• Elastomers and Composites
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• 제45권4호
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• pp.291-297
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• 2010

차량에서 스트러트 인슐레이터는 도로노면으로부터 발생하는 소음과 진동을 방지하는 역할을 한다. 대부분의 점탄성 마운트들은 고무로 되어있으며 천연고무가 주성분이다. 이러한 고무 부품들은 초기에는 제 역할을 하지만 오랜 시간 고온과 반복하중에 노출되면 성능저하가 일어난다. 고무성능 변화는 NVH를 떨어뜨리고 승차감을 저하시킨다. 본 연구에서는 차량실험을 통해 스프링 변위를 측정하였고, 재현실험에서 가속도 센서를 이용하여 운행거리와 차량연식에 따른 인슐레이터 고무성능을 가속도 값, 고무 영구 변형량, 경도를 나타내었다.

• Elastomers and Composites
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• 제43권4호
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• pp.213-220
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• 2008

본 연구에서는 다양한 온도에서 고무재료의 경도에 대한 가교시스템의 영향에 대해 고찰하였다. 다양한 가교밀도의 시편을 얻기 위하여, NR과 SBR에 여러 가지 함량의 황 또는 peroxide를 첨가하여 가교하였다. 가교된 고무시편의 온도변화에 따른 경도변화와 가교밀도 변화를 측정하고 상호관계를 고찰하였으며, 시편에 발생하는 온도응력을 측정하여 온도변화에 따른 엔트로피의 변화를 조사하였다. 실온 이상에서 NR과 SBR 시편은 온도가 증가함에 따라 경도가 증가하였으며, 측정된 온도응력도 온도가 증가함에 따라 증가하였다. 그러나 측정조건 내에서 시편의 가교밀도 변화는 온도의 변화에 의해 거의 영향이 없었고 가교시스템에도 무관하였다.

• 한국환경과학회지
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• 제13권4호
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• pp.421-427
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• 2004

With the help of mechanical mixing method such as Banbury mixer and open 2 roll mill, ethylene propylene diene terpolymer (EPDM) was blended with the chloroprene rubber (CR) then mechanical properties and ozone resistance test of blends were subsequently investigated. It was noted that the hardness increased with an increasing of CR contents. Generally the hardness was increased with heat aging time most likely due to the post cure. In ozone resistance test of blend, after 8 hours a portion of fine crack is obtained for pure CR. It is confirmed that ozone resistance is greatly improved by addition of 25wt% EPDM to CR.

• 한국소음진동공학회논문집
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• 제19권9호
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• pp.967-972
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• 2009

To investigate the vibration characteristics of compact disc player(CDP) due to excited vibration and disturbances, it is necessary to consider the transmissibility of the CDP. The disturbances as well as the temperature in the vehicle are the one of the important factors when CDP is designed. In this study, the effect on the temperature of the oil damper, which is applied to anti-vibration system of the CDP, was investigated. When the temperature was changed from $-30^{\circ}C$ to $90^{\circ}C$ and the properties of the oil damper (hardness of rubber, viscosity of oil) were changed, the transmissibility was measured. When the damper rubber has the large hardness, the difference of the transmissibility and natural frequency due to temperature showed the remarkable change as compared with the those of damper viscosity.

• 소성∙가공
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• 제16권1호
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• pp.31-35
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• 2007

Automotive weather strip should have good weather ability, sealability, durability, etc. to perform its duty as body sealing for vehicles under different harsh environments. Due to its comprehensive properties, thermoplastic vulcanizate(TPV) is widely employed in weather strip as alternative for ethylene propylene diene rubber(EPDM). In this study, the influences of the recycled TPV on the tensile strength and hardness were investigated. As results of the injection molding experiment, the recycled TPV's tensile strength and hardness were higher than the virgin TPV and recycled TPV's extension was improve. The morphology showed that recycled TPV's rubber particles became smaller than virgin TPV's rubber particles.

• Elastomers and Composites
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• 제42권3호
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• pp.143-150
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• 2007

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 Inter-national Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR 시편의 여러 온도에서 경도변화를 측정하였으며 Young's modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young's modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young's modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다.

• Elastomers and Composites
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• 제37권3호
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• pp.183-191
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• 2002

우수한 신장성과 탄성복원 능력으로 여러 산업분야에 방진, 제진, 충격흡수 및 완충재료로 널리 사용되고 있는 고무재료에 대하여 주파수, 변형률 진폭 및 온도변화가 동특성에 미치는 영향을 실험을 통하여 검토하였다. 동특성 시험은 5종류의 경도에 대하여 인장.압축시험과 전단시험용의 천연고무 시험 편으로 비 공진법으로 수행하였다. 시험결과, 경도가 높을수록 동적 특성 값들이 크게 나타났으며 저장탄성계수와 손실계수는 주파수가 증가할수록 서서히 증가하였으며 변형률 진폭이 커질수록 감소하였다. 또한, 온도 특성을 $-50^{\circ}C$ 영역에서 저장탄성계수가 급격히 상승하며 손실계수가 최대로 나타나는 전이역임을 알 수 있었다.

• 한국정밀공학회지
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• 제21권3호
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• pp.100-108
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• 2004

Contamination of environment induces the shortage of drinkables. In this trend, the leakage of water that occurs by breakage or erosion of rubber valve seats is serious problem. Rubber is apt to cause breakage between two materials when they contact with each other. The possible way to avoid leakage of water by damage and breakdown of rubber is to replace that with metal. Because of this reason, nowadays, rubber is being substituted with metal as valve seat materials for water works. In tribology, a severe from of wear is characterized by local, macroscopic material transfer, removal, or formation of surface protrusions when two solid surfaces experience relative sliding under load. One of the major problems in sliding of metals is galling due to bad surface quality. Experimentally, there are various elements which influence on incipient galling, such as hardness, surface roughness, temperature, load, velocity and external environments. This paper is aimed at verifying the galling tendencies according to hardness, surface roughness, load and velocity and showing how much effect the factors have on the galling tendencies.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.271-276
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• 1998

To apply the wear resistant steel plate for heavy duty vehicle, the wear characterisms of various kinds of commercial steel plates were invesigated by dry sand/rubber wheel tester which was tested under scratch abrasion mode. The wear tested pnaterials were boron steels which were manufactured by thereto machanical control process (TMCP) in order to achieve higher hardness. As the result of the test, wear resistance of steel plate increases with the hardness and carbon content. The wear loss of wear resistance steel plate (Hv440) is a half times than tinat of SWS490A (Hv160) steel plate in dry sand-rubber wheel test and the result in field test is similar to this dry sand/rubber wheel test result. Therefore, dry sand/rubber wheel tester can be used to predict the scratch abrasion life of the parts for heavy duty vehicle.

• 한국기계연구소 소보
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• 통권13호
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• pp.27-43
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• 1984

In order to obtain the high resilience, low compression set and less of hardness change in the wiper blade rubber, vulcanization system and receipes must be controlled. To improve the above the above Physical properties, the system should be taken as follows. i) peroxide vulcanization system and sulfur vulcanization system. ii) rubber having more cis-form than trans-form. iii) moderate particle size cabon black. v) usage of other improvement agent. The rubber blade with 4.4% compression set, 76% resilience, Hs 0 $\pm$ 2 hardness change could be abtained through vulcanization system, In addition, the surface of wiper blade must be treated by chemically and physically to minimize for the skid and friction.