Abstract: A flexographic printing system uses a flexographic printing plate to produce printed patterns on a substrate. An ink recirculation system is used to reduce variability in system performance resulting from ink viscosity changes. A recirculation pump moves ink through an ink recirculation line connected to an ink reservoir. A metering pump adds a controlled flow rate of solvent from a solvent replenishment chamber into the ink recirculation line, thereby providing replenished in which is returned to the ink reservoir. A control system is used to control the flow rate of solvent provided by the metering pump responsive to an ink density measured using a density sensor.

Abstract: A method of printing an image with a continuous inkjet printer system employing bimodal drop size generation with pigmented inkjet ink compositions comprising a polymer additive, wherein the liquid ink is an aqueous inkjet ink comprises dispersed pigment colorant particles having a mean particle size of less than 150 nanometers and at least about 0.1 wt % of polymer additive distinct from any polymer dispersant used to disperse the pigment particles, and recirculating liquid ink supplied to the nozzle if the printer system from a liquid ink source is in-line filtered with a filter selected to be effective at retaining particles having particle sizes equal to and greater than 0.6 micrometers from the liquid ink and to pass the dispersed pigment particles. The invention enables high quality drop control in a continuous inkjet printing system.

Abstract: A method of printing an image with a continuous inkjet printer system employing bimodal drop size generation with pigmented inkjet ink compositions comprising a polymer additive, wherein the liquid ink is an aqueous inkjet ink comprises dispersed pigment colorant particles having a mean particle size of less than 150 nanometers and at least about 0.1 wt % of polymer additive distinct from any polymer dispersant used to disperse the pigment particles, and recirculating liquid ink supplied to the nozzle if the printer system from a liquid ink source is in-line filtered with a filter selected to be effective at retaining particles having particle sizes equal to and greater than 0.6 micrometers from the liquid ink and to pass the dispersed pigment particles. The invention enables high quality drop control in a continuous inkjet printing system.

Abstract: A continuous ink jet printer aqueous ink composition including pigment particles dispersed with a dispersant or self dispersing pigment particles without the need for a dispersant, and a polymer additive distinct from any dispersant used to disperse the pigment particles, wherein the polymer additive comprises a water soluble block copolymer having one or more poly(ethylene oxide) block segments wherein the polymer additive is present in an amount effective to stabilize the ink composition against shear induced agglomeration caused by pumping the ink composition through a continuous ink jet printing fluid system.

Abstract: The invention is a sampling device (4) and method used to remove bubble free samples from a bubble laden liquid. The device includes a power supply (10), a transducer (6) and a sampling probe (5). The power supply (10) converts normal line voltage to 20 kHz electrical energy. This high frequency electrical energy is converted to mechanical vibrations via the piezoelectric transducer (6). These mechanical vibrations propagate down the sampling probe (5) and emanate from the tip of the probe in the form of ultrasonic waves. The ultrasonic waves emanating from the probe tip serve to push away air bubbles from the vicinity of the tip. This allows the removal of a bubble free sample from the bubble laden liquid for further analysis.