Session 18: Measuring & Testing
Chair: Kurt Wood, Arkema, USAnalysing, testing and characterization of raw materials and products are essential in both the development and production of industrial products. The six papers of this session present important studies on weathering and aging of coatings systems for different substrates including plastics as well as analytical investigations of raw materials, discussing new methods and standards for accelerating tests as well as measurements of coatings, composites and their properties.
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Tuesday Afternoon 14.00 – 17.30 h
Room Shanghai
18.1 14.00 – 14.30 h Accelerated weathering test of plastics and coatings - New technologies and standardization Dr. Artur Schönlein, Atlas Material Testing Technology, DE The natural factors of weather have to be simulated as close to real life as possible during artificial weathering tests. In doing so, the weathering device requires a sufficient acceleration with maximum correlation to outdoor weathering results. The simulation of the solar radiation is of particular importance. Absorption of UV radiation or light trigger primary photochemical processes. Xenon, special fluorescent, and metal halide lamps are the most important laboratory weathering instrument light sources used today. Material degradation processes initiated by radiation are temperature dependent. In weathering tests, surface temperatures are characterized by placing panels with black and white coated surfaces in the exposure plane and measuring the temperatures of these surfaces. The measurement and automatic control of the most important climate parameters as well as the calibration of the applied measuring systems in accordance to ISO 17025 are essential elements of the equipment technology for reliable test results.  | ||
| 18.2 14.30 – 15.00 h Accelerated aging of thermoset coatings below their glass transition temperature Fabio Aguirre, Dow Coating Solutions, US The service life of polymers is often predicted by extrapolation from accelerated aging tests. High temperatures are typically employed to accelerate the aging. This approach assumes the aging mechanism is the same in the accelerated tests as it is for the lower service temperature. If the use temperature for a thermoset coating is near its Tg, accelerating the aging via temperature will require testing above Tg. Diffusion rates of polymeric chain segments and many small molecules decrease very rapidly upon cooling through the Tg. Thus the validity of a temperature derived extrapolation that traverses the Tg is in question. Our approach for oxidative aging processes is to accelerate the oxidation using increased oxygen concentration allowing data collection in a reasonable time below Tg. This could prove a more valid method to predict service life of polymers in high service temperature applications. | ||
| 18.3 15.00 – 15.30 h Characterization of interphase adhesion in multi-layer coating systems Matthias Wanner, Research Institute for Pigments and Coatings (FPL), DE Multi-layer coating systems are state of the art by painting of metal and plastic surfaces e.g. in the automotive industry. Utilizing such systems consisted of several specialized coating materials a high adhesion and a good corrosion protection can be reached, along with good barrier properties, chemical and scratch resistance as well as appealing surface appearance. The interphase regions between single layers by such systems represent areas of a potential weakness, where a delamination and a premature coating degradation can start. To test this coating property, a special cyclic hydro-thermal loading was developed, which causes the accelerated build-up of the internal stress within the coating system. Using an electrochemical impedance spectroscopy with various optimized electrode geometries, it was possible to detect the early stages of the coating degradation and to compare different coating systems. Internal stress measurements contributed additionally to more understanding about the progress of the coating degradation. 15.30 – 16.00 h Networking: Refreshments & Coffee Break | ||
| 18.4 16.00 – 16.30 h Analytical investigations on migratable/extractibles/odor in coatings and composites Corinne Roqueta, Sartomer Europe, FR The continued demand for coatings and inks with improved low migration, low odour and low paint properties, is driven in part by Legislation and in part by consumer demand. For the formulation of coatings and inks, this has required improvement and development of new analytical techniques in order to better assess this complex situation. This paper will offer an overview of the Regulatory and tests aspects before presenting a generic approach and analysis for a raw material perspective. Examples will be given for the UV/EB food packing application, coatings emissions as well as odour generation. | ||
| 18.5 16.30 – 17.00 h Categorizing TiO2 pigments based on fundamental principles Johan Rommens, DuPont, GB By taking a close look at fundamental TiO2 properties, (Color, Optical Density, Dispersion, Durability, Surface Treatment) TiO2 pigments can be categorized into distinct groups. These groups impact: -Paint optical properties -Hiding /Tint Strength -Milling Equipment -HSD / Media Mills -Market Space -Durability / Sheen / Color This paper describes the measurement of TiO2 fundamental properties, including recently developed measuring techniques. The paper also shows how to interpret those results and how to categorize TiO2 pigments. | ||
| 18.6 17.00 - 17.30 h Major advances in the reliable measurement of the color and appearance of special effects Reinhard Feld, X-Rite, DE Companies involved in design, formulation and application of coatings have found there is not a reliable method for measuring the color and appearance of special effect paints due to their reflective qualities. Traditional in-plane spectrophotometric measurements are insufficient when characterizing modern automotive colors. Companies still rely on human inspection of pieces painted with special-effect finishes, which consumers now demand in a wide range of products. Perceptual concepts such as Sparkle and Coarseness are Gonio-Apparent and simple in-plane and single camera geometries are insufficient and unreliable measures. Using newly designed equipment containing out of plane geometries and software, engineers have created a three-dimensional mathematical model for any special effect paint that can be used as a distinguishing fingerprint for designers, paint manufactures and their end users. Paint companies can achieve a competitive advantage by helping customers at every tier in the supply chain with hard, accurate data. Production personnel can immediately identify and troubleshoot defects that are not detected using other methods. This paper will explain the science behind the technology and present results of studies to illustrate applications in the field, giving the audience a sense of what can be measured and determined with alternate geometries. | ||
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