Mold design best practices advise against attempting to mold several part variations at the same time. However, when balancing tooling cost and piece price, building a family tool can often be the only option. Fortunately, we can use molding simulation software to give us the best chance at a perfectly balanced fill on the first trial run.
Attempting to fill different sized parts with the same size feeding system can cause unwanted processing conditions. These may include individual cavity pressure spikes, flashing, short shots and other other defects. Therefore, it’s important to get the fill time balanced in each cavity. Even better is to get it right the first time, avoiding welding or re-machining the feed system.
We were able to use a four drop hot runner to break the tooling into four quadrants and build out individual runner systems from there using injection molding simulation software. As you can see by varying runner diameters and gates sizes, we were able to achieve balanced fill. This is great in simulation but the real test was when this tool was put in a press for the first time. The results? The fill was balanced with no flash, no short shots, and no pressure spikes. This was all accomplished on the first run of the tool with no modifications to the feed system required. This is a true testament to simulation software used at Basilius and the great engineers that are running it.