Abstract
This paper describes improvement of injection molding characteristics using a sprue bush circulated with coolant channels. Since shortening of cooling time is necessary to shorten fomining cycle time, an injection molding tool was manufactured by diffusion bonding of laminated metal plates to obtain high temperature response due to circulated coolant. In the case that the molded part is thickest at the sprue runner, however, the minimum cooling time is determined by the cooling rate at the sprue runner. Hence, we produced a sprue bush circulated with coolant channels by the technique of difiusion bonding of laminated metal plates, and researched the effects on injection molding characteristics.
