• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1117-1119
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• 1995

Fluoroplastics have been used widely for chemical or electrical facility materials and lubricable engineering structural materials because they have the superior characteristics such as thermal stability, chemical stability, solid lubricity, arc resistance, wearable durability and good sealing property. In this study, PTFE composite materials for the insolation parts of high voltage and current breaker were investigated and estimated.

• Journal of the Korean Chemical Society
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• v.59 no.3
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• pp.233-237
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• 2015

The effect of ultrasonication on PTFE and its composites with zeolite and fluoroplast F-4NTD-2 was studied. Ultrasonication was found to cause changes in the supramolecular structure, and consequently, the tensile strength, relative elongation, and mass wear rate. Changes in the topology of the materials following ultrasonication were investigated by scanning electron microscopy. The optimum enhancement of the desired properties was found in the PTFE composite containing 2% activated zeolite.

• Transactions of Materials Processing
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• v.29 no.4
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• pp.179-187
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• 2020

Existing composite forming processes such as the autoclave, prepreg compression forming (PCF), RTM, etc. require high production costs because of their long processing time. On the other hand, microwave heating process (MHP) can reduce the production costs since both mold and composite material can be heated directly. The aim of this study is to manufacture a mold consisting of polytetrafluoroethylene (PTFE), quartz glass, stainless steel clamps, and polyether ether ketone (PEEK) bolts for fabricating FML based on self-reinforced polypropylene (SRPP) using the MHP. First, the flame test was carried out prior to the MHP to check the temperature on the mold and whether the spark occurred at the mold and the edge of the FML. Second, the uniaxial tensile test was then conducted to obtain the mechanical properties of the FML manufactured by the MHP. The mechanical properties were compared with those of the FML fabricated by the PCF. As a result, the MHP using the PTFE mold can manufacture the FML more rapidly than the PCF, and obtain acceptable mechanical properties.

• Membrane Journal
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• v.33 no.4
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• pp.201-210
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• 2023

Dust filter membranes play a crucial role in human life and various industries, as they contribute to several important aspects of human health, safety, and environmental protection. This study presents the development of a polysulfone@polyphenylene sulfide/polytetrafluoroethylene (PSf@PPS/ePTFE) composite dust filter membrane with excellent thermal stability and adhesion properties for high-temperature conditions. FT-IR analysis confirms successful impregnation of PSf adhesive onto PPS fabric and interaction with ePTFE support. FE-SEM images reveal improved fiber interconnection and adhesion with increased PSf concentration. PSf@PPS/ePTFE-5 exhibits the most suitable porous structure. The composite membrane demonstrates exceptional thermal stability up to 400℃. Peel resistance tests show sufficient adhesion for dust filtration, ensuring reliable performance under tough, high-temperature conditions without compromising air permeability. This membrane offers promising potential for industrial applications. Further optimizations and applications can be explored.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.1-9
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• 2020

Objectives: The purpose of this case study is to assess workers' exposure to carbon nanotubes(CNTs) and characterize particles aerosolized during the process of producing CNT-enabled polytetrafuoroethylene(PTFE) composites at a worksite in Korea. Methods: Personal breathing zone and area samples were collected for determining respirable concentrations of elemental carbon(EC) using NIOSH(National Institute for Occupational Safety and Health) Method 5040. Personal exposure to nano-sized particles was measured as the number concentration and mean diameter using personal ultrafine particle monitors. The number concentration by particle size was measured using optical particle sizers(OPS) and scanning mobility particle sizers(SMPS). Transmission electron microscopy (TEM) area samples were collected on TEM grids and analyzed to characterize the size, morphology, and chemistry of the particles. Results: Respirable EC concentrations ranged from 0.04 to 0.24 ㎍/㎥, which were below 23% of the exposure limit recommended by NIOSH and lower than background concentrations. Number concentrations by particle size measured using OPS and SMPS were not noticeably elevated during CNT-PTFE composite work. Instant increase of number concentrations of nano-sized particles was observed during manual sanding of CNT-PTFE composites. Both number concentrations and mean diameters did not show a statistically significant difference between workers handing CNT-added and not-added materials. TEM analyses revealed the emission of free-standing CNTs and CNT-PTFE aggregate particles from the powder supply task and composite particles embedded with CNTs from the computer numerical control(CNC) machining task with more than tens of micrometers in diameter. No free-standing CNT particles were observed from the CNC machining task. Conclusions: Significant worker exposure to respirable CNTs was not found, but the aerosolization of CNTs and CNT-embedded composite particles were observed during handing of CNT-PTFE powders and CNC machining of CNT-PTFE composites. Considering the limited knowledge on the toxicity of CNTs and CNT composite particles to date, it seems prudent to take a precautionary approach for the protection of workers' health.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.12
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• pp.1685-1693
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• 2002

다양한 용도로 사용되고 있는 라미네 이 팅 직물은 주로 별도로 제조된 고분자 필름 또는 막을 접착제, 열, 압력 등을 이용하여 기포(基布)와 결합시키는 방법으로 제조되어 진다. 이축연신시킨 Poly(tetrafluoroethylene) (PTFE) sheet는 매우 우수한 높은 투과성을 지니는 다공성 물질이 며, 본 연구에서는 이 막을 나일론 직물에 라미네이팅시킨 투습방수직물을 시료로 사용하여 라미네이팅 후의 역학특성 변화를 분석 하였다. 라미네이팅에 따른 투습방수직물의 물성과 역학특성의 변화에 관하여 살펴본 결과 다음과 같은 결과를 얻었다. 3-layer 라미네이팅 직물(base fabric-PTFE membrane-knitted lining)의 인열강도는 2-layer라미네이팅 직물 (base fabric-PTFE membrane)에 비해 매우 높게 나타났으며, 가공 전 직물과 비교하여 코팅직물에서 나타난 것과 같은 인열강도의 감소는 나타나지 않았다. 직물-PTFE 막 복합체 의 경우, 라미네 이 팅 이 파단강도 및 파단신도 의 증가에 기여 한 것으로 나타났으며 특히 3-layer 라미네이팅 직물의 경우, 신장률이 20%를 넘어서면서 강도가 현저히 증가하였다. 의복을 착용하였을 때 가해질 수 있을 정도의 소변형(small deformation) 하에서의 역학특성 에 있어서는 라미네이팅에 의해 전단특성이 가장 유의한 변화를 나타내었다. 전단강성(G)과 전단 히스테리시스 (2HG,2HG5)모두 증가하였고, primary hand value 중에서는 stiffness 가장 현저한 증가를 나타내었다

• Tribology and Lubricants
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• v.12 no.4
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• pp.7-12
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• 1996

Present study was undertaken to investigate the leakage and friction of self-lubricating piston seal rings. A crank-piston type gas leakage test set-up was constructed. The piston rings were made of PTFE-polyimide composite. The free gap configurations of the seal rings were butt and step types. Eccentric tension rings were used to give the seal rings prepressure between the seal rings and cylinder wall. Two sizes of the tension rings were installed to investigate their effect on the gas leakage and friction of the seal rings. The results showed that step type seal rings are superior than the butt types. High tension spring rings resulted in low leakage and high friction loss. In order to reduce the gas leakage and friction loss of the piston seal rings, there should be compromise between the number of ring stages and prepressure of the tension rings.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.440-441
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• 2008

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.189-193
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• 2008

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.241-247
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• 2003

The sealing performance of O-ring is effected in environments of the O-ring seal, like that applied pressure, working temperature, pre-compressed ratio and materials. In this paper, design of composite O-ring under pressurized, compressed was optimized based on Taguchi experimental design method. and it analysed numerically using non-linear finite element method. Ogden model in which is developed based on the experimental data is used for simulating the contact stress and strain in NBR and PTFE materials. Sensitivity analysis was performed with FEM results, which are contact stress, strain and temperature as variable.