In this application note we explore how multiple techniques can help complete the puzzle of investigative failure analysis.
Two techniques and several accessories; UV-Vis, and FTIR with TGA, ATR and FT-Raman, collectively provide decisive root cause analysis crucial to identifying where failures occur and guide next steps. See how these techniques, many of which can be found on one instrument, work together to complete the puzzle of failure analysis.
Application Note Preview: Investigating Why a Plastic Part Failed
Abstract Manufacturers employing plastic parts routinely face the challenge of analyzing failed parts to determine the root cause and corrective actions. The tools used to perform this analysis often include infrared and Raman spectroscopy for chemical composition, UV-Visible spectroscopy for color and optical transmissivity, and thermal analysis for determination of physical properties. This paper describes a study utilizing all of these tools to determine why a plastic part failed.
Introduction A manufacturer of precision optical equipment designed a plastic cover for a device with specifications for chemical composition, surface texture, color and optical transmission. Briefly, the cover was to be made from a polycarbonate – acrylonitrile butadiene styrene (PC-ABS) blend with sufficient titanium dioxide to provide a slightly off-white color and optical transmissivity less than 0.01% T over a wide spectral range – from the UV into the near-infrared. The opacity was required to prevent ambient (room) light from entering the optical device and interfering with low light level measurements. Initially, all parts supplied met the specifications and the product provided satisfactory performance. A re-engineering project was subsequently initiated to reduce costs and make the product more competitive. Alternate suppliers for various parts, including the cover, were asked for quotations. A new supplier underbid the original cover supplier, and the test parts met all the requirements for opacity. Production was shifted to incorporate this new supplier.
Shortly thereafter, the product began to fail critical performance tests. The failures were immediately traced to ambient light causing elevated backgrounds, strongly affecting low level optical measurements. Visual inspection of the covers did not reveal apparent differences from the original, but various control experiments led to tracing of the failure to the new cover. A root cause analysis using many techniques was undertaken to quickly identify and contain the issue.