within the liquid reservoir); detection means configured to at least identify (i) a decrease in said first amount of said depletable chemical below said predetermined threshold, and / or (ii) a decrease in the functionality of said at least one depletable chemical; a transfer means configured to transfer at least a portion of said second amount of at least one depletable chemical from said replenishment reservoir to said liquid reservoir once said decrease is identified, said transfer means being optionally a manual means; Includes.

[0019] In another of its aspects, the present invention provides a method for preventing or minimizing print defects in a printing process, the print defects being associated with a decrease in a first amount of at least one depletable chemical contained in an aqueous formulation, optionally in a liquid carrier, the method comprising: Identifying / detecting a decrease in the first amount of the at least one depletable chemical below a predetermined threshold and / or a decrease relative to the amount of at least another component in the formulation; Upon identifying / detecting said degradation, adding at least a portion of a second amount of at least one depletable chemical to the formulation, said at least a portion of the second amount being sufficient to restore a first amount of the depletable chemical in said liquid formulation substantially to or above said predetermined threshold, and / or said at least a portion of the second amount being sufficient to counteract said degradation of the first amount relative to an amount of at least another component in the formulation, thereby preventing or minimizing said print defects. Includes.

[0020] In yet another of its aspects, the present invention provides a method for preventing or minimizing print defects in a printing process, the method utilizing the system described herein.

[0021] Additionally, in a further of its aspects, the present invention provides systems and processes as described herein. [Brief description of the drawings]

[0022] In order to better understand the subject matter disclosed herein and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0023] [Figure 1A] 1 shows a schematic diagram of a system (eg, apparatus) according to some embodiments of the present invention. [Figure 1B] 1 is a schematic side view of a printing system (e.g., a digital printing system) according to some embodiments of the present invention. [Diagram 2] 1 shows a chart depicting average viscosity versus time measurements of treatment formulations according to some embodiments of the present invention. [Diagram 3] 1 shows a chart depicting average surface tension versus time measurements of treatment formulations according to some embodiments of the present invention. [Figure 4A] 1 shows portions (enlarged, zoomed-in portions) of printed images obtained in an indirect printing process utilizing treatment formulations, the formulations at different temperatures and with different aging, according to some embodiments of the present invention. [Figure 4B] 1 shows portions (enlarged, zoomed-in portions) of printed images obtained in an indirect printing process utilizing treatment formulations, the formulations at different temperatures and with different aging, according to some embodiments of the present invention. [Figure 4C] 1 shows portions (enlarged, zoomed-in portions) of printed images obtained in an indirect printing process utilizing treatment formulations, the formulations at different temperatures and with different aging, according to some embodiments of the present invention. [Figure 5A] 5A and 5B show printed images obtained in an indirect printing process utilizing a fresh processing formulation that has not been used previously (FIG. 5A) and a processing formulation that has been used in the printing process for several printing cycles (FIG. 5B), according to some embodiments of the present invention. [Figure 5B]5A and 5B show printed images obtained in an indirect printing process utilizing a fresh processing formulation that has not been used previously (FIG. 5A) and a processing formulation that has been used in the printing process for several printing cycles (FIG. 5B), according to some embodiments of the present invention. [Figure 6A] 1 shows a print image and corresponding magnified (zoomed in) portions thereof obtained in an indirect printing process utilizing fresh (unused) processing formulation (TF) and used TF in combination with fresh and used (old) blankets (ITM) according to some embodiments of the present invention. [Figure 6B] 1 shows a print image and corresponding magnified (zoomed in) portions thereof obtained in an indirect printing process utilizing fresh (unused) processing formulation (TF) and used TF in combination with fresh and used (old) blankets (ITM) according to some embodiments of the present invention. [Figure 6C] 1 shows a print image and corresponding magnified (zoomed in) portions thereof obtained in an indirect printing process utilizing fresh (unused) processing formulation (TF) and used TF in combination with fresh and used (old) blankets (ITM) according to some embodiments of the present invention. [Figure 6D] 1 shows a print image and corresponding magnified (zoomed in) portions thereof obtained in an indirect printing process utilizing fresh (unused) processing formulation (TF) and used TF in combination with fresh and used (old) blankets (ITM) according to some embodiments of the present invention. [Figure 7] 1 shows a chart depicting the effect of treatment formulation aging (time) and temperature on graining of printed images produced in an indirect printing process, according to some embodiments of the present invention. [Figure 8] 1 shows a diagram depicting the effect of ink contamination in a processing formulation (at room temperature, RT) on graining of a printed image produced in an indirect printing process, according to some embodiments of the present invention. [Figure 9]1 shows a diagram depicting the effect of the presence of ink contamination in a processing formulation (at 50° C.) on graining of a printed image produced in an indirect printing process, according to some embodiments of the present invention. [Figure 10A] 1 shows printed images obtained in an indirect printing process utilizing fresh TF, TF laced with ink (of different ages and temperatures) and filtered treatment formulations according to some embodiments of the present invention. [Figure 10B] 1 shows printed images obtained in an indirect printing process utilizing fresh TF, TF laced with ink (of different ages and temperatures) and filtered treatment formulations according to some embodiments of the present invention. [Figure 10C] 1 shows printed images obtained in an indirect printing process utilizing fresh TF, TF laced with ink (of different ages and temperatures) and filtered treatment formulations according to some embodiments of the present invention. [Figure 10D] 1 shows printed images obtained in an indirect printing process utilizing fresh TF, TF laced with ink (of different ages and temperatures) and filtered treatment formulations according to some embodiments of the present invention. [Figure 11A] 11A and 11B show images (Zygo ×50) of polyethylene terephthalate (PET) slides coated with treatment formulations containing polyethyleneimine (PEI) (FIG. 11A) and not containing PEI (FIG. 11B), according to some embodiments of the present invention. [Figure 11B] 11A and 11B show images (Zygo ×50) of polyethylene terephthalate (PET) slides coated with treatment formulations containing polyethyleneimine (PEI) (FIG. 11A) and not containing PEI (FIG. 11B), according to some embodiments of the present invention. [Figure 12] 1 shows the phase separation and precipitation observed in a glass tube upon addition of the ink binder to a solution of PEI. [Figure 13A]Shown are images of PET slides (left side of figure) coated with treatment formulations containing PEI (FIG. 13A), treatment formulations not containing PEI (FIG. 13B), TF contaminated with ink aged 3 days and 50° C. (FIG. 13C) and TF contaminated with ink but with an additional repair amount of PEI (FIG. 13D). Additionally, shown are corresponding print images (zoomed in) (right side of figure) obtained with an indirect printing process according to some embodiments of the invention utilizing the corresponding treatment formulations. [Figure 13B] Shown are images of PET slides (left side of figure) coated with treatment formulations containing PEI (FIG. 13A), treatment formulations not containing PEI (FIG. 13B), TF contaminated with ink aged 3 days and 50° C. (FIG. 13C) and TF contaminated with ink but with an additional repair amount of PEI (FIG. 13D). Additionally, shown are corresponding print images (zoomed in) (right side of figure) obtained with an indirect printing process according to some embodiments of the invention utilizing the corresponding treatment formulations. [Figure 13C] Shown are images of PET slides (left side of figure) coated with treatment formulations containing PEI (FIG. 13A), treatment formulations not containing PEI (FIG. 13B), TF contaminated with ink aged 3 days and 50° C. (FIG. 13C) and TF contaminated with ink but with an additional repair amount of PEI (FIG. 13D). Additionally, shown are corresponding print images (zoomed in) (right side of figure) obtained with an indirect printing process according to some embodiments of the invention utilizing the corresponding treatment formulations. [Figure 13D] Shown are images of PET slides (left side of figure) coated with treatment formulations containing PEI (FIG. 13A), treatment formulations not containing PEI (FIG. 13B), TF contaminated with ink aged 3 days and 50° C. (FIG. 13C) and TF contaminated with ink but with an additional repair amount of PEI (FIG. 13D). Additionally, shown are corresponding print images (zoomed in) (right side of figure) obtained with an indirect printing process according to some embodiments of the invention utilizing the corresponding treatment formulations. [Figure 14A]FIG. 14A shows a diagram depicting graining in a printed image produced in an indirect printing process utilizing fresh TF, ink-contaminated TF, and ink-contaminated TF with an added (repair) amount of PEI, and FIG. 14B shows a zoomed-in portion of a corresponding printed image obtained in an indirect printing process utilizing a corresponding treatment formulation according to some embodiments of the present invention. [Figure 14B] FIG. 14A shows a diagram depicting graining in a printed image produced in an indirect printing process utilizing fresh TF, ink-contaminated TF, and ink-contaminated TF with an added (repair) amount of PEI, and FIG. 14B shows a zoomed-in portion of a corresponding printed image obtained in an indirect printing process utilizing a corresponding treatment formulation according to some embodiments of the present invention. [Figure 15A] 15A shows printed images produced in an indirect printing process utilizing a fresh TF (FIG. 15A), an ink-contaminated TF (FIG. 15B), and an ink-contaminated FT with an added (repair) amount of PEI (FIG. 15C), top, along with zoomed-in portions of the corresponding printed images (bottom), in accordance with some embodiments of the present invention. [Figure 15B] 15A shows printed images produced in an indirect printing process utilizing a fresh TF (FIG. 15A), an ink-contaminated TF (FIG. 15B), and an ink-contaminated FT with an added (repair) amount of PEI (FIG. 15C), top, along with zoomed-in portions of the corresponding printed images (bottom), in accordance with some embodiments of the present invention. [Figure 15C] 15A shows printed images produced in an indirect printing process utilizing a fresh TF (FIG. 15A), an ink-contaminated TF (FIG. 15B), and an ink-contaminated FT with an added (repair) amount of PEI (FIG. 15C), top, along with zoomed-in portions of the corresponding printed images (bottom), in accordance with some embodiments of the present invention. [Figure 16] 1 shows a schematic illustrating the detection of PEI by the addition of copper ions to a PEI solution, which results in blue emission from the solution and strong absorption at about 275 nm (with low absorption at about 650 nm). [Figure 17A] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17B] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17C] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17D] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17E] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17F] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17G] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17H] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17I] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17J]The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17K] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 17L] The color reaction observed upon titration of various fresh TFs with different PEI concentrations with copper is shown (with the corresponding observed granularity values, which are numbers listed at the top of these figures). [Figure 18] 13 shows the absorption spectra observed upon addition of copper to various TFs with different PEI concentrations, according to some embodiments of the present invention. [Figure 19] 1 shows a calibration curve at 285 nm generated with treatment formulations having known PEI concentrations in the presence of copper according to some embodiments of the present invention. [Figure 20] FIG. 19 shows the concentration of PEI for various TFs at two different dilutions, according to some embodiments of the present invention, calculated based on the calibration curve in FIG. [Figure 21] FIG. 19 shows the PEI concentrations of various TFs according to some embodiments of the present invention, with and without copper, calculated based on the calibration curve, with the latter serving as a control test. [Figure 22] 1 shows the correlation between graininess of a printed image and the concentration of PEI in the TF used to generate the image, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention is based on the novel concept of ensuring the quality of the printed image obtained in a printing process by replenishing certain components used in the printing process.

[0025] Thus, in one of its aspects, the present invention provides a system for printing, comprising: a liquid reservoir configured to hold a formulation, the formulation comprising a first amount of at least one depletable chemical, said first amount being substantially equal to or greater than a predetermined threshold, said formulation optionally further comprising at least one additional component; a refill reservoir configured to hold a second quantity of said at least one depletable chemical, optionally in at least one liquid carrier; detection means configured to at least identify (i) a decrease in said first amount of said depletable chemical below a predetermined threshold, and / or (ii) a decrease in the functionality of said at least one depletable chemical; a transfer means configured to transfer at least a portion of said second amount of at least one depletable chemical from said replenishment reservoir to said liquid reservoir once said decrease is identified, said transfer means being optionally a manual means; Includes.

[0026] In another of its aspects, the present invention provides a method for preventing or minimizing print defects in a printing process, the print defects being associated with a decrease in a first amount of at least one depletable chemical contained in an aqueous formulation, optionally in a liquid carrier, the method comprising: Identifying / detecting a decrease in the first amount of the at least one depletable chemical below a predetermined threshold and / or a decrease relative to the amount of at least another component in the formulation; Upon identifying / detecting said degradation, adding at least a portion of a second amount of at least one depletable chemical to the formulation, said at least a portion of said second amount being sufficient to restore a first amount of the depletable chemical in said liquid formulation substantially to or above said predetermined threshold, and / or said at least a portion of said second amount being sufficient to counteract said degradation of the first amount relative to an amount of at least another component in the formulation, thereby preventing or minimizing said print defects. Includes.

[0027] Various embodiments are now detailed in relation to the aforementioned aspects, it being noted that one or more embodiments detailed in relation to the system of the invention may also be applied mutatis mutandis to the method of the invention, and vice versa.

[0028] In some embodiments, the first and second amounts of depletable chemical in the liquid reservoir and in the refill reservoir, respectively, are provided in % w / w (e.g., grams of depletable chemical per 100 grams of the formulation / solution in which it is contained).

[0029] Unless otherwise specified, the term "concentration" refers to w / w-i.e., the weight of a component of a formulation / solution / dispersion (e.g., processing formulations, printing liquids such as ink formulations, and the like) per total weight of that formulation / solution / dispersion. Sometimes, the concentration is provided in w / w% (interchangeable with % w / w or weight %), i.e., the weight of a component of a formulation / solution / dispersion (e.g., processing formulations, printing liquids such as ink formulations, and the like) per 100 grams of the formulation / solution / dispersion in which it is contained.

[0030] The systems and methods of the present invention aim to improve print quality by counteracting the effects associated with the depletion of at least one depletable chemical, the presence of which in the printing process is critical to the performance of the printing process and the quality of the resulting printed image. Unless otherwise specified, the depletion of said depletable chemical may be reflected in one or more of the following "degradation" scenarios which the systems and methods of the present invention aim to counteract: - a decrease below a predetermined threshold in a first amount of a depletable chemical; - a decrease in the functionality of at least one depletable chemical, and - A reduction in a first amount of a depletable chemical relative to the amount of at least another component in the formulation.

[0031] In some embodiments, depletion of a depletable chemical may be reflected by a drop in a first amount of the depletable chemical below a predetermined threshold.

[0032] In some embodiments, depletion of a depletable chemical may be reflected in a decrease in the functionality of at least one depletable chemical.

[0033] In some embodiments, depletion of a depletable chemical may be reflected in a reduction in a first amount of the depletable chemical relative to an amount of at least another component in the formulation.

[0034] The following disclosure further elaborates on the degradation scenarios detailed above.

[0035] Accordingly, at least one depletable chemical is present in the formulation in a first amount that is substantially equal to or greater than a predetermined threshold value.

[0036] The term "predetermined threshold" is used herein in reference to an amount of at least one depletable chemical in a formulation (held in a liquid reservoir), said amount being less than or equal to a first amount and indicating an essentially well-defined value (i.e., a well-defined integer ± standard deviation) that is pre-determined based on a reference formulation with qualities that satisfy one or more of the formulation's stability, functionality, and compatibility (e.g., with a printing process in which the formulation is utilized). These qualities may be directly related to the quality of an image produced utilizing the formulation in a printing process.

[0037] The phrase "and / or" is used herein to be considered to define either or the other or both terms to which said phrase refers.

[0038] According to the present invention, the depleted chemicals, either alone or in combination, fulfill one or more functions that are important for the performance of the formulation in the printing process, said functions may also be reflected in the image print quality. Thus, as used herein, the terms "functionality", "function" or any linguistic variant thereof, as used in relation to the depletable chemicals, refer to said one or more functions.

[0039] Non-limiting examples of functions that a depletable chemical may have are: affecting one or more of the formulation's solubility, hydration, viscosity, elasticity, adhesion, moisture absorption, density, porosity, and tensile strength.

[0040] Further non-limiting functions of the depletable chemicals are to provide one or more of: good surface hydration of the ITM coated with the formulation containing the depletable agent, good adhesion of the thin film formed on the ITM, improved ink image quality (which may be reflected in low graininess of the image), good ink wetting and ink spreading properties on the coated ITM. To this end, in some embodiments, the depletable chemicals may function as one or more of a wetting agent, a surfactant, and a fixing agent (the latter inter alia improving the fixing of the treatment formulation to the ITM to reduce coalescence of the wet treatment coating from the ITM).

[0041] In some embodiments, the functions performed by the depletable chemical are one or more of a surfactant, a wetting agent, and a fixative.

[0042] In some embodiments, the function of the depletable chemical agent is to provide good hydration of the surface of the ITM that is coated with the treatment formulation containing the depletable agent.

[0043] The functionality of a depletable agent may be directly related to its amount in a processing formulation according to the present invention utilized in a printing process. Thus, sometimes, a decrease in the functionality of at least one depletable chemical is directly related to a decrease in a first amount of the depletable chemical in the formulation below a predetermined threshold.

[0044] In some embodiments, for example, when utilized in an indirect printing system, a decrease in the functionality of at least one depletable chemical and / or a decrease in a first amount of the depletable chemical below a predetermined threshold directly correlates to print quality.

[0045] In some embodiments, print quality may be reflected in the graininess of the printed image (the lower the graininess, the better the quality). To this end, depletable chemicals may play a role related to the graininess of the image.

[0046] In some embodiments, the first amount of the depletable chemical may be substantially equal to or greater than the predetermined threshold value discussed above.

[0047] In some embodiments, the amount of a chemical that can be depleted can be provided by weight, volume, or concentration.

[0048] In some embodiments, the replenishment reservoir is configured to hold only at least one depletable chemical, optionally in at least one liquid carrier, i.e., no other functional components of the formulation in the liquid formulation are present in the replenishment reservoir and only the depletable chemical is replenished.

[0049] In some embodiments, at least one depletable chemical is present in the replenishment reservoir in liquid form (e.g., a solution or dispersion, optionally in a liquid carrier that is the same as or different from the liquid carrier present in the liquid reservoir).

[0050] In some embodiments, the refill reservoir and the liquid reservoir are in liquid communication (e.g., via a fluid conduit) to enable transfer of an amount of at least one depletable chemical (e.g., at least a portion of said second amount) from the refill reservoir to the liquid reservoir (e.g., upon identifying a drop in a first amount of the depletable chemical below a predetermined threshold or a drop in the functionality of at least one depletable chemical).

[0051] In some embodiments, the transfer means may further comprise regulating means configured to regulate the amount of depletable chemical transferred from the refill reservoir to the liquid reservoir and / or to avoid backflow of liquid from said liquid reservoir to said refill reservoir.

[0052] In some embodiments, the system of the present invention may further comprise means (e.g., regulating means) for avoiding backflow of liquid from the liquid reservoir to the refill reservoir (e.g., for avoiding contamination, e.g., ink contamination that may result from ink penetration into the liquid reservoir). In some embodiments, said means comprise at least one safety valve that allows one-way flow of liquid from the refill reservoir to the liquid reservoir. For example, a closed valve may be placed between the liquid reservoir and the refill reservoir, which, when opened, allows refill fluid to be transferred from the refill reservoir to the liquid reservoir. In some embodiments, the system of the present invention may further comprise means for operating the valve to an open state and means for closing the valve when refilling is completed, e.g., when the amount of at least one depletable chemical in the liquid reservoir (in said transfer) reaches a value equal to or greater than the predetermined threshold value as described above.

[0053] In some embodiments, refilling may be considered complete when the amount of at least one depletable chemical in the liquid reservoir reaches a value above a detected / measured value that is below a first amount (at the time of said transfer) but below a predetermined threshold.

[0054] In some embodiments, refilling may be considered complete when the amount of at least one depletable chemical in the liquid reservoir is below a first amount (at the time of said transfer) but reaches a value greater than a predetermined threshold.

[0055] In some embodiments, the second amount (e.g., wt.%) of the at least one depletable chemical in the refill reservoir can exceed the first amount (e.g., wt.%) of the at least one depletable chemical in the liquid reservoir, and upon transfer, dilution of the transferred amount of the depletable chemical occurs in the liquid reservoir.

[0056] The methods and systems of the present invention may involve mixing of at least one depletable chemical, for example to provide uniformity. Thus, in some embodiments, the system optionally further comprises a mixing means (e.g., in one or more of the liquid reservoir and the refill reservoir) configured to mix (and / or uniformly distribute) at least one depletable chemical in the liquid reservoir and / or the refill reservoir. To this end, the methods of the present invention may further comprise corresponding mixing.

[0057] The system of the present invention includes a transfer means configured to transfer at least a portion of said second amount of at least one depletable chemical from the refill reservoir to the liquid reservoir. In some embodiments, the system may further include a metering pump for pumping a controlled amount of the depletable chemical from the refill reservoir to the liquid reservoir and optionally a mixing means, e.g., a mixing device, for mixing the transferred amount in the liquid reservoir.

[0058] In some embodiments according to the present invention, the transfer may be accomplished manually, for example, by a system operator.

[0059] In some embodiments, the amount of depletable chemical present in the refill reservoir to be added may be provided in solid form. To this end, the depletable chemical is present in the refill reservoir in solid form, and the system may optionally further comprise a means for mixing, dissolving (e.g., solubilizing) or dispersing the solid depletable chemical, for example, in at least one liquid carrier, which may be the same as or different from the liquid carrier of the formulation contained in the liquid reservoir. To this end, the method of the present invention may further comprise mixing, dissolving (e.g., solubilizing) or dispersing the depletable chemical present in the refill reservoir.

[0060] In some embodiments, the method may further include mixing at least a portion of the second amount of the at least one depletable chemical into the liquid formulation.

[0061] In some embodiments, the methods and systems may involve heating to assist in solubilizing the solid depletable agent. To this end, the systems of the invention may further comprise heating means configured to assist in solubilizing the solid depletable chemical. To this end, the methods of the invention may further comprise corresponding heating (to assist in solubilizing the solid depletable chemical).

[0062] In some embodiments, the systems and methods of the present invention are for indirect printing.

[0063] In some embodiments, the systems of the present invention may further include at least one printing liquid reservoir (e.g., a print bar) configured to hold a printing liquid, which optionally is an ink, and further optionally is an aqueous ink (e.g., an aqueous ink formulation).

[0064] In some embodiments, the system may further include an intermediate transfer member (ITM).

[0065] In methods and systems of the present invention, in some embodiments, the formulation in the liquid reservoir is a treatment formulation (e.g., substantially as described herein) configured to be applied to at least one region of the release surface of the ITM to form a coating layer thereon.

[0066] In some embodiments, the formulation is applied onto the release surface before the printing liquid (eg, a water-based ink formulation) is applied onto the release surface.

[0067] As used herein, the term "treatment formulation" means that the formulation is for use with an ITM of a printing system for the purpose of treating the release surface of the ITM with said formulation. The treatment formulation may also be used to cool and / or clean the release surface of the ITM.

[0068] In some embodiments, the methods and systems of the present invention may utilize one or more detection means (such as a detection unit) configured to identify, optionally continuously, the presence of a depletable chemical in a formulation (e.g., a treatment formulation) and measure and / or calculate its amount in the formulation and / or calculate its proportion with respect to the formulation volume or with respect to other components of the formulation. Non-limiting examples of such detection means are spectroscopic means [e.g., visual (colorimetric), infrared], physical means, conductivity measuring means, pH measuring means, refractive index measuring means, density measuring means, specific gravity measuring means or any combination thereof. The detected value (e.g., measured and / or calculated) may then be compared to a predetermined threshold value and the amount of the depletable chemical is replenished if so required.

[0069] In some embodiments, the detection means is selected from visual means, spectroscopic means, spectrophotometric means, electronic means, chemical means, physical means, print quality based means or any combination thereof.

[0070] In some embodiments according to the invention, the detection means is configured to measure and / or calculate a drop in the first amount of the depletable chemical below a predefined threshold. To this end, the method of the invention may involve measuring and / or calculating said drop.

[0071] In some embodiments according to the invention, the detection means is configured to detect / measure an amount of at least one depletable chemical in the liquid reservoir and the system is configured to calculate a drop below a predefined threshold in the first amount of the at least one depletable chemical based on the detected / measured amount. To this end, the method of the invention may involve the detection / measurement and / or calculation of said drop.

[0072] In some embodiments, the method of the present invention further comprises identifying a decrease in the first amount of the at least one depletable chemical below a predetermined threshold, wherein the identifying is accomplished by a detection means selected from visual means, spectroscopic means, spectrophotometric means, electronic means, chemical means, physical means, print quality based means or any combination thereof, and the method further comprises calculating a decrease in the first amount of the at least one depletable chemical relative to an amount of one or more other components in the formulation based on the identified decrease in the first amount of the at least one depletable chemical.

[0073] In some embodiments according to the invention, the detection means is configured to measure and / or calculate a decrease in the first amount of the depletable chemical relative to the amount of at least one further component in the formulation. To this end, the method of the invention may involve measuring and / or calculating said decrease.

[0074] In some embodiments according to the invention, the detection means are configured to measure and / or calculate a decrease in the functionality of said at least one depletable chemical. To this end, the method of the invention may involve measuring and / or calculating said decrease.

[0075] In some embodiments, the system includes means for detecting, measuring or calculating a concentration of a depletable chemical in a formulation contained within a liquid reservoir and calculating therefrom a reduction in a first amount of said depletable chemical.

[0076] In some embodiments, the method comprises detecting and / or measuring and / or calculating a concentration of a depletable chemical in the liquid formulation and calculating therefrom a reduction in a first amount of said depletable chemical.

[0077] In some embodiments according to the invention, the detection means is configured to record and / or report (eg to a system operator) one or more of the aforementioned degradations.

[0078] In some embodiments according to the invention the detection means are configured to activate the transport means once one or more of the aforementioned degradations are identified.

[0079] In some embodiments according to the invention, the system may further comprise a control unit configured to control the replenishment of at least one depletable chemical in the liquid reservoir and optionally configured to activate the transfer means once a drop in a first amount of said depletable chemical below a predetermined threshold and / or a drop in the functionality of the at least one depletable chemical is identified.

[0080] In some embodiments, control can be automatic or semi-automatic (a combination of machine and human operation).

[0081] In some embodiments, the transfer may be manual.

[0082] In some embodiments according to the present invention, the system may further comprise communication means configured to transfer data / information between the detection means and the control unit.

[0083] In some embodiments according to the present invention, the transfer means may be one or more of a pressure-based means, a jet means, a spray means, or a gravity means. Other means known in the art may also be suitable. To this end, the method of the present invention may further involve utilizing the means.

[0084] In some embodiments, the detection means may be configured to specifically identify a decrease in the amount of a depletable chemical agent as disclosed herein based on its chemical and / or physical properties. To this end, the method of the present invention may involve quantifying the amount of a depletable chemical agent in the formulation based on the chemical and / or physical properties of said agent.

[0085] In some embodiments, the system of the present invention may further comprise a kit configured to quantify the amount of a depletable chemical agent in a formulation based on the chemical and / or physical properties of said agent.

[0086] In some embodiments, the depletable chemical comprises nitrogen atoms and the detection / measurement means and / or kit is specific for the detection of nitrogen atoms.

[0087] In some embodiments, the depletable chemical is a nitrogen-containing agent (e.g., polyethyleneimine) and said detection unit comprises spectroscopic means (e.g., in the visible and / or infrared) configured to detect the nitrogen-containing agent based on the reaction of copper cations / salts with said nitrogen-containing depletable chemical. To this end, the system of the present invention may further comprise a kit configured to quantify the amount of the depletable chemical in the formulation, the kit comprising a solution of copper ions and instructions for use.

[0088] In some embodiments, the systems and methods of the present invention may further comprise sampling an aliquot from the liquid formulation for analysis (e.g., identifying / determining / measuring / calculating the amount of said at least one depletable chemical in the formulation). To this end, the systems of the present invention may further comprise at least one sampling unit configured to withdraw an aliquot of the formulation from the liquid reservoir for further analysis.

[0089] In some embodiments, sampling is performed on demand and / or at predetermined time intervals and / or after a predetermined number of print cycles.

[0090] In some embodiments, the sampling unit is configured to withdraw an aliquot of formulation from said liquid reservoir on demand, for example when poor print quality is observed and an amount to be replenished needs to be determined, and / or at predetermined time intervals, and / or after a predetermined number of print cycles.

[0091] In some embodiments, the system of the invention may further comprise means for detecting and / or measuring and / or calculating the concentration of the depletable chemical in the formulation contained within the liquid reservoir and calculating therefrom a reduction in the first amount of the depletable chemical. To this end, the method of the invention further comprises detecting and / or measuring and / or calculating the concentration of the depletable chemical and calculating therefrom a reduction in the first amount of the depletable chemical, e.g., below a predetermined threshold.

[0092] In some embodiments according to the invention, the reduction in the first amount of the depletable chemical may be relative to the amount of one or more other components of the formulation, i.e., the amount of one or more other components of the formulation, e.g., the relative concentration and thus the amount of the other components of the formulation, remains constant in the treatment formulation, while only the concentration of the depletable chemical is reduced. In other words, the depletable chemical is the only agent that is depleted, while the remaining components maintain constant amounts, e.g., wt.%, relative to each other.

[0093] In some embodiments, the system of the present invention is configured to identify a decrease in a first amount of at least one depletable chemical relative to the amount of at least another component in the formulation. In some embodiments, the system is configured to provide a signal indication to indicate the need to add the at least one depletable chemical to the liquid formulation, thereby restoring the first amount of the depletable chemical in the liquid formulation to substantially equal or exceed the predetermined threshold, thus counteracting the decrease in the first amount of the at least one depletable chemical relative to the amount of at least another component in the formulation. In this regard, the method of the present invention includes identifying a decrease in a first amount of the at least one depletable chemical relative to the amount of at least another component in the formulation, and adding at least a portion of a second amount of the at least one depletable chemical to the formulation, thereby restoring the first amount of the depletable chemical in the liquid formulation to substantially equal or exceed the predetermined threshold, thus counteracting the decrease in the first amount of the at least one depletable chemical relative to the amount of at least another component in the formulation. To this end, the method may further provide a signal indication to indicate the need to add at least one depletable chemical to said liquid formulation.

[0094] It should be noted that in this regard, the depletion of the depletable chemical should not be attributed to the consumption of the depletable chemical for the printing process (e.g., consumption of the processing formulation for coating the ITM). In the printing process, the depletable chemical is consumed together with other components of the formulation in a controlled manner, e.g., according to a predetermined program. Thus, the relative amount of the depletable chemical to the amount of other components of the formulation is maintained substantially constant during the printing process. Once depletion of the depletable chemical occurs (e.g., due to ink contamination), the aforementioned relative amount changes depending on the extent of depletion. The system and method of the present invention are utilized to offset such depletion by adding an additional amount of the depletable agent to make up for the depletion, thereby minimizing the adverse effects associated with such depletion (e.g., loss in print quality).

[0095] In some embodiments, upon identifying a drop in the first amount of the depletable chemical below the aforementioned predetermined threshold in the methods and systems of the present invention, a desired amount of at least one depletable chemical is added to the liquid formulation, for example, to restore the first amount of the depletable chemical in the liquid formulation or at least increase the amount above the predetermined threshold. The addition may be provided in a predetermined profile, referred to herein as the predetermined replenishment profile.

[0096] In some embodiments, the predetermined replenishment profile is selected to increase the amount of the chemical that may be depleted to reach a value substantially equal to or greater than the predetermined threshold value discussed above, or sometimes to any other value below / above the predetermined threshold value.

[0097] To this end, the system of the present invention may further comprise a control unit configured to control the replenishment of at least one depletable chemical in the liquid reservoir according to said replenishment profile.

[0098] 1A, a schematic diagram of a system 100 (e.g., apparatus) according to some embodiments of the present invention is shown. The system includes a liquid reservoir 102 configured to hold a formulation containing a first amount of at least one depletable chemical. The system further includes a refill reservoir 104 holding an amount of the at least one depletable chemical. The system further includes a transfer unit 106 configured to transfer an amount of the at least one depletable chemical from the refill reservoir 104 to the liquid reservoir 102. The transfer unit 106 may further include a regulating means configured to regulate the amount transferred and / or prevent backflow.

[0099] An example of such a transfer unit 106 is a fluid conduit enabling the transfer of a quantity of at least one depletable chemical from the refill reservoir 104 to the liquid reservoir 102. To this end, the system optionally further comprises a safety valve configured to avoid backflow of liquid from the liquid reservoir 102 to the refill reservoir 104.

[0100] In FIG. 1A, the system 100 further includes a detection unit 108 configured to measure the amount of and / or identify the depletion of at least one depletable chemical in the liquid reservoir 102 .

[0101] The system may further include a sampling unit (not shown in FIG. 1A) configured to withdraw an aliquot of the formulation in the liquid reservoir 102 for further analysis (e.g., to determine the amount of the at least one depletable chemical). Alternatively, the detection unit may measure and / or detect the at least one depletable chemical and / or identify its depletion in the reservoir.

[0102] The system optionally further includes a control unit 110 configured to control the replenishment of at least one depletable chemical in the liquid reservoir 102 by actuating the transfer of a quantity of the depletable chemical from the replenishment reservoir 104 to the liquid reservoir 102.

[0103] The control unit 110 can control replenishment on demand, for example based on feedback from the detection unit, and / or can activate replenishment periodically based on a predetermined replenishment profile (e.g., a predetermined amount of chemical that may be depleted once per predetermined period of time).

[0104] In some embodiments, the system 100 in FIG. 1A may further include one or more units, for example, as detailed herein.

[0105] In some embodiments, a system of the present invention, such as system 100 in FIG. 1A, may form part of a printing system, for example as detailed herein (see, for example, printing 10 system in FIG. 1B).

[0106] In some embodiments, the systems of the present invention may further include processing utilities.

[0107] In some embodiments, the processing utility may be configured to provide a signal indication to a user (e.g., a system operator) upon identifying a drop in the first amount of the depletable chemical below the aforementioned predetermined threshold and / or upon identifying a drop in the functionality of the at least one depletable chemical (which may be reflected in the quality of the printed image) to indicate the need to replenish the at least one depletable chemical in the liquid reservoir.

[0108] In some embodiments, the signal indicator may be a visual signal, an audio signal, or a combination thereof.

[0109] In some embodiments, replenishment may be performed by a user, e.g., according to a profile determined based on printing conditions, optionally according to a pre-defined replenishment profile, or may be performed automatically, e.g., by a control unit, upon approval by a system operator, e.g., by activating a controller, e.g., an ON / OFF switch, according to a pre-defined replenishment profile.

[0110] In some embodiments, the system may optionally further include means for stopping the printing process and resuming the printing process once the refill is accomplished / completed.

[0111] In some embodiments, the replenishment profile may define one or more of: the amount (e.g., volume) of at least one depletable chemical to be transferred from the replenishment reservoir to the liquid reservoir, the frequency of replenishment, the duration of transfer, the method of transfer (e.g., continuous or sequential), and the transfer rate.

[0112] In some embodiments, the replenishment profile may be determined based on one or more of: the first amount and / or the second amount of the depletable chemical, the extent of the decline, the detected decline (e.g., the amount of the depletable chemical remaining in the liquid reservoir after the decline), the amount of the depletable chemical relative to the amount of the formulation or the amount of one or more other components contained in the formulation.

[0113] In some embodiments, the replenishment profile may be defined based on one or more of the printing conditions, such as the nature of the print media, printing time / duration, number of print cycles, number of pages printed, printing temperature / temperatures, printing speed, quality / age of the formulation, quality / age of the ITM, degree of contamination of the formulation by external contaminants such as ink.

[0114] In some embodiments, the system and method of the present invention further comprises processing the image generated by the printing process and evaluating its image print quality, and if said image print quality falls below a predetermined required quality, replenishment / addition of the depletable chemical in the liquid formulation is required (thus, addition of at least a part of the second amount of at least one depletable chemical to the liquid formulation is performed).To this end, the system of the present invention utilizes a processing utility configured to process the image and evaluate its print quality, and if the image print quality falls below a predetermined required quality, the control unit of the system is configured to control the replenishment of at least one depletable chemical in the liquid reservoir.

[0115] In some embodiments, the method and system of the present invention generates an output indicative of the quality of the image, and if said output falls below a predefined threshold parameter, replenishment / addition of the depletable chemical in the liquid formulation is required (thus, addition of at least a portion of the second amount of at least one depletable chemical to the liquid formulation is performed).To this end, the system of the present invention utilizes a processing utility configured to generate said output, and if said output falls below a predefined threshold parameter, the control unit is configured to control or cause replenishment of said at least one depletable chemical in said liquid reservoir.

[0116] In some embodiments, image print quality is judged based on the graininess of the image (the less grainy the better the quality). To this end, the output reflects a value indicative of the graininess of the image.

[0117] In some embodiments, the systems and methods of the present invention display said output on a visual display unit, an audio device, or a combination thereof. To this end, the systems of the present invention may further comprise a display unit.

[0118] In some embodiments, the predetermined threshold parameter comprises an essentially distinct value or range of values ​​that represents a desired quality of the printed image (e.g., print quality may be determined based on one or more image pixels and the threshold parameter is a distinct value of one pixel, an average of several pixels or a range of values ​​for various pixels).

[0119] In some embodiments, if the output is below a predetermined threshold (e.g., indicating a defective image), the system of the present invention is configured to provide an alert to the user, and the method provides an alert to the user and sometimes automatically stops the printing process, optionally resuming the printing process once refilling of potentially depleted chemicals (in the liquid reservoirs) is completed.

[0120] In some embodiments, the system of the present invention may further include a user interface. Sometimes the user interface may be for enabling a user to input one or more desired printing conditions for the printing process into the processing utility.

[0121] In some embodiments, the system of the present invention may further include a memory containing a database of predetermined threshold parameter(s) of image quality of the printing process.

[0122] In some embodiments, the processing utility is configured to correlate predetermined image quality threshold parameters from the database with the output produced by the printing process.

[0123] In some embodiments, the system of the present invention may further comprise a means for recording the refill history. For this purpose, the system may be configured to record the occurrence of refills and optionally store them in memory. The system may further be configured to determine the quality of the processing formulation based on the latter and, when a certain amount of refill cycles and / or a certain amount of depletable chemicals has been refilled and / or a certain amount of depletable chemicals in the refill reservoir has been consumed, to stop the printing process and / or provide the user with an indication regarding the refill history, optionally following a decision made by the user (or automatically / semi-automatically) to proceed with further refills or to discard the formulation in the liquid reservoir (if its quality is insufficient, for example due to a large number of refill cycles exceeding a predetermined number of refill cycles) and fill it with a new (fresh) formulation.

[0124] In some embodiments, the decrease in the first amount of the depletable chemical or the decrease in the functionality of the at least one depletable chemical may be due to an undesirable side reaction of the depletable chemical.

[0125] In some embodiments, undesirable side reactions of depletable chemicals result in the formation of undesirable by-products.

[0126] The term "undesirable by-product" as used herein refers to a by-product generated upon reaction of at least one component with a depletable chemical that does not form part of the processing formulation or does not fulfill any functionality, which by-product has no functionality in the formulation, e.g., in the processing formulation and / or in the printing process.

[0127] In some embodiments, the systems and methods of the present invention may further include detection of the formation of undesired by-products, and optionally measuring the amount thereof. To this end, the systems of the present invention may further include means for detecting and measuring / determining / calculating the amount of the by-products in the liquid reservoir.

[0128] In some embodiments, the methods and systems of the present invention may further include correlating the detected formation of the undesired by-product with a decrease in the first amount of the depletable chemical. To this end, the systems of the present invention may further include means configured to correlate the detected formation of the undesired by-product with a decrease in the first amount of the depletable chemical. In some embodiments, the systems may further include means configured to calculate a decrease in the first amount of the depletable chemical from the amount of the undesired by-product in the liquid reservoir.

[0129] In some embodiments, the decrease in the first amount of the depletable chemical may be due to contamination of the formulation (within the liquid reservoir) with at least one contaminant and formation of at least one undesirable by-product resulting from an interaction (which may be a reversible interaction or an irreversible interaction) between the at least one depletable chemical and the at least one contaminant.

[0130] In some embodiments, the method and system of the present invention is for printing. To this end, the system further comprises at least one printing liquid reservoir (e.g., ink reservoir) configured to hold a printing liquid (e.g., and ink formulation), and the decrease in the first amount of the depletable chemical is due to printing liquid contamination (e.g., ink contamination) in the liquid reservoir holding the processing formulation according to the present invention (e.g., contamination of ink components into the liquid reservoir holding the processing formulation containing the depletable chemical).

[0131] In some embodiments, the system of the present invention may further comprise a means for removing ink image residue or processing formulation residue from the release layer surface of the ITM and recirculating the processing formulation residue (to the liquid reservoir). To this end, the system of the present invention comprises: (i) a mechanical residue removal mechanism adapted to mechanically remove ink image residue or processing formulation residue from the release layer surface; (ii) a scraping blade mechanism adapted to mechanically remove ink image residue or processing formulation residue from the release layer surface; and (iii) a cleaning station for removing any ink image residue or processing formulation residue from the release layer surface; and The system optionally further comprises a means for recirculating the treatment formulation residue to the liquid reservoir.

[0132] In some embodiments, ink contamination occurs from recycling of processing formulation residues.

[0133] In some embodiments, ink contamination may result from one or more of: ink spillage, ink splashing (e.g., from an inkjet nozzle), insufficient removal of ink image residue, presence of ink residue in the recirculated processing formulation residue (e.g., due to insufficient transfer of ink from the ITM to the final substrate).

[0134] In some embodiments, the ink contamination may result from one or more of ink spillage, ink splashing, and the recirculation process of the treatment formulation.

[0135] In some embodiments, the ink contamination may result from the recirculation process of the treatment formulation.

[0136] Sometimes, ink contamination can increase with increased print cycles due to an undesirable buildup of ink contamination.

[0137] In some embodiments, the printing liquid is an ink (e.g., an ink formulation) comprising at least one binder (e.g., a negatively charged organic polymer resin) and at least one colorant (e.g., the colorant comprises a pigment), and the decrease in the first amount of the depletable chemical or the decrease in the functionality of the at least one depletable chemical is due to an undesirable side reaction of the depletable chemical with the at least one binder, forming an undesirable by-product (within the liquid reservoir holding the processing formulation according to the present invention).

[0138] In some embodiments, in systems according to the invention, the refill reservoir is positioned sufficiently far (sufficiently spaced) from at least one ink reservoir (e.g., print bar) to avoid the effects of ink contamination of the refill reservoir (e.g., due to ink splash / spill).

[0139] In some embodiments, the system of the present invention may further comprise a protection unit configured to protect the liquid reservoir (holding the treatment formulation of the present invention) from contamination, e.g., ink contamination. To this end, the method of the present invention further comprises protecting the liquid formulation from contamination.

[0140] In some embodiments, the protection unit may selectively capture one or more ink components, for example, by utilizing a selective filter that chemically interacts with one or more ink components, such as the binder. The protection unit may be located downstream of or in close proximity to the opening of the liquid reservoir, or at the opening of the liquid reservoir. To this end, the system may further include a coupling means configured to couple the protection unit to the liquid reservoir. The system may further utilize the same protection unit to protect the refill reservoir.

[0141] In some embodiments, the methods and systems of the present invention may further comprise the removal of undesired by-products. To this end, the systems of the present invention may further comprise means configured to remove said by-products from said liquid reservoir (e.g., once formed and / or once detected). Such means may allow for further performance of the treatment formulation and optionally avoid undesired side effects associated with said by-products, such as clogging one or more of the system components / units.

[0142] Non-limiting examples of means for removing undesirable by-products are one or more of: filtration, e.g., if the by-product is a solid or semi-solid that can be physically removed from the liquid treatment formulation; phase separation, e.g., if the by-product forms a distinct phase, such as a gel that forms a separate phase from the liquid formulation; circulation, optionally followed by decantation of the liquid component (solution) and disposal of the by-product, e.g., if the by-product is a solid product, and recirculation of the liquid component to a liquid reservoir.

[0143] In some embodiments, the method and system of the present invention further comprises measuring the volume of the liquid formulation (in said liquid reservoir), and if the measured volume is below a predetermined minimum volume, the printing process is stopped and the liquid formulation is replenished with an additional amount of liquid formulation until the volume reaches substantially equal to or greater than said predetermined minimum volume. For this purpose, the system of the present invention may further comprise measuring means configured to measure the volume of liquid in said liquid reservoir, and the system (e.g. control unit or processing unit) is configured to indicate to the user to replenish the liquid reservoir with new liquid formulation. Similarly, the system of the present invention may further comprise measuring means configured to measure the amount (e.g. volume / liquid or weight / solid) of a chemical that may be depleted in the refill reservoir, and if the measured amount is below a predetermined minimum amount, the control unit is configured to indicate to the user to replenish the refill reservoir with an additional amount (volume / weight) of the chemical that may be depleted.

[0144] As previously mentioned, the system of the present invention includes several units, which may communicate using wired or wireless communication modules, as will be appreciated by those skilled in the art.

[0145] In some embodiments, the depletable chemical agent may be a polymeric agent that contains amine nitrogen atoms in multiple functional groups (e.g., primary, secondary, tertiary amines or quaternary ammonium salts, which may be linear, branched or cyclic) that can be attached, but need not be the same.

[0146] In some embodiments, the depletable chemical agent may be a polymeric agent having a relatively high charge density.

[0147] In some embodiments, the depletable chemical agent can be a polymeric agent having a molecular weight of 10,000 g / mol or greater.

[0148] In some embodiments, the depletable chemical agent may be a polymeric agent having one or more of: (a) a positive charge density of said agent of at least 3 meq / g and an average molecular weight of at least 5,000; (b) a positive charge density of said agent of at least 6 meq / g and an average molecular weight of at least 1,000; (c) a nitrogen content of at least 1 wt.% and an average molecular weight of at least 50,000; and (d) a nitrogen content of at least 18 wt.% and an average molecular weight of at least 10,000.

[0149] In some embodiments, the depletable chemical is (1) A nitrogen content of at least 1 wt.%; and (a) a chemical having a positive charge density of at least 3 meq / g and an average molecular weight of at least 5,000; (b) a chemical having a positive charge density of at least 6 meq / g and an average molecular weight of at least 1000; (c) an average molecular weight of at least 50,000; and / or (2) a nitrogen content of at least 18 wt.% and an average molecular weight of at least 10,000; The polymeric agent may have the formula:

[0150] In some embodiments, the chemical agent that can be depleted can be a polymeric agent that has a positive charge density.

[0151] In some embodiments, the positive charge density can be at least 0.5 meq / g, at least 1 meq / g, at least 2 meq / g, at least 3 meq / g, at least 4 meq / g, at least 5 meq / g, at least 6 meq / g, at least 7 meq / g, at least 8 meq / g, at least 9 meq / g, at least 10 meq / g, at least 11 meq / g, at least 12 meq / g, at least 13 meq / g, at least 14 meq / g, at least 15 meq / g, at least 16 meq / g, at least 17 meq / g, at least 18 meq / g, at least 19 meq / g, or at least 20 meq / g of the agent.

[0152] In some embodiments, the depletable chemical agent can be a polymeric agent having an average molecular weight of at least 500, at least 800, at least 1,000, at least 1,300, at least 1,700, at least 2,000, at least 2,500, at least 3,000, at least 3,500, at least 4,000, at least 4,500, at least 5,000, at least 10,000, at least 15,000, at least 20,000, at least 25,000, at least 50,000, at least 100,000, at least 150,000, at least 200,000, at least 250,000, at least 500,000, at least 750,000, at least 1,000,000, or at least 2,000,000.

[0153] In some embodiments, the depletable chemical agent can be a polymeric agent having an average molecular weight of at least 2,000, at least 10,000, or at least 25,000.

[0154] In some embodiments, the chemical agent that can be depleted can be a polymeric agent that contains one or more positively charged nitrogen atoms.

[0155] As used herein, the term "positively chargeable polymer" or "positively chargeable group" refers to a polymer that can be readily protonated (e.g., -NH2) or that has a permanent positive charge (e.g., -N(CH3)3). + ) polymer or chemical moiety. In some embodiments, these terms refer to an inherent property of the polymer or moiety and thus can encompass a polymer or moiety in an environment to which such protons are added, and a polymer in an environment to which such protons are not added. In contrast, the term "positively charged" polymer or group refers to a polymer or group in an environment to which one or more such protons are added or which has a permanent positive charge. In some embodiments, the one or more charged nitrogen atoms of the depletable chemical are selected from primary, secondary, and tertiary amines and quaternary ammonium salt groups and combinations of such groups. In some embodiments, such groups are covalently attached to the polymer backbone and / or constitute part of such backbone. In some embodiments, the one or more nitrogen atoms are part of a cyclic moiety.

[0156] In some embodiments, the one or more nitrogen atoms constitute at least 1%, at least 1.4%, at least 2%, at least 5%, at least 8%, at least 10%, at least 15%, at least 18%, at least 20%, at least 24%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% by weight of the depletable chemical.

[0157] In some embodiments, the depletable chemical is poly(diallyldimethylammonium chloride) [ [ka] It is a polymeric agent containing units.

[0158] In some embodiments, the depletable chemical is polyallylamine [ [ka] It is a polymeric agent containing units.

[0159] In some embodiments, the depletable chemical is poly(4-vinylpyridine) [ [ka] It is a polymeric agent containing units.

[0160] In some embodiments, the depletable chemical polymeric agent is selected from the group consisting of linear polyethyleneimine, branched polyethyleneimine, modified polyethyleneimine, poly(diallyldimethylammonium chloride), poly(4-vinylpyridine), polyallylamine, vinylpyrrolidone-dimethylaminopropyl methacrylamide copolymer (ViViprint 131), vinylcaprolactam-dimethylaminopropyl methacrylamide hydroxyethyl methacrylate copolymer (ViViprint 200), quaternized copolymer of vinylpyrrolidone and dimethylaminoethyl methacrylate with diethyl sulfate (ViViprint 650), guar hydroxypropyltrimonium chloride, and hydroxypropyl guar hydroxypropyltrimonium chloride.

[0161] In some embodiments, the chemical polymeric agent that can be depleted is polyethyleneimine (PEI) (eg, Loxanol P, Loxanol MI6730).

[0162] In some embodiments, the concentration (e.g., first amount) of the depletable chemical polymer agent in the formulation (within the liquid reservoir) is less than or equal to about 5 wt.%, 4 wt.%, 3 wt.%, 2 wt.%, 1 wt.%, 0.5 wt.%, 0.4 wt.%, 0.3 wt.%, 0.2 wt.%, 0.1 wt.%, or is equal to or at least about 0.01 wt.%, sometimes at least about 0.05%.

[0163] In some embodiments, the depletable chemical is PEI and the first amount thereof is at a concentration by weight in the formulation (within the liquid reservoir) of at least 0.01%, at least 0.05%, at least 0.10%, at least 0.15%, or at least 0.20%.

[0164] In some embodiments, the depletable chemical is PEI and the predetermined threshold is a concentration by weight in the formulation (within the liquid reservoir) of at least 0.01%, at least 0.05%, at least 0.10%, at least 0.15%, or at least 0.20%.

[0165] In some non-limiting embodiments according to the present invention, the first amount of PEI (in the liquid reservoir) can be a 0.25% concentration by weight in the treatment formulation (e.g., 0.75 gr of PEI in a liquid reservoir holding 300 L of treatment formulation). The second amount of PEI (in the refill reservoir) can be 25 wt.% (e.g., in water). When the first amount of PEI (in the liquid reservoir) falls below a predetermined threshold, e.g., 0.01 wt.% (e.g., below said value, PEI no longer fulfills its function in the printing process), the method and system of the present invention are configured to transfer at least a portion of the second amount of PEI from the replenishment reservoir to the liquid reservoir, thereby replenishing the amount of PEI (in the liquid reservoir) to a value equal to or greater than the predetermined threshold, e.g., equal to or greater than 0.01 wt.%, or replenishing the amount of PEI (in the liquid reservoir) to the first amount, e.g., equal to 0.25 wt.% (the latter being an example where a 100x dilution of PEI is required during transfer from the replenishment reservoir to the liquid reservoir, i.e., transfer of 3 L of replenishment 25 wt.% solution to 300 L of liquid formulation in the liquid reservoir).

[0166] In some embodiments, the depletable chemical agent PEI and the first amount thereof is at a concentration by weight in the formulation (within the liquid reservoir) of up to 6%, up to 5%, up to 4%, up to 3%, up to 2.5%, up to 2.0%.

[0167] In some embodiments, the depletable chemical is PEI and the first amount is a concentration by weight in the formulation (within the liquid reservoir) that is in the range of 0.01-1%, 0.01-0.8%, 0.01-0.7%, 0.01-0.6%, 0.1-0.5%, 0.2-0.7%, 0.2-0.6%, or 0.2-0.5%.

[0168] In some embodiments, the PEI has an average molecular weight of at least 20,000, at least 50000, at least 100,000, at least 200,000, at least 350,000, at least 500,000, at least 700,000, at least 750,000, and optionally up to 3,000,000, up to 2,500,000, or up to 2,000,000.

[0169] In some embodiments, the PEI has an average molecular weight of 750,000.

[0170] In some embodiments, the depletable chemical agent is a polymeric agent that is PEI, said PEI being a surfactant, a wetting agent, a fixative, or any combination thereof.

[0171] In some embodiments, PEI is the surfactant.

[0172] In some embodiments, PEI is a wetting agent.

[0173] In some embodiments, PEI is the fixative.

[0174] In some embodiments, the charge density of the PEI polymer is in the range of 16-20 meq / g of material.

[0175] In some embodiments, the PEI has a charge density of 8 meq / g.

[0176] In some embodiments, the depletable chemical is silicon-functionalized PEI [e.g., X223939A (Shin Edsu)], for example, a silicon function of the following structure:

[0177] [ka]

[0178] In some embodiments, the chemical that can be depleted is a quaternary ammonium compound.

[0179] In some embodiments, the quaternary ammonium compound is Larostat 264A (BASF).

[0180] In some embodiments, the quaternary ammonium compound is Foamquat SAQ (linoleamidopropylethyldimonium ethosulfate 90).

[0181] In some embodiments, the depletable chemical is water-dispersible (eg, a polymer water-dispersible).

[0182] In some embodiments, the depletable chemical is water soluble (eg, a water soluble polymer).

[0183] In some embodiments, the depletable chemical is a solid at room temperature.

[0184] In some embodiments, at least one binder in the ink formulation is an anionic binder, such as an acrylic binder and / or a sulfonic binder. Similar anionic binders are within the scope of the present invention.

[0185] In some embodiments, at least one binder in the ink formulation is a negatively charged organic polymer resin.

[0186] In some embodiments, the negatively charged organic polymer resin has an average molecular weight of at least 8,000.

[0187] In some embodiments, at least one binder in the ink formulation is an acrylic polymer and / or an acrylic-styrene copolymer (eg, having an average molecular weight of about 60,000 g / mole).

[0188] In some embodiments, at least one binder in the ink formulation is Joncryl® 538 BASF.

[0189] In some embodiments, the depletable chemical agent is PEI, the decrease in the first amount of which is due to its undesired side reaction with the at least one basic binder, e.g. having COO- or SOOO- groups as side chains.

[0190] In some embodiments, the formulation (within the liquid reservoir) may further comprise at least one competing component that is inert with respect to the printing process, i.e., has no functionality in the printing process itself, selected to rapidly interact (relative to the depletable chemicals) with one or more contaminating components of the ink (e.g., the binder), thereby preventing or minimizing depletion of the depletable chemicals, e.g., PEI, due to interaction of the competing component (and not the depletable chemicals) with contaminating ink components (e.g., the ink binder). A non-limiting example of such a competing component is a polyanionic material.

[0191] To this end, in some embodiments, the system may further include means for removing products formed between at least one competing component and one or more contaminating ink components.

[0192] In some embodiments, the system of the present invention is for indirect printing, the system comprising: i. an intermediate transfer member (ITM) comprising a release layer surface; ii. a treatment station including a liquid reservoir configured to hold an aqueous treatment formulation as disclosed herein, the treatment station being configured to apply the aqueous treatment formulation to a release layer surface of the ITM to form a treatment layer thereon; iii. a refill unit comprising a refill reservoir as disclosed herein; iV. an imaging station configured to apply a printing fluid to form an image on the aqueous treatment formulation formed on the intermediate transfer member; V. A transfer station for transferring an image onto a print substrate, e.g., by pressure contact between the ITM and the print substrate. Further includes:

[0193] In some embodiments, the printing liquid is ink, optionally applied by jetting, and the system further comprises: a drying station configured to at least partially dry the ink on the aqueous treatment formulation formed on the intermediate transfer member to produce an ink image residue, and optionally drying means for drying the aqueous treatment formulation. Further includes:

[0194] In some embodiments, in the method of the present invention, the liquid formulation is configured to be applied onto a substrate onto which an image is to be printed, or onto an intermediate transfer member in an indirect printing process.

[0195] In some embodiments, the method of the present invention is utilized in an indirect printing process, the method comprising: i. providing an intermediate transfer member (ITM); ii. providing a treatment formulation as disclosed herein; iii. applying a treatment formulation to an image receiving surface of the ITM to form a wet treatment layer; iV. at least partially drying the wet treatment layer to form an at least partially dry treatment layer; V. applying a printing fluid to the at least partially dried processing layer to form an image; Vi. Transferring an image to a printing substrate by pressurized contact between said surface of the ITM and the printing substrate. Further includes:

[0196] In some embodiments, the printing liquid is an ink, optionally a water-based ink, and the method comprises: applying ink droplets onto the at least partially dried treatment layer to form an ink image; and at least partially drying the wet ink image on the aqueous treatment layer to form a partially dried ink image film that is transferred to a print substrate. Further includes:

[0197] 1B provides a diagram of an exemplary printing system of which the system of the present invention forms a part. Specifically, FIG. 1B is a schematic side view of a digital printing system 10 in accordance with some embodiments of the present invention. In some embodiments, system 10 includes a rotating flexible blanket 12 that circulates through an imaging station 14, a drying station 16, an impression station 18, and a blanket treatment station 20.

[0198] As used herein, the term "blanket" refers to a flexible transfer member that can be mounted in a printing apparatus to form a belt-like structure over two or more rollers, at least one of which can rotate or move the blanket (e.g., by moving the belt) around the rollers.

[0199] As used herein, the terms "blanket" and "intermediate transfer member" ITM are used interchangeably to refer to a flexible member that includes at least a release layer used as an intermediate member configured to receive an ink image and transfer the ink image to a target substrate, as described herein.

[0200] In an operational mode, imaging station 14 is configured to form a mirror ink image, also referred to herein as an “ink image” (not shown), of the digital image on an upper run of the surface of blanket 12. The ink image is then transferred to a target substrate (e.g., paper, folding carton, or any suitable flexible packaging material in the form of a sheet or continuous web) disposed beneath a lower run of blanket 12.

[0201] As used herein, the terms "ink image" and "image" are used interchangeably. Sometimes, the terms refer to a printed image formed on blanket 12 and transferred to a target substrate. Sometimes, they refer to an image on the substrate itself (e.g., paper, folding carton, or any suitable flexible packaging material in the form of a sheet or continuous web). Thus, these terms should be interpreted within the context of the text in which they are used.

[0202] As used herein, the term "run" refers to the length or segment of blanket 12 between any two given rollers over which blanket 12 is guided.

[0203] In some embodiments, during installation, the blanket 12 may be attached edge-to-edge (e.g., sewn together) to form a continuous blanket loop (not shown). One example of a method and system for seam attachment is described in detail in U.S. Provisional Application No. 62 / 532,400, the disclosure of which is incorporated herein by reference.

[0204] In some embodiments, imaging station 14 typically includes multiple print bars 22, each mounted (e.g., using a slider) on a frame (not shown) that is positioned at a fixed height above the surface of the upper run of blanket 12. In some embodiments, each print bar 22 includes a strip of print heads the same width as the print area on blanket 12 and includes individually controllable print nozzles.

[0205] In some embodiments, imaging station 14 may include any suitable number of bars 22, and each bar 22 may include a printing fluid, such as a different colored water-based ink. The inks typically have visible colors, such as, but not limited to, cyan, magenta, red, green, blue, yellow, black, and white. In the example of FIG. 1B, imaging station 14 includes seven print bars 22, but may include four print bars 22 having any selected color, such as, for example, cyan, magenta, yellow, and black.

[0206] In some embodiments, the print heads are configured to eject ink droplets of different colors onto the surface of blanket 12 to form an ink image (not shown) on the surface of blanket 12 .

[0207] In some embodiments, the different print bars 22 are spaced from one another along the axis of motion of the blanket 12, represented by arrow 24. In this configuration, precise spacing between the bars 22 and synchronization between the direction of the ink droplets of each bar 22 and the motion of the blanket 12 is essential to enable precise placement of the image pattern.

[0208] In some embodiments, the system 10 includes heaters, such as hot gas or air blowers 26, disposed between the print bars 22 and configured to partially dry the ink droplets deposited on the surface of the blanket 12.

[0209] This flow of hot air between the print bars can help, for example, to reduce condensation on the surface of the print head, and / or to deal with satellites (e.g., residue or small droplets dispersed around the main ink droplets), and / or to prevent clogging of the inkjet nozzles of the print head, and / or to prevent droplets of different color inks on the blanket 12 from unnecessarily intermixing with each other. In some embodiments, the system 10 includes a drying station 16 configured to blow hot air (or another gas) onto the surface of the blanket 12. In some embodiments, the drying station includes a blower or any other suitable drying device.

[0210] At drying station 16, the ink image formed on blanket 12 is exposed to radiation and / or hot air to more completely dry the ink, evaporating most or all of the liquid carrier and leaving only a layer of resin and colorant that is heated to the point where it becomes a tacky ink film.

[0211] In some embodiments, the system 10 includes a blanket transport assembly 26 configured to move a rotating ITM, such as the blanket 12. ’ In some embodiments, the blanket transport assembly 26 ’ includes one or more rollers 28, at least one of which includes an encoder (not shown) configured to record the position of the blanket 12 in order to control the position of the sections of the blanket 12 relative to the respective print bars 22. In some embodiments, the encoder of the rollers 28 typically includes a rotary encoder configured to generate a rotary-based position signal indicative of the angular displacement of the respective roller.

[0212] Additionally or alternatively, blanket 12 may include built-in encoders (not shown) for controlling the operation of various modules of system 10. Built-in encoders are described in detail, for example, in U.S. Provisional Application No. 62 / 689,852, the disclosure of which is incorporated herein by reference.

[0213] In some embodiments, the system 10 includes an impression station 18 where the blanket 12 passes between an impression cylinder 30 and a pressure cylinder 32, which are configured to transport a compressible blanket.

[0214] In some embodiments, the system 10 includes a control console (not shown) that is configured to control multiple modules and assemblies of the system 10 .

[0215] In some embodiments, the blanket treatment station 20 can also function as a cooling station and is configured to treat the blanket, for example, by cooling it and / or applying a treatment fluid to the outer surface of the blanket 12 and / or cleaning the outer surface of the blanket 12. Treatment can be performed by passing the blanket 12 over one or more rollers or blades configured for cooling and / or cleaning and / or applying a treatment fluid onto the outer surface of the blanket.

[0216] In the example of FIG. 1B, station 20 is mounted between two particular rollers 28, however, station 20 may be mounted adjacent to blanket 12 at any other suitable location between printing station 18 and image-forming station 14.

[0217] In some embodiments, the liquid reservoir of the system of the present invention forms part of station 20 .

[0218] In some embodiments, the refill reservoir of the system of the present invention forms part of station 20 .

[0219] In some embodiments, the impression cylinder 30 of the impression station 18 is configured to press an ink image onto a target substrate, such as an individual sheet 34, conveyed by a substrate transport module 36 (shown diagrammatically) through the impression cylinder 30 from an input stack 38 to an output stack 40. In some embodiments, the target substrate may include any suitable substrate, such as, but not limited to, a flexible substrate, a partially flexible substrate (e.g., having a flexible portion and a rigid portion), or a rigid substrate.

[0220] In some embodiments, system 10 includes additional printing stations to allow for double-sided printing (ie, printing on both sides of sheet 34).

[0221] In alternative embodiments, different configurations of substrate conveyor 36 may be used for printing on continuous web substrates. Detailed descriptions and various configurations of sheet-fed simplex and duplex printing systems, as well as systems for printing on continuous web substrates, are provided, for example, in U.S. Pat. Nos. 9,914,316 and 9,186,884, PCT International Publication No. WO 2013 / 132424, U.S. Patent Application Publication No. 2015 / 0054865, and U.S. Provisional Application No. 62 / 596,926, the disclosures of each of which are incorporated herein by reference.

[0222] The particular configuration of system 10 is shown as an example, however, embodiments of the present invention are in no way limited to this particular type of example system, and the principles described herein may be applied to any other type of printing system as well.

[0223] In some embodiments, the formulation (within the liquid reservoir), e.g., the treatment formulation, may further include one or more of: (a) at least one water soluble polymer; (b) at least one surfactant; (c) at least one water retention agent; and (d) at least one humectant.

[0224] In some embodiments, the formulation (within the liquid reservoir), e.g., the processing formulation, may further comprise at least one particulate material selected from (i) at least one thermoplastic polymer particulate material, (ii) at least one thermosetting polymer particulate material, or (iii) a combination thereof.

[0225] As used herein, the term "thermosetting polymeric particulate material" or any linguistic variant thereof refers to a particulate material that is a polymeric material (e.g., having a relatively high molecular weight) that becomes irreversibly hardened when cured, for example, by the action of heat or by suitable irradiation. Once hardened, the material cannot be remelted.

[0226] Non-limiting examples of thermosetting polymeric particulate materials are polytetrafluoroethylene (PTFE), perfluoroalkoxyalkanes (PFA), fluorinated ethylene propylene (FEP).

[0227] In some embodiments, the thermoset polymeric particulate material is PTFE.

[0228] As used herein, the term "thermoplastic polymer particulate material" or any linguistic variation thereof refers to a particulate material that is a polymeric material (e.g., having a relatively high molecular weight) that becomes flexible or moldable above a certain temperature and solidifies upon cooling. The material can be remelted and reformed.

[0229] A non-limiting example of a thermoplastic polymer particulate material is a wax particulate material.

[0230] In some embodiments, the wax particulate material is an oxidized polyethylene wax particulate material.

[0231] In some embodiments, the wax particulate material is a coated wax particulate material.

[0232] In some embodiments, the coated wax particulate material is a silicon dioxide coated wax particulate material.

[0233] Treatment formulations containing such particulate materials are disclosed in U.S. Provisional Application No. 62 / 787,984, U.S. Provisional Application No. 62,825,568, and International Application No. PCT / IB2020 / 050001, the contents of each of which are incorporated herein by reference.

[0234] In some embodiments, the formulation (within the liquid reservoir), eg, the treatment formulation, may further comprise at least one modified polysaccharide (eg, cellulose derivatives, cellulose ethers, methylcellulose, and hydroxypropylmethylcellulose).

[0235] As used herein, the term "modified polysaccharide" refers to a polymeric carbohydrate molecule composed of long chains of monosaccharide units linked together by glycosidic bonds, in which at least one of the hydrogen atoms of the hydroxyl groups in the monosaccharide units is replaced with another group, e.g., R.

[0236] Treatment formulations containing such modified polysaccharides are disclosed in U.S. Provisional Application No. 62 / 790,890, U.S. Provisional Application No. 62,825,568 and International Application No. PCT / IB2020 / 050001, the contents of each of which are incorporated herein by reference.

[0237] In some embodiments, the formulation (within the liquid reservoir) may optionally further comprise at least one antimicrobial agent.

[0238] In some embodiments, the formulation (within the liquid reservoir), e.g., the treatment formulation, at least one water soluble polymer, At least one particulate material selected from: (i) at least one thermoplastic polymer particulate material, optionally in the form of an emulsion and / or dispersion; (ii) at least one thermosetting polymer particulate material, optionally in the form of a dispersion and / or emulsion; or (iii) a combination thereof; A carrier liquid comprising water, and Optionally, one or more of: (a) at least one water retention agent; (b) at least one surfactant; and (c) at least one wetting agent. Includes.

[0239] In some embodiments, the water soluble polymer can be at least one modified polysaccharide (eg, cellulose derivatives, cellulose ethers, methylcellulose, and hydroxypropylmethylcellulose).

[0240] In some embodiments, the modified polysaccharide is hydroxypropyl methylcellulose.

[0241] In some embodiments, the water soluble polymer may be selected from the group consisting of polyvinyl alcohol, water soluble cellulose, polyvinylpyrrolidone (PVP), polyethylene oxide, and water soluble acrylates.

[0242] In some embodiments, the water soluble polymer can be a polyethylene oxide chain (PEO) or polypropylene oxide chain (PPO) based polymer.

[0243] In some embodiments, the concentration of the water soluble polymer in the formulation (within the liquid reservoir) is in the range of 0.5-8%, 2.5-6.5%, 2.5-6%, 2.5-5.5%, or 2.5-5%, optionally up to 10% or up to 8% or up to 6% or up to 5%.

[0244] In some embodiments, the solubility in water of at least one water-soluble polymer (within the liquid reservoir) at 25° C. is at least 2%, at least 7%, at least 10%, at least 12%, at least 15%, at least 20%, or at least 25%, and optionally up to 80% or up to 60%.

[0245] In some embodiments, the surfactant can be a non-ionic surfactant, for example a non-ionic silicone-containing surfactant.

[0246] In some embodiments, the formulation (within the liquid reservoir) has a total surfactant concentration in the range of at least 0.3%, at least 0.5%, at least 0.75%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12% and optionally 6-40%, 6-30%, 6-20%, 7-30%, 7-20%, 7-15%, 8-25%, 8-20%, 8-15%, 8-13%, 9-25%, 9-20%, 9-15%, 9-13%, 10-25%, 10-20%, 10-15%, or 10-13%.

[0247] In some embodiments, the formulation (within the liquid reservoir) comprises at least 6%, at least 7%, at least 8%, at least 9%, or at least 10% non-ionic surfactant by weight.

[0248] In some embodiments, the formulation (within the liquid reservoir) comprises up to 18%, up to 16%, up to 15%, up to 14%, or up to 13% non-ionic surfactant by weight.

[0249] In some embodiments, the concentration of the nonionic surfactant in the formulation (within the liquid reservoir), by weight, is in the range of 0.5-18%, 1-18%, 2-16%, 6.5-18%, 6.5-16%, 7.5-18%, 7.5-16%, 8.5-18%, 8.5-16%, 9.5-18%, 9.5-16%, 10.5-18%, or 10.5-16%.

[0250] In some embodiments, the solubility of the nonionic surfactant in water at 25° C. is at least 2%, at least 8%, at least 10%, at least 12%, at least 15%, at least 20%, at least 25%, or at least 30%, and optionally up to 80% or up to 60%.

[0251] In some embodiments, the nonionic surfactant is a polyethoxylated sorbitan ester.

[0252] In some embodiments, the polyethoxylated sorbitan ester comprises at least one species or at least two species selected from the group consisting of PEG-4 sorbitan monolaurate, PEG-20 sorbitan monolaurate, PEG-20 sorbitan monopalmitate, PEG-20 sorbitan monostearate, and PEG-20 sorbitan monooleate.

[0253] In some embodiments, the HLB number of the nonionic surfactant is at least 11, at least 12, at least 13, at least 14, or at least 14.5, and optionally up to 22, up to 21, up to 20, up to 19, up to 18, or up to 17, and further optionally within the range of 11-25, 11-23, 11.5-21, 11.5-20, 11.5-18, 12.5-21, 12.5-20, 12.5-18, 13.5-21, 13.5-20, 13.5-18, 14-20.5, 14-18.5, 14.5-20, 14.5-19, 14.5-18, or 14.5-17.5.

[0254] In some embodiments, the formulation (within the liquid reservoir) comprises at least 6%, at least 7%, at least 8%, at least 9%, or at least 10% non-ionic surfactant by weight.

[0255] In some embodiments, the formulation (within the liquid reservoir) comprises up to 18%, up to 16%, up to 15%, up to 14%, or up to 13% non-ionic surfactant by weight.

[0256] In some embodiments, the nonionic surfactant in the formulation (within the liquid reservoir) is in the range of 2-18%, 5.5-18%, 5.5-16%, 6.5-18%, 6.5-16%, 7.5-18%, 7.5-16%, 8.5-18%, 8.5-16%, 9.5-18%, 9.5-16%, 10.5-18%, or 10.5-16% by weight.

[0257] In some embodiments, the solubility of the nonionic surfactant in water at 25° C. is at least 2%, at least 8%, at least 10%, at least 12%, at least 15%, at least 20%, at least 25%, or at least 30%, and optionally up to 80% or up to 60%.

[0258] In some embodiments, the concentration by weight of the nonionic surfactant in the formulation (within the liquid reservoir) is in the range of 2-18%, 1-18%, 1-15%, 1-12%, 1-10%, 1-8%, 2-18%, 2-15%, 2-12%, 2-10%, 2-8%, 3-18%, 3-15%, 3-12%, 3-10%, 3-8%, or 4-18%, 4-15%, 4-12%, 4-10%, or 4-8%.

[0259] In some embodiments, the formulation (in the liquid reservoir) further comprises a non-ionic silicone-containing surfactant selected from a polysiloxane-polyoxyalkylene copolymer, optionally having a concentration of at least 0.3%, at least 0.5%, at least 0.75%, or at least 1.0% by weight, and further optionally at most 5%, at most 4%, at most 3%, at most 2.5%, at most 2%, or at most 1.75% by weight.

[0260] In some embodiments, the formulation (within the liquid reservoir) comprises at least 0.3%, at least 0.5%, at least 0.75%, or at least 1.0% by weight, and optionally up to 5%, up to 4%, up to 3%, up to 2.5%, up to 2%, or up to 1.75% by weight, of an additional non-ionic silicone-containing surfactant.

[0261] In some embodiments, the additional nonionic silicone-containing surfactant comprises a polysiloxane-polyoxyalkylene copolymer, optionally having a concentration of said polysiloxane-polyoxyalkylene copolymer by weight of at least 0.3%, at least 0.5%, at least 0.75%, or at least 1.0%, and further optionally up to 5%, up to 4%, up to 3%, up to 2.5%, up to 2%, or up to 1.75% by weight.

[0262] In some embodiments, the formulation (in the liquid reservoir) comprises at least 0.3%, at least 0.5%, at least 0.75%, or at least 1.0% by weight, and optionally up to 5%, up to 4%, up to 3%, up to 2.5%, up to 2%, or up to 1.75% by weight of said additional non-ionic silicone-containing surfactant.

[0263] In some embodiments, the formulation (within the liquid reservoir) has a total surfactant concentration in the range of at least 2%, at least 6%, at least 7%, at least 8%, at least 10%, or at least 12%, and optionally, 6-40%, 6-30%, 6-20%, 7-30%, 7-20%, 7-15%, 8-25%, 8-20%, 8-15%, 8-13%, 9-25%, 9-20%, 9-15%, 9-13%, 10-25%, 10-20%, 10-15%, or 10-13%.

[0264] In some embodiments, the formulation (within the liquid reservoir) includes at least one humectant.

[0265] In some embodiments, the wetting agent is PEI.

[0266] In some embodiments, the PEI is one or more of the PEIs listed in Table 1 below: [Table 1]

[0267] In some embodiments, the PEI is provided in an aqueous solution (Lupasol® PS, BASF).

[0268] Non-limiting examples of applicable depletable chemicals are N-Hance™ BF 17 cationic guar, N-Hance™ CCG 45 cationic guar, N-Hance™ HPCG 1000 cationic guar, N-Hance™ BF 13 cationic guar, N-Hance™ CG 13 cationic guar, N-Hance™ 3196 cationic guar (all from Ashland Specialty Ingredients).

[0269] In some embodiments, the depletable chemical is guar hydroxypropyltrimonium chloride (GHPTC).

[0270] In some embodiments, the depletable chemical is hydroxyl guar hydroxypropyltrimonium chloride (HGHPTC).

[0271] Further non-limiting examples of applicable depletable chemicals are listed in Table 2 below: [Table 2]

[0272] Further non-limiting examples of applicable depletable chemicals are listed in Table 3 below: [Table 3]

[0273] Further details regarding treatment formulations suitable for the methods and systems according to the present invention are disclosed, for example, in WO 2013 / 132418, WO 2013 / 132339 and WO 2019 / 111223, the contents of each of which are incorporated herein by reference.

[0274] Further details of non-limiting examples of ink compositions suitable for the printing process and system of the present invention are disclosed in WO 2013 / 132439, PCT / IB13 / 51755 (WO 2013 / 132439) or US2015 / 0025179, PCT / IB14 / 02395 (WO 2015 / 036865) or US14 / 917461, all of which are incorporated herein by reference.

[0275] In some embodiments, the formulations, for example, the treatment formulations and the ink formulations, are as disclosed and exemplified herein.

[0276] It will be appreciated that certain features of the invention that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as appropriate with any other described embodiment of the invention.

[0277] Detailed Description of the Embodiments The following examples are in no way intended to limit the scope of the claimed invention.

[0278] Example 1: Aqueous Treatment Formulation Exemplary aqueous treatment formulations used in this study, referred to herein as V1, V2 and V3, are provided in Tables 4, 5 and 6, respectively.

[0279] Treatment formulation V1 was prepared by mixing the ingredients listed in Table 4 below: [Table 4]

[0280] Treatment formulation V2 was prepared by mixing the ingredients listed in Table 5 below: [Table 5]

[0281] Treatment formulation V3 was prepared by mixing the ingredients listed in Table 6 below: [Table 6]

[0282] It should be noted that the components of the treatment formulation according to the present invention can be mixed in any suitable manner to form a composition that can be applied as a coating on the intermediate transfer member. Sometimes the mixed components can form a dispersion. To this end, the system of the present invention is configured to provide a mixing means to provide a homogenous dispersion of the treatment formulation.

[0283] Example 2: Ink formulation Pigment Preparation The pigments used in the examples described below are generally supplied with an initial particle size of a few micrometers. Such pigments were milled to the submicron range in the presence of a dispersant, and the two materials were fed as an aqueous mixture to a milling device (bead mill). The progress of the milling was controlled based on particle size measurements (e.g., MalVern or Nanosizer instruments). The average particle size (d V 50) The milling was stopped when the particle size reached 70–100 nm.

[0284] Exemplary Ink Compositions In this example, the preparation of an ink composition is described: As described, Heliogen® Blue D7079 was milled together with Disperbyk® 190 and the materials were mixed in the following proportions: Heliogen® Blue D7079 30g Disperbyk® 190 (40%) 30g 140g water ============================= Total 200g

[0285] The finely divided concentrate has a diameter of less than 100 nm, typically between 70 and 100 nm, DV % pigment concentration. The millbase concentrate had a mass of 1.50 g and was further diluted with 50 g of water to yield about 12 wt. % pigment concentration. The millbase concentrate was further processed as described below for the preparation of the ink compositions.

[0286] In the first step, 2.4 g of sodium dodecanoate was added to 200 g of millbase concentrate to obtain a millbase. The mixture was stirred until homogeneous (magnetic stirrer at 50 rpm for 5 min) and incubated at 60° C. for 1 day. The mixture was then left to cool to ambient temperature.

[0287] In a second step, the ink ingredients were added to the millbase as follows: Millbase concentrate (from step 1) 202.4g Joncryl® 538 (46.5%) 154.8g BYK® 349 5g BYK® 333 2g 240g propylene glycol Water 595.8g ================= Total 1200g

[0288] The mixture was stirred at ambient temperature for 30 minutes resulting in an ink-jettable ink composition having a viscosity of less than 10 cP.

[0289] Example 3: Study of factors influencing the shelf life of treatment formulations A stock of the treatment formulation was prepared in approximately 200L volume.

[0290] To coat the ITM, approximately 0.5 gr of treatment formulation was consumed per page printed in the printing process.

[0291] Replenishment of the treatment formulation with additional amounts of treatment formulation (including all components) was required based on consumption (weekly replenishment of approximately 100 L for a total volume of approximately 300 L, total replenishment usage of approximately 300 L per month).

[0292] The inventors of the present invention have realized the need to replenish the processing formulation very frequently, which does not reflect the need to replenish it based on a calculation of 0.5 gr of processing formulation per printed page.

[0293] In order to reduce to a minimum (zero) the use of processing formulation beyond what is needed for printing, the effect of various factors was tested as detailed below:

[0294] Viscosity and surface tension measurements: The viscosity and surface tension of the treatment formulations were tested at both room temperature and at 50° C. for a period of six months.

[0295] The results are shown in Figures 2 and 3.

[0296] Figure 2 shows a plot representing the measurement of the average viscosity of the treatment formulation versus time. Figure 3 shows a plot representing the measurement of the average surface tension of the treatment formulation versus time.

[0297] Both Figures 2 and 3 show that the treatment formulation maintained its physical properties over time.

[0298] Measurement of print quality as a function of processing formulation ageing and temperature: Print quality was investigated as a function of treatment formulation age and temperature.

[0299] 4A-4C show portions of printed images obtained in an indirect printing process utilizing a freshly prepared treatment formulation (t=0) (FIG. 4A), a one-month-old treatment formulation at room temperature (FIG. 4B), and a one-month-old treatment formulation at 50° C. (FIG. 4C).

[0300] 4A-4C show that no change in print quality was observed due to aging (up to 1 month) of the treatment formulation, and that the formulation maintained its performance characteristics at both room temperature and 50° C. for at least 1 month.

[0301] Measurement of print quality as a function of the use of processing formulations: Problematic processing formulations were tested from the press that resulted in poor print quality as judged based on print graininess.

[0302] No differences in the physical properties were measured compared to the freshly prepared treatment formulation.

[0303] 5A-5B show printed images obtained with an indirect printing process utilizing fresh processing formulation that has not been used previously (FIG. 5A) and processing formulation that has been used in the printing process for several printing cycles (FIG. 5B).

[0304] 5A-5B clearly show the poor quality of the images produced utilizing the processing formulation used.

[0305] Measurement of print quality as a function of the use of treatment formulations and as a function of blanket aging: The effect of blanket aging and its combination with the utilization of treatment formulations from the press was examined.

[0306] 6A-6D show print images and enlarged (zoomed in) portions thereof obtained with an indirect printing process utilizing the following combinations: fresh blanket, fresh processing formulation (FIG. 6A), fresh blanket, used processing formulation (FIG. 6B), old blanket, fresh processing formulation (FIG. 6C), and old blanket, used processing formulation (FIG. 6C).

[0307] 6A-6D show that high graininess in the image indicates poor quality of the processing solution that required a refresh of the processing formulation stock on the printing press. Sometimes the refresh was insufficient to minimize the graininess in the image and a complete replacement of the processing formulation in the printing process was required.

[0308] Effect of processing compound age and temperature on image graininess: The effect of temperature and aging of the processing formulation on image quality as reflected by image graininess was examined.

[0309] Fresh treatment formulations (not used in a printing process) were used.

[0310] Three time points were determined as t=0, t=1d (1 day) and t=3d (3 days) and two temperatures were determined, namely room temperature and 50°C.

[0311] The experiment used a 2-hour aged blanket at 135°C.

[0312] Graininess - K570, 70%, QEA (K570 - black ink, 70% - percentage of black ink coverage in print, QEA - digital microscope).

[0313] FIG. 7 shows a diagram depicting the effect of treatment formulation aging (time) and temperature on graining of printed images.

[0314] As reflected in Figure 7, the time frames and temperatures investigated did not affect the graininess of the images formed.

[0315] Effects of ink contamination and filtration on image graininess: The effect of ink contamination on image graininess was tested.

[0316] Fresh treatment formulations (not used in a printing process) were used.

[0317] Three time points were determined as t=0, t=1d (1 day) and t=3d (3 days). Two temperatures were investigated: room temperature and 50°C.

[0318] The experiment used a 2-hour aged blanket at 135°C.

[0319] Graininess - K570, 70%, QEA (K570 - black ink, 70% - percentage of black ink coverage in print, QEA - digital microscope).

[0320] The ink formulations (YMCK) were dosed into the fresh processing formulation at 4% and 8% wt.

[0321] Some formulations were filtered as follows.

[0322] FIG. 8 shows a diagram illustrating the effect on graining of printed images produced at room temperature using processing formulations with ink contamination.

[0323] FIG. 9 shows a plot of the effect on graining of printed images produced at 50° C. using processing formulations with ink contamination.

[0324] 10A-10D show print images obtained with the indirect printing process utilizing fresh TF (FIG. 10A), 50° C., 3-day-old, inked TF (FIG. 10B), filtered, room temperature, inked fresh TF (FIG. 10C), and filtered, 50° C., 3-day-old, inked TF (FIG. 10D).

[0325] Figures 8, 9 and 10A-10D clearly show that ink contamination has a significant adverse effect on processing formulation properties that are essential to the printing process, as reflected in the increased graininess observed in images produced with processing formulations spiked with the ink formulation. The adverse effect of ink contamination on processing formulation properties was observed both at room temperature and at 50°C. Filtration of the contaminated processing formulation did not improve the performance of the processing formulation.

[0326] Note that over time, poor print quality was also observed with the freshly prepared (time zero) processing formulation that was dosed with the ink formulation, i.e., the adverse effect of ink contamination is immediate (Figure 8), which cannot be remedied by filtration of the contaminated processing formulation (Figure 10C).

[0327] Impact of ink contamination on PEI performance: The above results showed that while aging of the processing formulation and its temperature does not affect its performance, ink contamination strongly affects the processing formulation's ability to function, resulting in the need to refresh the processing formulation (i.e., add fresh processing formulation to the liquid reservoir that holds the processing formulation in the printing process). Sometimes the quality of the processing formulation is impaired to such an extent that its disposal is required.

[0328] The adverse effects of ink contamination cannot be counteracted by filtration of the contaminated processing formulation, which means that it is a reaction between one of the ink components and the processing formulation that affects the quality of the processing formulation.

[0329] The inventors investigated the possibility that a reduction in the amount of the chemical PEI in the treatment formulation could affect its quality. Specifically, the inventors investigated whether a reduction in the amount would adversely affect the wetting of the treatment formulation, which is necessary for its good performance.

[0330] Figures 11A-11B show images of polyethylene terephthalate (PET) slides coated with treatment formulations containing PEI (Figure 11A) and not containing PEI (Figure 11B). From Figures 11A-11B, it is clear that the coating lacking PEI is less homogeneous, indicating wetting problems (reduced wetting ability) in the absence of PEI.

[0331] The inventors have surprisingly found that PEI interacts with the binder in the ink formulation. Figure 12 shows the phase separation and precipitation observed upon addition of the ink binder Joncryl 538 BASF to a PEI solution.

[0332] Figures 13A-13D show images (left side) of PET coated with a treatment formulation containing PEI (Figure 13A), a treatment formulation not containing PEI (Figure 13B), TF contaminated with 3 day old ink at 50°C (Figure 13C), and TF contaminated with ink but containing an additional amount of PEI (Figure 13D). Figures 13A-13D further show corresponding portions (zoomed in) of printed images (right side) obtained with an indirect printing process utilizing the corresponding treatment formulations.

[0333] Figures 13A-D clearly show the importance of the presence of PEI in the treatment formulation. Its absence resulted in inhomogeneity in the coating of the ITM (e.g., wetting problems), which resulted in poor print quality (Figure 13B). A similar effect was observed in the ink-contaminated treatment formulation (Figure 13C). The inhomogeneity in the coating of the ITM was restored by simply adding PEI to the contaminated treatment formulation (Figure 13D).

[0334] Figure 14A shows a diagram depicting graining of printed images produced in an indirect printing process utilizing fresh TF, TF contaminated with ink, and TF contaminated with ink containing an additional amount of PEI, while Figure 14B shows a portion of the corresponding printed image obtained in an indirect printing process utilizing the corresponding treatment formulation.

[0335] 15A-15C show printed images produced by an indirect printing process utilizing fresh TF (FIG. 15A), ink-mixed TF (FIG. 15B), and ink-mixed TF containing an additional amount of PEI (FIG. 15C), and further show portions (zoomed in) of the corresponding printed images.

[0336] The above results show that PEI alone can be replenished to restore the performance of the treatment formulation, and that it was not necessary to replenish the treatment formulation as a whole. These results further show that the decrease in print quality was due to a decrease in the amount of PEI. This decrease was due to the reaction of PEI with the binder of the ink formulation.

[0337] Without wishing to be bound by theory, the inventors believe that the immediate phase separation and precipitation observed upon addition of the ink binder to the PEI solution (FIG. 12) may be due to the charged properties of the PEI (which has a positively charged nature) and the ink binder (which has a negatively charged nature) and due to the high molecular weight of PEI which requires its low concentration to react with the ink binder.

[0338] The above results show the importance of the presence of PEI in the treatment formulation. Even a slight decrease in its concentration in the treatment formulation affected the performance of the treatment formulation. Even a relatively small amount of ink contamination in the treatment formulation adversely affected its functionality.

[0339] The results of the aforementioned study show that ink contamination of the processing formulation has a strong negative effect on the performance of the processing formulation. The performance of the processing formulation can be restored by the addition of PEI. This addition counteracted the decrease in PEI concentration in the processing formulation, which was the result of the ink contamination causing a fast reaction between the binder of the ink formulation and the PEI. The depletion of PEI strongly affected the quality of the ITM coating and, therefore, the quality of the printed image. The findings of the aforementioned study are important and contribute to the improvement of the costs associated with the printing process, especially since the replenishment of the entire processing formulation is not necessary, but only the replenishment of PEI. Stability of print quality is obtained together with the reduction of unnecessary waste otherwise associated with the need to discard large amounts of poor quality processing formulation.

[0340] Example 4: Detection and quantification of PEI in treatment formulations To determine whether the addition of PEI was required to restore its depletion in the treatment formulation, the concentration of PEI in the treatment formulation was detected using spectroscopic means well known in the art, see for example the following link: https: / / www.sciencedirect.com / science / article / pii / S1878535213001779 https: / / www.ncbi.nlm.nih.goV / pubmed / 12560058 https: / / onlinelibrary.wiley.com / doi / abs / 10.1002 / pol.1967.150050816 https: / / www.researchgate.net / publication / 299346733_Validation_of_a_New_Method_for_Spectrophotometric_Determination_of_Polyethyleneimine

[0341] Specifically, PEI detection was performed using an assay involving reaction with copper: PEI can be detected using the addition of copper ions, resulting in blue emission from solution and strong absorbance at 285 nm (note that absorbance at 650 nm can also be utilized, but is less intense relative to that observed at 285 nm).

[0342] The inventors tested various samples of the treatment formulation. 1 ml of the sample was placed in a 3 ml bottle and 0.1 M Cu solution was added by pipette. The solution was mixed for 3 seconds using a vortex.

[0343] FIG. 16 shows a scheme illustrating the detection of PEI by the addition of copper ions to a PEI solution, which results in blue emission from the solution and strong absorbance at 285 nm.

[0344] Figures 17A-L show the color reaction observed upon titration of various fresh TF with different PEI concentrations with copper (the corresponding observed granularity values ​​are noted as numbers on the vials containing titrated TF). Figures 17A-L show that 80 μl of 0.1 M Cu was sufficient for 1 ml sample detection (no further change in color was observed above 80 μl).

[0345] Figure 18 shows the absorption spectra observed upon addition of copper to various TFs with different PEI concentrations (PEI+Cu spectra). (3 ml of sample was placed in a vial. 20 μl of 0.1 M Cu solution was added. The sample was first diluted to 0.01% and then a second dilution was performed.) The final sample was placed in a cuvette and analyzed spectrally.

[0346] FIG. 19 shows a calibration curve at 285 nm generated with treatment formulations having known PEI concentrations in the presence of copper. The calibration curve has a high R 2 brought value.

[0347] Figure 20 shows the concentrations of PEI for various TFs at two different dilutions, determined based on the calibration curve in Figure 19. Figure 20 shows that the different dilutions did not interfere with the readings.

[0348] Figure 21 shows the concentrations of PEI in various TFs with and without copper, the latter serving as a control test, determined based on the calibration curve in Figure 19. As expected, the absorption intensity observed without the addition of Cu was very low for all samples.

[0349] Figure 22 shows the correlation between the graininess of a printed image and the concentration of PEI in the TF used to generate that image. Figure 22 shows that there is a clear boundary between "good" (graininess ≤ 2.3) and "bad" (graininess ≥ 2.3). All "good samples" have a deep blue color (shown in grayscale in the figure), while others have different / lighter shades of blue (shown in grayscale in the figure).

[0350] Exemplary embodiments The following embodiments are illustrative and are not intended to limit the claimed subject matter.

[0351] EMBODIMENT 1 a liquid reservoir configured to hold a formulation, the formulation comprising a first amount of at least one depletable chemical, said first amount being substantially equal to or greater than a predetermined threshold, said formulation optionally further comprising at least one additional component; a refill reservoir configured to hold a second quantity of said at least one depletable chemical, optionally in at least one liquid carrier; detection means configured to at least identify (i) a decrease in said first amount of said depletable chemical below said predetermined threshold, and / or (ii) a decrease in the functionality of said at least one depletable chemical; a transfer means configured to transfer at least a portion of said second amount of at least one depletable chemical from said refill reservoir to said liquid reservoir once said decrease is identified, optionally said transfer means being a manual means; A system for printing, comprising:

[0352] Embodiment 2 A system according to embodiment 1, wherein said detection means is configured to measure and / or calculate said decrease.

[0353] Embodiment 3. A system according to embodiment 1 or 2, wherein said detection means is configured to record and / or report said decrease.

[0354] Embodiment 4 A system according to any one of embodiments 1 to 3, wherein said detection means are configured to activate said transport means once said degradation is identified.

[0355] Embodiment 5 A system according to any one of embodiments 1 to 4, said system further comprising a control unit configured to control the replenishment of at least one depletable chemical in a liquid reservoir, and optionally configured to activate said transfer means once said degradation is identified.

[0356] Embodiment 6 The system according to embodiment 5, further comprising communication means configured to transfer data / information between said detection means and said control unit.

[0357] Embodiment 7 A system according to any one of embodiments 1-6, wherein said transfer means is selected from a pressure-based means, a jet means, a spray means or a gravity means.

[0358] Embodiment 8 A system according to any one of embodiments 1 to 7, wherein the system further comprises at least one printing liquid reservoir configured to hold a printing liquid, the printing liquid optionally being an ink, further optionally being a water-based ink.

[0359] Embodiment 9 A system according to any one of embodiments 1 to 8, said system being for indirect printing.

[0360]

[0023] Embodiment 10. The system according to embodiment 9, said system further comprising an intermediate transfer member.

[0361] Embodiment 11 A system according to any one of embodiments 8-10, wherein the formulation is a treatment formulation configured to be applied to at least one region of a release surface of the intermediate transfer member to form a coating layer thereon.

[0362] Embodiment 12. The system according to embodiment 11, wherein a formulation is applied to the release surface before the printing liquid is applied to the release surface.

[0363] Embodiment 13 A system according to any one of embodiments 1 to 12, wherein at least one depletable chemical is present in liquid form in the refill reservoir, and the refill reservoir and the liquid reservoir are in liquid communication to enable transfer of at least a portion of the second amount of at least one depletable chemical from the refill reservoir to the liquid reservoir once the decline is identified.

[0364] Embodiment 14 A system according to embodiment 13, wherein the transfer means further comprises regulating means configured to regulate the amount of the depletable chemical transferred from the replenishment reservoir to the liquid reservoir and / or to avoid backflow of liquid from the liquid reservoir to the replenishment reservoir.

[0365] Embodiment 15. A system according to embodiment 14, wherein said regulating means comprises at least one relief valve allowing unidirectional flow of liquid from the refill reservoir to the liquid reservoir.

[0366] Embodiment 16 A system according to any one of embodiments 1 to 15, wherein the second amount of the at least one depletable chemical in the refill reservoir is greater than the first amount of the at least one depletable chemical in the liquid reservoir.

[0367] Embodiment 17 A system according to any one of embodiments 1 to 16, said system optionally further comprising a mixing means configured to mix said at least one depletable chemical in said liquid reservoir and / or in said refill reservoir.

[0368] Embodiment 18. The system according to any one of embodiments 1 to 17, wherein at least one depletable chemical in the replenishment reservoir is present in solid form.

[0369] Embodiment 19. The system according to embodiment 18, said system optionally further comprising means configured to mix, dissolve or disperse the solid depletable chemical.

[0370] Embodiment 20. The system according to embodiment 18 or 19, said system optionally further comprising heating means configured to assist in solubilizing said solid depletable chemicals.

[0371] Embodiment 21 A system according to any one of embodiments 1 to 20, wherein upon detecting / identifying the decrease, the control unit is configured to control the replenishment of the at least one depletable chemical in the liquid reservoir according to a replenishment profile selected to increase the amount of the depletable chemical in the liquid reservoir to reach a value substantially equal to or greater than the predetermined threshold value.

[0372] Embodiment 22 The system according to any one of embodiments 1 to 21, wherein said system further comprises a processing utility.

[0373] Embodiment 23 A system according to embodiment 22, wherein the processing utility is configured to, upon identifying the degradation, provide a signal indication to a user to indicate the need to replenish the at least one depletable chemical in the liquid reservoir.

[0374] Embodiment 24 A system according to any one of embodiments 1 to 23, said system optionally further comprising means for stopping the printing process and resuming the printing process once the refill is achieved / completed.

[0375] Embodiment 25 A system according to any one of embodiments 21 to 24, wherein the replenishment profile defines one or more of: the amount of at least one depletable chemical to be transferred from the replenishment reservoir to the liquid reservoir, the frequency of replenishment, the duration of transfer, the method of transfer, and the transfer rate.

[0376] Embodiment 26 The system according to any one of embodiments 21 to 25, wherein the replenishment profile is determined based on one or more of: the first amount and / or the second amount of the depletable chemical, the extent of the decline, the amount of the depletable chemical relative to the amount of the formulation or the amount of one or more other components contained in the formulation.

[0377] Embodiment 27 A system according to any one of embodiments 21 to 26, wherein the replenishment profile is defined based on one or more printing conditions.

[0378] Embodiment 28 A system according to any one of embodiments 22 to 27, wherein the processing utility is configured to process an image generated by the system and evaluate its image print quality, and if the image print quality falls below a predetermined required quality, the control unit is configured to cause replenishment of the at least one depletable chemical in the liquid reservoir.

[0379] Embodiment 29 A system according to embodiment 28, wherein the processing utility is configured to generate an output indicative of the quality of the image, and if the output falls below a predetermined threshold parameter, the control unit is configured to cause replenishment of the at least one depletable chemical in the liquid reservoir.

[0380]

[0081] Embodiment 30. The system according to embodiment 29, wherein the processing unit is configured to display the output on a visual display unit, an audio device, or a combination thereof.

[0381]

[0081] Embodiment 31: The system according to embodiment 29, wherein the predetermined threshold parameter comprises a substantially distinct value or range of values ​​representative of a desired quality of the printed image.

[0382] Embodiment 32 A system according to any one of embodiments 29 to 31, wherein if the output falls below a predetermined threshold parameter, the system is optionally configured to immediately warn a user to stop the printing process or to automatically stop, and optionally to resume the printing process once refilling of depletable chemicals in the liquid reservoir is completed.

[0383] Embodiment 33 A system according to any one of embodiments 29 to 32, wherein the output reflects a value indicative of the graininess of an image.

[0384] Embodiment 34 The system according to any one of embodiments 1 to 33, further comprising a user interface.

[0385]

[0081] Embodiment 35: A system according to embodiment 34, wherein the user interface is for enabling a user to input one or more desired printing conditions for a printing process into a processing utility.

[0386] Embodiment 37 A system according to any one of embodiments 1 to 35, further comprising a memory.

[0387]

[0082] Embodiment 38: A system according to embodiment 36, wherein the memory includes a database of predetermined threshold parameter(s) of image quality of the printing process.

[0388]

[0081] Embodiment 39. The system according to embodiment 36 or 37, wherein the processing utility is configured to correlate image quality predetermined threshold parameters from the database with the output.

[0389] Embodiment 40. The system according to any one of embodiments 1 to 38, wherein said system further comprises means for recording a replenishment history.

[0390] Embodiment 41 A system according to any one of embodiments 1 to 39, wherein the detection means is selected from visual means, spectroscopic means, spectrophotometric means, electronic means, chemical means, physical means, print quality based means or any combination thereof.

[0391] Embodiment 42 A system according to embodiment 40, wherein the means is configured to detect / measure an amount of the at least one depletable chemical in the liquid reservoir, and the system is configured to calculate a decrease in the first amount of the at least one depletable chemical based on the detected / measured amount.

[0392] Embodiment 43. The system according to any one of embodiments 1 to 41, wherein said system further comprises a sampling unit configured to withdraw an aliquot of the formulation from said liquid reservoir for further analysis.

[0393] Embodiment 44. The system according to embodiment 42, wherein the sampling unit is configured to withdraw an aliquot of formulation from the liquid reservoir on demand and / or at predetermined time intervals and / or after a predetermined number of printing cycles.

[0394] Embodiment 45 The system according to any one of embodiments 1 to 43, wherein said reduction in the first amount of said depletable chemical is relative to an amount of one or more other components of the formulation.

[0395] Embodiment 46 The system according to any one of embodiments 1 to 44, wherein the decrease in the first amount of the depletable chemical occurs due to an undesirable side reaction of the depletable chemical.

[0396] Embodiment 47 A system according to embodiment 45, wherein the undesired side reaction of the depletable chemical results in the formation of undesired by-products in the liquid reservoir, and the system optionally further comprises means configured to remove the by-products.

[0397] Embodiment 48. The system according to embodiment 46, wherein said system further comprises means for detecting the formation of said undesired by-products and, optionally, measuring / determining their amount in said liquid reservoir.

[0398] Embodiment 49. The system according to embodiment 47, further comprising means configured to correlate the detected formation of the undesired by-product with a decrease in the first amount of the depletable chemical.

[0399] Embodiment 50. The system according to any one of embodiments 1 to 48, wherein the decrease in the first amount of the depletable chemical is due to contamination of a formulation in a liquid reservoir with at least one contaminant, and the formation of at least one undesirable by-product is due to an interaction of the at least one depletable chemical with the at least one contaminant.

[0400] Embodiment 51 A system according to any one of embodiments 1 to 49, wherein the system further comprises at least one printing liquid reservoir configured to hold a printing liquid, optionally the printing liquid being ink, and wherein the decrease in the first amount of the depletable chemical is due to printing liquid contamination in a liquid reservoir.

[0401] Embodiment 52. The system according to embodiment 50, wherein the printing liquid is an ink and comprises at least one binder and at least one colorant, and the decrease in the first amount of the depletable chemical is due to an undesirable side reaction of the depletable chemical with the at least one binder.

[0402] Embodiment 53. The system according to any one of embodiments 1 to 51, wherein the system further comprises a protection unit configured to protect the liquid reservoir from contamination, for example ink contamination.

[0403] Embodiment 54 A system according to any one of embodiments 1 to 52, wherein the system optionally further comprises a measuring means configured to measure the volume of liquid in the liquid reservoir, and if the measured volume is below a predetermined minimum volume, the system is configured to indicate to a user to refill the liquid reservoir with an additional amount of the liquid formulation.

[0404] Embodiment 55 A system according to any one of embodiments 1 to 53, wherein the system optionally further comprises a measuring means configured to measure the amount (e.g. volume / liquid or weight / solid) of the chemical that may be depleted in the refill reservoir, and if the measured amount is below a predetermined minimum amount, the control unit is configured to indicate to a user to refill the refill reservoir with an additional amount of the chemical that may be depleted.

[0405] Embodiment 56 A system according to any one of embodiments 1 to 54, wherein the depletable chemical agent is a polymeric agent that contains amine nitrogen atoms in multiple functional groups that can be bonded, not necessarily the same.

[0406] Embodiment 57 The system according to embodiment 55, wherein the polymer has a relatively high charge density.

[0407] Embodiment 58 The system according to embodiment 55 or 56, wherein the polymer has a molecular weight of 10,000 g / mol or more.

[0408] Embodiment 59 A system according to any one of embodiments 1 to 57, wherein the depletable chemical agent is a polymeric agent having one or more of: (a) a positive charge density of the agent of at least 3 meq / g and an average molecular weight of at least 5,000; (b) a positive charge density of the agent of at least 6 meq / g and an average molecular weight of at least 1,000; (c) a nitrogen content of at least 1 wt.% and an average molecular weight of at least 50,000; and (d) a nitrogen content of at least 18 wt.% and an average molecular weight of at least 10,000.

[0409] Embodiment 60 The system according to any one of embodiments 1 to 58, wherein the depletable chemical agent is a polymeric agent having a positive charge density.

[0410] Embodiment 61 The system according to embodiment 59, wherein the positive charge density is at least 0.5 meq / g, at least 1 meq / g, at least 2 meq / g, at least 3 meq / g, at least 4 meq / g, at least 5 meq / g, at least 6 meq / g, at least 7 meq / g, at least 8 meq / g, at least 9 meq / g, at least 10 meq / g, at least 11 meq / g, at least 12 meq / g, at least 13 meq / g, at least 14 meq / g, at least 15 meq / g, at least 16 meq / g, at least 17 meq / g, at least 18 meq / g, at least 19 meq / g, or at least 20 meq / g of the agent.

[0411] Embodiment 61 The system according to any one of embodiments 1 to 60, wherein the depletable chemical agent is a polymeric agent having an average molecular weight of at least 500, at least 800, at least 1,000, at least 1,300, at least 1,700, at least 2,000, at least 2,500, at least 3,000, at least 3,500, at least 4,000, at least 4,500, at least 5,000, at least 10,000, at least 15,000, at least 20,000, at least 25,000, at least 50,000, at least 100,000, at least 150,000, at least 200,000, at least 250,000, at least 500,000, at least 750,000, at least 1,000,000, or at least 2,000,000.

[0412] Embodiment 62 The system according to any one of embodiments 1 to 61, wherein the depletable chemical agent is a polymeric agent having an average molecular weight of at least 2,000, at least 10,000, or at least 25,000.

[0413] Embodiment 63. The system according to any one of embodiments 1 to 62, wherein the depletable chemical agent contains one or more positively charged nitrogen atoms.

[0414] Embodiment 64 The system according to embodiment 63, wherein the one or more nitrogen atoms constitute at least 1%, at least 1.4%, at least 2%, at least 5%, at least 8%, at least 10%, at least 15%, at least 18%, at least 20%, at least 24%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% by weight of the depletable chemical.

[0415] Embodiment 65 The system according to any one of embodiments 1 to 64, wherein the depletable chemical is poly(diallyldimethylammonium chloride) [ [ka] It is a polymeric agent containing units.

[0416] Embodiment 66. The system according to any one of embodiments 1 to 64, wherein the depletable chemical is polyallylamine [ [ka] It is a polymeric agent containing units.

[0417] Embodiment 67 The system according to any one of embodiments 1 to 64, wherein the depletable chemical is poly(4-vinylpyridine) [ [ka] It is a polymeric agent containing units.

[0418] Embodiment 68: The system according to any one of embodiments 1 to 67, wherein the depletable chemical polymer agent is selected from the group consisting of linear polyethyleneimine, branched polyethyleneimine, modified polyethyleneimine, poly(diallyldimethylammonium chloride), poly(4-vinylpyridine), polyallylamine, vinylpyrrolidone-dimethylaminopropyl methacrylamide copolymer (ViViprint 131), vinylcaprolactam-dimethylaminopropyl methacrylamide hydroxyethyl methacrylate copolymer (ViViprint 200), quaternized copolymer of vinylpyrrolidone and dimethylaminoethyl methacrylate with diethyl sulfate (ViViprint 650), guar hydroxypropyltrimonium chloride, and hydroxypropyl guar hydroxypropyltrimonium chloride.

[0419] Embodiment 69 The system according to embodiment 68, wherein the depletable chemical polymer agent is polyethyleneimine (PEI).

[0420] Embodiment 70 A system according to any one of embodiments 1 to 69, wherein the first amount of the depletable chemical polymer agent in the formulation in the liquid reservoir is less than or equal to about 5 wt.%, 4 wt.%, 3 wt.%, 2 wt.%, 1 wt.%, 0.5 wt.%, 0.4 wt.%, 0.3 wt.%, 0.2 wt.%, 0.1 wt.%, or is equal to or at least about 0.05 wt.%, or sometimes at least about 0.01%.

[0421] Embodiment 71 A system according to any one of embodiments 1 to 70, wherein the depletable chemical agent is a polymeric agent that is PEI, and the predetermined threshold is at least 0.01 wt.%, at least 0.05 wt.%, at least 0.10 wt.%, at least 0.15 wt.% or at least 0.20 wt.%.

[0422] Embodiment 72 A system according to any one of embodiments 1 to 71, wherein the depletable chemical agent is a polymeric agent that is PEI, and the first amount thereof in the liquid reservoir is at a concentration by weight of up to 6%, up to 5%, up to 4%, up to 3%, up to 2.5%, or up to 2.0%.

[0423] Embodiment 73. The system according to any one of embodiments 1 to 72, wherein the depletable chemical agent is a polymeric agent that is PEI, and said first amount thereof in the liquid reservoir is at a concentration by weight in the range of 0.01 to 1%, 0.01 to 0.8%, 0.01 to 0.7%, 0.01 to 0.6%, 0.01 to 0.5%, 0.2 to 0.7%, 0.2 to 0.6%, or 0.2 to 0.5%.

[0424] Embodiment 74 A system according to any one of embodiments 1 to 73, wherein the at least one depletable chemical is PEI, a first amount thereof in the formulation in the liquid reservoir is 0.25 wt.%, and a second amount thereof in the replenishment reservoir is 25 wt.% in water.

[0425] Embodiment 75 A system according to embodiment 74, wherein when the first amount of PEI in the liquid reservoir falls below a predetermined threshold of 0.01 wt.%, the system is configured to transfer a portion of the second amount of PEI from the replenishment reservoir to the liquid reservoir, thereby replenishing the amount of PEI in the liquid reservoir to a value equal to or exceeding the predetermined threshold (0.01 wt.%) or replenishing the amount of PEI in the liquid reservoir to a value equal to the first amount (0.25 wt.%).

[0426] Embodiment 76 The system according to any one of embodiments 1 to 75, wherein the depletable chemical agent is a polymeric agent that is PEI, having an average molecular weight of at least 20,000, at least 50,000, at least 100,000, at least 200,000, at least 350,000, at least 500,000, at least 700,000, at least 750,000, and optionally up to 3,000,000, up to 2,500,000, or up to 2,000,000.

[0427] Embodiment 77 The system according to any one of embodiments 1 to 76, wherein the depletable chemical agent is a polymeric agent that is PEI, said PEI being a surfactant, a wetting agent, a fixative, or any combination thereof.

[0428] Embodiment 78 The system according to any one of embodiments 1 to 77, wherein the depletable chemical agent is a polymeric agent that is PEI, and the charge density of the PEI polymer is in the range of 16 to 20 meq / g of material.

[0429] Embodiment 79 The system according to any one of embodiments 1 to 77, wherein the depletable chemical agent is a polymeric agent that is PEI, and the charge density of the PEI polymer is 8 meq / g.

[0430] Embodiment 80 The system according to any one of embodiments 1 to 79, wherein the depletable chemical is a silicon-functionalized PEI.

[0431] Embodiment 81 The system according to any one of embodiments 1 to 80, wherein the depletable chemical is a quaternary ammonium compound.

[0432] Embodiment 82 The system according to embodiment 81, wherein the quaternary ammonium compound is Larostat 264A (BASF).

[0433] Embodiment 83 The system according to embodiment 81, wherein the quaternary ammonium compound is Foamquat SAQ (linoleamidopropylethyldimonium ethosulfate 90).

[0434] Embodiment 84 The system according to any one of embodiments 1 to 83, wherein the depletable chemical is water dispersible.

[0435] Embodiment 85 The system according to any one of embodiments 1 to 83, wherein the depletable chemical is water soluble.

[0436] Embodiment 86 The system according to any one of embodiments 1 to 85, wherein the depletable chemical is a solid at room temperature.

[0437] Embodiment 87 The system according to any one of embodiments 51 to 86, wherein at least one binder in the ink is an anionic binder.

[0438] Embodiment 88. The system according to embodiment 87, wherein the anionic binder is an acrylic binder and / or a sulfone binder.

[0439] Embodiment 89 The system according to any one of embodiments 51 to 88, wherein at least one binder in the ink is a negatively charged organic polymer resin.

[0440] Embodiment 90 The system according to embodiment 89, wherein the negatively charged organic polymer resin has an average molecular weight of at least 8,000.

[0441] Embodiment 91 The system according to embodiment 89 or 90, wherein at least one binder in the ink is an acrylic polymer and / or an acrylic-styrene copolymer.

[0442] Embodiment 92 The system according to any one of embodiments 51 to 91, wherein the binder is Joncryl 538 BASF.

[0443] Embodiment 93 The system according to any one of embodiments 51 to 92, wherein the depletable chemical is PEI, and the decrease in the first amount of PEI is due to its undesirable side reaction with the at least one binder.

[0444] Embodiment 94. A system according to any one of embodiments 1 to 93, wherein the system further comprises means for detecting, measuring or calculating a concentration of a depletable chemical in the formulation contained in the liquid reservoir and calculating therefrom a reduction in the first amount of the depletable chemical.

[0445] Embodiment 95 The system according to embodiment 94, wherein the depletable chemical is PEI.

[0446] Embodiment 96. The system according to embodiment 94, wherein said means is a spectroscopic means configured to detect PEI based on a reaction of copper with PEI.

[0447] Embodiment 97 A system according to any one of embodiments 1 to 96, wherein the printing system is an indirect printing system, i. an intermediate transfer member (ITM) comprising a release layer surface; ii. a treatment station including a liquid reservoir configured to hold an aqueous treatment formulation as disclosed herein, the treatment station being configured to apply the aqueous treatment formulation to a release layer surface of the ITM to form a treatment layer thereon; iii. a refill unit comprising a refill reservoir as disclosed herein; iV. an imaging station configured to apply a printing fluid to form an image on the aqueous treatment formulation formed on the intermediate transfer member; V. A transfer station for transferring an image onto a print substrate, e.g., by pressure contact between the ITM and the print substrate. Further includes:

[0448]

[0082] Embodiment 98. The system according to embodiment 97, wherein the printing liquid is an ink, optionally applied by jetting, the system further comprising: a drying station configured to at least partially dry the ink on the aqueous treatment formulation formed on the intermediate transfer member to produce an ink image residue, and optionally drying means for drying the aqueous treatment formulation. Further includes:

[0449] Embodiment 99. The system according to any one of embodiments 11 to 98, wherein the treatment formulation comprises: at least one water soluble polymer, At least one particulate material selected from: (i) at least one thermoplastic polymer particulate material, optionally in the form of an emulsion and / or dispersion; (ii) at least one thermosetting polymer particulate material, optionally in the form of a dispersion and / or emulsion; or (iii) a combination thereof; A carrier liquid comprising water, and Optionally, one or more of: (a) at least one water retention agent; (b) at least one surfactant; and (c) at least one wetting agent. Includes.

[0450] Embodiment 100. The system according to embodiment 99, wherein the treatment formulation further comprises at least one wetting agent.

[0451] Embodiment 101 The system according to embodiment 100, wherein the wetting agent is PEI.

[0452] Embodiment 102 The system according to embodiment 99, wherein said water-soluble polymer is at least one modified polysaccharide.

[0453] Embodiment 103. The system according to embodiment 102, wherein said modified polysaccharide is selected from cellulose derivatives, cellulose ethers, methylcellulose, hydroxypropylmethylcellulose or any combination thereof.

[0454] Embodiment 104. The system according to embodiment 103, wherein said modified polysaccharide is hydroxypropyl methylcellulose.

[0455] Embodiment 105. The system according to any of the embodiments 1 to 104, wherein said treatment formulation is as disclosed and exemplified herein.

[0456]

[0081] Embodiment 106. A method for preventing or minimizing print defects in a printing process, the print defects being associated with a decrease in a first amount of at least one depletable chemical contained in an aqueous formulation, optionally in a liquid carrier, the method comprising: Identifying / detecting a decrease in the first amount of the at least one depletable chemical below a predetermined threshold and / or a decrease relative to the amount of at least another component in the formulation; Upon identifying / detecting said degradation, adding at least a portion of a second amount of at least one depletable chemical to the formulation, said at least a portion of the second amount being sufficient to restore a first amount of the depletable chemical in said liquid formulation substantially to or above said predetermined threshold, and / or said at least a portion of the second amount being sufficient to counteract a degradation of the first amount relative to an amount of at least another component in the formulation, thereby preventing or minimizing said print defects. Includes.

[0457] Embodiment 107 The method according to embodiment 106, wherein the second amount of the at least one depletable chemical is provided in liquid form.

[0458] Embodiment 108 The method according to embodiment 106, wherein the second amount of the at least one depletable chemical is provided in a solid form.

[0459] Embodiment 109 The method according to any one of embodiments 106 to 108, wherein the method further comprises mixing at least a portion of a second amount of at least one depletable chemical agent into the liquid formulation.

[0460] Embodiment 110 The method according to embodiment 108, further comprising dissolving or dispersing the solid depletable chemical in at least one liquid carrier (which may be the same as or different from the liquid carrier of the formulation).

[0461] Embodiment 111 The method according to embodiment 110, further comprising heating the solid depletable chemical, thereby assisting it in dissolving.

[0462]

[0081] Embodiment 112. The method according to any one of embodiments 106 to 111, wherein the liquid formulation is configured to be applied onto a substrate onto which an image is to be printed, or onto an intermediate transfer member in an indirect printing process.

[0463] Embodiment 113. The method according to any one of embodiments 106 to 112, comprising: i. providing an intermediate transfer member (ITM); ii. providing a treatment formulation; iii. applying a treatment formulation to an image receiving surface of the ITM to form a wet treatment layer; iV. at least partially drying the wet treatment layer to form an at least partially dry treatment layer; V. applying a printing fluid to the at least partially dried treatment layer to form an image; Vi. Transferring an image to a printing substrate by pressurized contact between said surface of the ITM and the printing substrate. Further includes:

[0464]

[0082] Embodiment 114. The method according to embodiment 113, wherein the printing liquid is an ink, optionally an aqueous ink, the method comprising the steps of: applying ink droplets onto the at least partially dried treatment layer to form an ink image; and at least partially drying the wet ink image on the aqueous treatment layer to form a partially dried ink image film that is transferred to a print substrate. Further includes:

[0465] Embodiment 115 A method according to any one of embodiments 106 to 114, wherein the addition of at least a portion of the second amount of at least one depletable chemical is carried out according to a predetermined replenishment profile selected to increase the amount of the depletable chemical in the liquid formulation to a value substantially equal to or greater than a predetermined threshold value.

[0466] Embodiment 116 A method according to any one of embodiments 106 to 115, the method further comprising identifying a decrease in the first amount of the at least one depletable chemical relative to an amount of at least another component in the formulation and providing a signal indication indicating the need to add the at least one depletable chemical to the liquid formulation, thereby restoring the first amount of the depletable chemical in the liquid formulation to substantially equal to or greater than the predetermined threshold, thus counteracting the decrease.

[0467]

[0071] Embodiment 117: The method according to embodiment 116, wherein the replenishment profile is a predetermined profile determined based on one or more of the printing conditions.

[0468] Embodiment 118 A method according to any one of embodiments 106 to 117, wherein the method further comprises processing an image produced by the method and evaluating its image print quality, and if the image print quality falls below a predetermined required quality, the method comprises adding at least a portion of the second amount of the at least one depletable chemical to the liquid formulation.

[0469] Embodiment 119 A method according to embodiment 118, the method comprising generating an output indicative of a quality of the image, and if the output is below a predetermined threshold parameter, the method comprises adding the second amount of the at least one depletable chemical to at least a portion of the liquid formulation.

[0470]

[0071] Embodiment 120. The method according to embodiment 119, wherein the method includes displaying the output on a visual display unit, an audio device, or a combination thereof.

[0471]

[0081] Embodiment 121: The method according to embodiment 119 or 120, wherein the output reflects a value indicative of the graininess of an image.

[0472]

[0081] Embodiment 122: The method according to embodiment 119, wherein the predetermined threshold parameter comprises a substantially distinct value or range of values ​​that represents a desired quality of the printed image.

[0473] Embodiment 123 The method according to any one of embodiments 106 to 122, further comprising identifying a decrease in the first amount of the at least one depletable chemical below a predetermined threshold, wherein the identifying is achieved by a detection means selected from visual means, spectroscopic means, spectrophotometric means, electronic means, chemical means, physical means, print quality based means or any combination thereof, and the method further comprises calculating a decrease in the first amount of the at least one depletable chemical relative to an amount of another one or more ingredients in the formulation based on the identified decrease in the first amount of the at least one depletable chemical.

[0474] Embodiment 124 The method according to any one of embodiments 106 to 123, further comprising sampling an aliquot of the liquid formulation for analysis.

[0475] Embodiment 125 The method according to embodiment 124, wherein the sampling is performed on demand and / or at predetermined time intervals and / or after a predetermined number of printing cycles.

[0476] Embodiment 126 The method according to any one of embodiments 106 to 125, wherein the reduction in the first amount of the depletable chemical is relative to the amount of one or more other components contained in the formulation.

[0477] Embodiment 127 The method according to any one of embodiments 106 to 126, wherein the decrease in the first amount of the depletable chemical is due to an undesired side reaction of the depletable chemical.

[0478] Embodiment 128 The method according to embodiment 127, wherein the undesired side reaction of depletable chemicals results in the formation of undesired by-products in the liquid formulation.

[0479] Embodiment 129 The method according to embodiment 128, wherein said method further comprises detecting the formation of said undesired by-products and optionally measuring / determining their amount in said liquid formulation.

[0480] Embodiment 130. The method according to embodiment 129, wherein the method further comprises correlating the detected formation of the undesired by-product with a decrease in a first amount of a depletable chemical.

[0481] Embodiment 131 The method according to any one of embodiments 106 to 130, wherein the decrease in the first amount of the depletable chemical is due to contamination of the liquid formulation with at least one contaminant, and the formation of at least one undesirable by-product is due to an interaction of the at least one depletable chemical with the at least one contaminant.

[0482]

[0081] Embodiment 132. The method according to any one of embodiments 106 to 131, wherein the decrease in the first amount of the depletable chemical is due to ink contamination in a liquid formulation.

[0483]

[0081] Embodiment 133. The method according to embodiment 132, wherein the ink contamination results from one or more of ink spillage, ink splashing, and a recirculation process of the treatment formulation.

[0484] Embodiment 134 The method according to any one of embodiments 114 to 133, wherein the ink comprises at least one binder and at least one colorant, and the decrease in the first amount of the depletable chemical is due to an undesired side reaction of the depletable chemical with the at least one binder.

[0485] Embodiment 135 The method according to any one of embodiments 106 to 134, wherein the method further comprises protecting the liquid formulation from contamination.

[0486] Embodiment 136 The method according to any one of embodiments 128 to 135, wherein the method further comprises removing the by-products from the liquid formulation.

[0487] Embodiment 137 A method according to any one of embodiments 106 to 136, wherein the method further comprises measuring a volume of the liquid formulation, and if the measured volume is below a predetermined minimum volume, the method further comprises refilling the liquid formulation with liquid formulation until it is substantially equal to or greater than the predetermined minimum volume.

[0488] Embodiment 138 The method according to any one of embodiments 106 to 137, wherein the depletable chemical agent is a polymeric agent that contains amine nitrogen atoms in multiple functional groups that can be bonded, not necessarily the same.

[0489] Embodiment 139 The method according to embodiment 138, wherein the polymer has a relatively high charge density.

[0490] Embodiment 140 The method according to embodiment 138 or 139, wherein the polymer has a molecular weight of 10,000 g / mol or more.

[0491] Embodiment 141 The method according to any one of embodiments 106 to 140, wherein the depletable chemical agent is a polymeric agent having one or more of: (a) a positive charge density of the agent of at least 3 meq / g and an average molecular weight of at least 5,000; (b) a positive charge density of the agent of at least 6 meq / g and an average molecular weight of at least 1,000; (c) a nitrogen content of at least 1 wt.% and an average molecular weight of at least 50,000; and (d) a nitrogen content of at least 18 wt.% and an average molecular weight of at least 10,000.

[0492] Embodiment 142 The method according to any one of embodiments 106 to 141, wherein the depletable chemical agent is a polymeric agent having a positive charge density.

[0493] Embodiment 143 The method according to embodiment 142, wherein the positive charge density is at least 0.5 meq / g, at least 1 meq / g, at least 2 meq / g, at least 3 meq / g, at least 4 meq / g, at least 5 meq / g, at least 6 meq / g, at least 7 meq / g, at least 8 meq / g, at least 9 meq / g, at least 10 meq / g, at least 11 meq / g, at least 12 meq / g, at least 13 meq / g, at least 14 meq / g, at least 15 meq / g, at least 16 meq / g, at least 17 meq / g, at least 18 meq / g, at least 19 meq / g, or at least 20 meq / g of the agent.

[0494] Embodiment 144 The method according to any one of embodiments 106 to 143, wherein the depletable chemical agent is a polymeric agent having an average molecular weight of at least 500, at least 800, at least 1,000, at least 1,300, at least 1,700, at least 2,000, at least 2,500, at least 3,000, at least 3,500, at least 4,000, at least 4,500, at least 5,000, at least 10,000, at least 15,000, at least 20,000, at least 25,000, at least 50,000, at least 100,000, at least 150,000, at least 200,000, at least 250,000, at least 500,000, at least 750,000, at least 1,000,000, or at least 2,000,000.

[0495] Embodiment 145 The method according to any one of embodiments 106 to 144, wherein the depletable chemical agent is a polymeric agent having an average molecular weight of at least 2,000, at least 10,000, or at least 25,000.

[0496] Embodiment 146 The method according to any one of embodiments 106 to 145, wherein the depletable chemical agent contains one or more positively charged nitrogen atoms.

[0497] Embodiment 147 The method according to embodiment 146, wherein the one or more nitrogen atoms constitute at least 1%, at least 1.4%, at least 2%, at least 5%, at least 8%, at least 10%, at least 15%, at least 18%, at least 20%, at least 24%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% by weight of the depletable chemical.

[0498] Embodiment 148 The method according to any one of embodiments 106 to 147, wherein the depletable chemical is poly(diallyldimethylammonium chloride) [ [ka] It is a polymeric agent containing units.

[0499] Embodiment 149 The method according to any one of embodiments 106 to 147, wherein the depletable chemical is polyallylamine [ [ka] It is a polymeric agent containing units.

[0500] Embodiment 150 The method according to any one of embodiments 106 to 147, wherein the depletable chemical is poly(4-vinylpyridine) [ [ka] It is a polymeric agent containing units.

[0501] Embodiment 151 The method according to any one of embodiments 106 to 147, wherein the depletable chemical polymeric agent is selected from the group consisting of linear polyethyleneimine, branched polyethyleneimine, modified polyethyleneimine, poly(diallyldimethylammonium chloride), poly(4-vinylpyridine), polyallylamine, vinylpyrrolidone-dimethylaminopropyl methacrylamide copolymer (ViViprint 131), vinylcaprolactam-dimethylaminopropyl methacrylamide hydroxyethyl methacrylate copolymer (ViViprint 200), quaternized copolymer of vinylpyrrolidone and dimethylaminoethyl methacrylate with diethyl sulfate (ViViprint 650), guar hydroxypropyltrimonium chloride, and hydroxypropyl guar hydroxypropyltrimonium chloride.

[0502] Embodiment 152 The method according to embodiment 151, wherein the depletable chemical polymeric agent is polyethyleneimine (PEI).

[0503] Embodiment 153 A method according to any one of embodiments 106 to 152, wherein the first amount of the depletable chemical polymer agent in the formulation in the liquid reservoir is less than or equal to about 5 wt.%, 4 wt.%, 3 wt.%, 2 wt.%, 1 wt.%, 0.5 wt.%, 0.4 wt.%, 0.3 wt.%, 0.2 wt.%, 0.1 wt.%, or is equal to or at least about 0.05 wt.%, or sometimes at least about 0.01%.

[0504] Embodiment 154 A method according to any one of embodiments 106 to 153, wherein the depletable chemical agent is a polymeric agent that is PEI, and the predetermined threshold is at least 0.01 wt.%, at least 0.05 wt.%, at least 0.10 wt.%, at least 0.15 wt.% or at least 0.20 wt.%.

[0505] Embodiment 155 The method according to any one of embodiments 106 to 154, wherein the depletable chemical agent is a polymeric agent that is PEI, and its first amount by weight in the liquid formulation is up to 6%, up to 5%, up to 4%, up to 3%, up to 2.5%, up to 2.0%.

[0506] Embodiment 156 The method according to any one of embodiments 106 to 155, wherein the depletable chemical agent is a polymeric agent that is PEI, and said first amount by weight thereof in the liquid formulation is in the range of 0.01 to 1%, 0.01 to 0.8%, 0.01 to 0.7%, 0.01 to 0.6%, 0.01 to 0.5%, 0.2 to 0.7%, 0.2 to 0.6%, or 0.2 to 0.5%.

[0507] Embodiment 157 A method according to any one of embodiments 106 to 156, wherein the at least one depletable chemical is PEI, a first amount thereof in the formulation in the liquid reservoir is 0.25 wt.%, and a second amount thereof in the replenishment reservoir is 25 wt.% in water.

[0508] Embodiment 158 ​​A method according to embodiment 157, wherein when the first amount of PEI in the liquid formulation falls below a predetermined threshold of 0.01 wt.%, a portion of the second amount of PEI is added to the liquid formulation, thereby replenishing the amount of PEI in the liquid formulation to a value equal to or exceeding the predetermined threshold (0.01 wt.) or replenishing the amount of PEI in the liquid formulation to a value equal to the first amount (0.25 wt.%).

[0509] Embodiment 159 The method according to any one of embodiments 106 to 158, wherein the depletable chemical agent is a polymeric agent that is PEI, having an average molecular weight of at least 20,000, at least 50,000, at least 100,000, at least 200,000, at least 350,000, at least 500,000, at least 700,000, at least 750,000 and optionally up to 3,000,000, up to 2,500,000, or up to 2,000,000.

[0510] Embodiment 160 The method according to any one of embodiments 106 to 159, wherein the depletable chemical agent is a polymeric agent that is PEI, said PEI being a surfactant, a wetting agent, a fixative, or any combination thereof.

[0511] Embodiment 161 The method according to any one of embodiments 106 to 160, wherein the depletable chemical agent is a polymeric agent that is PEI, and the charge density of the PEI polymer is in the range of 16 to 20 meq / g of material.

[0512] Embodiment 162 The method according to any one of embodiments 106 to 160, wherein the depletable chemical agent is a polymeric agent that is PEI, and the charge density of the PEI polymer is 8 meq / g.

[0513] Embodiment 163 The method according to any one of embodiments 106 to 162, wherein the depletable chemical is a silicon-functionalized PEI.

[0514] Embodiment 164 The method according to any one of embodiments 106 to 163, wherein the depletable chemical is a quaternary ammonium compound.

[0515] Embodiment 165 The method according to embodiment 164, wherein the quaternary ammonium compound is Larostat 264A (BASF).

[0516] Embodiment 166 The method according to embodiment 164, wherein the quaternary ammonium compound is Foamquat SAQ (linoleamidopropylethyldimonium ethosulfate 90).

[0517] Embodiment 167 The method according to any one of embodiments 106 to 166, wherein the depletable chemical is water dispersible.

[0518] Embodiment 168 The method according to any one of embodiments 106 to 166, wherein the depletable chemical is water soluble.

[0519] Embodiment 169 The method according to any one of embodiments 106 to 168, wherein the depletable chemical is a solid at room temperature.

[0520]

[0081] Embodiment 170 The method according to any one of embodiments 134 to 169, wherein at least one binder in the ink formulation is a negatively charged organic polymer resin.

[0521] Embodiment 171 The method according to embodiment 170, wherein the negatively charged organic polymer resin has an average molecular weight of at least 8,000.

[0522] Embodiment 172 The method according to embodiment 170 or 171, wherein at least one binder in the ink formulation is an acrylic polymer and / or an acrylic-styrene copolymer.

[0523] Embodiment 173 The method according to embodiment 170, wherein the binder is Joncryl 538 BASF.

[0524] Embodiment 174 The method according to any one of embodiments 106 to 173, wherein the depletable chemical is PEI, and the decrease in the first amount of PEI is due to its undesirable side reaction with the at least one binder.

[0525] Embodiment 175 The method according to any one of embodiments 106 to 174, wherein the method further comprises detecting and / or measuring and / or calculating a concentration of a depletable chemical in the liquid formulation and calculating therefrom a reduction in the first amount of the depletable chemical.

[0526] Embodiment 176 The method according to embodiment 175, wherein the depletable chemical is PEI and said detection and / or measurement and / or calculation is carried out by spectroscopic means exploiting the reaction of copper with said PEI.

[0527] Embodiment 177 The method according to any one of embodiments 106 to 176, wherein the treatment formulation comprises: at least one water soluble polymer, At least one particulate material selected from: (i) at least one thermoplastic polymer particulate material, optionally in the form of an emulsion and / or dispersion; (ii) at least one thermosetting polymer particulate material, optionally in the form of a dispersion and / or emulsion; or (iii) a combination thereof; A carrier liquid comprising water, and Optionally, one or more of: (a) at least one water retention agent; (b) at least one surfactant; and (c) at least one wetting agent. Includes.

[0528] Embodiment 178 The method according to embodiment 177, wherein the treatment formulation further comprises at least one wetting agent.

[0529] Embodiment 179 The method according to embodiment 178, wherein the wetting agent is PEI.

[0530] Embodiment 180 The method according to embodiment 177, wherein said water-soluble polymer is at least one modified polysaccharide.

[0531] Embodiment 181 The method according to embodiment 180, wherein the modified polysaccharide is selected from a cellulose derivative, a cellulose ether, a methylcellulose, a hydroxypropylmethylcellulose, or any combination thereof.

[0532] Embodiment 182. The method according to embodiment 181, wherein the modified polysaccharide is hydroxypropyl methylcellulose.

[0533] Embodiment 183 The method according to any of embodiments 1 to 182, wherein the treatment formulation is as disclosed and exemplified herein.

Claims

1. 1. A system for printing, comprising: a liquid reservoir configured to hold a formulation, the formulation including a first amount of at least one depletable chemical, the first amount being substantially equal to or greater than a predetermined threshold; a refill reservoir configured to hold a second amount of the at least one depletable chemical; detection means configured to at least identify (i) a decrease in the first amount of the depletable chemical below the predetermined threshold, and / or (ii) a decrease in the functionality of the at least one depletable chemical, the decrease occurring due to an undesired side reaction of the at least one depletable chemical; a transfer means configured to transfer at least a portion of the second amount of the at least one depletable chemical from the replenishment reservoir to the liquid reservoir once the degradation is identified; A system comprising:

2. The system of claim 1 , wherein the refill reservoir is configured to hold a second quantity of the at least one depletable chemical in at least one liquid carrier.

3. The system further comprises a control unit configured to control the replenishment of the at least one depletable chemical in the liquid reservoir.

3. A system according to claim 1 or 2.

4. The system of any one of claims 1 to 3, further comprising at least one printing liquid reservoir configured to hold a printing liquid.

5. The system of claim 4 , wherein the printing liquid is ink or a water-based ink.

6. The system is for indirect printing and further comprises an intermediate transfer member; the formulation is a treatment formulation configured to be applied to at least one region of the release surface of the intermediate transfer member to form a coating layer thereon; The formulation is applied to the release surface before a printing liquid is applied to the release surface. A system according to any one of claims 1 to 5.

7. a) comprising a control unit configured to activate the transfer means upon identification of (i) a drop in the first amount of the depletable chemical below the predetermined threshold, and / or (ii) a drop in the functionality of the at least one depletable chemical; b) further comprising communication means configured to transfer data / information between said detection means and said control unit; and c) upon detecting / identifying said decrease, said control unit is configured to control the replenishment of said at least one depletable chemical in said liquid reservoir according to a replenishment profile selected to increase said amount of said depletable chemical in said liquid reservoir to reach a value substantially equal to or greater than said predetermined threshold value; characterized by at least one of A system according to any one of claims 3 to 6.

8. the system further comprising a processing utility configured to process an image generated by the system and to evaluate an image print quality thereof, and if the image print quality falls below a predetermined required quality, the control unit is configured to trigger a replenishment of the at least one depletable chemical in the liquid reservoir. A system according to any one of claims 1 to 7.

9. the undesired side reaction of the depletable chemical results in the formation of undesired by-products in the liquid reservoir; A system according to any one of claims 1 to 8.

10. The system comprises: (i) a means for detecting said formation of said undesired by-products; (ii) a means for measuring or determining the amount of said undesirable by-products in said liquid reservoir; (iii) means configured to correlate the detected formation of the undesired by-product with the decrease in the first amount of the depletable chemical; and (iv) means configured to remove said undesired by-products; Further comprising at least one of The system of claim 9.

11. 11. The system of any one of claims 1 to 10, wherein the decrease in the first amount of the depletable chemical is due to contamination of the formulation in the liquid reservoir with at least one contaminant, and the formation of at least one undesirable by-product is due to an interaction of the at least one depletable chemical with at least one contaminant.

12. the system further comprising at least one printing liquid reservoir configured to hold a printing liquid, the decrease in the first amount of the depletable chemical being due to printing liquid contamination in the liquid reservoir. A system according to any one of claims 1 to 11.

13. The printing liquid is (A) an ink comprising at least one binder and at least one colorant, wherein the decrease in the first amount of the depletable chemical is due to an undesired side reaction of the depletable chemical with the at least one binder; and (B) including polyethyleneimine (PEI) as the depletable chemical; characterized by at least one of The system of claim 12.

14. 1. A method for preventing or minimizing print defects in a printing process, the print defects being associated with a decrease in a first amount of at least one depletable chemical contained in a liquid formulation, the method comprising: Identifying / detecting a decrease in the first amount of the at least one depletable chemical below a predetermined threshold and / or a decrease relative to the amount of at least another component in the formulation; Upon identifying / detecting said degradation, adding at least a portion of a second amount of said at least one depletable chemical to said formulation, said at least a portion of said second amount being sufficient to restore said first amount of said depletable chemical in said liquid formulation substantially to or above said predetermined threshold, and / or said at least a portion of said second amount being sufficient to counteract said degradation of said first amount relative to an amount of at least another component in said formulation, thereby preventing or minimizing said print defects. Including, the decrease is due to an undesirable side reaction of the at least one depletable chemical. method.

15. The method of claim 14 , wherein the liquid formulation is configured to be applied onto a substrate onto which an image is to be printed, or onto an intermediate transfer member in an indirect printing process.

16. said adding at least a portion of said second amount of said at least one depletable chemical is performed according to a predetermined replenishment profile selected to increase the amount of said depletable chemical in said liquid formulation to a value substantially equal to or greater than a predetermined threshold value.

16. The method according to claim 14 or 15.

17. The method further comprises processing an image produced by the method and evaluating an image print quality thereof, and if the image print quality falls below a predetermined required quality, the method comprises adding at least a portion of the second amount of the at least one depletable chemical to the liquid formulation. The method according to any one of claims 14 to 16.

18. The method further includes generating an output indicative of a quality of the image, and if the output is below a predetermined threshold parameter, the method includes adding the second amount of the at least one depletable chemical to the at least a portion of the liquid formulation.

20. The method of claim 17.

19. 19. The method of any one of claims 14 to 18, further comprising identifying a drop in the first amount of the at least one depletable chemical below a predetermined threshold, wherein the identifying is accomplished by a detection means selected from visual, spectroscopic, spectrophotometric, electronic, chemical, physical, print quality based means or any combination thereof, the method further comprising calculating the drop in the first amount of the at least one depletable chemical relative to an amount of another one or more ingredients in the formulation based on the identified drop in the first amount of the at least one depletable chemical.

20. the undesirable side reaction of the depletable chemical results in the formation of undesirable by-products in the liquid formulation; The method according to any one of claims 14 to 19.

21. The method further comprises detecting the formation of the undesired by-products; (I) measuring or determining the amount of said undesirable by-products in said liquid formulation; and (II) correlating the detected formation of the undesirable by-product with the decrease in the first amount of the depletable chemical; The method of claim 20, further comprising at least one of:

22. the decrease in the first amount of the depletable chemical is due to contamination of the liquid formulation with at least one contaminant, and the formation of at least one undesirable by-product is due to an interaction of the at least one depletable chemical with the at least one contaminant. The method according to any one of claims 14 to 21.

23. 23. The method of claim 22, wherein the decrease in the first amount of the depletable chemical is due to ink contamination in the liquid formulation, the ink comprising at least one binder and at least one colorant, and the decrease in the first amount of the depletable chemical is due to an undesirable side reaction of the depletable chemical with the at least one binder.

24. 24. The method of claim 23, wherein the depletable chemical is polyethyleneimine (PEI).

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