Forensic Engineers & Investigators
Failure analysis of plastics and polymers
Capabilities and Services
We investigate the cause of failures of a wide range of plastics and polymer materials. Typical factors contributing to these types of failures include gradual deterioration from environmental exposure, poor design, incorrect specification or poor selection of material for the purpose intended and conflict with other chemicals and materials. The type of plastic coating can also be relevant.
Investigation process: The comprehensive investigation process that we provide may utilise some or all of the following techniques:
Detailed in-situ inspection and reconstruction
Optical and Scanning Electron Microscopy
Reference to applicable international test standards and procedures
Strength testing
Review of environmental conditions and operation history
Maintenance records
Chemical analysis and testing of material constituents
Failure of plastic component
Premature failure of ABS Polymer extrusion due to chemical attack
ABS stands for Acyrlonitrile Butadiene Styrene, a “terpolymer”. It is a versatile industrial and commercial polymer used widely in appliances and technical equipment such as battery cases, phones, TV’s and computing hardware.
A domestic appliance manufacturer experienced many failures of an ABS Polymer extrusion component early in the machine warranty period. Investigations using returned failed product traced the cause to chemical cleaners new to the marketplace
This involved microscopy to study the damaged surfaces and chemical analysis of extremely small quantities of residues found inside some cracks. The morphology of the crack surfaces appeared to be consistent with chemical attack, a phenomenon known as Environmental Stress Cracking (ESC). A selection of cleaners available in the market place were tested for compatibility with the chemicals identified in the crack residue. These tests identified the cleaning chemicals responsible for the failures.
Once the cause of the plastic failures were known, it was possible to disseminate appropriate product information advice in order to prevent the use of inappropriate cleaners.
Success was achieved when the warranty claims began to rapidly reduce. This was supported over the longer term by an improved selection process that considered chemical resistance of plastic materials during the design process.
Crack surface morphology, typical of ‘ESC’