Reducing mold qualification time

Lead-time reduction remains a critical factor in the development of new injection molded products. While there are many areas that can be addressed to reduce the time it takes to validate the mold and parts, the time from initial mold sampling until the parts are production-approved is one of the biggest windows of opportunity for improvement. Based on experience, about one-third of the total amount of time used for designing, building and qualifying a new injection mold is consumed in the qualification/validation cycle. That means that a mold with an eight-week lead time to produce might take another four to five weeks to get ready for production. Most suppliers don’t allow for enough time for mold qualification and process validation, and the team becomes frustrated by the delays.

Normally a new mold is sampled the first time and parts are inspected and compared to the product drawing. This may be accompanied by a capability study examining the critical part features to ensure the potential does not exist to produce a part outside of the print tolerance zone. Once this process is competed, a “punch list” is created outlining all the out-of-spec dimensions that require steel adjustments in order to mold a good part. The next steps of adjusting the mold, re-sampling and inspecting, can take weeks to complete and in some cases will need to be done a second time.

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