• Title/Summary/Keyword: Jetting velocity

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Performance Analysis of the Industrial Inkjet Printing Head Using 1D Lumped Model (1 차원 Lumped 모델을 이용한 산업용 잉크젯 프린팅 헤드 토출 특성 해석)

  • Sim, Won-Chul;Kim, Young-Jae;Park, Chang-Sung;Yoo, Young-Seuck;Joung, Jae-Woo;Oh, Yong-Soo;Park, Sung-Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.11
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    • pp.101-107
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    • 2007
  • Jettability analysis using one-dimensional(1D) lumped parameter model has been investigated to design the industrial inkjet head with proper drop velocity and drop volume. By simplifying the inkjet head system into an equivalent electrical circuit, lumped model has been developed. Performance of the lumped model is verified by the comparison between measured results of droplet velocity and ejection volume and predicted value. Also, the jetting performance of an inkjet head is characterized by varying the design parameter and driving condition. As a result, simulation results shows good agreement with the experimentally measured value. The developed lumped model enables to easily understand the effect of dimension change and predict the jetting performance.

Experimental Analysis of Droplet Formation Process for Inkjet Printhead (잉크젯 헤드를 이용한 액적 토출 현상의 실험적 분석)

  • Jo, Y.M.;Park, S.J.
    • Journal of ILASS-Korea
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    • v.15 no.4
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    • pp.163-169
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    • 2010
  • Jetting stability is the most important factors in inkjet printing because printing quality is totally determined by shape of the droplets on the substrate. In order to acquire stable jet, viscosity and dynamic behavior of the ink must be considered. In addition, waveform to drive the inkjet printhead is also to be controlled. In this study, the driving waveform composed of rising time, dwell time and falling time is optimized to obtain a stable jetting using drop watcher system. Also, effect of ink viscosity on jetting is experimentally investigated by changing the temperature of ink cartridge. As a result, jetted drop having uniform velocity is acquired.

Experimental Investigations into the Precision Cutting of High-pressured Jet for Thin Multi-layered Material (다층박판재료의 초고압 젯 정밀가공에 대한 실험적 연구)

  • Park, Kang-Su;Bahk, Yeon-Kyeung;Lee, Jung-Han;Lee, Chae-Moon;Go, Jeung-Sang;Shin, Bo-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.7
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    • pp.44-50
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    • 2009
  • High-pressured jetting is now widely used in the advanced cutting processes of polymers, metals, glass, ceramics and composite materials because of some advantages such as heatless and non-contacting cutting. Similarly to the focused laser beam machining, it is well known as a type of high-density energy processes. High-pressured jetting is going to be developed not only to minimize the cutting line width but also to achieve the short cutting time as soon as possible. However, the interaction behavior between a work piece and high-velocity abrasive particles during the high-pressured jet cutting makes the impact mechanism even more complicated. Conventional high-pressured jetting is still difficult to apply to precision cutting of micro-scaled thin work piece such as thin metal sheets, thin ceramic substrates, thin glass plates and TMM (Thin multi-layered materials). In this paper, we proposed the advanced high-pressured jetting technology by introducing a new abrasives supplying method and investigated the optimal process conditions of the cutting pressure, the cutting velocity and SOD (Standoff distance).

Development of a Test Stand for Measuring Ink Jetting Performance (잉크젯 토출 특성 평가 장치 개발)

  • Kwon, Kye-Si
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.8
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    • pp.45-50
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    • 2008
  • An ink jetting measurement system has been developed such that the velocity as well as the volume of ink droplets can be measured. In order to measure the ink droplet, a strobe LED light was synchronized to the droplet firing signal in order to obtain frozen droplet images. Then, a LabVIEW based software was developed for the analysis of the droplet image. For the efficient droplet analysis, a user generated rectangular shaped ROI (Region of Interest) was used. By using ROI, the ink droplet image can be easily isolated from the other structures such as printhead and the processing area can be minimized.

Experimental investigations and development of mathematical model to estimate drop diameter and jet length

  • Roy, Amitava;Suneel, G.;Gayen, J.K.;Ravi, K.V.;Grover, R.B.
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3229-3235
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    • 2021
  • The key process used in nuclear industries for the management of radiotoxicity associated with spent fuel in a closed fuel cycle is solvent extraction. An understanding of hydrodynamics and mass transfer is of primary importance for the design of mass transfer equipment used in solvent extraction processes. Understanding the interfacial phenomenon and the associated hydrodynamics of the liquid drops is essential for model-based design of mass transfer devices. In this work, the phenomenon of drop formation at the tip of a nozzle submerged in quiescent immiscible liquid phase is revisited. Previously reported force balance based models and empirical correlations are analyzed. Experiments are carried out to capture the process of drop formation using high-speed imaging technique. The images are digitally processed to measure the average drop diameter. A correlation based on the force balance model is proposed to estimate drop diameter and jet length. The average drop diameter obtained from the proposed model is in good agreement with experimental data with an average error of 6.3%. The developed model is applicable in both the necking as well as jetting regime and is validated for liquid-liquid systems having low, moderate and high interfacial tension.

NUMERICAL ANALYSIS OF FLOW AND COOLING CHARACTERISTICS OF SLIT JETS IMPINGEMENT (슬릿젯의 유동 및 냉각 성능에 대한 수치적 연구)

  • Son, S.;Son, G.;Lee, P.;See, S.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.448-450
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    • 2010
  • Free surface liquid jet impingement, which is applicable to cooling of hot plates in a steel-making process, is investigated numerically by solving the conservation equations of mass, momentum and energy in the liquid and gas phases. The free-surface of liquid-gas interface is tracked by an improved level-set method incorporating a sharp-interface technique for accurate imposition of stress and heat flux conditions on the liquid-gas interface. The level-set approach is combined with a non-equilibrium $k-{\omega}$ turbulence model. The computations are made for slit nozzle jets to investigate their flow and cooling characteristics. Also, the effects of jetting angle, velocity and moving velocity of plate on the interfacial motion and the associated flow and temperature fields are quantified.

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A Study on the Simulation Analysis of Nozzle Length and Inner Spiral Structure of a Waterjet (워터젯 노즐의 길이와 내부 나선 구조 유무에 따른 유체거동에 관한 전산해석)

  • Gwak, Cheong-Yeol;Shin, Bo-Sung;Go, Jeung-Sang;Kim, Moon-Jeong;Yoo, Chan-Ju;Yun, Dan-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.1
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    • pp.118-123
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    • 2017
  • It is well known that water jetting is now widely used in the advanced cutting processes of polymers, metals, glass, ceramics, and composite materials because of some advantages, such as heatless and non-contacting cutting different from the laser beam machining. In this paper, we proposed the simulation model of waterjet by lengths and the inner spiral structure of the nozzle. The simulation results show that the outlet velocity of the nozzle is faster than the inlet. Furthermore, we found rapid velocity reduction after passing through the outlet. The nozzle of diameter ${\phi}500$ and length 70mm, shows the optimal fluid width and velocity distribution. Also, the nozzle with inner spiral structure shows a Gaussian distribution of velocity and this model is almost twice as fast as the model without spiral structure, within the effective standoff distance (2.5 mm). In the future, when inserting abrasive material into the waterjet, we plan to analyze the fluid flow and the particle behavior through a simulation model.

Effect of Marangoni Flow on Surface Roughness and Packing Density of Inkjet-printed Alumina Film by Modulating Ink Solvent System.

  • Oh, Yeon-Jun;Kim, Ji-Hoon;Yoon, Young-Joon;Yoon, Ho-Gyu;Kim, Jong-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.272-272
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    • 2010
  • We have fabricated alumina thick films by inkjet printing technology. Two different types of ink system were formulated in order to understand their evaporation behaviors and their evaporation effects on the powder distribution on, the surface during inkjet-printed alumina thick films. Single solvent system was formulated with N,N-dimethylformamide(DMF), which led to coffee ring effects which non-uniformly distributed alumina particles on the substrate during the ink evaporation. However, Co-solvent system which consists of both Water and DMF produced relatively uniform distribution of the particles on the substrate. We believe that these two different distributions of alumina particles are attributed to the ink fluid flow directions in the ink droplets ejected from the different ceramic ink system. We have modulated inkjet parameters such as dot-to-dot distance, line-to-line distance, jetting velocity and jetting drop size in order to find out the optimum condition for the printing of alumina thick films from two different ink systems. The surface roughness, microstructures and dielectric properties of these inkjet-printed alumina thick films were investigated.

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The Effects of Driving Waveform for Piezoelectric Drop On Demand Industrial Inkjet Head (산업용 압전 잉크젯 헤드의 구동신호에 따른 특성)

  • Kim Young-Jae;Yoo Young-Seuck;Sim Won-Chul;Park Chang-Sung;Joung Jae-Woo;Oh Yong-Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.8
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    • pp.417-422
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    • 2006
  • This paper presents the effect of driving waveform for piezoelectric bend mode inkjet printhead with optimized mechanical design. Experimental and theoretical studies on the applied driving waveform versus jetting characteristics were performed. The inkjet head has been designed to maximize the droplet velocity, minimize voltage response of the actuator and optimize the firing frequency to eject ink droplet. The head design was carried out by using mechanical simulation. The printhead has been fabricated with Si(100) and SOI wafers by MEMS process and silicon direct bonding method. To investigate how performance of the piezoelectric ceramic actuator influences on droplet diameter and droplet velocity, the method of stroboscopy was used. Also we observed the movement characteristics of PZT actuator with LDV(Laser Doppler Vibrometer) system, oscilloscope and dynamic signal analyzer. Missing nozzles caused by bubbles in chamber were monitored by their resonance frequency. Using the water based ink of viscosity of 4.8 cps and surface tension of 0.025 N/m, it is possible to eject stable droplets up to 20 kHz, 4.4 m/s and above 8 pl at the different applied driving waveforms.

Characteristic Analysis of High Speed Inkjet Printing Head for Digital Textile Printing (디지털날염용 고속 구동형 잉크젯 프린팅 헤드의 특성해석)

  • Lee, Duck-Gyu;Hur, Shin
    • Journal of Sensor Science and Technology
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    • v.27 no.6
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    • pp.421-426
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    • 2018
  • To develop a piezoelectric inkjet printhead for high-resolution and high-speed printing, we studied the characteristics of an inkjet printhead by analyzing the major design parameters. An analytical model for the inkjet printhead was established, and numerical analysis of the coupled first-order differential equation for the defined state variables was performed using state equations. To design the dimension of the inkjet printhead with a driving frequency of 100 kHz, the characteristics of the flow rate and discharge pressure of the nozzle were analyzed with respect to design variables of the flow chamber, effective sound wave velocity, driving voltage, and voltage waveform. It was predicted that the change in the height of the flow chamber does not significantly affect the Helmholtz resonance frequency and discharge speed of the nozzle. From the analysis of change in flow chamber width, it is observed that as the width of the flow chamber increases, the ejection speed greatly increases and the Helmholtz resonance frequency decreases considerably, thereby substantially affecting the performance of the inkjet printhead.