Glass Failure Analysis: Tempered Glass Pot Cover

California glass expert performs a root cause failure analysis on a failed tempered glass pot cover. The pot cover failed "spontaneously" in the users home, and the handle with captured glass was submitted to the California failure analysis lab for evaluation. The failure was caused by the interaction of the handle hardware (i.e. cup washer) with the tempered glass. Crush damage from the cup washer that caused the failure. The series of photo micro graphs above demonstrate the findings. The lesson to be learned here is: there should be no glass-to-metal contact with tempered glass. This type of contact raises the probability of failure. In the case of tempered glass the failure appears to be spontaneous.    

CA Glass Expert Performs Bottle Failure Analysis

Overview of Assembled Bottle 8X Mag.

View of Origin on Bottle 40X Mag.

View of Origin on Neck 40X Mag.

California glass expert was asked perform a glass failure analysis on numerous small cosmetic bottles. These bottles all failed where the neck intersected the shoulder of the bottle. Microscopic photos of a representative failure are given above. The glass fracture originates on the outside of the bottle and progresses inward before going around the bottle. These glass failures were found in the filling line, and the bottle manufacturer was notified. The root cause of these failures was determined to be a check (chill check?) in the neck where it intersects the bottle shoulder. This is a manufacturing defect that affects product liability.