• Journal of KIBIM
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• v.7 no.3
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• pp.1-10
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• 2017

3D concrete printing technology builds structural components layer-by-layer with concrete extruded through a nozzle without using forms. This technology can simplify construction processes by optimizing design flexibility, construction time, and cost. Furthermore, the 3D printing technology is easy to make an irregularly shaped and function embedded building(or object) which is difficult to be constructed by conventional construction method. However, the 3D printing concrete is not suitable for current commercial standard and the material itself. It is also difficult to apply it to the construction site due to the lack of initial strength and the nozzle which is clogged during the process. The research of mix proportion design process for 3D printing concrete which differs from the conventional concrete is necessary in order to solve the problems. This paper aims to calculate the 3D printing concrete mix proportion design process based on the mix materials and performance information derived from the previous researches. Therefore, the usage variation range, mutual influence relationship, and the importance priority of the mix proportion are analyzed. Based on this results, the basic design process of 3D printing concrete which contains planning design phase, basic design phase and validating performance phase is suggested. We anticipate to confirm applicability verification about the actual production by referring to this 3D printing concrete mix proportion study. In the future, this study can be utilized for blueprint of the 3D printing concrete mix proportion.

• Textile Coloration and Finishing
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• v.19 no.4
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• pp.1-9
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• 2007

In recent years, the application of digital textile printing has increased. The benefits of using this method include the ease of sampling and the production of printed textiles. However, the production process of digital textile printing differs from that of conventional printing. For successful digital textile printing by ink-jet technology, the pretreatment of fabrics is very important in order to overcome the following problems. Low viscosity ink can spread easily on the textile surface leading to poor resolution. As a result, the combination of ink and pretreatment chemicals is still impractical and consequently most fabrics used in digital textile printing will require a pre treated coating in order to prevent the ink colours from bleeding on the fabric. Research presented in this paper shows some preliminary attempts to establish the relationship between the pre treatment and the digital textile printing quality. Various cotton fabrics were treated with pre treatment agents including ingredients like thickener, alkali and humectant, and then ink spread effect and colour yield of printed fabrics by reactive ink were analysed by using an optical microscope and K/S value. The results show that digital textile printing quality on cotton fabrics can be optimized with appropriate pre treatments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.82-90
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• 2019

In this paper, the effects of different 3D printing conditions including oil lubrication and annealing are observed for their effects on tensile testing. In 3D printing, a press-out extrude filament is rapidly heated and cooled to create internal stress in the printed part. The 3D printing internal stress can be removed using oil-coated filament and annealing. During the oven cooling at an annealing temperature of $106^{\circ}C$, the stress of the specimens with laminated angle $0^{\circ}$ tends to increase by 12.6%, and that of the oil-coated filament printing specimens is increased by 17%. At the annealing temperature of $106^{\circ}C$, the stress of the oil-coated filament printing specimens tends to increase by 35%. In this study, we have found that the oil lubrication and annealing remove the internal stresses and increase the strength of the printed specimens. The oil lubrication and annealing reform the crystalline structures to even out the areas of high and low stress, which creates fewer fragile areas. These results are very useful for the manufacture of 3D printing products with a suitable mechanical strength for applications.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.22-24
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• 2004

This paper proposes a printing quality inspection system of film-type envelopment. Since the printing system is running at very high-speed (140m/min.) and the line error has very narrow width, we have to choose one-dimensional high-speed and high-resolution line scan camera. The vibration of the printing machine and the illumination environment make the inspection problem more harder. To obtain reliable inspection results, many software image processing techniques are applied and many parameters are tuned. The performance of the proposed system is proved by many simulations and long time real-plant experiments.

• Journal of Institute of Convergence Technology
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• v.5 no.2
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• pp.33-36
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• 2015

In this paper, the development history of random packings for several generations was briefly introduced. We demonstrate the application of 3D printing to the fabrication of Pall rings, directly using computer aided design (CAD) models. The CAD was used to design Pall rings with different number of blades. The models were then printed by using UV curing of acrylonitrile-butadiene-styrene (ABS) resins. The results show that 3D printing is a promising method for producing precisely controlled packing materials. It is also expected that 3D printing is helpful for the fundamental studies of highly efficient packing materials with complex geometrical shapes.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.83-100
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• 2004

In this paper, the quantity of dot gain in off-set printing is estimated by using the method of UCR(under color removal) and GCR(gray component replacement) and the degree of dot gain is researched through measurement of dot coverage of each color patch at the output film that is variously applied to discretionary quantity of dot gain each line in screen in the printing for the process of color separation and at the offset printing. Also, the best appropriate quantity of dot gain treatment is examined by printing each line in screen for reproduction of colors.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.9
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• pp.781-786
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• 2015

Recently, studies of 3D printing methods have been working in various applications. For example, the powder base method laminates the prints by using a binding or laser sintering method. However, the draw back of this method is that the post process is time consuming and does not allow for parts to be rapidly manufactured. The binding method requires the post process while the time required for the post process is longer than the manufacturing time. This paper proposes a UV curing binding method with an integrated piezo printing head system. The optimization of an arbitrary waveform generation for the control of a UV curable resin droplet was researched, in addition to developed optimized UV curing processes in multi nozzle ink jet heads.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.45-57
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• 2006

Offset lithography is the most widely used printing process in domestic printing industry, but there are no industry-wide specifications for press control to assure consistent quality across printing plants. As printing becomes more of a commodity and less of an art, it is necessary to develop a print quality specification standard suitable for Korea offset printing field. This study aims to contribute to improving the quality of domestic offset color prints by comparative study on color reproduction properties of 2 kinds of domestic process color ink composed of C(cyan), M(magenta), Y(yellow) and K(black) and of 3 kinds of domestic coated paper, using colorimetric color measurement method.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.77-92
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• 2005

Offset lithography is the most widely used printing process in domestic printing industry, but there are no industry-wide specifications for press control to assure consistent quality across printing plants. As printing becomes more of a commodity and less of an art, it is necessary to develop a print quality specification standard suitable for Korea offset printing field. This study aims to contribute to improving the quality of domestic offset color prints by comparative study on color reproduction properties of 3 kinds of domestic process color ink composed of C(cyan), M(magenta), Y(yellow), and K(black), and of 3 kinds of domestic coated paper, using densitometric color measurement method.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.2
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• pp.69-82
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• 2000

Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. CRT monitors are also often used as a soft proofing device. However, it is very difficult to match the color image displayed on CRT monitors to the actual images printed on papers, because the color space of CRT monitors is RGB color system, and it is different with the CMY color system of the printing devices. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on CRT monitors. This paper shows the LUT and gamut mapping method considering the printing characteristics of output device is useful for the compensation.