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.
Crack surface morphology, typical of ‘ESC’
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.