In this case, the customer was buying as many parts as the molder can produce. The ejected parts were sub-gated for part removal while the parts are being dropped onto a conveyor belt. Since the material was a TPO, the parts were flexible and needed a 2 second ejection forward delay to ensure the part completely fell off of the ejector pins before the mold closed. Air blasts were previously tried, but the parts were not falling well and the result was part damage and increased inspection.

To speed up the removal process, we replaced the sprue picked with a high-speed robot. Since the robot can move with the ejection system, the part were picked up during ejection, and the ejection was retracted quickly. We were also allowed to reduce the mold opening distance which resulted in an overall cycle time reduction of 1.5 seconds which quickly justified the cost of the high-speed robot.

Don’t overlook the big things when attempting to tweak a process. Sometimes replacing a major component such as a screw, barrel, robot, or even mold will give you a significant ROI. The key is to cover the small details first.

-Andy