• Elastomers and Composites
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• v.43 no.4
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• pp.281-287
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• 2008

Using solid state $^{13}C$ NMR, polybutadiene rubber vulcanizates were qualitatively and quantitatively analyzed. In the filled conventional system of BR vulcanizate accelerated with TBBS, addition to the olefinic double bond and substitution in the $\alpha$ position to the double bond occurred simultaneously. Also the latter $\alpha$ substitution reaction was faster than the former addition reaction at initial reaction time. In addition, it was suggested that double bond-addition-polysulfide structures might be modified into 5-membered and 6-membered cyclic structures in overcure time. These chain modifications were correlated with the decrease in the chemical crosslink density in overcure time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.738-742
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• 2005

Rapid Prototype has been used to design and Production of part in a variety of fields ; Car, Electronic products, Aviation, Heavy industry etc. Moreover development of hardware gave rise to use the method of Rapid Prototype more and more at high precision and complicated shapes. Expecially, to be using process of products that shapes of Micro-hole ; Cellular phones, Antennas, Jewels, Semi conductor cases. In case of Micro-shape, precision of the shape turns on various condition ; Laser size, Laminate height, scanning speed, overcure, viscosity of resin, etc. Sometimes breaks out the case that interner hole of shape is blocked by viscosity of resin. The phenomenon has solved easily to reduce viscosity of resin. But, in case of the method brings about the problem that strength goes down in actuality products hardening. This study on verify to change of shape of Micro-hole and makes the semiconductor case which has shape of Micro-hole by using resin of higher viscosity, scanning speed and overcure

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.77-84
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• 2007

As a life cycle of product bas shortend, Rapid prototypiug has come into the spotlight to shortened the time of producint a prototype. But It followed in laminated directivity and of the prototype production which is decided the interference which Beccuase of invisible rough surface, some inferences have occured during an assembly hour. Consequently, This study on rapid prototyping has parameter to determine surface roughness and surface form precision of total shape. In order to improve Surface form precision, it can control parameters which are Laminate Height, Layer Hatch Overcue, Fill Cure Depth. In addition, we found the parameter which have a deep effect on surface roughness among various parameters, and then, tried to reduce the interference that can be occurred by surface roughness during assembly.