scholarly journals Charged Satellite Drop Avoidance in Electrohydrodynamic Dripping

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 172 ◽  
Author(s):  
Lei Guo ◽  
Yongqing Duan ◽  
Weiwei Deng ◽  
Yin Guan ◽  
YongAn Huang ◽  
...  

The quality of electrohydrodynamic jet (e-jet) printing is crucially influenced by the satellite drop formed when the primary drop detaches from the meniscus. If the satellite drop falls onto the substrate, the patterns on the substrate will be contaminated. The electric charge carried by the satellite drop leads to more complex satellite/meniscus interaction than that in traditional inkjet printing. Here, we numerically study the formation and flight behavior of the charged satellite drop. This paper discovered that the charge relaxation time (CRT) of the liquid determines the electric repulsion force between the satellite drop and meniscus. The satellite drop will merge with the meniscus at long CRT, and fail to merge and deteriorate the printing quality at short CRT. The simulations are adopted to discover the mechanism of generation and flight behavior of charged satellite drops. The results show that the critical CRT decreases with the dielectric constant of the liquid and the supplied flow rate. Namely, for small dielectric constant and fixed CRT, the satellite drop is less likely to merge with the meniscus, and for high flow rate, the satellite drop is prone to merge with the meniscus due to the delay of necking thread breakup. These results will help to choose appropriate parameters to avoid the satellite drop from falling onto the substrate.

2013 ◽  
Vol 684 ◽  
pp. 352-356 ◽  
Author(s):  
Ning Bin Bu ◽  
Yong An Huang ◽  
Zhou Ping Yin

In this paper, the behavior of ejected jet is studied at three different substrates (conductive, semiconductor and dielectric) in continuous electrohydrodynamic inkjet printing mode. Because the polarization charges will accumulate at the surface of the substrate in a short nozzle-to-collector distance, one can observe that the different flight behavior in the space. Results show that the substrate has little effect on the threshold voltage and the relaxation time of the substrate can be used to indicate the behavior of the jet. When the lifetime of the jet is larger than the relaxation time of the substrate, the jet can be deposited on the substrate regularly. Based on this guideline, a designed parallel lines and grid pattern are fabricated with several micrometers on a silicon substrate. These show that the designed pattern could be fabricated in a controllable jet. In the future, this method is able to be utilized to fabricate the mirco/nano-devices.


2013 ◽  
Vol 469 ◽  
pp. 348-353 ◽  
Author(s):  
Hai Ying Tian ◽  
Xian Fu Wei ◽  
Bei Qing Huang

The era of environmental protection and personalization has become increasingly prominent, and people not only focus on the beauty of the design, but also pay more attention to the quality of the clothing. For inkjet printing, the viscosity and surface tension of ink are major factors that affect the quality of ink-jet printing. In order to obtain a better print quality, the samples of five different viscosity and surface tension of ink were prepared respectively by changing the content of the resin and the surface active agent. Using these samples to print on the fabric by Epson printer, and to discuss the influence of the ink in different viscosity and surface tension on the ink-jet printing quality, such as apparent color depth (K / S), color parameters (L, C), permeability, clarity. The results showed that: with the increase of the ink viscosity, the apparent depth of color yield increased gradually and became darker in color. L value decreased gradually and had a increasing trend, and tends to be stable. C value increased and vividness of the color was improved. And it also had a certain impact on the infiltration resistance and clarity. Surface tension also had a significant impact on the depth of the apparent color, vividness of the color and directly affected the ink permeability and clarity.


2012 ◽  
Vol 200 ◽  
pp. 676-680 ◽  
Author(s):  
Jing Mei Sun ◽  
Xian Fu Wei ◽  
Bei Qing Huang

Piezoelectric Inkjet Printing is the main ink-jet printing at present, and drop state will have great influence to ink-jet printing quality, so the ink-jet drop state of edible ink is researched based on piezoelectric inkjet printing. The viscosity of the ink is adjusted by the way of adding different levels of resin, and then the samples which have different viscosity are got. Drop state is observed through drops observatory which installs Spectra Polaris nozzle (35pl), then the speed, volume, tail length and roundness of the drops are measured at certain moment in order to evaluate the influence of viscosity to ink-jet drop state. The result shows that viscosity has big influence to ink-jet drop state, when the viscosity becomes larger, the speed of drops becomes smaller, the variation of volume is not so obvious, the tail length of drops becomes smaller and roundness becomes larger accordingly, until the viscosity is 10mPa•s, the tail length is the smallest and roundness is the biggest, the drop state is the best , when viscosity is bigger than 10mPa•s, the tail length will become bigger and roundness smaller.


2012 ◽  
Vol 262 ◽  
pp. 282-286
Author(s):  
Jing Mei Sun ◽  
Xian Fu Wei ◽  
Bei Qing Huang

In the process of the ink drops forming and spreading out, the viscosity and surface tension of the ink play an important role, and then the drops’ injection and printing quality will be influenced by this process. Besides, drops control technology is the key of ink-jet printing technology, and the drops’ injection state will also influence the printing quality. In order to research the influencing factors to printing quality, many samples with different performances are prepared and their drop states include speed, tail length and volume are measured with drop observatory. And then, the specimen pages include lines of different width are printed, order to assessment the printing quality comprehensively, their line width, raggedness, blurriness, density and contrast are measured. The result show that the inks with different performance show different speed, tail length and volume, and their corresponding printing qualities are different too, and there exists linear relationship between printing quality and the drops’ viscosity, surface tension and speed.


2010 ◽  
Vol 174 ◽  
pp. 329-332
Author(s):  
Yun Zhi Chen ◽  
Ting Zhu ◽  
Shu Sun

Compared with conventional surface sizing agents, polymers surface size agents are good film and printing quality. In this work, different types of SMA (Styrene Maleic Anhydride) from the United States Hercules and Sartomer companies were investigated. Firstly, each of SMA sizing agents was studied respectively for choosing the optimized SMA depending on the improvement of physical and ink-jet printing properties, and then the effects of different formulation surface size agents containing the optimum SMA and cationic starch on paper and ink-jet printing properties were also studied in order to analyzing the synergism effects of the two surface size agents. The results show that S520 was better than several other SMA surface sizing agents in the improvement of physical properties and ink-jet printing performance of paper. S520 could produce good film property which could reduce the paper permeability, improve smoothness have less loss whiteness and opacity. It could also enhance the color density, expand the scope of the dark tone and improve dots clarity degree of printed paper.


Cellulose ◽  
2021 ◽  
Vol 28 (16) ◽  
pp. 10609-10624
Author(s):  
Mohit Sharma ◽  
Roberto Aguado ◽  
Dina Murtinho ◽  
Artur J. M. Valente ◽  
Paulo J. T. Ferreira

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.


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