Glass Manufacturing Defect
Wine Bottle Failure Analysis that Revealed a Manufacturing Defect as the Cause of Failure
Introduction
A root cause failure analysis was performed by Read Consulting on a failed wine bottle. The failure initiated in the bottle neck under the label.
Strategy
Examine the visible fracture surfaces and determine the approximate location of the fracture initiation site.
Expose the fracture surface at the initiation site and perform a root cause failure analysis
Results
An overview of the bottle as it was received for the failure analysis is shown in Figure #1. The travel directions of the exposed cracks indicated that the failure origin was in the bottle neck under the foil.
Figure #1: Overview of the as received wine bottle.
The foil was removed (Figure #2) and what appeared to be the failure origin was inside the neck (Figure #3). Therefore, the neck was cut from the opposite side of where the apparent origin was seen. The neck was opened up and the failure origin was exposed (Figure #’s 4 & 5).
Figure #2: Photograph of the neck of the failed wine bottle. This photo was taken after the foil was removed.
Figure #3: Detailed photograph of the neck in the region of the failure initiation site (star shaped crack cluster right of the red bar).
Figure #4: Photograph of one-half of the bottle neck after the neck had been opened up to allow proper failure analysis. The failure origin is the milky white region in the photograph.
Figure #5: Close-up of the failure origin. The cracking emanates from the milky white material in the center of the photograph. It appears as if the root cause of this failure is a piece of un-melted cullet (recycled glass) (Mag. 20X).
Root Cause of Failure
This failure analysis revealed that a piece of unmelted glass had created cracks in the bottle as it cooled down from the forming operation. The final failure occurred when the corkscrew was leveraged to remove the cork.