JEC COMPOSITES MAGAZINE - Issue #47 - March/April 2009 - 22

EQUIPMENT Non-Destructive Testing designed for non-destructive, on-site surface and bulk analysis applications. Weighing only 3.2 kg including the data system and batteries, the Exoscan features superior ease of use, coupled with analytical performance that rivals far larger traditional analytical FTIR spectrometers. This system is ideal for sampling a wide variety of materials including solids, pastes, gels and liquids. Coupled with the unique A2 Technologies diamond internal reflection sampling system, it is also capable of large surface analysis. Controlled and operated via a PDA device, the Exoscan spectrometer combines all the unique capabilities of a laboratorybased FTIR system with the advantages of a portable instrument that can be used in the field to ensure real-time results. …/… New kind of portable NDT device maintenance, building and construction material analysis, biomedical product manufacturing, semiconductors, polymers/composite manufacturers and end users. In the composite industry, it can be virtually used all along the production value chain. In most cases, the system is calibrated using a reference sample that is used for control purposes. The Exoscan software provides multiple levels of user interaction. The administrator level allows for full use of the system to develop methods, while the technician level allows untrained users to collect data and view results of established methods. The system can be used by experienced personnel to conduct the measurements needed to develop an analysis, or by manufacturing or maintenance personnel to routinely check for damaged parts. EQUIPMENT EQUIPMENT EQUIPMENT EQUIPMENT Main features The Exoscan can be used to determine whether: • A metal surface has been properly cleaned for painting or coating; • A surface has been properly prepared for a bonding process; • The correct primer or coating has been applied, including thickness control; • A surface has the expected level of homogeneity; • Anodizing processes have been carried out correctly; • Spots, streaks, stains or blemishes on a surface are problematic; • A high-value composite material has been damaged by heat, UV, or chemical exposure; • Polymers and composites are properly cured; • Quality requirements are met. measurement can predict the amount of heat a sample has been exposed to, the physical properties can also be predicted. The system has been used to measure aircraft parts which have been heatdamaged in an engine fire. Due to heat transfers from the supporting structures, the damage was not uniform across this part. In cases such as this, the extent of damage needs to be measured at various points on the part in order to determine which areas of the composite can be repaired. Here, an increase in the absorbance in the carbonyl region (in organic chemistry, a carbonyl group is a functional group composed of a carbon atom that is double- or triple-bonded to an oxygen atom) is characteristic of heat damage. The heat damage was found to be highest in areas closest to metal support structures, most likely due to a large heat transfer between the metal and the composite. Maintenance technicians can use this information to determine which areas of the part need to be completely replaced or whether the areas can be repaired via a patch. More information: www.a2technologies.com Example: heat damage of composite aircraft parts Thermal damage causes oxidation of the epoxy resin component in composite materials, which can lead to loss of strength in the composite part. Since FTIR spectroscopy is uniquely suited for identifying and quantifying oxidation products, it can be an effective method for identifying heat damaged areas. However, because it is typically carried out in a laboratory, measurement of heat damaged composites by reflection infrared spectroscopy has not been widely employed. This results from the need to destructively disassemble these large samples so that they can be measured by a laboratory FTIR system. Even though FTIR is a non-destructive technique, measurement in a laboratory requires that large samples are destroyed in order to be accommodated by the spectrometer. The Exoscan overcomes this problem. The measurement of heat damage on aircraft composites takes approximately 20 seconds. Characteristic spectra show the effect of heat damage in the resin. Oxidation of the epoxy resin due to heat damage has been shown to reduce the physical properties and mechanical strength of a composite. If a The Exoscan software provides multiple levels of user interaction. Applications In addition to the on-site measurement of samples that were typically measured in the lab such as incoming raw materials or finished products, Exoscan is equally useful for the analysis of samples that tend to be difficult or impossible to analyze in a lab. It is very effective at analyzing samples that are too large or inconvenient to bring to the lab for analysis, as well as samples that are too valuable to be removed. Polymers, liquids, solids, gels, composites, coatings or paints can be analyzed by this apparatus. Fields of applications include: aerospace/aircraft manufacture and 22 jec composites magazine / No47 March-April 2009

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JEC COMPOSITES MAGAZINE - Issue #47 - March/April 2009

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #47 - March/April 2009