How to sort good, defective and borderline injection-molded samples, label them without hiding defects, and which production data and photos to send.
How should we prepare samples to have short shot and burr inspection of our injection-molded parts reviewed?
Prepare good and defective parts together, sort the defects by type, and make sure the samples cover variation across cavities, lots and colors. Do not mark directly on the defects; identify the parts with numbered tags and a list. Sending the part size, the faces to inspect and the production speed along with the samples speeds up the review.
Who this guide is for You want to inspect injection-molded parts automatically for visual defects such as short shots, burrs, scratches and foreign matter You want to send samples or photos first to check whether the inspection is feasible You want to turn your manual visual inspection criteria into criteria for automated inspection Start by defining the defects you want to find Short shot: The resin does not fill the mold completely, so part of the shape is missing or underfilled. Burr / flash: Resin leaks out at the mold parting surface or through a gap and hardens into a thin layer. Some sites also call the rough remnant left where the gate was cut a burr, so please note which one you mean. Acceptance criteria differ from company to company, even for defects with the same name. Write down at what location and above what size a part counts as defective. If you have limit samples that show the criteria, include them. Divide the samples into three sets Set · What to prepare · Why it is needed Good parts · Good parts picked from several lots, cavities and colors · Knowing the normal range of variation reduces false rejects, where good parts are judged defective Defective parts · Defects sorted by type: short shot, burr/flash, crack, deformation and so on · Each type looks different and appears in different places Borderline cases · Parts where pass or fail is unclear · Needed to align the decision criteria The quantity needed depends on the defect types, how often they occur…