Failure Analysis

Approaches

Failure analysis often begins with an examination of the part, often using microscopic methods.  For a physical failure, the crack surface can provide clues about the nature of the failure, such as whether the part underwent brittle or ductile failure, or whether it was the result of environmental stress cracking (ESC). 

If chemical attack is suspected, chromatographic techniques may be applied to look for the presence of a solvent or other compound that could break down the part.  Additionally, if certain types of degradation are suspected, analysis of the additives by chromatographic methods may be carried out.

Molecular weight analysis of good and bad parts may be applied to confirm that degradation is occurring.

Thermal analysis (DSC) can be used to look at differences in thermal history which could manifest in variations in crystallinity.  Crystallinity can affect mechanical properties.

Nuclear Magnetic Resonance Spectroscopy (NMR) may be applicable for materials that are blends or copolymers to verify the correct ratios of components.

In some cases, mechanical testing may be carried out to confirm the suspected failure mode.  In addition, verification of fillers may also be important.

Sample Considerations

It is strongly recommended that a known “good” sample be provided for comparison to the failed part. 

In addition, any information about the specifications and composition of the product can be helpful. 

Any information about the environment in which the part was used can be helpful.  A few examples include:

• Is the product or material exposed to sunlight? 
• To what cleaning products might it have been exposed? 
• What temperature ranges does the product or material routinely encounter? 

Experience

We've tested a wide variety of products to determine the cause of failure.  Some examples of those products include:

• Snack Containers (off odors)
• Pet food packaging 
• CPVC Pipe 
• Soccer balls 
• Conveyor belts
• Tires
• Carpet
• Tubing used in a medical device
• Silicone pump from a medical product