Mold temperature control

Abstract

A method and system for controlling the temperature of a fluid cooled high temperature injection mold having fluid channels formed therein. A high temperature injection mold has an operating temperature above the boiling point of water. A flow of either elevated pressure or low pressure cooling water is passed through the fluid channels in the high temperature injection mold for a limited duration during the molding cycle to thereby reduce the temperature of the injection mold to a desired level. Elevated pressure cooling water is elevated to a pressure level such that the cooling water will remain in a liquid state while passing through the fluid channels. Low pressure cooling water is at a pressure level such that the cooling water enters the fluid channels in a liquid state and transitions to a vapor state within the fluid channels. The cooling water may be provided to the high temperature injection mold in a closed loop system, wherein cooling water which is treated to remove contaminants therefrom is stored in a cooling water supply tank. Used high temperature cooling water emerging from the fluid channels of the high temperature injection mold is preferably mixed with lower temperature cooling water from the cooling water supply tank before being returned to the cooling water supply tank. Elevated or low pressure cooling water may be passed through some fluid channels in an injection mold while high temperature heating water is passed simultaneously through other fluid channels in the same mold.