Jun 11 2009
Innovatech Labs, a contract materials testing lab specializing in materials characterization, is helping ensure product cleanliness and composition for engineers and manufacturers with Fourier Transform Infrared Spectroscopy (FTIR) testing.
FTIR analysis is valuable for identification of contaminates such as particles, residues, films or fibers. FTIR can also be used for comparison of a good and failed part, reverse engineering to identify the material makeup of a product and identification of additives in materials.
"FTIR analysis is ideal for identifying unknown contaminants and foreign materials on a product. You can't figure out the why, without understanding the what," said Gary Smith, President of Innovatech Labs. "Once the contaminant is identified, then the customer is able to determine where the contamination is happening and find a solution."
Using the microscope attachment to the FTIR, samples as small as 10 microns may be effectively analyzed. Samples can be tested in various forms including liquid, solid or gaseous.
The FTIR testing process measures wavelengths in the infrared region that are absorbed by the material being tested. The absorption bands identify molecular components and structures according to the frequencies and by searching the FTIR Spectrum against a large database of reference spectra.
FTIR in Action
Two plastic parts were submitted to Innovatech Labs for analysis. Of the two plastic parts, one had fractured during use.
The purpose of the analysis was to determine the difference between the 'good' and 'failed' parts. A sample of the material comprising each part was analyzed by FTIR and compared. The bulk of the materials comprising both plastic parts were found to be very similar by FTIR.
The next step then, was to soak them in isopropyl alcohol. The alcohol was decanted, then evaporated. The remaining residues from the two extracts were then analyzed using attenuated total reflectance (ATR) FTIR. Each of the extracts contained dioctylphthalate (DOP, a common plasticizer), however the amount extracted from the 'fail' part was much less than that extracted from the 'good' part. The failure was due to not enough plasticizer present in the part that had fractured.
In another test, FTIR was used to support manufacturing when plastic packaging trays for medical devices had fibers present. The fibers were removed and analyzed using FTIR which identified the fibers as cellulose.
In working with the manufacturer, it was identified that the fibers matched the cardboard inserts used in the production process. The manufacture eliminated the cardboard inserts in the process line and the fibers disappeared.