• Journal of Advanced Marine Engineering and Technology
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• 제15권5호
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• pp.47-54
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• 1991

The lip seals widely used nowadays in stern tube sealing system of ships have radial sealing contact with shafts or liners, on the other hand the face seals of stern tube sealing system have axial sealing contact with seat. Because of axial sealing contact, the face seals have a large number of merits such as durability of life, simplicity of structure, easy fitting and replacement, etc. In this paper, for the purpose of development of face seals, the fundamental properties of axial sealing contact were analyzed and a trial face seal was designed and manufactured using N.B.R. rubber and Thordon which is widely used for bearing materials. The seal proper of trial face seal was made from N.B.R. rubber and the face insert was made from Thordon, thermosetting resins which are three dimensional, cross linked condensation polylmers. The performance test of trial face seal was carried out on the test bench which was specially designed and manufactured. The results were satisfactory enough to be used in practical stern tube sealing system.

• 공업화학
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• 제2권4호
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• pp.301-310
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• 1991

대표적인 열가소성 수지인 에폭시 수지는 그 용도 및 응용분야가 광범위하지만, 경화 후 수지의 brittleness와 고온 및 습윤하에서 물성이 좋지 않아 시용에 제한을 받고 있다. 본고에서는 수지의 최대결점인 brittleness 개선과 고온 습윤 특성의 향상 방법에 대해 고찰하였다. Brittleness 개선 방법으로는 rubber 및 열가소성 수지를 에폭시 수지에 도입하여, 이에 따른 toughness 향상 정도를 중점적으로 다루었으며, 고온 습윤 특성을 향상시키기 위해 에폭시 수지의 molecular design 및 열가소성 수지의 응용방법에 대해 기술하였다.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.166-175
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• 2002

Tank track rubbers, which undergo dynamic stresses and strains under various road conditions, leads to a result of considerable internal temperature rise due to the heat generation. Since rubber materials are not fully elastic, a part of the mechanical energy is converted into heat because of the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build-up, i.e. internal temperature rise which, if excessive, exerts a bad influence upon the performance and the life of the tank track rubbers. The purpose of this paper is to predict temperature distributions of the rubber components off tank track subjected to complex dynamic loads under various read conditions. In steady state analysis temperature fields are displayed in contour shapes, and in unsteady analysis the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1668-1671
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• 2005

Vulcanized natural rubber was pulverized using a single screw extruder in a non-cryogenic Solid Shear Extrusion process where rubber granulates were subjected to high compressive and shear stresses. The producted particles had diameters ranging from 40 to 1200$\{mu}m$. A principle used in this paper was developed in Russia. The development method for producing a polymeric material powder consists in compressing said material by shearing the material during a pressure increase and cooling. Consecutive breakdown is carried out by shearing the material during the pressure decrease and cooling.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.886-889
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• 2002

Finite Element Method for 3-D static loaded passenger car tire on the rigid surface is performed for studying the stiffness of tire to compare with experimental data. The tire elements used for FEM are defined each component to allow an easy change for the design parameters. Also, a hyperelastic material which is composed of tread and sidewall has been used to consider a large deformation of rubber components. The orthotropic characters of rubber-cord composite materials are used as well. The air pressure, a vertical and a lateral load are applied step by step and iterated by Modified Newton method for geometric and boundary condition nonlinear simulation. This study shows nonlinear analysis method for tire and the bearing capacity of tire due to the external force.

• 소성∙가공
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• 제15권5호
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• pp.354-359
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• 2006

The elastomer forming process was employed for many operations which included piercing, sheet metal forming and tube metal forming process. This paper presents cylindrical tube forming process using rubber material such as polyurethane. For elastomer forming process, tensile tests at room temperature were performed to obtain the material properties of polyurethane and tube. In particular, biaxial tensile test were carried out to obtain the coefficient of strain energy function of the rubber material. Finite element analyses were also carried out to investigate the forming load and formability of tube. It was compared with the experimental results about the forming load and the formability of tube. From these results, it was investigated a forming process to decrease the forming load for elastomer forming process.

• 소성∙가공
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• 제20권2호
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• pp.93-98
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• 2011

Electroforming is a kind of metal molding technology. After gilding on the possession object(conductivity, nonconductivity) separate it with possession object and produce a part or duplicate. This process has an excellent ability of duplicating detailed figure. To simplify the manufacturing process of a rotary screen, this study was adopted electroforming technology and produced silicon rubber mandrel. Furthermore, to indicate the optimal condition for the acquisition of high-qualified rotary screen product, the experiment was executed with pH, time, sulfamate nickel solution according to density which were the main factors to decide the condition, then compared it with the product made by original "S" company in Holland. As a result, the figure of hole was more obvious and correct. Also the open size increased by more than 2-3%.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.279-284
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• 2007

Elasto-forming has been dedicated to specific and limited production. Today, using enhanced pad materials, it has become an efficient and economical process alternative for low and medium volume metal-forming production. The non-linear properties of elastomer which are described as strain energy function are important parameter to design and evaluate of elastomer component. These are determined by material tests which are uni-axial tension and bi-axial tension. In order to investigate the design paramerer, Finite element analysis was carried out for elasto-forming process.

• 한국염색가공학회지
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• 제4권3호
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• pp.116-121
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• 1992

This paper is on for a material to replace the petroleum-based resins used as adhesives for the fiber in rubber composite materials. The study limited to the reaction properties of tannin with formaldehyde. Tannin-formaldehyde(TF) reactions were carried out in aqueous media. Rates of reaction were strongly dependent on concentration, temperature, pH, and the mole ratio of tannin to formaldehyde. Viscosities of reaction mixtures were followed up to gelation. The reactivity of tannin-formaldehyde resins was greater than that of resorcinol-formaldehyde resins. To formulate an adhesive, a styrene-butadiene-vinyl pyridine terpolymer latex(L) was added to the TF. This preliminary results suggest that the condensed tannins have considerable promise as substitutes for resorcinol used in resin formulation for bonding of fiber to rubber.

• 고무기술
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• 제12권1호
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• pp.1-7
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• 2011

Nanotechnology is the fast becoming key technology of the $21^{st}$ century. Due to its fascinating size-dependent properties, it has gained significant important in various sectors. Myths are being formed on the proverbal nanotechnology market, but the reality is the nanotechnology is not a market but a value chain. The chain comprises of - nanomaterials (nanoparticles) and nanointermediates (coatings, compounds, smart fabrics). Elastomer based nanocomposites reinforced with low volume fraction of nanofillers is the first generation nanotechnology products and it has attracted great interest due to their fascinating properties. The incorporation of nanofillers such as nanolayered silicates, carbon nanotubes, nanofibers, metal oxides or silica nanoparticles into elastomers improves significantly their mechanical, thermal, barrier properties, flame retardency etc., Extremely small particle size, high aspect ratio and large interface area yield an excellent improvement of the properties in a wide variety of the materials. Uniform dispersion of the nanofillers is a general prerequisite for achieving desired properties. In this paper, current developments in the area of elastomer based nanocomposites reinforced with layered silicate and carbon nanotube fillers are highlighted.