Pyrex Glass Failure Analysis: Glass Baking Dish Failure Analysis

California glass expert witness performed a failure analysis on a pyrex glass baking dish. This dish was made from pyrex borosilicate glass, and the glass failure occured as the dish was being removed from the oven. The failure initiated at an internal glass defect. The defect appears to be a colapsed bubble (seed) in the bottom of the dish. The upper left (Mag 8X) photomicrgraph is an overview of the failure origin. Upper right is a higher power (Mag 40X) magnification of the origin. It appears as if the bubble colapsed during hot forming of the pyrex glass baking dish. Because the surfaces of the bubble did not re-weld, a stress riser was created that caused later failure as a result of thermal stresses created during normal use.

Champagne Bottle Glass Failure Analysis

Glass failure expert performed a complete glass failure analysis on numerous champagne bottles that had failed in the riddling process. These bottles are used for riddling and they are made from a large amount of re-cycled glass. Several of these bottle failures initiated at a site that had a piece of unmelted cullet (Note: Cullet is ground glass that is re-melted). The photographs above show one such failure from two vantages. The "lump" of unmelted cullet was larger in diameter than the thickness of the glass (0.120"). The bottle manufactrurer was made aware of the manufacturing process problem and is in the process of fixing it. This is a manufacturing defect that could potentially become a product liability.