Development of Ink-Particle Flight Simulation for Continuous Inkjet Printer (original) (raw)

Ink drop motion in wide-format printers: II. Airflow investigation

2009

Quality ink jet printing is being used increasingly for many types of applications. This paper investigated the relative motion of the printing head, which induces airflow between the head and the printing media. This airflow may interfere with the ejected ink drops as they fly towards the media, resulting in printing inaccuracy. The airflow was investigated experimentally (particle image velocimetry, PIV).

Flight behavior of charged droplets in electrohydrodynamic inkjet printing

Applied Physics Letters, 2010

Flight behaviors of charged droplets are presented for electrohydrodynamic (EHD) inkjet printing. Three different kinds of EHD spraying techniques, pulsed dc, ac, and single potential (SP) ac, have been investigated and both conductive and dielectric target surfaces were considered. Experimental results show that the flight paths of charged droplets may deviate from their regular straight route, i.e., directly from the nozzle to the substrate. Depending on the droplet charge and applied electric field, droplets may deflect, reflect, or retreat to the meniscus. We can solve these drawbacks by SP EHD printing.

Numerical Modeling of the Motion and Interaction of a Droplet of an Inkjet Printing Process with a Flat Surface

Applied Sciences

The numerical simulation and analysis of the ejection of an ink droplet through a nozzle as well its motion through air until its contact with a surface and taking up of a stable form is performed. The fluid flow is modeled by the incompressible Navier–Stokes equations with added surface tension. The presented model can be solved using either a level set or a phase field method to track the fluid interface. Here, the level set method is used to determinate the interface between ink and air. The presented work concentrates on the demonstration how to check the suitability of ink for inkjet printhead nozzles, for instance, for the use in printers. The results such as velocity, change of size, and volume dependence on time of an ink droplet are presented. Recommendations for the use of specific inks are also given.

Development of an Improved Model for PiezoElectric Driven Ink Jets

Numerical modeling and experimentation are used at Xerox Office Group to design, optimize, and verify the fluid dynamic behavior of phase-change ink jets, including the individual jets in a print head. A typical model of an ink jet is based upon lumped-parameter (no spatial variation) assumptions. While quite accurately predicting the main Helmholz resonant frequency (a key performance measure), a lumped-parameter model does not predict other parasitic frequencies that occur in a typical ink jet. As printer performance improves by increasing the jetting frequency, understanding and controlling these other resonant frequencies becomes critical. This paper documents the improvement of an existing lumped-parameter model by incorporating one-dimensional transmission line elements which substantially increases the ability of the model to predict the frequency response of an ink jet.

Flow characteristics of ink-jet inks used for functional printing

Istrazivanja i projektovanja za privredu, 2015

The rheology-related effects of nozzle clogging in inkjet printing can seriously affect ink ejection rate and result in irregular droplet trajectory, resulting in poor printing results. In this study three different inkjet inks, used for functional printing with a Dimatix materials inkjet printer, are investigated rheologically. In connection with rheological observation a novel method of inkjet trajectory image analysis gives insight into the irregularity of directional deviation due to clogging of nozzles of the printer It is found that the type of solvent used in the ink formulation has an important influence on the rheological behaviour in the printing regime, which directly has an effect on ink-droplet trajectory and contact characteristic with the substrate.

Optimization of Experimental Parameters To Determine the Jetting Regimes in Electrohydrodynamic Printing

Langmuir, 2013

The harmony of ink and printing method is of importance in producing ondemand droplets and jets of ink. Many factors including the material properties, the processing conditions, and the nozzle geometry affect the printing quality. In electrohydrodynamic (EHD) printing where droplets or jets are generated by the electrostatic force, the physical as well as the electrical properties of the fluid should be taken into account to achieve the desired performance. In this study, a systematic approach was suggested for finding the processing windows of the EHD printing. Six dimensionless parameters were organized and applied to the printing system of ethanol/terpineol mixtures. On the basis of the correlation of the dimensionless voltage and the charge relaxation length, the jet diameter of cone-jet mode was characterized, and the semicone angle was compared with the theoretical Taylor angle. In addition, the ratio of electric normal force and electric tangential force on the charged surface of the Taylor cone was recommended as a parameter that determines the degree of cone-jet stability. The cone-jet became more stable as this ratio got smaller. This approach was a systematic and effective way of obtaining the Taylor cone of the cone-jet mode and evaluating the jetting stability. The control of the inks with optimized experimental parameters by this method will improve the jetting performance in EHD inkjet printing.

Flows on the nozzle plate of an inkjet printhead

Experiments in Fluids, 2007

Flow patterns of ink layers on the nozzle plate of a piezo-driven printhead are investigated. Two different flow types are identified. First, a jet of droplets induces a radial airflow in the direction of the jet, which in turn causes a liquid flow towards the nozzle. Second, the movement of the meniscus in the nozzle causes an equally strong flow, but completely different flow patterns. The results are presented in a phase diagram with pulse amplitude and firing frequency as parameters.

Significance of paper properties on print quality in continuous ink jet printing

Journal of Imaging Science and Technology, 2000

In this article, we discuss the relationship between a high-speed continuous ink jet system and the printing substrate. Nonabsorbent materials, with different surface topographies were used to evaluate the importance of the droplet impact and spreading without capillary penetration. Commercial papers were also used to evaluate the potential of the existing grades, and to find their essential performance parameters. A laboratory scale testing environment was used for the high-speed imaging of ink jet drops. The impact, spreading, absorption, and drying of the ink droplets on the samples can be observed and analyzed in this testing environment on the time scale of microseconds up to several minutes. The image technical performance of the samples was measured with an image analysis system which was specially designed for the analysis of print quality with non-impact printing techniques.

The dynamics of the piezo inkjet printhead operation☆

Physics Reports, 2010

The operation of a piezo inkjet printhead involves a chain of processes in many physical domains at different length scales. The final goal is the formation of droplets of all kinds of fluids with any desired volume, velocity, and a reliability as high as possible. The physics behind the chain of processes comprise the two-way coupling from the electrical to the mechanical domain through the piezoelectric actuator, where an electrical signal is transformed into a mechanical deformation of the printhead structure. The next two steps are the coupling to the acoustic domain inside the ink channels, and the coupling to the fluid dynamic domain, i.e. the drop formation process. The dynamics of the printhead structure are coupled via the acoustics to the drop formation process in the nozzle. Furthermore, wetting of the nozzle plate and air bubbles can have a negative influence on the printhead performance. The five topics (actuation, channel acoustics, drop formation, wetting, and air bubbles) are reviewed in this paper. This research connects the product developments for many emerging new industrial applications of the inkjet technology to the fundamental physical phenomena underlying the printhead operation.