• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.26 no.4
• /
• pp.351-356
• /
• 2017

The resistance of printed patterns for electrodes fabricated using printing technology should be minimized. This parameter depends on the pattern width and thickness; however, from the viewpoint of printability, the printed patterns should be printed at the designed width. The resistance of the printed patterns as well as printability is affected by various printing conditions. In this paper, the printing condition is optimized to minimize the resistance of electrodes printed by the roll-to-roll gravure method. This is done by considering the spread ratio of pattern width as a parameter of printability using design experiments. The drying temperature, dryer fan speed, and printing speed are selected as effective factors for the experiment objective. The optimized conditions are obtained and reproducibility test using these demonstrates that the optimized conditions can produce low-resistance electrodes for printability of the pattern width.

• Journal of Powder Materials
• /
• v.31 no.2
• /
• pp.137-145
• /
• 2024

In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.103-109
• /
• 2010

An ink transfer is modeled and experimentally verified using roll-to-roll electric direct gravure printing process. The ink transfer model based on the physical mechanism for the maximum ink transfer rate is proposed, and experimented by the electric printing machine in FDRC for the relations of the maximum ink transfer rates to the printing pressure, the operating speed, the operating tension, the surface roughness of substrates, and the contact angle between substrate and silver ink. The free ink split coefficient and immobilized ink under the maximum ink transfer rate are calculated by the physical parameter in a printing process and contact angle between substrates and ink. Numerical simulations and experimental studies were carried out to verify performances of the proposed ink transfer model. Results showed that the proposed ink transfer model was effective for the prediction of the amount of transferred ink to the substrate in a direct gravure printing systems.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.749-752
• /
• 2005

In the industry, three-dimensional coloring has been needed for realistic prototype from rapid prototyping. Z-corporation developed a 3D printer which provides three-dimensional colored prototype. However, the existing process cannot be adopted to models from other rapid prototyping process. In addition, time and cost for manufacturing colored prototype still remain to be improved. In this study, a new coloring process using ink-jet head is proposed for color printing on three-dimensional prototype surface. Process parameters such as the angle and the distance between ink-jet nozzle and the three-dimensional surface should be investigated from experiments. The correction matrix according to sloped angle to minimize the distortion of 2D image was proposed by analysis of printing error. Therefore, approximated method for angle and discrete length according to the radius of curvature for printing on the curved surface was proposed. By printing image on the doubly curved surface, the method was verified. As a practical example, helmet was chosen for printing images on the curved surface. The character images were applied with approximated method for angle and discrete length and was printed on the helmet surface.

• Journal of the Microelectronics and Packaging Society
• /
• v.17 no.3
• /
• pp.43-49
• /
• 2010

Direct printing technology is an attractive metallization method, which has become immerging as "Green technology" to the conventional photolithography, on account of low cost, simple process and environment-friendliness. In order to commercialize the printed electronics in industry, it is essential to evaluate the electrical properties of conductive circuits using direct printing technology. In this contribution, we focused on the electrical characteristics of inkjet-printed circuits. A Cu nanoink was inkjet-printed onto a Bisaleimide triazine(BT) substrate with parallel transmission line(PTL) and coplanar waveguide(CPW) type, then was sintered at $250^{\circ}C$ for 30 min. We calculated the resistivity of printed circuits through direct current resistance by the measurement of I-V curve: the resistivity was approximately 0.558 ${\mu}{\Omega}{\cdot}cm$ which is about 3.3 times that of bulk Cu. Cascade's probe system in the frequency range from 0 to 30 GHz were employed to measure the Scattering parameter(S-parameter) with or without a gap between the substrate and the probe station chuck. The result of measured S-parameter showed that all printed circuits had over 5 dB of return loss in the entire frequency range. In the curve of insertion loss, $S_{21}$, showed that the PTL type circuits had better transmission of radio frequency (RF) than CPW type.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.12
• /
• pp.1017-1023
• /
• 2007

This study is intended to analyze the effect of thin ink-film thickness around rotating printing roll on the printing quality in the gravure printing process which is used for making electronics circuit like a RFID tag with a conductive ink. The present work numerically estimates the film thickness around rotating roller partially immersed in ink for which the volume of fluid (VOF) method was adopted to figure out the film formation process around rotating roller. Parameter studies were performed to compare the effect of ink properties (viscosity, surface tension), operating condition (roller rotating speed, initial immersed angle) on the film thickness. The result indicates that the film thickness has a strong dependency on the rotating speed, while the surface tension has negligible effect.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.2 s.179
• /
• pp.181-190
• /
• 2006

In the industry, three-dimensional coloring has been needed for a realistic prototype. The Z-corporation developed a 3D printer which provides a three-dimensional colored prototype. However, the process cannot be adopted to models fabricated by other rapid prototyping processes. In addition, time and cost for manufacturing colored prototypes still remain to be improved. In this study, a new coloring process using an ink-jet head is proposed for color printing on a three-dimensional surface. Process parameters such as the angle and the distance between the ink-jet nozzle and the three-dimensional surface should be investigated through experiments. In order to minimize the distortion of a 2D image, the correction matrix according to the sloped angle is proposed and obtained by analysis of printing errors. An image on the doubly curved surface is printed so as to verify the proposed method. As a practical example, a helmet is chosen for printing images on the curved surface. The practical applicability of the correction matrix is then demonstrated by printing the character images on the surface of the helmet.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.30 no.3
• /
• pp.89-114
• /
• 2012

For as to world, the concern about the environment problem is enhanced than any other time in the past because of being 21 century. And the environment problem is highlighted as the world-wide issue. The time of the environment problem intimidates the alive of the mankind and presence of an earth over the time. It becomes the essentiality not being selection in the personal living or the economical viewpoint now to prepare for the climatic modification. As to the company management, the green growth period which it excludes the environment management considering an environment, cannot carry on the company the continued management comes. That is, in the change center of the management paradigm, there is the environment management. Nearly, the greenhouse gas which the publication industry is the environmental toxic material like all industries is generated. The greenhouse gas is ejected in the process of running the manufacturing process and print shop of the various kinds material used as the raw material of the book. Particularly, the tree felling for getting the material of the paper is known to reach the direct influence on the global warming. This study does according to an object it considers and organizes the environment parameter based on this kind of fact as to the publication industry. And it is determined as the reference which is used as the basic materials preparing the case that carbon exhaust right transaction(CAP and TRADE) drawing are enforced in all industries and is sustainable the management of the publication industry and reduces the environmental risk among the company many risk management elements and plans and enforces the publication related policy that there is a value. In the printing publication industry, this study tried to inquire into elements discharging the environmental pollutant or the greenhouse gas. Additionally, in the printed publication production process, it tried to inquire into the effort for an environment-friendly and necessity at the printing paper and the printers ink, regarded as the element discharging the greenhouse gas all kinds of the printing materials, operation of the print shop and all kinds of the machines and recycle process, and etc. These considerations make these industrial field employees aware of the significance about a conservation and environmental protection. They try to give a help in the subsequent study producing quantitatively each environmental parameter emission of green house gas. This makes the calculation of the relative $CO_2$ output reproached ultimately possible. Meanwhile, in a sense, many research protects and improving an environment in connection with the contents of research at the printing publication industrial field is in progress. There will be the voluntary human face that it has to protect an environment but this can not do by the outside factor according to all kinds of environment related law and regulation. Anyway, because of acting on company management as the factor of oppression, the increase of this environment-related correspondence cost could know that the research that the environment loading relates with a procurement and development, environment management system introduction, quality control standard, including, normalizing including a material, and etc. through the part of the effort to reduce the cost low was actively in progress. As to the green growth era, as follows, this paper prescribed the subject and alternative of the print publication industry. It is surrounded by the firstly new digital environment and the generation of the subject. And secondly the printing industry is caused by the point of time when the green growth leaves by the topic which is largest in the global industry and it increases. The printing publication industry has to prepare the bridgehead for the environment-friendly green growth as the alternative for this resolution with first. The support blown in each industry becomes the obligation not being selection. Prestek in which the print publishing was exposed to spend many energies and which is known as the practice of the sustainable print publishing insisted that it mentioned importance of the green printing through the white pages in 2008 and a company had to be the green growth comprised through the environment-friendly activity. The core management for the sustainable printing publication industry presented from Presstack white pages is compacted to 4 words that it is a remove, reduce, recover, and recycle. Second, positively the digital printing(POD) system should be utilized. In the worldwide print out market, the digital printing area stops at the level of 10% or so but the change over and growth of the market of an analog-to-digital will increase rapidly in the future. As to the CEO Jeff Hayes of the Infoland, the offset print referred to that it of the traditional method got old and infirm with the minor phase of the new printing application like the customer to be wanted publication and the print of the digital method led the market. In conclusion, print publishers have to grasp well the market flow in the situation where a digitalization cannot be generalized and a support cannot avoid. And it keeps pace with the flow of the digital age and the recognition about the effort for the development and environment problem have to be raised. Particularly, the active green strategy is employed for the active green strategy.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.10 no.1
• /
• pp.7-14
• /
• 2004

Migration behavior of selected solvents and food samples showed differences of the chemical structures and polarities, the food samples which have similar polar expresses more higher affinity than different polar degrees. Water which is polar has a highest partitioning coefficient values on polar isopropanol, and oil which is nonpolar has highest partitioning value on non-polar toluene. The increasing order of partitioning values was accord with increasing water contents in food samples. It is showed that the wheat flour with 13.2% moisture content has the highest partitioning coefficient values on the isopropanol with -OH. Kp value of sugar showed remarkable lower partitioning coefficient values than other food samples due to high degree crystallinity. This phenomenon can be predictable with ${\delta}$ values, because order of partitioning coefficient values which comes out through the experiment and the sequence of Hildebrand solubility parameter value difference between food sample and printing ink solvent correspond almost. This Hildebrand solubility parameter value can be easily applied to the food package industry because the effect of food-safety can be considered without passing through complicated steps by using this method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.1390-1393
• /
• 2004

In the present industry, three-dimensional colored shape has required for realistic prototype in rapid manufacturing. Z-corporation developed 3D printer which can color three-dimensional prototype but this process can't be adopted to other rapid prototype products and spend much time and cost coloring 3D shape. In this study a new coloring process on three-dimensional surface is proposed for realistic prototype. Three-dimensional surface coloring apparatus is composed of HP ink jet head and X-Y plotter. Distance and angle between ink jet nozzle and 3D surface are set as process parameter. Based on the experiment of process parameters, it is shown that distance and angle affected on printed image on 3D surface. Circle and line shape are chosen as standard image shape because the shape has widely used as standard in 2D printing. Consequently, the distorted image on 3D surface is corrected by transformed input image data.