Quality assurance in accordance with VDA (German Association of the Automotive Industry) Various analytical methods are available for investigating the emission behavior of materials and components in car interiors. Although there is no uniform regulation, responsible governmental departments, automotive manufacturers and the large group of suppliers are interested in a worldwide harmonization of testing methods, also from financial aspects.
vda 278 test method
Sample preparation and analytical conditions The VDA 278 standard specifies a strict workflow, starting with testing instrument performance using a control standard solution consisting of 18 components (see figure 1). In the next step, two calibration standards are measured. Toluene is used to determine the response factor for the VOC calibration and hexadecane respectively for determination of the response factor for the FOG calibration. Desorption tubes filled with Tenax (an absorber material) were used for the preparation of the calibration samples. After injection of the standard solution, the solvent is evaporated for five minutes under a continuous flow of nitrogen (100 mL/min).
PU foam waste can be recycled by using physical, thermochemical and chemical methods. The physical recycling methods include regrinding, rebinding, adhesive pressing, injection molding and compress molding, while the most common chemical methods are hydrolysis, acidolysis and glycolysis [4]. Degradation of the chemical structure of the polymer allows for the depolymerization of the PU waste to oligomers terminated with hydroxyl groups, further using this product as a part of polyol component for the synthesis of new polyurethane materials [5]. Efforts in reducing fossil-based materials were studied by Serrano et al. to obtain biodegradable polyurethane foams [6]. Wenqing et al. studied the recyclability of rigid polyurethane foam [7]. Deng et al. recently presented an extensive overview of thermo-chemical recycling possibilities of PU foams. TDI and mostly polyol can be recovered by using these procedures, but pure feedstock cannot be produced, so a further upgrading of the condensate is needed, together with a thermal or alternative treatment of the non-condensable [8].
Although several chemical methods to recover polyurethane foam waste are described in the literature and numerous patents certifying the interest of the industry were issued in this topic [14,15,16,17,18,19,20,21,22,23], the large-scale production of recycled polyol is seldom mentioned [24]. Together with the imperative environmental issues, a viable and economically feasible recycling solution should involve high recycle yield and product quality at the same level as obtained with the virgin raw materials.
Considering the high amount of polyurethane foam waste available for recovering, as well as the global effort to reduce the fossil consumption, there is a clear demand to identify new methods or improve the efficiency of the existing methods. All of this research must be accomplished in close connection with the requirements, possibilities and prospects of the polyurethane industry.
At automobile industry sector continuous quality enhancement is a permanent challenge for developement of new products and control of their quality. Increasing quality demands a more and more complex testing system.Quality characteristics with high importance are the emission behaviour of car interior materials as well as its resistance and ageing behaviour.CC Automotive and its Division Car Interior Material Testings has a long time competence and expert knowledge of this testing subjects. We are one of the biggest contractors for automotive emission tests in Europe. Testings according to manufacturers` norms (as: Audi, BMW, DaimlerChrysler, GM, Jaguar, Porsche, RR, Saab, Toyota, Volvo, VW and many more) belong to our standard program as well as generally accepted methods according to VDA, DIN, EN or ISO.
Among the OEM norms, the PB VWL 709 (VDA 278) of DaimlerChrysler has to be emphasized. This method allows extensive statements about the roots of the emissions and is therefore very helpfull for the process of developing and improving new products.
In recent years the reduction of emissions from plastics, in particular in the automotive industry has increasingly gained in importance. In the meantime the emissions requirements of the Japanese automobile manufacturers are amongst the most stringent in the world. The TER Plastics POLYMER GROUP distributes the entire DURACON POM product assortment of the Japanese global market leader Polyplastics within their pan-European sales network.Polyplastics, the largest POM manufacturer of in the world, started at an early stage to analyse the causes of formaldehyde emission from POM and to reduce the level of emissions. For the European automobile market both the VDA 275-Test, as well as the test methods of VDA 277 and VDA 278 were established in the Polyplastics Technical Solution Centre in Fuji. Using these test methods we researched the causes of emissions from POM. The knowledge gained from these was finally converted into the new product group DURACON LV (= Low Volatiles). The opening of the new DURACON production plant in Malaysia, which works with a newly developed Polyplastics polymerisation process, has made the manufacture of a POM raw polymer material with a significantly improved stability possible. In addition, in the production of DURACON LV types a new kind of stabilisation has been used, which contains an improved formaldehyde capture. The types of DURACON LV resulting from this display a significantly reduced formaldehyde emission with identical mechanical characteristics. With DURACON LV Standard types a level of emissions of under 2 mg/kg is achieved (measured in the VDA 275-Test).
The VDA 278 guideline is one of the most required emission test methods for automotive interior. In order to make the test procedure easier and more precise imat developed an innovative concept for sample preparation.
The imat high precision micropunch can be used to prepare standardized samples specimens suitable for tests according to VDA 278. In comparison to a conventional belt punch, much less force is needed to cut out the specimens. The device makes it possible to cut out specimens in an optimized size for meeting the required weight of 30mg. Specimens produced by the imat high precision micropunch are highly accurate with respect to best reproducibility. It allows quick adjustment of the tool either for cylindrical cores, strips or the fixed size for lacquer samples applied to aluminum foil.
Polyurethanes were invented in 1937 by Otto Bayer and his co-workers. Flexible PU foams were developed and used in car seats in the early 1950s. In the 1990s, the first low-emission foams were developed and, due to emanations control, were extended to subsurface materials used, such as seat cushions. Raw material suppliers were asked to explore the sources of the emanations and work with OEMs to reduce their overall quantity. At that time, silicone surfactants played a key role in low emissions. A general overview on the emissions and the analytical methods used to analyze PU foam emissions was published in 2018, but it focused mainly on emissions under well-established methods such as VDA 278, which is one of the standard European methods. As other markets such as the Asia-Pacific economic zone may have different requirements and quality standards when emissions are considered, we summarize in this paper the main volatile components currently monitored in this region and how they are analyzed. We also discuss analytical data regarding the contribution of silicone surfactants to emissions and how they can be improved to meet customer requirements.
components following the trend of customers worldwide looking for less emission-intensive environmental conditions. Low volatile organic components (VOC) are thus a requirement of the industry and different methods have been used worldwide for the material testing. Some requirements are generally recognized in some countries or economic areas, like the VDA (Verband der Automobilindustrie) methods in Europe, while other methods are specific for each car producer and they have some differences that make it difficult to obtain standardized methods and comparable values.
The list of volatile substances includes a variety of aromatic structures, three aldehydes and acrolein. They are characterized by a low boiling point (below 150 C), and regarding its toxicity (based on LD50 (lethal dose to kill 50% of test population) data), the values are quite variable, ranging from dangerous substances like acrolein and formaldehyde to substances with less toxicity like toluene.
With this new range of additives, the emissions under methods like VDA278 were very low, especially in some of the last references introduced into the market. But the emissions of certain aldehydes were found to be not as low as some customers require.
The new references had shown excellent emissions results, under well-established methods like VDA-278 and also regarding aldehydes, aromatic substances and odor, compared with existing surfactants. The materials had been evaluated in different countries and using different methods, showing in all cases improved values compared with materials made with Concentrol STB PU-12XX PF. It also showed, in most cases, improved values of emissions compared with other well-established references available on the market.
Gaseous VOC constituents emitted from test samples are captured and identified depending on the chosen method. Some of the most used methods for the analysis of aldehydes and aromatic substances are summarized in table 2.
Regarding the aldehydes, it is believed that they are degradation products (mainly from oxidation processes), most of them coming from the polyether part of the surfactant. The siloxane backbone is not believed to be a major constituent of aldehyde emissions, nor of aromatic ones. Usually, the VOC emissions of the siloxane backbone are low molecular weight linear siloxanes and cyclic structures (Dx), that are usually well analyzed by thermo desorption methods like VDA278. 2ff7e9595c
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