Biocomposites Since the
Biocomposites Since the beginning of March 2019, the German Plastics Center SKZ, in cooperation with Kunststofftechnik Paderborn (KTP), has been researching possibilities for improving the filling behaviour of natural fibre-filled melts by adding foaming agents in the injection moulding process in a two-year project. The density of the natural fibres is approx. 1 g/cm³. In contrast, mineral fillers typically have a density of more than 2 g/cm³. Due to the lower density of the filler, natural fibre-filled plastics, such as wood polymer composites (WPC), are ideally suited for use as lightweight construction materials with high rigidity. Injection molding of WPC materials with fill levels of more than 40 % by weight often leads to problems such as the formation of flow anomalies or segregation during the filling process. These phenomena have a considerable impact on component quality and also make it difficult to predict the filling of the molded part and the resulting component properties. The two research institutes SKZ and KTP want to counteract this problem by adding blowing agents and thus develop innovative solutions for the use of natural fibres in injection moulding. Based on the results of the precursor project, in which WPC has already been successfully used as core material for sandwich injection moulding, the filling behavior of natural fiber-filled melts is now to be optimized. The addition of blowing agents can significantly reduce the material viscosity of the WPC during the filling process. This effect is to be used to significantly improve the flow behavior by specifically adapting the WPC formulation and the blowing agent addition. The question of the optimum wall thickness for foamed, natural fiber-filled injection molded components will also be clarified. In the cooperation of the two research centres, experimental investigations with different WPC formulations using chemical and physical blowing agents will be carried out on an injection mould to be developed. In order to gain a deeper understanding of the processes during the injection moulding process of foamed WPC, a comprehensive rheological characterisation of the materials used is also planned. The knowledge gained with regard to the foaming of WPC will finally be transferred and applied to the 2K sandwich injection moulding process. The successful completion of the project opens up a wide range of possibilities for the use of WPC in previously inaccessible areas of application, for example as a lightweight construction material. The IGF project 20365 N of the Forschungsvereinigung FSKZ e. V. is funded by the AiF within the framework of the Programme for the Promotion of Industrial Community Research (IGF) of the Federal Ministry of Economics and Energy on the basis of a resolution of the German Bundestag. Companies interested in the project are welcome to contact SKZ. www.skz.de Improved filling characteristics of natural fiber-filled melts 38 bioplastics MAGAZINE [04/19] Vol. 14
Biocomposites Biosourced composites for aerospace applications using bamboo fibres T he French companies Expleo, Arkema, Cobratex, Specific Polymers, Cirimat, Compositadour, Lisa Aeronautics and Mécano ID have come together in Paris, France, late last year to design new biosourced technical composites based on long bamboo fibres. Known as BAMCO (Bamboo long fibre reinforced biobased Matrix Composite), this innovation will eventually reduce the environmental footprint of aircraft, as well as delivering benefits that extend well beyond the aerospace industry. Controlling its environmental impact is an increasing concern for industry. In aerospace, research is focusing specifically on the design of new materials. Some polymer composites, including the glass/phenolic composites currently used, will soon be impacted by the European REACh regulation. As a result, there is an urgent need to develop equally effective alternative solutions. For the last four years, Expleo and Cirimat have been working closely together on the concept of a biocomposite created using continuous bamboo fibre to reinforce a biosourced thermoplastic matrix. Already validated in the laboratory, this concept must now be validated on the industrial scale. The FUI BAMCO collaborative project aims to respond specifically to this challenge by developing new biocomposites created from long bamboo fibres. Although there are already other solutions available that use flax or hemp fibres, these biocomposites are completely new and unprecedented materials that could beneficially replace glass/phenolic composites as a result of their lightness (reducing overall weight, and therefore fuel consumption), their thermal resistance and the mechanical properties in terms of strength and impact/vibration absorption. The cultivation of bamboo also delivers an effective response to a series of ecological imperatives: rapid growth with low water consumption, low soil usage and the absence of any need for fertilisers or pesticides. In aerospace, BAMCO composites could be used in cabin interiors, in cover panels and fuselage cladding panels, and even in the onboard galleys used to prepare and store in-flight meals on aircraft. They could also have applications in the manufacture of finished components for use in the marine and leisure sports markets. Certified by the Aerospace Valley competitiveness cluster, and approved by the Direction Générale des Entreprises (DGE) for inclusion in the FUI 24 single interministerial fund earmarked to provide finance for competitiveness cluster projects, the BAMCO project is supported by the French regions of Occitanie Pyrénées-Méditerranée and Normandie, as well as by Bpifrance. It draws on the expertise of eight industry stakeholders, company and research laboratory consortium members. The BAMCO project is supported by Expleo, the world-class partner in engineering, quality and digital solutions, which has developed this innovation. With its in-depth experience of materials engineering and aerospace industry expertise, Expleo is involved in designing the prototype components. It also provides the governance structure for this extensive project, with its important implications for tomorrow’s industry. Arkema and Specific Polymers have responsibility for the formulation and application of the biosourced polymers (presumably e.g. Arkema’s biobased polyamides - MT) used for the composite matrices. Cobratex will research and propose candidate species of bamboo, some of which are grown in France. In responding to the constraints involved in using the full range of matrices and composite processes, Cobratex will optimise its own conversion process, as well as its own innovative reinforcement technologies. The company will also be responsible for the upscaling of the techniques used to apply the technical reinforcement solutions and semi-finished products developed directly by Cirimat. The research laboratories Cirimat and Compositadour are involved in using the biocomposites in the laboratory, and on an industrial scale respectively. The Cirimat contribution focuses on the design and laboratory-scale production of continuous bamboo fibre composites using thermoplastic and thermosetting matrices. Mécano ID is responsible for conducting the vibration absorption tests and modelling biocomposite behaviour. Lastly, plane maker Lisa Aeronautics will incorporate a prototype component in its future aircraft. The BAMCO entered its operational phase end of 2018 with the launch of development work. The first prototype components are scheduled for 2021. MT www.expleogroup.com bioplastics MAGAZINE [04/19] Vol. 14 39
