Contamination Causes Part Failure

Dr. Duane Priddy, Plastic Expert Group

A manufacturer of a device contracted the manufacture of a frame (shown below) for the device. The client was experiencing periodic failure of the frame. Our experts analyzed the fracture surfaces of a broken plastic frame using optical microscopy, FTIR, and DSC to determine the failure mode and the root cause of failure. The results of these tests revealed that the failure mode was tensile overload and that the root cause of failure was due to contamination of the HIPS resin with ABS. HIPS and ABS are not compatible with each other resulting in significant decrease in mechanical strength of the composite material. The lower tensile strength of the composite material caused failure by tensile overload when force was applied to the frame. Plastic Expert Group recommended to the client that they work with their contract manufacturer to implement a system to insure that the HIPS raw material did not get contaminated with ABS.

The complete 7 page article about this study is available by email at