A project aimed at developing a new technology for the production of PLA is currently being financed by the EU and coordinated by the German Fraunhofer Institute for Chemical Technology. The goal of the InnoREX project, as it is called, is to improve the homogeneity of PLA and to exclude the use of the metallic catalysts currently used to improve the polymerisation rate of lactones.
The 12 partners in the InnoREX consortium are therefore seeking a new polymerisation route for polylactic acid (PLA) through a novel reaction concept for the continuous, highly precise, metal-free polymerisation via reactive extrusion.
To ensure short market entry times, commercially well-established co-rotating twin screw extruders will be used as reaction vessels. Commercial polymerisations have not yet been carried out in twin screw extruders, because of the short residence time and the static energy input of the extruder. As a result, no dynamic control of the reaction is possible. The InnoREX consortium aims to overcome these obstacles by using the rapid response time of microwaves, ultrasound and laser light to achieve a precisely-controlled and efficient continuous polymerisation of high molecular weight PLA in a twin screw extruder. The low intensity but highly-targeted input of alternative energies in the reaction volume will ensure a high molecular weight polymerisation within the limited residence time of an extruder. Additionally, significant energy savings will be achieved by combining polymerisation, compounding and shaping in one production step.
The project also includes a detailed analysis of the packaging life cycle. The prototype obtained will be a single thin-walled monolayer packaging (wall thickness of a millimetre or less) intended for the food sector.
The InnoREX consortium consists of 5 RTD partners, 6 industrial partners and an association, one of which is the Spanish plastics technology centre AIMPLAS.
The role of AIMPLAS within the project is mainly related to the study of the processability (injection and extrusion) of developed PLA grades and the mechanical, physical and thermal characterisation of prepared packages by injection moulding, and extrusion cast-sheet and thermoforming. It will also include an extensive development of additivation strategies.
The project, which started in December 2012, will run until May 2016. In addition, AIMPLAS will organize a workshop on October 20th at their premises, targeted at suppliers of raw materials, end users, researcher centres and universities. The workshop will focus on the project main objectives and its developments.
The InnoREX project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 309802.