A Rapid Resolution for a Medical Device Manufacturing Mystery

A medical device manufacturer was experiencing an intermittent problem with an injection-molded plastic component. During startup, parts would come off the line with a small blister in the plastic. The problem would persist for a period of time before gradually disappearing. Parts with the blister had to be rejected.

Internal investigations did not turn up any differences in the raw materials, injection molding process, timing or environmental conditions. They came to Battelle for help in solving the mystery.

The client already had a Rapid Response contract in place, so the Battelle team was able to get started right away. The medical device team, who had familiarity with the part and the injection molding process, called in a specialist from Battelle’s Advanced Materials group. Examining the part with a scanning electron microscope (SEM) showed traces of an unintended plastic material that clearly did not belong—but where did it come from?

Further investigation with the client and their contract manufacturer traced the issue to the purge and flush process for the mold. Changing the purge and flush protocol eliminated the problem.