• Elastomers and Composites
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• 제57권4호
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• pp.165-174
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• 2022

The effect of fumed silica loading on the thermal stability and mechanical properties of fluorosilicone (FVMQ) rubber was investigated. The distribution of fumed silica inside FVMQ was characterized using scanning electron microscopy, and the thermal stability of composites was evaluated using thermogravimetric analysis and by the changes in mechanical performance during thermo-oxidative aging. The function mechanism of fumed silica was studied by Fourier transform infrared spectroscopy. The results show that with increasing silica content, the crosslink density of composites, the modulus at 100%, and tensile strength also increased, whereas the elongation at break decreased. Furthermore, increasing the silica content of composites increased the initial decomposition temperature (T_d) and residual weight of the composite after exposure to nitrogen. In addition, the thermal oxidative aging experiment demonstrated improved aging resistance of the FVMQ composites, including lower change in tensile strength, elongation at break, and modulus at 100%.

• Elastomers and Composites
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• 제3권1호
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• pp.32-38
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• 1968

The physical properties of NR-SBR and NR-BR blends were studied. 1. In blending, tensile strength decreased with increase in synthetic rubber contents. It was most effective when the ratio of NR/Syn. R is 75/25. 2. Tensile strength decreased with order of NR, SBR and BR and modulus after aging is proportional of synthetic rubber contents. 3. Elongation is less influenced by synthetic rubber ratio that on the other hand, the decrease of elongation is proportional to synthetic rubber contents after aging. 4. Hardness decreased with increase in the synthetic rubber contents and on the other hand, the hardness increased after aging.

• 한국응용과학기술학회지
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• 제17권3호
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• pp.198-202
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• 2000

PVA blend films were prepared by solution blending method for the purpose of useful antibiotic polymers. Characteristics properties of blending films such as elongation and tensile strength were determined. Tensile strength and elongation were rapidly reduced as increasing the blending ratio of natural polymer. Blend films were found that phase separation was occured as more than 25wt% increasing the blend ratio of chitosan. Also, The antibiotics of blend films were examined against gram(+) and gram(-) by disk susceptibility test. As a result, kind of blending films to show the highest antibiotics was chitosan 20wt% and the selectivity of mold strain was observed.

• 한국의류산업학회지
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• 제6권4호
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• pp.511-514
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• 2004

We studied on the bleaching properties of silk fabric by vapor type ozone processing using ozone's strong oxidation instead of 28% $H_2O_2$ chemical treatment. When vapor type ozone processing was directly treated to fabrics retaining water to 50~70% pick up ratio, high concentration ozone was generated 14,000ppm(168 mg/h) approximately and finally its bleaching improved. The fabric's bleaching effect was improved because vapor type ozone generated the highest decomposition to oxidation of surface and inter molecules. The experiment revealed that fabric's bleaching was improved by change of the pick-up ratio of vapor type ozone processing. However, tensile strength and elongation were reduced by increase of time, and the time that was assumed as the most optimized time to minimize the reduction of fabric's tensile strength and elongation as well as maximizing the fabric's bleaching was 30 minutes.

• 소성∙가공
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• 제15권8호
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• pp.586-590
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• 2006

42Ni-Fe Invar alloy strips were fabricated using conventional ingot casting and melt drag casting followed by rolling. Mechanical properties such as tensile strength, elongation and blanking deformability of the strips were evaluated. The properties were strongly depended on fabrication methods. Tensile strength and elongation of all strips were in the range of $40-60kg/mm^{2}$ and 26-35%, respectively, which are enough values for the manufacture of the final products. In some of the strips, however, burrs occurred at deformed surface. The properties of strips were explained in terms of microstructure such as grain size and texture formation during rolling. Additionally, strips by melt drag casting method were compared to those by conventional ingot casting.

• 대한가정학회지
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• 제25권4호
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• pp.1-8
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• 1987

The effects of Aspergillus niger H-18(AN) and A.fumigatus E-29(AF) on the deterioration of test materials were examined. 1. When the fungi were inoculated to the cotton fibers placed on Czapeck agar, malt extract agar, and potato agar, they grew best on potato agar which in that context was chosen as a basal medium for deterioration studies. The tensile strength of ontton fiber on which AN was grown for 30 days decreased by 33.9% with a concommitant increase in elongation by 43.1%. 2. Cotton fabric lost the weight by 1.35%, when inoculated with AN while it lost the weight by 0.86% when inoculated with AF. 3. When AN and AF were inoculated separately on cotton fibers, tensile strength decreased by 52.8% and 43.3%, respectively, with concommitant increases in elongation by 34.2% and 29.4%, respectively. 4. The cotton was damaged more severely by AN than AF, when they were observed by scanning electron microscope.

• 한국의류산업학회지
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• 제3권4호
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• pp.362-366
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• 2001

We studied on the softness properties of polyester fabric by vapor type ozone processing using ozone's strong oxidation instead of 25% NaOH chemical treatment. When vapor type ozone processing was directly treated to fabrics retaining water to 40% pick up ratio, high concentration ozone was generated oxidation of 3~4% approximately in polyester fabrics and finally its softness improved. The fabric's softness effect was improved because vapor type ozone generated the highest decomposition to oxidation of surface and inter molecules. The experiment revealed that fabric's softness was improved by change of the time of vapor type ozone processing. However, tensile strength and elongation were reduced by increase in time, 60 minute was assumed as the most optimized time to minimize the reduction of fabric's tensile strength and elongation as well as maximizing the fabric's softness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.179-182
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• 2002

XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

• 한국강구조학회 논문집
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• 제12권6호
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• pp.649-659
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• 2000

본 연구에서는 고장력 용접구조용 압연강재인 SM570을 건축구조용으로 사용하기 위해서 판두께에 따른 화학성분과 기계적 성질의 분포특성을 정량적으로 평가하였다. 또한 건축구조용 강재로 주로 사용되는 일반구조용 압연강재인 SS400과 용접구조용 압연강재인 SM490을 비교재로 사용해서 SM570 강재와 비교 평가하였다. 본 연구결과 모든 두께에서 SM570 강재의 화학성분, 탄소당량, 용접 갈라짐 감수성 조성과 항복강도, 인장강도, 연신률 및 충격강도는 한국산업규격을 만족하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.139-142
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• 2003

In this study, casting/forging process was used to produce an aluminum lower control arm for automobiles. Firstly, casting experiments were carried out to get an enhanced preform for forging the lower control arm. In the casting experiment, the effect of an additive, Sr, on the mechanical properties such as tensile strength and elongation and the microstructure of a cast preform were investigated. And a finite element analysis was peformed to determine an optimal configuration of the cast preform. Lastly, a forging experiment was carried out to make the final product of aluminum lower control arm by using the above cast preform. In the casting experiments, when 0.025% Sr was added into molten A356, the maximum values of tensile strength and elongation of the cast preform were obtained. In the forging experiment, It was confirmed that the optimal configuration of a cast preform predicted by FE analysis was very useful. The cast/forged product using designed preform was made without any defects.