Glass failure analysis expert performs a root cause failure analysis on a bottle failure. In this case a manufacturing defect was causing numerous failures on a manufacturing line. The tops of these small bottles were coming off. The upper left photomicrograph is with the two halves of the bottle re-assembled. The upper right photomicrograph is of one of the glass fracture surfaces. The failures were occuring just below the transfer ring at a glass molding defect. The molding defect is a fold in the glass that acts as a stress concentrator. The lower left photograph is of an unused bottle with the defect. This is an unacceptable manufacturing defect and the parts werre returned as non-conforming.