• Title/Summary/Keyword: polyethylene

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Performance of Wood-plastic Panel Made from Populus alba × glandulosa and Low Density Polyethylene (은수원사시나무와 저밀도 폴리에틸렌으로 제조된 목질플라스틱패널의 성능)

  • Kwak, Jun-Hyuk;Oh, Yong-Sung
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.1
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    • pp.67-72
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    • 2004
  • Wood/polyethylene panels were manufactured from Populus alba × glandulosa particles and low density polyethylene particles at three mixing rates, 50:50, 60:40, and 70:30. A total of 15 wood/polyethylene panels was made at 145℃ and 5 minutes hot-press time. Wood/polyethylene panels were tested for internal bond, bending, and dimensional stabilities such as thickness swell and water absorption. Panel performance data were analyzed using the SAS programing package. The test results of the wood/polyethylene panels showed that as the polyethylene mixing rates were increased, the panel property values increased. Based on panels' dimensional stabilities, the optimum wood/polyethylene mixing ratio appeared to be 60:40.

Silk Reelability of the Cocoon Stored in a Pelyethylene Bag (Polyethylene대 저견이 조사에 미치는 영향)

  • 최병희;송기언
    • Journal of Sericultural and Entomological Science
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    • v.6
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    • pp.31-33
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    • 1966
  • This work has been carried out for many months to check whether polyethylene bag cocoon storging method bring better reeling result against the normal cotton bag storing method. The obtained results were as followings. 1. The pupa killed cocoons could be stored on the ground in case of packing in polyethylene-bag until the secondary dry process. 2. The raw silk percentage of cocoon stored in polyethylene bag, increased 0.5% than the cotton bag storing method, not because of its reelability, but because of the better yield of cocoon bave. 3. Musty cocoon was not shown during the polyethylene hag storage, but the cocoons were attacked by rats as usually. 4. Polyethylene bag storing method invited more insects attack than the normal method, but the attack was able to cease by enclosing two naphthalene tablets in each bag.

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Graphene Growth with Solid Precursor-Polyethylene (고체 전구체-폴리에틸렌을 이용한 그래핀 성장)

  • Ryu, Jongseong;An, Sung Jin
    • Korean Journal of Materials Research
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    • v.29 no.5
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    • pp.304-310
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    • 2019
  • Chemical vapor deposition method using $CH_4$ gaseous hydrocarbons is generally used to synthesize large-area graphene. Studies using non-gaseous materials such as ethanol, hexane and camphor have occasionally been conducted. In this study, large-area graphene is synthesized via chemical vapor deposition using polyethylene as a carbon precursor. In particular, we used a poly glove, which is made of low-density polyethylene. The characteristics of the synthesized graphene as functions of the growth time of graphene and the temperature for vaporizing polyethylene are evaluated by optical microscopy and Raman spectroscopy. When the polyethylene vaporizing temperature is over $150^{\circ}C$, large-area graphene with excellent quality is synthesized. Raman spectroscopy shows that the D peak intensity increased and the 2D peak intensity decreased with increasing growth time. The reason for this is that sp3 bonds in the graphene can form when the correct amount of carbon source is supplied. The quality of the graphene synthesized using polyethylene is similar to that of graphene synthesized using methane gas.

Biofilm Formation Characteristics of Major Foodborne Pathogens on Polyethylene and Stainless Steel Surfaces

  • Kim, Hyeong-Eun;Kim, Yong-Suk
    • Journal of Food Hygiene and Safety
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    • v.35 no.2
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    • pp.195-204
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    • 2020
  • This research was investigated the effects of temperature and time against the formation of biofilms by foodborne pathogens on surfaces of polyethylene and stainless steel. After preliminary experiments with 32 strains from 6 species of foodborne pathogens (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella Typhimurium), one strain from each species with the highest biofilm formation efficiency was selected. All foodborne pathogens showed a tendency toward an increased ability for biofilm formation with increasing temperature, but there was no consistency between the two materials and between foodborne pathogens. At all tested temperatures, the biofilm formation ability of E. coli and P. aeruginosa on the polyethylene surface was higher than that on the stainless steel surface with significant differences. The foodborne pathogens all formed biofilms immediately upon inoculation, and biofilm formation by E. coli, P. aeruginosa, and S. Typhimurium increased on both the polyethylene and stainless steel surfaces at 1 h after inoculation compared to at 0 h. At 7 days after biofilm formation, the other strains except S. aureus showed no difference in survival rates on polyethylene and stainless steel. The ability of these 6 foodborne pathogens to form biofilms showed different trends depending on the type of bacteria and the instrument material, i.e., polyethylene and stainless steel.

Surface Deterioration Phenomena in Polyethylene under Corona Discharge (Corona 방전에 의한 Polyethylene의 표면열화현상)

  • 성영권;송진수;민남기
    • 전기의세계
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    • v.24 no.5
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    • pp.82-90
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    • 1975
  • This study investigated the deterioration phenomena of the Polyethylene surface contaminated with organic(Saccharose) or inorganic(NaCl) matters through electrical and optical experiments. And also these experimental results relatively well coincided with which was treated by theoretical process. On the electrical experiment, relation between electric field intensity in corona discharge and time reached to the breakdown, and relation between total amount of charges discharged and increment of applied voltage were investigated. On the optical experiment, discharge time dependence of surface deterioration rate and process of surface deterioration in the X-ray diffraction pattern were investigated. It was concluded that chemical effects by the corona discharge deteriorated insulation characteristics of Polyethylene surface.

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Electrical Properties of XLPE/VLDPE B1ends (XLPE/VLDPE 블렌드의 전기적 성질)

  • 고정우;서광석;김종은;강형식;김덕주
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.215-218
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    • 1998
  • XLPE/VLDPE (Crosslinked polyethylene/very low density polyethylene) blends were prepared by a twin screw extruder and their electrical properties such as water tree and breakdown characteristic were measured. it was found that both water tree and breakdown characteristics of XLPE were improved by the addition of VLDPE to polyethylene. It was also found that the extent of improvement of electrical properties by the addition of VLDPE to polyethylene depends on the type and concentration of VLDPE.

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Improving wettability of polyethylene(PE) surface by ion assisted reaction (이온보조반응법에 의한 Polyethylene(PE) 표면의 친수성 증가)

  • 석진우;최성창;장홍규;정형진;최원국;고석근
    • Journal of the Korean Vacuum Society
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    • v.6 no.3
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    • pp.200-205
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    • 1997
  • Surface of polyethylene film was modified by ion assisted reaction in which ion beam is irradiated on polymer in reactive gas environments. Ion (argon and oxygen) beam energy was 1 keV, doses were varied from $1{\times}10^{14}$ to $1{\times}10^{17}$ inons/ $\textrm{cm}^2$, and amount of blowing oxygen from 0 to 4 sccm(ml/min). Wettability was measured by water contact angle measurement, and the surface functionality was analyzed by x-ray photoelectron spectroscopy. The contact angles of water to polyethylene modified by oxygen ion beam only decrease from 95 to degrees, and surface energy was not changed much. The contact angles remarkably decrease to 28 degrees and surface energy increase to 67 erg/ $\textrm{cm}^2$ when the films were modified by argon ion with various ion doses with blowing oxygen gases near the polyethylene surface. Improvement of wettability and surface energy are mainly due to the new functional group formation such as C-O or C=O, which are known as hydrophilic groups from the XPS analysis, and the assisted reaction is very effective to attach oxygen atoms to form functional groups on C-C bond chains of polyethylene.

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A Study on the Effect of Some Packing Materials in Chilling of Persimmon (Teabong- Si) (감(대봉시(大奉枾))의 냉장(冷藏)에 있어서 포장효과(包裝效果)에 관(關)한 연구(硏究))

  • Park, Won-Ki
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.6 no.1
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    • pp.1-8
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    • 1977
  • The sample persimmons were obtained from the of Yung-am Kun, Korea on October 24, and November 9, 1973. These persimmons were kept at room temperature overnight, then packed and stored on the following day at $0^{\circ}C$ and $85{\sim}100%$ humidity. Seven experimental items were studied : 1. control, 2. packing with excelsior in wooden boxes, 3. packing with rice hull in wooden boxes, 4. packing in bags of 0.03 mm polyethylene membrane, 5. packing in bags of 0.06 mm polyethylene membrane, 6. packing in bags of 0.08 mm polyethylene membrane, 7. packing in sealed desiccators. The dimension of polyethylene bags were $14{\times}28cm$ and three persimmons were packing in each bag. The results are as follows: 1. The persimmons both in polyethylene bags and in desiccators lost only 1 % or less of weight, while in control (1) packing with excelsior (2) or with rice hull (3) the loss was 6-7 % in weight after $2{\sim}3$ months. The persimmons became visibly shriveled and spongy-like in it's texture when it lost 5 % of weight. 2. Carbon dioxide content within the polyethylene bags and desiccators rapidly increased during the early storage period, and reached 5 % (in 0.03 mm polyethylene bags) to 50 % or more (in desiccator) after 1 month. In the polyethylene bags of 0.08 mm and desiccator, the carbon dioxide accumulated to a dangerous level and the persimmon showed physiological damage in a longer storage period. 3. The advance of after-ripening and deterioration of persimmon sealed in the polyethylene bags was slower than that in open bags when moved out to room temperature from the chilling and the polyethylene bags of 0.06 mm retarded the after-ripening most effectively. 4. On the basis of these results, a temperature of $0^{\circ}C$, relative humidity of almost $85{\sim}100%$ and combinations of 5 % oxygen and $5{\sim}8%$ carbon dioxide seem to be the optimum condition for the storage of persimmon (Teabong-Si). The most successful method of storing was to pack them in polyethylene bags of 0.06 mm and then to store them at $0^{\circ}C$.

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Decrosslinking of Cross-linked Polyethylene using Supercritical Methanol (초임계 메탄올을 이용한 가교 폴리에틸렌의 탈가교화)

  • Hong, Soon Man;Cho, Hang-kyu;Koo, Chong Min;Lee, Jang Hoon;Park, Wan Yong;Lee, Hong-Shik;Lee, Youn-Woo
    • Korean Chemical Engineering Research
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    • v.46 no.1
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    • pp.63-68
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    • 2008
  • We investigated the recycling method to re-plasticize cross-linked polyethylene by using supercritical methanol. The cross-linked polyethylene is successfully fragmented to thermoplasticized polyethylene with little degradation reactions in supercritical fluids. The thermo-plasticization reaction was accelerated with increase in temperature in the range from $360^{\circ}C$ to $400^{\circ}C$, resulting in decrease in crosslinking density, molecular weight and mechanical properties. However, the thermoplasticized polyethylene at $360^{\circ}C$ showed comparable tensile strength and impact strength with a raw resin of crosslinked polyethylene. Chemical structure of main chain of polyethylene was not affected by reaction condition.

Potential of Baeyer-Villiger monooxygenases as an enzyme for polyethylene decomposition (폴리에틸렌 분해를 위한 효소로써 Baeyer-Villiger monooxygenases의 잠재력)

  • Yoon, Ye Rin;Jang, Yu-Sin
    • Journal of Applied Biological Chemistry
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    • v.64 no.4
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    • pp.433-438
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    • 2021
  • Polyethylene is widely used as an agricultural film, but eco-friendly technology is lacking for its decomposition. Thus, recently, much attention has been paid to develop a technology for biological polyethylene decomposition. It has been expected that several oxidation steps will be required in the biological degradation of polyethylene. First, secondary alcohol is formed on the polyethylene chain, and then the alcohol is oxidized to a carbonyl group. In the subsequent process, the carbonyl group is converted to an ester by Baeyer-Villiger monooxygenase (BVMO), and this ester bond is expected to be cleaved by lipase and esterase in the final step. In this work, we reviewed BVMO as one of the promising enzymes for polyethylene decomposition, in terms of its reaction mechanism, classification, and engineering. In addition, we also give a brief perspective on polyethylene decomposition using BVMO.