Read Consulting

Specializing in: product liability, failure analysis, patent disputes and intellectual property. We have 25 years experience with glass, ceramics, plastics, wood and metals; 100 depositions & many court appearances.

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Procedure

2 triangles   Failure Analysis; Small Glass Bottle

Introduction

The materials Engineers at Read Consulting LLC performed a root cause glass failure analysis of a small lacquer bottle that arrived broken at the customerís site.

1. Visually examine the failed glass bottle.
2. Clean the Lacquer off the fracture surfaces of the failed bottle.
3. Using a low power microscope, perform a fractographic analysis of the bottles and document the results

Results Summary

The subject bottle had the neck separate from the bottle at the shoulder. The root cause of the failure was determined to be an impact to the bottle on the shoulder where it intersects the neck.

Discussion

The impact point is odd in that it isnít on the outer perimeter of the bottle. If this damage had occurred on the production line, one would expect the mechanical damage to have occurred on the bottleís outer perimeter. The location of the damage suggests that it occurred during shipping.

broken subject bottle in situ
Figure #1: : Photograph of one of the broken subject bottle as it was received from the customer.
broken subject bottle and top
Figure #2: : Subject bottle and top after the top has been removed from the cap and much of the red lacquer has been removed.
Fractured top of broken bottle
Figure #3: : Photomicrograph of the origin of the fracture top of the bottle. This Fracture initiated at an impact point on the shoulder near the neck. The impact is verified by the presence of conchoidal fractures that are a result of impact (Mag. 8X).
fracture initiation of broken bottle
Figure #4: : The Fracture initiated at an impact point on the shoulder near the neck. The impact is verified by the presence of conchoidal fractures that are a result of impact. This photo focuses on the subsurface conchoidal fractures (Mag. 20X).
Left Side Near Origin Right Side Near Origin
Left Side Near Origin Right Side Near Origin
Figure #5:Photomicrographs of the fracture surfaces on the bottle top near the origin the markings (i.e. Wallner Lines) show that the crack is exiting the origin (Mag. 40X).
fracture initiation of broken bottle
Figure #4: : Top down photomicrograph of the assembled broken bottle. This failure was caused by impact to the bottle where the neck intersects the shoulder (Mag. 8X).