Abstract:
An ink jet printing method is disclosed wherein an ink jet print head and an ink jet ink are provided. The ink jet print head has an ink channel and electrically actuable means to eject a number of successive droplets (d1,d2). The method includes the steps of (i) applying a number of successive electrical drive signals to the electrically actuable means, each electrical drive signal for ejecting a corresponding droplet, each electrical drive signal inducing in the ink channel an underpressure pulse (51 2 ) followed by a pressure pulse (52 2 ) for ejecting the corresponding droplet and each electrical drive signal is unipolar and of the same polarity; (ii) after applying the last electrical drive signal for ejecting the last droplet of a maximum number of successive droplets, applying a electrical cancel signal for reducing residual acoustic pressure waves in the ink channel. The electrical cancel signal induces in the ink channel an underpressure pulse (51 c ),and a pressure pulse (52 c ), and at least one of the underpressure pulse or the pressure pulse is applied in antiresonance with the pressure pulse of the last electrical drive signal.
Abstract:
A single pass inkjet printing method including the steps of: a) providing a radiation curable inkjet ink set containing at least a first and a second radiation curable inkjet ink having a dynamic surface tension of no more than 30 mN/m measured by maximum bubble pressure tensiometry at a surface age of 50 ms and at 25°C; b) jetting a first radiation curable inkjet ink on an ink-jet ink-receiver moving at a printing speed of at least 35 m/min.; c) at least partially curing the first inkjet ink on the ink receiver within the range of 40 to 500 ms after the first inkjet ink landed on the ink receiver; d) jetting a second radiation curable inkjet ink on the at least partially cured first inkjet ink; and e) at least partially curing the second inkjet ink within the range of 40 to 500 ms after the second inkjet ink landed on the first inkjet ink. A single pass inkjet printer is also disclosed.
Abstract:
A method for operating an inkjet print head is presented. The inkjet print head has an ink chamber (15) and electrically actuable means (2,3) associated with the ink chamber and actuable in accordance with print tone data, thereby to eject a number of successive ink droplets from the ink chamber (15) to form a printed dot of appropriate tone on the receiving medium. The method includes the step of providing print tone data to the inkjet print head so as to eject either zero or at least two successive ink droplets from the ink chamber (15) in response to the print tone data. The method thereby avoids the use of a single-droplet drop which generally has deviating ejection characteristics compared to multi-droplet drops.
Abstract:
A method and an inkjet printing device (10) are disclosed for single pass printing on an ink-receiver (50) having a surface (51), the device including a plurality of sets of nozzles (15-18, 25-28) for jetting N inks on the surface (51), wherein N is larger than or equal to one, the N inks including a first ink, and wherein the plurality of sets of nozzles includes a first (15) and a second (25) set of nozzles for jetting the first ink; the device further including means for radiation curing (19, 41-43) the first ink when jetted on the surface by the first set of nozzles, wherein the means for radiation curing (19, 41-43) is positioned between the first set of nozzles (15) and the second set of nozzles (25).