• Elastomers and Composites
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• v.51 no.4
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• pp.280-285
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• 2016

The purpose of this study is to get optimum design and operation conditions of the heating rubber roller for laminating process. The cause of performance degradation of heating rubber roller is delamination of rubber on metal tube, rubber aging due to high temperature. We measured the material properties of thermal expansion, thermal conductivity, specific heat and density and analyzed thermal distributions of rubber layer using finite element method. As a result of heat/flow analysis, the density distribution of heating coil must shorten the stabilization time by reducing the temperature deviation on the length direction at the temperature rising section after increasing the density of the area contacting with the laminate film at the center part which is an opposite of the current composition while enabling to maintain the temperature of heater to be consistent while maintaining the temperature deviation to be low when heat loss is created. Finally, we determined optimum heating method of heating rubber roller.

• Polymer(Korea)
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• v.33 no.6
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• pp.525-529
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• 2009

In order to manufacture 2-layer flexible copper clad laminate (FCCL) s having the excellent performance high adhesion properties between copper foil and polyimide film are required. Silane coupling agents with specific functional groups as an adhesion promoter are generally used to enhance the adhesion. In our study, we synthesized a novel silane coupling agent for increasing the adhesive property between copper layer and polyimide layer. The surface morphology of rolled copper foil, as a function of the concentrations of the coated silane coupling agent, was fully characterized. As fabricated 2-layer FCCL, we observed that adhesive properties were changed by the surface morphology and we confirmed that the novel silane coupling agent affects adhesive properties in FCCL with two types of poly (amic acid)s.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.2
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• pp.1-6
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• 2007

This study investigated the magnetic properties of $Ni_{80}Fe_{20}/SiO_2$ laminates with shape-induced magnetic anisotropy. The multilayer films were deposited on Si or upilex substrates, from separate $Ni_{80}Fe_{20}$ and $SiO_2$ (at %) alloy targets using a rf diode sputtering system. $Ni_{80}Fe_{20}/SiO_2$ laminates with a various number of bilayers (N) were prepared. The laminates with ellipse array patterns were prepared using photolithographic technique. The magnetic properties were measured at room temperature using a B-H hysteresisgraph and a high frequency permeameter. The several steps during domain wall reversal were observed in multilayer films, attributing to inter-magnetic layer coupling. Intrinsic uniaxial anisotropy field increases with N. The experimental values of the total anisotropy field are found to be in good agreement with the calculated values. This study utilized the shape anisotropy of the laminated film objects with small ellipse array patterns to induce a larger uniaxial anisotropy so as to maximize their operating frequency.

• Journal of Adhesion and Interface
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• v.17 no.3
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• pp.89-95
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• 2016

An environmentally friendly water-based pressure sensitive adhesive (PSA) was designed in an attempt to replace the solvent-based adhesive for dry lamination used in flexible food packaging films. Instead of using a low molecular weight surfactant, which may have variable material properties, a high molecular weight dispersant was used for emulsification. A polymeric nano-dispersant (PND) was synthesized using solution polymerization, and it was used as a micelle seed in the surfactant, resulting in the synthesis of a core/shell grafted acrylic adhesive. The shell and core exhibited different $T_g$ values, so that the initial adhesion strength and holding power were complemented by the film's flexibility, which is required to provide good adhesion of thin films. Results showed that the PSA designed in this study using the PND instead of traditional low molecular weight surfactant had adhesive properties applicable to the flexible packaging with appropriate tack.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.33-42
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• 2015

오늘날 연성회로기판(FCCL : Flexible Copper Clad Laminate)은 디스플레이, 스마트폰, 자동차, 항공, 의료 기기, 산업용 컨트롤 기기 등 거의 모든 고급 전자 제품들에 사용되고 있다. 특히 디스플레이 분야에서는 뛰어난 연성과 내구성을 바탕으로 경박단소화에 유리할 뿐만 아니라 구동부에 적용이 가능한 장점 등으로 그 적용처가 점점 늘어나고 있는 추세이다. 이 가운데서도 LCD와 OLED의 구동소자(Display Driver IC)를 장착하는 COF(Chip on Film)는 대표적인 연성회로기판(FCCL) 적용 부품으로서, 최근 인기를 끌고 있는 디스플레이의 제로-베젤(Zero-bezel)을 가능케 하는 핵심 부품이다. COF용 연성회로기판(FCCL) 소재로는 우수한 평탄도, 파인피치(Fine-pitch)구현성, 내굴곡성, 광투과성 등을 보유하고 있는 Sputtering Type FCCL이 사용되고 있다. 특히 최근 Display 분야의 화두가 되고 있는 POLED(Plastic-OLED) 패널을 장착한 Flexible Mobile 디스플레이의 경우, 기존의 COG(Chip on Glass) 접합방식이 아닌 COF 접합방식을 채택하고 있으며, 기존의 단면 COF보다 3배의 고해상도 구현이 가능한 양면 COF를 채택하기에 이르렀다. 기존의 COF 제작공정과 달리 Semi Additive 공정으로 제작되는 양면 COF 시장의 태동으로 양면 연성회로기판(FCCL)의 수요 증가가 예상되는 등 최근 디스플레이 기술 발전은 소재 분야에도 큰 변화를 잉태하고 있다. 이러한 최근 디스플레이 업계의 고해상도, 고속 신호 전송, 슬림화, Flexible 추세에 대응 가능한 최적의 특성을 보유하고 있는 Sputtering Type FCCL을 중심으로 디스플레이의 발전에 대응하는 소재의 기술 개발 동향을 살펴보고자 한다.

• Advances in nano research
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• v.5 no.4
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• pp.337-357
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• 2017

Knowledge of thin films mechanical properties is strongly associated to the reliability and the performances of Nano Electro Mechanical Systems (NEMS). In the literature, there are several methods for micro materials characterization. Bulge test is an established nondestructive technique for studying the mechanical properties of thin films. This study improve the performances of NEMS by investigating the mechanical behavior of Nano rectangular thin film (NRTF) made of new material embedded in Nano Electro Mechanical Systems (NEMS) by developing the bulge test technique. The NRTF built from adhesively-bonded layers of basalt fiber reinforced polymer (BFRP) laminate composite materials in Nano size at room temperature and were used for plane-strain bulging. The NRTF is first pre-stressed to ensure that is no initial deflection before applied the loads on NRTF and then clamped between two plates. A differential pressure is applying to a deformation of the laminated composite NRTF. This makes the plane-strain bulge test idea for studying the mechanical behavior of laminated composite NRTF in both the elastic and plastic regimes. An exact solution of governing equations for symmetric cross-ply BFRP laminated composite NRTF was established with taking in-to account the effect of the residual strength from pre-stressed loading. The stress-strain relationship of the BFRP laminated composite NRTF was determined by hydraulic bulging test. The NRTF thickness gradation in different points of hemisphere formed in bulge test was analysed.

• Textile Coloration and Finishing
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• v.33 no.1
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• pp.40-47
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• 2021

As modern society develops, it becomes very complex and diverse, and interests in the convenience of life and the natural environment are gradually increasing. Products used in our daily life are also changing according to the needs of consumers, and food packaging is one of them. In particular, retort packaging materials have been used for the purpose of long-term preservation of contents, but the appearance of products suitable for recent environmental issues has been somewhat delayed. Therefore, in order to develop eco-friendly and human-friendly products by replacing the metals used in the existing retort packaging materials, the possibility of substitution was examined using cellulose nanofibers, a natural material. As a result, it can be seen that all functions can be replaced according to the existing long-term storage characteristics for retort packaging films. In particular, not only oxygen permeability and water vapor permeability, which are one of the most important factors, but also heat resistance, which is heating durability, is evaluated as applicable to commercialization compared to products using metals currently in use.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.15-21
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• 1984

In order to ascertain the practical possibility of home made retort pouches for production of retort pouch foods in factory, two kinds of retortable pouches, i. e. 3 ply film (polyester film/Al. foil/casting polypropylene) and 4 ply film(polyester film/Al. foil/nylon/casting poll·propylene) were developed in Korea, and then, their physical properties, such as physical strength, heat resistance during thermal processing and preservability of foods and sanitary safety, were tested and compared with the foreign made pouches. The results obtained were summarized as follows. a. The physical strength of home made retort pouches in processing model foods(soybean oil 5 %, acetic acid 2%, starch 5 % and water to 100 %) was equal to that of foreign made pouches at accelerated examination condition($38^{\circ}C$, 98 % RH). But the lamination strength of home made products was a little bit superior to that of foreign made products. b. Home made retort pouches(SAMA-4 ply and SAMA-3 ply pouch) packed with rice or curry was possible to bear the thermal processing at $135^{\circ}C$ and shelf-life was one year or more at ambient temperature($20^{\circ}C$). c. Sanitary safety test showed that these home made retort pouches were acceptable comparing to the regulation recommended by the Ministry of Health and Social Affairs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.10
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• pp.966-978
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• 2011

Transpiration cooling is the most effective cooling technique for the high-performance liquid rockets and air-breathing engines operating in aggressive environments with higher pressures and temperatures. When applying transpiration cooling, combustor liners and turbine blades/vanes are cooled by the coolant(air or fuel) passing through their porous walls and also the exit coolant acting as an insulating film. Practical implementation of the cooling technique has been hampered by the limitations of available porous materials. But advances in metal-joining techniques have led to the development of multi-laminate porous structures such as Lamilloy$^{(R)}$ fabricated from several diffusion-bonded, etched metal thin sheets. And also with the availability of lightweight, ceramic matrix composites(CMC), transpiration cooling now seems to be a promising technique for high-performance engine cooling. This paper reviews recent research activities of transpiration cooling and its applications to gas turbines, liquid rockets, and the engines for hypersonic vehicles.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.600-606
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• 2016

Wood-based composite panels such as plywood, particleboard (PB), or medium density fiberboard (MDF) are mostly used in the lamination on their surface for the manufacturing of furniture, or interior building products, the concern on the formaldehyde emission (FE) from the surface laminated wood panels is increasingly attracting attentions from the public. Thus, this study was conducted to understand influence of surface laminating materials to the FE from PB and MDF with or without edge sealing, using 24-hour desiccator method. Both PB samples that had been laminated on their surface with low-pressure laminate (LPL) or polypropylene (PP) film and MDF that had been treated with poly(vinyl chloride) (PVC) or coating were tested for the FE with or without edge sealing. As expected, the FE of PB with the sealed edges decreased to 37.4% and 80.7% with the LPL and PP lamination, respectively. The surface laminated MDF with the sealed edges also showed a decrease in the emission up to 57.8% and 54.3%, with the PVC lamination and coating, respectively. However, the coated MDF samples showed 5.3% increase in the emission when their edges were not sealed, indicating a FE form the solvent used for coating. These results showed that the type of surface lamination materials on wood-based composite panels has a great impact on their resultant FE, indicating that the influence of surface laminating materials should be taken into consideration for the formaldehyde mission measurement.