A patented conformal cooling process developed by Ritemp Technologies Pty. Ltd., Edwardstown, South Australia, has been licensed to the mold manufacturing division of Rexam, located in Buffalo Grove, Ill. The technology is said to reduce molding cycle times 20% to 50% and to eliminate hot spots and mold-temperature variations. The technology has also been licensed to moldmaker Stackteck Systems, Inc., Brampton, Ont., and to Ryka Blow Molds Inc., Mississauga, Ont. The patented evaporative cooling approach provides cooling only where it is needed in the mold, resulting in highly uniform mold temperature regardless of mold geometry. Instead of conventional cooling channels, the Ritemp approach uses large conformal cooling chambers on the core and cavity sides of the mold. Air is partially evacuated from the chamber with a vacuum pump. Low pressure in the chamber allows a reservoir of water in the sealed chamber to boil at low temperature (50 F). Low boiling temperature permits more heat removal in the phase change from liquid to gas than occurs when merely heating liquid water. A heat exchanger at the top of each mold condenses half the steam back to water. The mold is not run cold enough to sweat. Ritemp supplies a controller to turn water flow to the heat exchange on and off depending on mold temperature detected by a sensor in each chamber.
Editor PickSidel’s Lightweight Bottle Design; One Relevant Example of Resin Savings
The current upward trajectory of PET prices makes such designs more attractive.