Researchers and political players worldwide are all working towards the establishment of a bioeconomy. As any progress unquestionably depends on the extent of public support, BIOPRO Baden-Württemberg GmbH launched a communication campaign called Biobased Fabrication Network (BioFabNet) in 2013 to show how a bioeconomy works in practice.
The idea behind the project, which came to an end in December 2015, was to use new biobased 3D printing filaments to inform the general public about the opportunities of a future biobased economy. This initiative was specifically addressed at a community of young people who use 3D printers in professional, semiprofessional and private contexts. The aim was to make those who tested the new biopolymer filaments familiar with the idea of a biobased economy, thus progressing the idea of establishing a bioeconomy. The project organisers also hoped that this would facilitate the breakthrough of biobased materials.
This is what the University of Stuttgart’s Institute of Plastics Technology (IKT), the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) and BIOPRO Baden-Württemberg set out to achieve in 2013 with funds provided by the German Federal Ministry of Education and Research (BMBF).
The IKT provided the right mix of materials and extruded the filaments that were then investigated by the Fraunhofer IPA to identify 3D printing processing properties. The result was different blends of PLA-based bioplastics filaments. BIOPRO Baden-Württemberg was in charge of coordination and PR, including setting up and managing the BioFabNet community of 3D printer users who tested the newly developed filaments on their own devices.
In addition to objects they chose themselves, the material testers printed test specimens – ductile test rods and pieces of a puzzle – which experts subsequently evaluated in terms of machine and material use. Based on the evaluation of the ductile test rods at the IKT, the material testers were provided with engineering parameters such as elastic modulus, maximum stress and elongation at break. The pieces of puzzle were evaluated by the IPA. Overall result was based on the individual evaluation of five separate areas.
The modulus of elasticity describes the relationship between stress and strain of a solid body that is subjected to a load, resulting in its deformation. It applies to the linear portion of the stress-strain curve. In the case of plastics, the maximum stress, also referred to as yield point (or yield strength), is maximum stress divided by original cross-sectional area of the specimen at which large increases in strain occur, without, however, leading to an increase in stress. This value is the maximum stress a plastic/ductile rod can withstand. When this maximum is reached, the ductile rod elongates and eventually breaks. The third parameter is the elongation at break, which is also referred to as strain at fracture in tension. It is expressed as a percentage and is the ratio between changed length (when the rod breaks) and initial length of the test specimen.
The material testers evaluated and documented the filaments and the print results on www.biofabnet-blog.de, which they also used as a platform to exchange information with each other. Feedback from the BioFabNet community was used by the project partners to optimise the filament materials.
In order to increase societal acceptance of the bioeconomy, new biobased materials that illustrate the opportunities of a biobased economy are needed as well as basic knowledge of the opportunities and risks of new technologies and their benefits for each one of us. This was achieved by the publication of specialist articles on the BioFabNet website and the possibility to exchange information face to face. BioFabNet participated in numerous events, including exhibitions where the material testers could participate in debates on the subject bioeconomy, raise questions and thus refine their opinions and reduce reservations.
One particular highlight was the Konradin publishing house’s invitation to present the project at the medizin&technik booth at Medtec Europe 2014. The Fraunhofer IPA kindly provided two exhibits from the field of medical technology that were made using generative manufacturing processes. These served to highlight the interfaces between medical technology and 3D printing.
“3D printing always plays a key role when it comes to small quantities or individual pieces. Complex moulds are not required in such cases. Supporting structures make this step obsolete,” says Prof. Dr. Ralf Kindervater, CEO of BIOPRO Baden-Württemberg and project coordinator. "However, material diversity needs to reach a level similar to materials made using injection moulding processes.”
The project has developed new biobased filament materials and optimised them for use with commercial 3D printers. In addition, more than 70 material testers from Germany, Austria and Switzerland, the Netherlands and as far afield as Ireland were brought on board to test the materials, thus inciting them to become motivated about a bioeconomy. The material testers have therefore become ambassadors for a biobased economy.