Straight cooling channels are the most common method of controlling part temperature in injection molding process. However, straight cooling channels are not enough to manage temperature uniformity of the parts. In this work, a numerical study is conducted to decrease cycle time and cost of the injection molded parts by using conformal cooling channels. For this purpose, the commercial injection molding simulation program Moldflow is used. The governing physical equations for injection molding were derived and presented. The assumptions of the model were checked for simple geometries by comparing analytical results and numerical results of Moldflow. Then, the effect of conformal cooling channels is investigated for injection molding of a half cylinder shell part. It was seen that conformal cooling channels cools part faster and more uniform than straight cooling channels without corruption on the surface appearance. Finally, a real life case study was presented. For this purpose, a refrigerator shelf that is manufactured by the Ar&ccedil / elik Company was studied. The process was simulated using actual process parameters and simulation results were compared with production results. Then, the process was simulated using conformal cooling channels and compared with production results. It is seen that the cycle time of the refrigerator shelf was decreased considerably while preserving surface quality appearance.

This study focuses on the cycle-averaged mold temperature of additively manufactured injection molding tooling and how it is affected by conformal cooling channels. This was done by producing a benchmark mold out of Digital ABS produced by Stratasys, an acrylic based photopolymer, which was then used to produce injection molded parts until tool failure. Another, more cost-effective material, High Temp Resin produced by Formlabs, another acrylic based photopolymer, was also tested but yielded very little success. Then the mold design was altered by adding conformal cooling channels and again tested by producing injection molded parts while tracking the mold temperature. This experimentation was then compared to an injection molding cooling channel model in order to validate the model for use with additively manufactured tooling with conformal cooling channels for use in injection molding. The benchmark Digital ABS mold was able to produce 66 shots in the injection molding machine before complete mold failure. The Digital ABS mold had a cycle-averaged mold temperature of about 155°F. The High Temp Resin mold was able to produce 3 shots before complete mold failure. The High Temp Resin material is much more brittle, and the mold design did not take into account how brittle the material was. The Digital ABS mold with conformal cooling channels had a cycle-averaged mold temperature of 111°F. This is significantly lower than without cooling channels and has a high potential for improving tooling life. The cooling channel model predicted the cycle-averaged mold temperature to be 116°F. This proved to be a very good model and can be used as a design tool when choosing cooling channel geometry and position in additively manufactured tooling. This research shows the potential that conformal cooling channels have to help improve additively manufactured tooling life for injection molding. As shown in other research done, the ability to maintain the mold below 120°F significantly improves the life of additively manufactured tooling. The results of this study demonstrate the effectiveness of conformal cooling channels in controlling mold temperature. It should be researched further, but the use of conformal cooling channels has the potential to produce more production or prototype parts with additively manufactured tooling for injection molding.