1988 Volume 7 Issue 6 Pages 930-934
A compression molding machine for applying the preform compression molding method was developed.Preforms used in this study were made from polysulfone, which has excellent characteristics of high-impact resistance, high-wear resistance and high chemical stability for a denture base resin.Molding conditions, such as preform heating temperature and mold heating temperature, were examined.It was necessary to remove water in the stone cast by heating above 200℃ whenever the preform was melted on the stone cast.The pre-heated preform to the temperature of the stone cast reduced the differences in temperature between upper side and lower side of the preform by far infrared ray heater.The denture base having a thin fin less than 0.1mm was obtained under the compression molding conditions, such as heating temperature of lower mold at 290℃ and upper mold at 130℃, and pre-heating temperature of preform set on the lower mold at 290℃.
