NCJ Number
187167
Journal
Journal of Forensic Sciences Volume: 46 Issue: 1 Dated: January 2001 Pages: 31-45
Date Published
January 2001
Length
15 pages
Annotation
Considering the pronounced changes in the binders that can now be found in automotive paints and their potential use in a wide variety of finishes worldwide, the Paint Subgroup of the Scientific Working Group for Materials conducted a validation study that examined the ability of commonly accepted methods of forensic paint examination to differentiate between these newer types of paints.
Abstract
Nine automotive paint systems typical of original equipment applications were acquired from General Motors Corporation in 1992. They consisted of steel panels coated with typical electrocoat primers and/or primer surfacers followed by a black nonmetallic base coat and clear coat. The primary purpose of this study was to evaluate the discrimination power of common forensic techniques when applied to the newer generation original automotive finishes. The second purpose was to evaluate interlaboratory reproducibility of automotive paint spectra collected on a variety of Fourier transform infrared (FT-IR) spectrometers and accessories normally used for forensic paint examinations. The results show that infrared spectroscopy is an effective tool for discriminating between the major automotive paint manufacturers' formulation types that are currently used in original finishes. Furthermore, the results show that the mid-infrared spectra of these finishes are generally reproducible even when comparing data from different laboratories; commercial FT-IR instruments; and accessories in a "real world," mostly uncontrolled environment. 2 tables, 13 figures, and 6 references