• Polymer(Korea)
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• v.25 no.3
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• pp.406-413
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• 2001

Blending has become an interesting way for preparing new materials with tailored properties. Unfortunately, many materials are incompatible due to the difference in their viscoelastic properties, surface energy and interaction. Therefore, the properties of polymer blends are not obtained as expected levels. Silicone rubber has an excellent heat-resistance and electrical characteristics, and ethylene propylene diene monomer (EPDM) rubber also has good mechanical properties. The purpose of this study is to develop a new engineering material which has excellent electrical and mechanical properties through blending of silicone with EPDM rubber.

• Elastomers and Composites
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• v.20 no.2
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• pp.115-131
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• 1985

Heavy residual fuel oils is a mixture of reduced crude from crude unit, bottom products from vacuum and/or catalytic cracking unit with distillate to meet the specification and generally used as heavy fuel oil for large combustion engines, boilers, etc$\cdots$. But this study was made to investigate heavy residual fuel oils for using as industrial raw material and resulted the following possiblities as valuable raw material as well as heavy fuel oil. 1) Production of straight asphalt through vacuum distillation unit. 2) Using straight asphalt from vacuum distillation unit for manufacturing of blown asphalts, cut back asphalts, emulsified asphalts and asphalt compound, rubber/asphalt sheet, etc$\cdots$. 3) Using waxy oil side streams for manufacturing of raw oil to be lube oil base stocks through solvent dewaxing. 4) Production of lube base oils and rubber process oils from dewaxed raw oil through chemical treatments. 5) Manufacturing of paraffine wax from slack wax to be produced as by product of dewaxing process.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.23-29
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• 2023

This study analyzed the fire status of a rubber product manufacturing factory based on 19 years of fire data. Through the analysis of the current state of fire, electrical fires accounted for 58.19%, and among electrical fires, motor fires were the highest at 26.21%. For the motor fire occurrence process, the curing process accounted for the highest rate of 51.9%. Therefore, the installation environment was investigated for the motor in the curing process, and it was confirmed that the motor's maximum ambient temperature exceeded 40℃. In particular, in the case of the motor for curing operation, the motor was installed in a separate motor room, so the average indoor temperature was 48.10℃ and the motor frame's maximum temperature was 72.80℃. In this study, the risk of motor fire was confirmed through a field survey, and a safety management plan was derived by finding a process with high fire risk and conducting an experiment on the motor's installation environment and electrical characteristics in that process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.42-47
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• 2004

Formed insert type tool satisfy both the surface roughness and geometric accuracy, so that cutting edge of formed tool can duplicate final feature. For experiment the formed tools with various clearance angles are machined. And the tools are evaluated with respect cutting force, flank rear and surface roughness to optimistic condition.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.34-39
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• 2011

Temperature control of a rubber injection mold is important for the dimensional accuracy of product. The main objective of this paper is to optimize the arrangement of heaters by FEM and optimal design method. Firstly, 3-dimensional transient heat transfer analysis was carried out for a square specimen mold. Results of FE analysis are a good agreement with the experimental results, showing about 1.22~7.22% error in temperature distribution. Secondly, we suggested the optimal method about an arrangement of heaters of rubber injection mold by using the optimal design technique. Distances between heater's center and the contact surface of mold, distances between heater's center and symmetric surface were considered as design variables. And the variances between the temperatures of cavity surfaces and their average temperature were used as the objective functions. Applying the optimal solution, the temperature variation was improved about 52.9~88.1 % compared to the existing mold. As a result of sensitivity analysis for design variables, design variables parallel to the direction of the split plane in mold affect the largest on the surface temperature variation in mold cavity.

• Elastomers and Composites
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• v.50 no.1
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• pp.55-61
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• 2015

Manufacturing process of OLED contains adsorption-desorption process of glass substrate. There are several adsorption methods of glass substrate such as atmospheric pressure, vacuum and electrostatic adsorption. However, these methods are very complex to connect system. Therefore, the adsorption method using silicone rubber based sticking chuck was proposed in this study. Three types of silicone rubbers having 0, 19.3 and 32.2 wt% of fluorine were used and their mechanical properties, surface energies and adsorption properties were examined. According to the results ${\sigma}_{300}$ and hardness increased with increasing fluorine contents, but elongation was decreased. Also, fluorosilicone rubber containing 32.2 wt% of fluorine showed the lowest surface tension, among three types of rubber and resulted in the highest initial tack with glass substrate. After the adsorption-desorption test of 300,000 cycles was performed, the adsorption force of S-1 (silicone rubber) decreased largely from 2.34 to 0.73 MPa. However, the S-3 (fluorosilicone rubber having 32.2 wt%. of fluorine) decreased only from 3.15 to 2.24 MPa. From this study, we obtained the valuable equations related to long term durability of silicone based sticking chuck. Finally the transfer of silicone rubber to glass substrate with the adsorption-desorption process was not occurred and this phenomenon was examined by UV-Visible spectroscopy.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.220-224
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• 2001

Waste tires are a significant problem with the increasing in number of automobiles. Therefore, many researches have been studied on this field. Recycling is the one of the popular method aspect to environmental and economical in the treatment methods of the waste tire, which loads that the reuse of scrap tire rubber has been a challenge in the past. However, it is not easy method to melt down and mold into new products because the in rubber is a cross-linked polymer. Most difficulty in recycling is the recycled product is not economic. Therefore, the goal of this study is to develop the high valuable products for reused waste tires. In this paper, we try to make an economic recycled technology using scrapped waste tires. This technology may applied for manufacturing the end products such as a rubber block and a ballast mat for high-speed train.

• The Monthly Technology and Standards
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• s.7
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• pp.92-102
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• 2002

• Elastomers and Composites
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• v.56 no.1
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• pp.20-31
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• 2021

There is an increasing demand for the rolling resistance reduction in truck bus radial (TBR) tires in the tire industry. In TBR tires, natural rubber is used as a base polymer to prevent wear and satisfy required physical properties (cut and chip). A binary filler system (silica and carbon black) is used to balance the durability of the tire and rolling resistance performance. In this study, natural rubber (NR) compounds applied with a binary filler system were manufactured at different cure temperatures for vulcanizate structure analysis. The vulcanizate structures were categorized into carbon black bound rubber, silica silane rubber network, and chemical crosslink density by sulfur. Regardless of the cure temperature, the cross-link density per unit content of carbon black had a greater effect on the properties than silica due to affinity with NR. The relationship analysis between the mechanical, viscoelastic properties with vulcanizate structure could be a guideline for manufacturing practical TBR compounds.

• Elastomers and Composites
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• v.29 no.3
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• pp.213-225
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• 1994

The Purpose of this dissertation is to study the preparation technique and physical properties of expanded rubber. The respective samples of NR, NBR and the standard compounds of EPDM rubber were prepared by mixing plasticizer DOP and LCR in various ratio. And their vulcanization characteristics, physical properties and foaming states were studied. Vulcanization characteristics were investigated using cure curve that had been obtained from Oscillating Disk Rheometer study, and the microscopic photographs of foaming states were obtained using electron microscope. The vulcanization characteristics of the samples, DOP 30phr and LCR 30phr, were found to be suitable. The tests, like hardness test and resilience, tensile test on the physical properties of each sample showed that plasticizing efficiencies of DOP and LCR were almost the same. Oil resistance test exhibited DOP was better than LCR and compression set test showed LCR was excellent plasticizer. The foaming states of NR, EPDM compounds were uniform, but those of NBR compounds were not uniform. Consequently vulcanization characteristics, physical properties and foaming states of all the samples satisfied the SAE requirements.