• Journal of Adhesion and Interface
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• v.14 no.2
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• pp.95-100
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• 2013

In this study, a series of hot-melt pressure sensitive adhesives (HMPSAs) based on metallocene polyolefin (me-PO) were prepared to investigate their possibility of replacing the HMPSAs based on styrenic block copolymers (SBCs). In addition, to optimize the performance of HMPSAs based on me-PO, several tackifiers having different softening point and molecular weight were evaluated. To achieve the HMPSAs which can satisfy the Dahlquist Criterion, hot melts required over 10% of process oil. To obtain the HMPSAs having low viscosity which can be applied by a spraying type applicator, secondary polymer having relatively low crystallinity was required. And, tackifier having high molecular weight attributed to increasing the cohesive strength of me-PO based HMPSAs.

• Journal of Radiation Industry
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• v.18 no.3
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• pp.227-233
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• 2024

Polyolefins (PO) are used in various industrial fields due to their excellent mechanical properties, processability, and chemical resistance. However, they have low flame retardancy, and when exposed to high temperatures, there are problem that mechanical properties deteriorate due to oxidation. In this study, we developed PO/metal hydroxide composites that exhibit excellent mechanical strength, heat resistance, and flame retardancy by using antioxidants and radiation crosslinking technology. To improve mechanical strength, heat resistance, and flame retardancy, PO/metal hydroxide/antioxidant composites were prepared and irradiated with an electron beam. Specifically, at temperatures above 200℃, the PO/metal hydroxide composites with primary and secondary antioxidants added and irradiated with a 100 kGy electron beam exhibited excellent thermal stability with a thermal shrinkage rate of less than 3%. In addition, the flame retardancy of the PO/metal hydroxide/antioxidant composites was improved due to enhanced thermal stability from electron beam irradiation and reduced thermal decomposition rate from the antioxidants. These results indicate that radiation crosslinking and antioxidants are effective method to simultaneously achieve mechanical properties, heat resistance, and flame retardancy.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.314-320
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• 2014

Three leaf vegetables, namely green lettuce, red lettuce (Lactuca sativa) and red-veined chicory (Cichorium intybus) were grown in minigreenhouses covered with two new functional films and conventional polyethylene film (PE). Seedlings of leaf vegetables were transplanted in a plastic troughs filled with soil-perlite mixture. Two functional films were made from polyolefin (PO) material. Measurement of optical characteristics showed that polyolefin films have better transmittance for the photosynthetic active radiation (PAR, 400-700nm) and higher absorptance for the ultraviolet radiation (UV, 300-400nm) in comparison with the conventional PE film. After three months of utilization higher loss in PAR transmittance was observed for conventional PE film. Leaf vegetables growth was enhanced and yield was increased in greenhouses covered by new functional films.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.312-318
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• 2023

In recent years, fine and yellow dust pollution has become serious in Korea and has negatively affected crop production. Particulate matter (PM) adheres to greenhouse coverings, and it reduces the amount of solar radiation transmitted into a greenhouse. A reduction in light transmittance can have a direct effect on crop photosynthesis and an indirect effect on air temperature in a greenhouse, which can lead to differences in crop yield. The objectives of this study were to investigate the changes in light transmittance of different cover materials by PM and to determine the changes in cucumber growth in a greenhouse due to reduced light transmittance. We measured the changes in light transmittance of polyethylene (PE) and polyolefin (PO) films in the PM generation chambers. Also, cucumber plants were cultivated in a greenhouse with four different light reduction treatments (0, 10, 20, and 30% reduction of light transmittance). The initial light transmittance of PO film was higher than that of PE film and the decrease in light transmittance of PO film due to PM was less than that of PE film. The vegetative growth of cucumber was promoted under the reduced light transmittance treatments; however, the yield of cucumber was highest in the control (0% reduction of light transmittance). From the results, we confirmed that PO film was less PM adhesion and that cucumber yield during the spring season can be reduced by the reduction in light transmittance due to PM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5906-5913
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• 2015

This paper analyzes the effect of adoption and complementarity of production technology bundles in horticultural greenhouse - more than 10m vinyl greenhouse ($T_1$), polyolefin film ($T_2$), winding branch ventilation ($T_3$), and more than 15 ounce lagging cover ($T_4$). The results are as follows: First, only using $T_1$, only using $T_2$, only using $T_3$, only using $T_4$, using $T_1$ and $T_3$, and using $T_1$ and $T_4$, have a higher net return. Second, when $T_3$ is used, $T_1$ and $T_2$ are complementary. Third, $T_1$ and $T_3$ are always complementary. Fourth, when $T_2$ and $T_3$ are not used, $T_1$ and $T_4$ are complementary. The results of this paper could contribute to government's technology diffusion policies and subsequent studies.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.95-99
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• 2016

As the survey results of cultivation area, farmhouse, yield and income to clarify the effect of PO Film on Korean melon industry in Seongju region, the covering areas of PE film of Korea, Kyungsangbuk-do and Seongju-gun in 2014 were decreased 91.5%, 94.9% and 95.2% as to 2010. In contrary, the covering areas of PO film of Korea, Kyungsangbuk-do and Seongju-gun in 2014 were increased 342.5%, 500% and 825% as to 2010. The cultivation area and farmhouse in 2015 were decreased 8.8% and 11.9% than those in 2010. The yield and production in 2015 were 38.2% and 25.9% increased han those in 2010. The gross and net income in 2015 were 1.3 and 2.7 times increased than those in 2010. Finally, to change as PO film, the productivity will be increased. And cleaning work and noxious materials discharge will be decreased.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.232-237
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• 2009

This study was performed to investigate the effect of high performance greenhouse films on growth and fruit quality of tomato. For this purpose, polyolefin (PO), fluoric, antidrop, antifog and thermal films were compared to normal film, ethylene vinyl acetate (EVA). In spectral irradiance of the films, UV ($300{\sim}400nm$) transmittance was highest in fluoric film and lowest in PO film. PAR (photosynthetically active radiation, $400{\sim}700nm$) transmittance was higher in fluoric, thermal and PO film, and near infrared ray (NIR, $700{\sim}1,100nm$) transmittance was higher in high performance films, compared to the EVA film. Total light transmittance was higher in order of fluoric, antifog, anti drop, PO, thermal, and EVA film. Day air temperature in greenhouse was highest under fluoric film and lowest under EVA film due to the light transmittance, while night air temperature was highest under PO and anti drop film due to the thickness of film. Tomato fruits grown under the high performance films had 0.2 to $0.5^{\circ}Bx$ higher soluble solids and 15 to 30% higher lycopene content, compared to those grown under the EVA film. The results showed that tomato fruit quality such as soluble solids and lycopene content can be heightened in terms of much irradiation and better light quality of high performance films, compared to the nomal film, EVA film.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.137-142
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• 2011

Individual solar cells must be connected together to give the appropriate current and voltage levels and they must also be protected from damage by the environment. [1] PV module consists of a glass/ polymer encapsulation/ solar cell string/ polymer encapsulation/ back sheet. Usually, encapsulation materials is used EVA(ethylene vinyl acetate), PVB(polyvinyl butyral), PO(polyolefin)sheet. This study is about fabrication of module using silicone material instead of above them. We got to know advantage that is fabrication time and efficiency of modules.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.428-439
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• 2020

This study was carried out to investigate the effect of PO film on the increase of crop yield and energy saving through PO and PE film greenhouse application and comparison test. As a experimental greenhouse, two single span greenhouses (1-1 W) and two double span greenhouses (1-2 W) were used. During winter season, PO film (0.15 mm outer layer, 0.10mm inner layer) was used as a covering material of greenhouse in double layers for double-span (B15) and single-span(B21), and PE film used for double-span (B15), and single-span (B23) as a control. The experimental vegetable was tomato(Solanum lycopersicum L.) cultivated in soil and the cultivar of that was 'Happiness'. That was cultivated from December 3, 2019 to April 30, 2020. The temperature at night inside the greenhouse was maintained at 15℃, and the side and roof windows were opened to maintain 23 ~ 24℃ during the day. As a result, this study showed that the yield in single-span greenhouse(B21) covered with a PO film increased 20% and that in double-span greenhouse (B16) increased by 9% compared to the greenhouse covered with a PE film (B23, B15). Fuel consumption of the single-span greenhouse (B21) with the cover of PO film was reduced by 12.4% and that of double-span greenhouse was done by 11.5% compared to that of the PE film greenhouse (B23, B15) without any difference between them in growing state.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.73-76
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• 2020

Silver nanowires (AgNWs) intrinsically possess high conductivity, ductility, and network structure percolated in a low density, which have led to many advanced applications of transparent and flexible electronics. Most of these applications require patterning of AgNWs, for which photolithographic and printing-based techniques have been widely used. However, several drawbacks such as high cost and complexity of the process disturb its practical application with patterning AgNWs. Herein, we propose a novel method for the patterning of AgNWs by employing UV-curable adhesive tape with a structure of liner/adhesive layer/polyolefin (PO) film and UV irradiation to simplify the process. First, the UV-curable adhesive tape was attached to AgNWs/polyurethane (PU), and then selectively exposed to UV irradiation by using a photomask. Subsequently, the UV-curable adhesive tape was peeled off and consequently AgNWs were patterned on PU substrate. This facile method is expected to be applicable to the fabrication of a variety of low-cost, shape-deformable transparent and wearable devices.