Contamination Identification


Customers often send resins or parts to determine if a material is contaminated.

A contaminant is anything which was not indented in the product and introduced unknowingly or accidentally either by raw material suppliers during storage, packaging, transport, or processing.

It is one of the most common causes of part failure. Failures are most serious when contaminants are incompatible. Contaminants can lead to both rapid and catastrophic failure or slow and gradual failure.

Many commonly occurring contaminants include unmelted pellets from different polymers, cross linked gels, rubber, sealants, broken pieces of gaskets, metallic pieces from tools or machine wear, adhesives, wood fibers, paper, cotton rag piece, staples, machine oil, hair, insects, degraded resin, or oxidized residue deposited on the walls of machines.

Unfortunately, one would not know if a material is contaminated until the final products are produced, shipped and used.

The first step is to look under the microscope to determine the shape, size  and structure of the contaminant. If the amount of contaminant is polymeric or organic in nature and is in significant quantity, it can be isolated and tested with ATR or FTIR. When the contaminant is an undesired additive, it can be isolated and extracted and further investigated. In some cases, making a thin film and doing ATR can detect the nature of additive.

Case Studies

Contamination in Thermoplastic Vulcanizate (TPV)
An injection molded black TPV part had randomly embedded white inclusions. Isolated white contaminants were soft and elastomeric. Upon testing, ...