• 한국임상수의학회지
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• 제24권2호
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• pp.201-207
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• 2007

The teat cup liner compounds with improved physical property were developed using tri-polymer blend of natural rubber(NR), ethylene propylene diene monomer rubber(EPDM) and butyl rubber, and the changes of the physical properties of compounds were measured under various conditions such as standard, thermal, alkaline detergent and acid solutions aging conditions. The hardness of the new teat cup liner compound 1 was 50 and that of the compound 2 was 51 under standard condition. The tensile strength and elongation of the new compound 1 were $154kgf/cm^2$ and 675% under the standard condition, respectively. Also, those of the new compound 2 were 180 kgf/cm and 634% under the same condition. Their hardness were increased about $2{\sim}6%$ and the tensile strength and elongation were decreased about 10% under the $25^{\circ}C$ water and detergent solutions. Even though the new teat cup liner compounds exhibited so much decreased tensile properties under the $105^{\circ}C$ thermal aged condition, they sustained more stable aged physical properties including tensile strength and elongation than those of imported teat cup liner materials. Consequently, the new teat cup liner compounds would give prolonged lift cycle if they are used as a teat cup liner product.

• 펄프종이기술
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• 제44권5호
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• pp.14-20
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• 2012

In this paper, the flame-retardant wall paper was successfully prepared with recycled polyethylene terephthalate (PET) short cut fiber with flame-retardant property and wood pulp using polyvinyl alcohol (PVA) as binder followed by treatment of non-halogen flame retardant. Physical properties such as formation index, tensile strength, elongation, and burst strength increased as defibrillation increased except tear strength. Bulk increased but formation index, tensile strength, elongation and burst strength decreased along with addition of PET short cut fiber. It was also found that tear strength rose significantly up to 30% of PET short cut fiber and then declined (fell) rapidly. As addition level of PVA increased tensile strength, elongation and burst strength increased, but tear strength decreased slightly. Addition of 20% of PET short cut fiber and 13% of PVA provided the flame-retardant wall paper with both improved flameproofing and physical properties.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.375-380
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• 2020

In this study, we tried to evaluate the mechanical properties of Polycarbonate(PC) and acrylonitrile-butadiene-styrene(ABS) plastic materials, which are frequently used as parts of home appliances and machinery, when repeated impacts were applied. A repeating impact tester for this research was designed and manufactured to apply repetitive impacts. Two types of plastic were repeatedly impacted under a constant load, and a tensile test was performed on the plastic material that was impacted. The tensile strength of PC plastic materials that received impact more than 2000 times was reduced by about 45 % and elongation was reduced by about 10 % when compared to impact free specimens. On the other hand, in ABS plastic, a reduction of tensile strength of about 20 % was observed at about 2,000 impacted specimen, but at about 20,000 repetitive impacted specimen, a tensile strength decrease of about 65 % was observed. And the elongation was reduced by 10 % due to the cyclic harding behavior of the material.

• 한국건축시공학회지
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• 제1권2호
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• pp.165-173
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• 2001

This study examinated the application in construction field and the development of waterproofing material system by the spray water-soluble rubber asphalt to solve the problems of synthetic polymer sheet and gio membrane(A mat sheet of Bentonite) that had been used domestic waterproofing material in advance. As the result of study, characters of study water-soluble rudder asphalt are the follows: 1) The amount of water absorption was '0.06'g and the seepage quality was '0'g in result. 2) The tensile strength was about 30.7kgf/$\textrm{cm}^2 and the elongation was about 72.4% in result. 3) After reliance of temperature test had been ended, the tensile strength was about 72.4kgf/$\textrm{cm}^2 in low temperature and about 30.7kgf/$\textrm{cm}^2 in normal temperature. 4) After acid and alkaline treatment had been ended, the tensile strength was about 19.7kgf/$\textrm{cm}^2$ and about 21.9kgf/$\textrm{cm}^2 in result. 5) After chlorine ion treatment had been ended, the tensile strength was 28.5kgf/$\textrm{cm}^2$ and the elongation was 250% in result. 6) The impact performance was subsided at 1.5m height. 7) After promotion weathering had been ended, the tensile and elongation was about 26.0kgf/$\textrm{cm}^2, 214% in result. So, this study can propose the spray water-soluble rubber asphalt to satisfy the and durability of waste filled land.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.136-140
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• 2002

Every year fish skin, bone and intestines are discarded as processing waste material. The use of fish processing waste material is more economical and environmental-friendly. The leather-like material was produced using shark intestine. Physical charactistics such as tensile strength, elongation, tongue tearing strength, and bursting strength of the leather-like material were measured, and compared with those of a commercial leather product. The values of tensile strength, elongation, tongue tearing strength, and bursting strength of the leather-like material were $3.3kg/mm^2$, $53\%$, 13.0kg/mm and $18kg/cm^2$, respectively. Elongation $(l09\%)$ of the leather-like material coated with lacquer was higher than that of a commercial leather material, and the other factors were similar. The tensile strength and tongue tearing strength of the leather-like material was higher than those of shoes leather, but bursting strength was lower. These results suggested a potential value to use the leather-like material from shark intestines as a substitute for commercial leathers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.201-202
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• 2022

In this study, the high performance silicone was developed to assure the inter-layer joint in apartment house. The tensile strength, the elongation, the bond strength and the fatigue tests were conducted. As a result, it was confirmed that the performance of high -performance silicone was superior to the existing elastic paint. Therefore, it is expected that it will help to secure the quality of inter-layer joints in apartment houses.

• 대한기계학회논문집
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• 제12권6호
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• pp.1296-1302
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• 1988

The study has been carried out under various experimental conditions to investigate mechanical properties by the transformation conditions of austempered low-alloy ductile cast iron. The amount of retained austenite and bainite after quenching was determined by the X-ray diffractometer and the point counting method and which the microstructure was investigated by the S.E.M. The mechanical properties of austempered low-alloy ductile cast iron can be varried over a comparatively wide range by changing the transformation conditions. During isothermal transformation of austenite in the bainite region, low-alloy ductile cast iron austempered at holding time of 40 minute has the maximum volume fraction(24%) of retained austenite in the cast iron matrix and which optimum values of mechanical properties correspond to the maximum amount of retained austenite, which falls with decreasing transformation temperature. The low values of both tensile strength and elongation in the initial stage of bainite transformation can be explained by premature fracture of tensile specimens and the tensile strength, hardness and elongation do not change considerably after a certain period. With a decreasing transformation temperature the tensile strength increase while the elongation decrease, especially the elongation has the maximum value at temperature $370^{\circ}C$.

• 한국해양공학회지
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• 제22권6호
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• pp.46-51
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• 2008

The effect of the addition of Co and N and subzero treatment on tensile strength and damping capacity was investigated in Fe-Cr-Mn alloy. Austenite was transformed into martensite by cold rollins increasing the degree of cold rollins led to an increase in the volume fraction of martensite. The damping capacity linearly increased with increasing volume fraction of ${\varepsilon}$ martensite in cold rolled specimens and subzero treated specimens after cold rolling. The volume fraction of ${\varepsilon}$ martensite, tensile strength and damping capacity was also increased by the addition of Co, while this treatment decreased the elongation. However, the volume fraction of ${\varepsilon}$ martensite, elongation and damping capacity were reduced by the addition of N, although the tensile strength increased. Tensile strength and damping capacity werealso increased by subzero treatment, while elongation decreased.

• 한국자동차공학회논문집
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• 제2권2호
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• pp.95-102
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• 1994

Aluminum sheet application to automobile body panels has now become an important objective to meet the requirements of automobile weight reduction. As the Mg content in Al-Mg based alloys increased up to 7.19%, the strength and elongation increased. For instance. Al-7.19Mg alloy had a high strength of 305MPa and a high elongation of 35%. A study was also made to investigate the interrelation between grain size and tensile properties with varying the contents of Mg, Ti and Zr elements and annealing conditions. The yield stress decreased as the grain size increased, which increased the uniform elongation. The strain hardening exponents n increased as the Mg content increased, which depended on the increasing difficulties of the cross slip of dislocation.

• 한국식품과학회지
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• 제34권6호
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• pp.1023-1029
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• 2002

본 연구는 천연전분과 hydroxypropyl화 전분에 가소제를 0, 16, 33, 50, 66% 비율로 첨가하여 RVA점도를 측정하고 필름을 제조한 후 물성을 측정하여 두 물성 사이의 상관관계를 알아보고자 행하였다. 필름의 인장강도는 가소제의 함량이 높아질수록 감소하였고 신장율과 수증기투과도는 증가하였으며 glycerol이 sorbitol보다 큰 변화를 보이는 것으로 나타났다. Hydroxypropyl화 전분이 천연전분에 비해 강도는 떨어지나 신장율은 높아지는 것으로 나타났고 수증기투과도는 2배 큰 것으로 나타났다. 가소제를 혼합하여 필름의 물성을 측정한 결과 sorbitol은 유연성보다는 필름의 강도를 유지하는 역할을 그리고 glycerol은 필름의 신장율을 증가시키는 역할을 하는 것으로 나타났다. RVA물성과 필름 물성의 관계에서 가장 연관성이 높은 것은 peak viscosity, 인장강도, 수증기투과도인 것으로 판명되었고 peak viscosity와 인장강도, peak viscosity와 수증기투과도의 관계는 각각 직선적인 것으로 나타났다. 따라서 RVA 물성 중 peak viscosity를 활용하여 필름의 인장강도, 수증기투과도를 예측할 수 있다고 판단되었다.