• Title/Summary/Keyword: Polyolefin

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Optical Characteristics of Two New Functional Films and Their Effect on Leaf Vegetables Growth and Yield (2종류의 기능성필름이 광학특성과 엽채류 생육과 수량에 미치는 영향)

  • Kwon, Joon Kook;Khoshimkhujaev, Bekhzod;Park, Kyoung Sub;Choi, Hyo Gil;Lee, Jae-Han;Yu, In Ho
    • 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.

Characterization of Polyolefin Separator Support Membranes with Hydrophilic Coatings (폴리올레핀계 다공성 세퍼레이터 지지체 막의 친수 코팅에 따른 특성 평가)

  • Park, Yun Hwan;Nam, Sang Yong
    • Membrane Journal
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    • v.27 no.1
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    • pp.92-103
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    • 2017
  • In this study, electrochemical performance of the hydrophilized separator for the lithium ion battery is studied. The polyolefin based material used as the separator for the lithium ion battery is hydrophobic, and the electrolytic solution using a carbonate-based organic solvent is hydrophilic. Therefore, the polyolefin separator is hydrophilized using various hydrophilic polymers because lithium ion battery uses an aqueous electrolyte solution. In order to evaluate change of the coated separator, the performances of separator in terms of surface morphology, porosity and the wettability are investigated. Finally, the resistance and the ionic conductivity of separator coated with lithium ion are measured to evaluate the performance of lithium ion battery. Separator coated with PMVE shows good hydrophilicity and excellent ionic conductivity because the porosity of the separator is maintained. We can confirm that this property makes potential candidates for lithium ion battery.

Changes in Quality Characteristics of Bell Pepper Packaged with Different Films (포장 조건에 따른 피망의 저장 중 품질 특성 변화)

  • 박우포;조성환;김철환
    • Food Science and Preservation
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    • v.10 no.2
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    • pp.131-135
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    • 2003
  • Bell pepper was packed with several plastic films, and investigated the quality Characteristics such as gas composition, weight loss, microbial load, soluble solid content, ascorbic acid and color during storage at 10$^{\circ}C$. Cast polypropylene (CPP), low density Polyethylene (LDPE), Polyolefin (MPD, PD961) and linear low density polyethylene (LLDPE) were used for this purpose. Oxygen concentration inside packages generally showed a 10∼14% after 1∼2 weeks, but package with CPP maintained above 15% throughout the storage. Carbon dioxide concentration of CPP was above 2%, but other treatments showed below 2%. Weight loss of all treatments was below 3.0% after 5 weeks. Total microbial count showed a similar pattern compared to yeast and mold, and CPP maintained the highest microbial load after 3 weeks. Yellowness (b value) of bell pepper was generally increased throughout the storage, and MPD and PD961 were higher than other treatments.

Electrochemical Properties of Core-Shell Polyolefin Nonwoven Fabric Modified with Sulfonic Acid Group (술폰산기를 갖은 코아-쉘형 폴리올레핀 부직포의 전기화학적 성질)

  • Choi, Seong-Ho;Zhang, Yu-Ping;Shon, Sang-Ho;Lee, Kwang-Pill
    • Analytical Science and Technology
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    • v.17 no.1
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    • pp.60-68
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    • 2004
  • The core-shell polyolefin nonwovon fabric (PNF), wherein the PNF comprises at least about 60% of polyethylene having a melting temperature at ${\sim}132^{\circ}C$ and no more than about 40% of second polypropylene having a lower melting temperature at ${\sim}162^{\circ}C$. The sulfonic acid group for battery separators were prepared by radiation-induced grafting of styrene onto PNF and by the subsequent sulfonation of polystyrene graft chains. The sulfonated PNF was characterized by XPS, SEM, DSC, TGA and porosimeter. The electrochemical properties such as electrolyte retension, electrical resistance, and transport number of the $K^+ions$ were evaluated after sulfonation. It was found that the electrolyte retension increased, whereas the electrical resistance decreased with increasing sulfonic acid content. The transport number of $K^+$ in PNF with sulfonic acid of 0.22 ~ 3.60 mmol/g was to be 0.90 ~ 0.93.

Study on flexural toughness and flexural tensile strength of fiber reinforced concrete by mixture ratio of different fibers (이종 섬유 혼입비에 따른 섬유보강 콘크리트의 휨 인성 및 휨 인장강도에 관한 연구)

  • Park, Hong-Yong;Ryu, Jong-Hyun;Jo, Yong-Bum
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.1
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    • pp.51-60
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    • 2010
  • Recently, a new type of polyolefin fiber having a good mechanical properties is being developed, and it is necessary to examine a possibility for the new fiber together to be used as a reinforcing fiber with other types of fiber or by itself. The objective of this study is to find flexural toughness and tensile strength of concrete reinforced with steel and polyolefin fibers. Four point beam tests were performed with 324 specimens following two standard tests methods: KS F 2566 and ASTM C 1399-02. From the test results, the effects of volume fraction of fibers, and aspect ratio of steel fiber on the toughness and tensile strength were investigated, and the optimal ratio of steel fiber to polyolefin fiber was suggested.

Processability of Bio-composites Applied Polyolefin to Recycled Fiberboard Flour (Polyolefin계 고분자에 섬유판 가공 부산물을 적용한 환경 친화형 바이오복합재의 가공성)

  • Choi, Seung-Woo;Kim, Hee-Soo;Lee, Byoung-Ho;Kim, Hyun-Joong;Ahn, Sye-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.6 s.134
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    • pp.55-62
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    • 2005
  • This study was conducted to evaluate the application of a bio-composite made by the addition recycled fiber board flour as filler. Recycled fiber board (high density fiber board, HDF) flour was added to polyolefin polymer low density polyethylene (LDPE) and polypropylene (PP) for the preparation of bio-composite materials. The mechanical properties and processability of the recycled HDF flour filled LDPE and recycled HDF flour filled PP bio-composites were then measured and compared to those of wood flour (WF) and rice-husk flour (RHF) filled LDPE and PP bio-composites, respectively. The tensile and impact strengths of the recycled HDF flour filled LDPE and PP bio-composites had similar mechanical properties to those of the WF and RHF filled LDPE and PP bio-composites. To measure the processability, torques of the bio-composites were also measured. The torques of the HDF flour filled LDPE and PP bio-composites were lower than those of the WF and RHF filled polyolefin (PP and LDPE) bio-composites with a filler loading of 30 wt.%. This result showed definite processability, which was not related with the distribution of the particle size of the material added. The recycled fiber board flour filled bio-composites showed applicability as substitutes for the bio-composites currently used in the bio-composites industry.

Quality Changes in 'Elliot' Blueberries and 'Sulhyang' Strawberries Packed with Two Different Packaging Materials during Refrigerated Storage (기체투과도가 다른 포장재로 포장한 '엘리오트' 블루베리와 '설향' 딸기의 냉장 저장 중 품질 변화)

  • Jung, Seung Hun;Kang, Ji Hoon;Park, Seung Jong;Seong, Ki Hyun;Song, Kyung Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.901-908
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    • 2014
  • Blueberries and strawberries are highly perishable and easily contaminated with microorganisms. To maintain the quality of these commodities during refrigerated storage, the effects of two packaging materials as well as passive modified atmosphere packaging on the quality of blueberries and strawberries were investigated. The harvested blueberries and strawberries were first treated with combined non-thermal treatment of aqueous chlorine dioxide and fumaric acid, followed by packaging with polyolefin film (6,000 mL $O_2/m^2{\cdot}24hr{\cdot}atm$ at $24^{\circ}C$) and polyamide/polyamide/polyethylene film (PA/PA/PE, 60 mL $O_2/m^2{\cdot}24hr{\cdot}atm$ at $24^{\circ}C$), respectively. After combined sanitizer treatment, the populations of total aerobic bacteria in blueberries and strawberries were reduced by 2.50 and 1.97 log CFU/g while those of yeast and molds were reduced by 1.95 and 2.18 log CFU/g, respectively, compared with the control. In particular, microbial growth in these samples packed with PA/PA/PE film was reduced during refrigerated storage. In addition, the blueberries and strawberries packed with PA/PA/PE film underwent lower weight loss than those packed with polyolefin film during storage. These results suggest that appropriate packaging with proper gas permeability is necessary to maintain the quality of blueberries and strawberries during refrigerated storage.

Effect of Long Period Usage of Polyolefin Film on Growth and Fruit Quality in Korea Melon(Cucumis melo L. var makuwa Makino) (폴리올레핀계 필름 장기사용이 참외의 생육 및 품질에 미치는 영향)

  • Shin, Yong-Seub;Yeon, Il-Kweon;Lee, Ji-Eun;Cheong, Jong-Do;Choi, Seong-Yong;Chung, Doo-Seok
    • Journal of Bio-Environment Control
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    • v.18 no.1
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    • pp.9-14
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    • 2009
  • This experiment was conducted to investigate the difference among 3-years-used Polyolefin films which were J-1, J-2 and J-3 having differences in film thickness, infrared absorption and ultraviolet penetration from Jan. 16,2006. And 1-year-used Polyethylene film K-1 used from Jan. 16,2008, for covering film of greenhouse for korea melon cultivation. J-2, J-3 and J-1 films were better for keeping heat in order, and J-2 film was the best in plant growth at early stage. The first blooming and harvesting days in J-2 film were earlier 10 days than those in K-1 film. Chromaticity and soluble solid of harvested fruit in J-3, J-1 and J-2 films were higher than those in K-1 film. Marketable yields in J-2, J-1 and J-3 films were higher in order.