• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.897-902
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• 2015

This study reports on a uniform resin coating method by using a doctor blade type dispenser. For high productivity, continuous imprint-lithography has been studied, and developed fabrication systems are used in several applications such as anti-reflection films, dry adhesives, and water collecting surfaces. In the continuous fabrication field, researchers have typically focused on patterning and demolding procedures. During the roll-to-roll fabrication process, however, the uniform resin coating process is also important in order to obtain a high quality product, which can be evaluated by uniform thickness, precise geometric expressions, and a thin residual layer. To achieve these, a doctor blade type dispenser was designed and fabricated. As a result, thickness of coated resin was well controlled by modulating the flow rate of the resin and blading gap. In addition, a very thin layer coating process (${\sim}10{\mu}m$) was achieved by softly contacting the blade on the substrate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.158-161
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• 2008

In the line array roll set (LARS) process, the initial plate is progressed into the final shape in a stepwise or pathwise manner according to the basic principle of the incremental forming process. The deformation proceeds simultaneously in the longitudinal and transverse directions. It was found that the curvature level of the formed plates in the previous study was well over the curvature required in shipyards. This fact shows that the LARS method has considerable potential for shipbuilding applications. In this study, several experiments with the LARS system is carried out fur manufacturing of plates with large curvatures. The bulbs at a stem and stern among ship hull plates correspond to these plates. Furthermore, the qualities of formed plates are evaluated according to the types of roll arrangements through experimental and numerical analyses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.813-820
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• 2015

We have studied commercialization and process optimization of protective film on transparent conductive coated substrate, nano silver on flexible PET (poly ethylene terephthalate), by means of roll-to-roll micro-gravure coater. Nanosilver on flexible PET substrate is potential materials to replace ITO (indium tin oxide). Protective film is most important to maintain unique silver pattern on top of transparent PET. PSA pressure sensitive adhesives) was developed solely for nano silver on PET and protective film was successfully laminated. We have optimized all process conditions such as coating thickness, line speed and aging time & temperature via experimental design. Transparent conductive film and its protective film developed in this research are commercially available at this moment.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.190-198
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• 2018

We fabricated high transmission and high scattering poly(ethylene-co-vinyl acetate)(EVA) films embedding $SiO_2$ nanoparticles to improve outcoupling efficiency in organic display. The 800nm diameter $SiO_2$ nanoparticles aggregated and formed $1.56{\mu}m$ (with ${\pm}0.853{\mu}m$ standard deviation) diameter microparticles in EVA. The total transmission of scattering film was 83.3% on Polyethylene terephthalate(PET), which was higher than reference 82.8% PET substrate. The diffuse transmission and haze of the $SiO_2$ embedded EVA film were 76.1% and 91.4%, respectively. The optimized condition was 1:1 weight ratio of $SiO_2$ nanoparticles to EVA in Tetrahydrofuran(THF) solution. When the ratio of $SiO_2$ was larger than 1, the total transmission decreased by the increase in backscattering of light due to high scattering. With the optimized condition, we could succeed to fabricate a large scale film(35m in length) with a roll-to-roll process.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.167-167
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• 2000

This study aims at the development of REC sensor causing the gauge error in the hot strip rolling process, and the improvement of the hydraulic AGC (Automatic Gauge Control) system. The gauge error outbreaks from the various reasons, however, mainly the roll eccentricity is considered to cause a such kind of error. In the study, the REC (Roll Eccentricity Control System) sensor is designed using sensor An On - line test of the system shows the comprehensive effects of controlling the gauge error of the hot strip. On - Line test shows the possibility of enhancing the accuracy for gauge.

• Membrane Journal
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• v.34 no.1
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• pp.79-86
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• 2024

The flat sheet membrane, one of the representative forms of polymeric membranes, is widely used from material research in laboratories to commercial membrane production due to its ease of fabrication. Porous polymeric flat sheet membranes used in microfiltration and ultrafiltration are mainly fabricated through phase separation processes, utilizing non-solvent-induced and vapor-induced phase separation methods. However, due to the nature of phase separation processes, variations between samples can easily occur depending on the surrounding environment and the experimenter, making it difficult to ensure reproducibility. Therefore, for scaling up and ensuring reproducibility of developed membrane fabrication technologies, there is a need for a controlled environment continuous large-area production device, such as a roll-to-roll manufacturing system. This research compared the changes in membrane characteristics due to differences in manufacturing environments when scaling up laboratory-scale fabrication technologies to roll-to-roll processes using knife and slot die coaters. By optimizing the continuous manufacturing process factors, uniformity of the membrane was ensured during large-area production.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.69-77
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• 1999

Roll profile design in spape rolling with a complex-shaped part depends on the designer's experience, which is general, is acquired through costly trial-and-error process. As a prerequisite for developing a scientific approach to roll profile design, we present a finite element model to simulate 3-D deformation of complex-shaped parts occuring in multi-pass sequence. Demonstrated is the process model's capability to deal with rolling of a complex-shaped part.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.51-58
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• 2018

In this paper, the organic material Poly(methyl methacrylate) PMMA is used with inorganic $Al_2O_3$ to fabricate organic-inorganic multilayer barrier thin films. The organic thin films are developed using a roll-to-roll electrohydrodynamic atomization system, whereas the inorganic are grown using a roll-to-roll low-temperature atmospheric pressure atomic layer deposition system. For the first time, these two technologies are used together to develop organic-inorganic multilayer barrier thin films in atmospheric condition. The films are grown under optimized parameters and classified into three classes based on the layer structures, when the total thickness of the barrier is maintained at ~ 160 nm. All classes of barriers show good morphological, optical and chemical properties. The $Al_2O_3$ films with a low average arithmetic roughness of 1.58 nm conceal the non-uniformity and irregularities in PMMA thin films with a roughness of 5.20 nm. All classes of barriers show a notably good optical transmission of ~ 85 %. The hybrid organic-inorganic barriers show water vapor and oxygen permeation in the range of ${\sim}3.2{\times}10^{-2}g/m^2/day$ and $0.015cc/m^2/day$ at $23^{\circ}C$ and 100% relative humidity. It has been confirmed that it can be mass-produced and used as a low-cost barrier thin film in various printing electronic devices.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.36-42
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• 2024

Roll-to-roll processing holds an integral position within the manufacturing landscape, and its significance reverberates across numerous industries. This versatile technology platform encompasses a diverse array of process methods and accommodates a wide spectrum of material categories, making it a cornerstone of modern production. Within this expansive domain, two commonly employed coating techniques, namely the slot die and gravure coating methods, have earned their prominence for their precision and efficiency in delivering flawless coatings. Additionally, the realm of drying processes relies heavily on thermal drying, infrared (IR) drying, and ultraviolet (UV) drying methods to expedite the transformation of materials from their liquid or semi-liquid states to solid, ready-to-use products. The undeniable importance of roll-to-roll processing lies in its ability to streamline manufacturing processes, reduce costs, and enhance product quality. This article embarks on a comprehensive journey to fathom the depth of this importance by delving into the intricacies of these common roll-to-roll process methods. Through rigorous research and meticulous data collection, we aim to shed light on the pivotal role these techniques play in shaping various industries and advancing the world of manufacturing. By understanding their significance, we can harness the full potential of roll-to-roll processing and pave the way for innovation and excellence in production.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.7-12
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• 2012

In order to cope with the requirements of smaller patterns, larger surfaces and lower costs in the fields of displays, optics and energy, greater attentions are now being paid to the development of micro-pattern machining technology. Compared with flat moulds, large drums with micro patterns (roll moulds) have the advantages of short delivery, ease of manufacturing larger surfaces, and continuous moulding. This paper introduced the machining process technology of the roll moulds for display industry. The environmental effects were discussed and the importance of temperature maintenance was experimentally emphasized. The real time monitoring system for micro machining was introduced. A commercial solution was used to simulate the micro grooving and a deformation model of micro machined pattern was finally introduced.