Materials PLA without
Materials PLA without metallic catalysts The European project InnoREX enables the production of monolayer bioplastic packaging without metallic catalysts thanks to the broad competence spectrum of the project’s consortium. The demand for biobased polymers is growing rapidly. However, due to inefficient production processes consisting of many successive batch processes, which also require the application of potentially harmful metal catalysts, biopolymers such as polylactic acid (PLA) have not yet been fully commercially exploited. In order to overcome these problems, twelve partners, including enterprises, universities, research centres and an association, launched the Innorex project in December last year. The project, which runs until May 2016, is financed by the European Community’s Seventh Framework Program and coordinated by the Fraunhofer Institute for Chemical Technology (ICT) in Germany. The project aims at the continuous, highly precise, metal-free polymerization of PLA using alternative energies for reactive extrusion. Take-out device of injection molding process of cups (Photo: Talleres Pohuer) Metal-free polymerization: Benefits for health and the environment The ambitious Innorex project seeks to develop a new technology for PLA production that will, among other benefits, improve the homogeneity of production and exclude the use of metallic catalysts. Up to now, metal-containing catalysts (typically: tin (II) 2-ethylhexanoate) have been used to improve the polymerization rate of lactones, but pose a potential hazard to health and the environment. Innorex will develop a novel reactor concept using alternative energies and replacing metal-containing catalysts by organic ones, thus rendering the process and product safer for consumers and the environment. Novel reactor concept: Continuous processing and quality assurance To ensure short market entry times, commercially well-established corotating twin-screw extruders will be used as reaction vessels. However, the use of an extruder as a reaction vessel to produce bioplastics made from polylactic acid is only one of the innovations in Innorex. An online viscometer and spectral analytics using NIR technology will be applied to the production line. “The online monitoring enables us to ensure the high quality of the material, and also provides us with insight into the reaction processes occurring within the twin-screw extruder, which up to now has always been a black box element in processing,” says Björn Bergmann, scientist at the Fraunhofer ICT and overall technical coordinator of Innorex. “Additionally, we are deepening understanding of the influencing 26 bioplastics MAGAZINE [04/13] Vol. 8
Materials Twin-screw extruder (Photo: Daniel Just, Fraunhofer ICT) parameters for the polymerization in the extruder, ensuring an efficient process development.” Alternative energies in extrusion for dynamic control Beside the reactive extruder technology, alternative energies will be utilized to enhance the reaction kinetics, namely laser, microwave and ultrasound technology. The low-intensity but highly-targeted input of alternative energies in the reaction volume will increase catalyst activity and ensure a high molecular weight polymerization within the limited residence time of a co-rotating twin-screw extruder. This adjustable input of alternative energies, in contrast to the static energy input by shear of an extruder, will enable a precise, dynamic control of the polymerization and the resulting material properties. Björn Bergmann: “We expect completely new concepts for variable material production and compounding, combining twin screw extruder technology with alternative energy input that has a low intensity but rapid response time, for process stability control and material modification.” International consortium meeting European demands The Innorex consortium consists of twelve partners from seven different European countries, ranging from fundamental research universities, applied research institutions, to equipment manufacturers and end users across the entire polymer value chain. Basic research is performed by the University of Mons in close collaboration with Materia Nova and the Fraunhofer ICT. The development of the purification device and the online viscometer is one of the main tasks of Gneuß GmbH. In close collaboration with the University of Cranfield, Sciences Computers Consultants incorporates simulation and characterization into the Ludovic Software. Together with the Fraunhofer ICT, Hielscher Ultrasonics GmbH and the microwave developer Muegge GmbH apply the alternative energies to the extruder. Additivation formulation development is carried out by AIMPLAS, application and evaluation of the research work in industrial scale is carried out at Talleres Pohuer and BH Industries. Assocomaplast is the Italian national association for the plastics industry and supports the project’s dissemination. “As Innorex reflects the needs and interests of all the partners, the work flow and cooperation within the consortium is excellent, with biweekly telephone conferences and 3-monthly meetings guaranteeing close communication,” says Daniela Meijer, overall administrative coordinator of Innorex, Fraunhofer ICT. “We are looking forward to our next meeting in Brussels in September, where new results will be presented.” During the 42 project months two multinationals in the sector - the French biorefining and starch production company Roquette and the Finnish flexible packaging and films production company Huhtamaki - are involved as members of the Industrial Exploitation Board, thus ensuring market application. InnoREX at K 2013 For more information on the project, and to meet the consortium members personally, you can visit Fraunhofer-ICT (hall 07/B05), AIMPLAS (hall 08aC32-3I) and Assocomaplast (hall 16/A56) at K’2013, Düsseldorf, Germany, 16 - 23 October 2013. Fraunhofer will also present this topic at the Bioplastics Business Breakfast (cf page 37, 41) Acknowledgement The research leading to these results has received funding from the European Community‘s Seventh Framework Programme (FP7-NMP.2012.3.0-1) under Grant Agreement number 309802. www.innorex.eu bioplastics MAGAZINE [04/13] Vol. 8 27
