California Glass Expert Performs a Failure Analysis of Sparkling Liquor Bottle Failures

A bottling line for sparkling drinks was suffering from a high rate of  bottle failures on the bottling line. In addition, several bottles failed on the shelf after bottling. Read Consulting was asked to perform a glass failure analysis to determine the cause of failure of three bottles that had failed "on the shelf". Two of the three bottles were from the same mold cavity, and both failed at the exact same height from the base (2 1/4"). The third bottle failed at 2 1/2" above the base. All three failure origins were the same. All three failures started on the outside of the bottle. All three had "crack arrest lines " near the origin. In addition, All three had no visible mechanical damage to the bottle exterior at the origin.  The presence of the crack arrest line confirms a delayed failure. These factors indicate that the failures are caused by defects caused by the bottle manufacturing process. This is a manufacturing defect that must be corrected by the bottle manufacturer.

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.

GLass Expert Analyzes Wine Bottle Failure

Glass expert analyzed several leaking wine bottles that eventually broke in half. All the bottle failures occured on the heal. Also, during failure analysis, it was discovered that all of the bottle failures were made in one cavity of a multi-cavity bow mold tool. Bottles from the other cavities did not have this problem. These bottles were made from very thick dark glass. It is believed that the failures were initiated as chill cracks. However, more process development work must be done at the factory to correct this manufacturing defect. Two suggestions are to eliminate any drafts in the factory and increase the amount of post mold flame heating on the conveyer. Bottles made from thick glass are more likely the have this glass failure mode.