GLass Expert Discusses Glass Bottle Strength

Glass failure analysis expert performed bottle strength tests to determine the strength of a cylindrical glass bottle. The bottle is approximately 0.85" in diameter and 2.35" tall. The glass thickness is approximately 0.040" thick. It was hypothesized that a female could squeeze the bottle hard enough to crush it. Glass strength was measured by compressing the bottle both radially and axially. Upper left photograph shows the radial "squeeze test. The human hand is soft; therefore the test bottle was compressed between soft vinyl plastic tubing. In this orientation the bottle could withstand a minimum og 240 pounds force. The upper right photograph shows the "axial" strength test. Again, no hard surface touches the vial. Axially the bottle can withstand a minimum of 130 pounds. Even though the bottle may have many surface defects, it is strong because it is under compressive stresses. Because glass fails in tension, the cylindrical shape insures the highest strength. Because the bottle has no flat surfaces, it can withstand very high forces. No average female could generate sufficent forces with their hand to crush this bottle.

Glass Expert Discusses Visibility of NiS Particles

Tempered glass failure analysis is mainly difficult because the panel disintegrates into a very large number of semi identical particles; therefore, the failure origin is impossible to locate. In several cases Read Consulting has had the opportunity to examine several failed (caused by Nickel Sulfide, NiS, particles) tempered glass panels that have remained intact. In some cases the windows were laminated; in the others, the windows remained verticle and stayed interlocked. Once the origin is located and preserved, an eyeloop or low power microscope is all that is required to see the NiS particle. The upper left photograph is a macrophotograph of an inplace failed laminated window. In this case the NiS particle is visible to the naked eye. It is a sphericle particle on the fracture surface. Upper right is an 8X photo-micrograph of the particle after the window has been taken apart. This root cause failure analysis does not require scanning electron microscope. This type of tempered glass fracture analysis merely needs an intact failed window.

Glass Expert Performs a Wine Bottle Failure Analysis

California glass expert performs a failure analysis on a wine bottle failure. In this case the root cause of the failure was due to an impact on the top of the bottle finish. it is apparent that this bottle was hit on the top. This is shown by the photomicrograph.

Glass Failure Analysis Of Bottle Defect

California Glass Expert Witness was assigned to determine the cause of failure of wine bottles at the manufacturing facility. During processing the bottles had a higher than normal failure rate. A root cause failure analysis was performed by the glass failure analysis expert witness. He inspected a large number of whole bottles and removed those with visible defects. In addition failure analysis was performed on those bottles that failed in manufacturing. Above left is a photomicrograph of a "crush" or "bruise" found on one of the unbroken bottles. This type of defect was found on several bottles. This bottle defect appears to be a result of impact damage. Curiously, there is an open surface bubble (i.e. seed) in the vacinity of the bruise. Upper right is a photomicrograph of the fracture surface of one of the failed bottles. The origin of this failure is at the same location on the bottle as the bruises found on whole bottles. In addition, this failure started at a small diameter bruise. The repetitive nature of the location and the nature of the defect indicates that this manufacturing defect is caused by the glass handling machinery either at the bottle manufacturing facility or at the bottling plant. Also, this damage is severe enough to cause bottle failure.