• Fire Science and Engineering
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• v.15 no.3
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• pp.7-13
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• 2001

In this paper, we had analyzed comsbustion gases according to pyrolysis $600^{\circ}c$, $800^{\circ}c$ and $1000^{\circ}c$ for polymeric material using a GASTEC colorimetric gas detector tube in order to combustion gases toxicity evaluation for flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam of polymeric material. As a result, comsbustion gases producted from small specimens of polymeric material had reached fatal to man at a 30 minute exposure time that had possesed toxicity index. Toxicity index at pyrolysis $800^{\circ}c$ of flexible polyvinyl chloride was 31.74. Flexible polyvinyl chloride was the highest toxicity index of flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam. The comsbustion gases producted commonly no concern with pyrolysis temperature had analyzed carbon dioxide($CO_2$) and carbon monoxide(CO). Toxicity index had investigated differently according to pyrolysis temperature even a similar materal.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.16-23
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• 2015

The industrialization and urbanization forced to increase the density of pipelines such as water supply, sewers, and gas pipelines. The materials used for the existing pipe lines are mostly composed of concretes and steels, but it is true that the development for more durable and efficient materials has been continued performed to produce long lasting pipe lines. Recently, underground pipes serve in diverse applications such as sewer lines, drain lines, water mains, gas lines, telephone and electrical conduits, culverts, oil lines, etc. In this paper, we present the result of investigation pertaining to the structural behavior of unplasticized polyvinyl chloride (PVC-U) flexible pipes buried underground. In the investigation of structural behavior such as a ring deflection, pipe stiffness, 4-point bending test, experimental and analytical studies are conducted. In addition, pipe stiffness is determined by the parallel plate loading tests and the finite element analysis. The difference between test and analysis is about 8% although there are significant variations in the mechanical properties of the pipe material. In addition, it was found by the 4-point bending test there is no problem in the connection between the pipes by coupler.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.8-12
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• 2000

The properties variation by deterioration of the 600V grade heat-resistant polyvinyl chloride insulated wire(HIV) was analyzed. The weight variation of the thermal deteriorated HIV was about 42% at 80$0^{\circ}C$ and over. From the analysis result of the metallurgical microscope photographs it shows that the sorface of normal wire showed the elongated structures. However the elongated structures did not appear at $900^{\circ} and over and we could observe that particles were grown. The grown oxidized substances in the thermally deteriorated electric wire were observed by SEM. The CuL, CuK, $CuK_b$, OK and CIK spectra of the thermally deteriorated HIV at $300^{\circ}C$ were uniform regardless of the scanning length, but the spectra of CIK could not found at above $700^{\circ}. At the DTA analysis, the endothermic reactions were occurred around $3006{\circ}C\; and\; 400^{\circ}C$ and the exothermic reactions were occurred around $470^{\circ}, respectively.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.62-62
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• 2010

PVC(Polyvinyl Chloride)와 HDPE(High-density Polyethlene) 하수도관은 수많은 고분자 재료 중에도 높은 기계적 강도를 가지며, 광범위하게 사용되고 있다. 하지만, PVC와 HDPE 하수관을 연결하기 위해 소모 접착제나 고무링 이용한 소켓 방법 이음 방법은 낮은 수밀성과 기계적 강도로 오 폐수의 누수가 발생되고, 이것이 흙에 스며들어 지하수, 하천 및 토양을 오염시키고 있다. 따라서, 대안으로 최근에는 열판을 이용한 맞대기 융착 용접을 PE 하수도 관에 제한적으로 적용하여 시공하고 있다. 그러나, PVC 하수관은 열을 가할 시 열에 의한 민감한 거동으로 인해 맞대기 융착 용접법이 적용되지 못하고 있는 실정이다. 따라서 본 연구에서는 하수도 관 중, 국내에서 가장 많이 사용되고 있는 내 충격 PVC 하수도관과 HDPE 이중 벽관의 DSC(Diffential Scanning Calorimeter), TGA(Thermogravimetric analyzer), TMA(Thermomechanical Analysis), DMA(Dynamic Mechanical Analysis) 분석으로 온도에 따른 열적 거동을 분석하여, 적절한 융착 온도 조건을 제시하였다. 또한 접합강도 향상을 위한 이음부 설계를 제안하여, 융착 용접 특성을 평가하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.8
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• pp.78-83
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• 2010

This paper describes the characteristic of tracking progress happened at the end of the polyvinyl chloride insulated cabtyre oval cord(VCTFK) that is widely used for distribution cord. Tracking is occurred owing to the drop of electrolyte at the end of the VCTFK. The tracking progress and its characteristic happened at the end of the VCTFK are as follow; Carbonization and electrical erosion are happened at the end of the VCTFK. Electrical erosion is begun at the insulation layer near conductors. After that, it is also happened at the sheath layer. Accumulation of carbonized insulation and sheath materials at the end of the VCTFK is begun after progress of electrical erosion. When the accumulation is progressed arc discharge is appeared and finally it goes to tracking breakdown.

• Nuclear Engineering and Technology
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• v.8 no.2
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• pp.89-99
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• 1976

The grafting of acrylic acid in aqueous solution to polyvinyl chloride fibers tab been studied in the presence of ferrous, ferric, and cupric salts, The mutual irradiation technique was adopted using a Co-60 source or a Van do Graaff accelerator. The grafting and homopolymerization were suppressed by the cations. Particularly the grafting was suppressed by the cations in the following order of effectiveness : $Cu^{2+}$>$Fe^{2+}$>$Cu^{3+}$. The rate of grafting (in %/hr) was proportional to the 0.76th power of the dose rate over the range from 8.5f $10^3$ rad/hr to $1.4\times10^5$ rad/dr. The apparent activation energy for the grafting was determined to be 6.1 Kcal/mole between $25^{\circ}$ and $75^{\circ}C$ for the mixture of AA-HaO-$(CH_2Cl)_2$, containing Mohr's salt, $4\times10^{-3}$ mole/l. The increase of the grafting was observed when total dose and dose intensity were raised, or when ethylene dichloride as a swelling agent was saturated in the monomer mixture. The grafted polyvinyl chloride fibers showed considerable improvement in moisture regain, heat shrinkage, and melting properties, but tensile properties were not significantly affected by grafting.

• Membrane Journal
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• v.19 no.4
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• pp.324-332
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• 2009

This study aimed to measure chemical resistance properties of the microfiltration flat-sheet membrane made by Chlorinated Polyvinyl Chloride (CPVC) with respect to the immersed time. The solutions of effective chlorine 0.5 wt% NaClO, HCl 1 wt% and pH 4 buffer under acidic condition, NaOH 4 wt% and pH 10 buffer under alkine condition were used as widely applied chemicals for membrane washing. The CPVC membrane samples were immersed in the above chemical solutions during 1, 3, 5 and 10 days at 5, 25 and $50^{\circ}C$, respectively. After then, the tensile strength and elongation at break as the chemical durability for the samples were measured and evaluated. The tensile strength decreased within 5% at $5^{\circ}C$, but decreased up to 17% at 25 and $50^{\circ}C$ for 0.5 wt% NaClO solution mainly used for membrane cleaning. The chemical resistance of CPVC membrane was good enough for HCl 1 wt% and pH 4 buffer acid solutions, but the most vulnerable for NaOH 4 wt% solution.

• 수도
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• s.6
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• pp.73-77
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• 1975

• 수도
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• s.60
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• pp.36-42
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• 1993

• Proceedings of the Korean Fiber Society Conference
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• 1999.04a
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• pp.347-348
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• 1999