The CellLoes‑3D‑Druck project, funded under the grant code 02P20E150 and supervised by the Karlsruhe Project Authority (PTKA), aimed to create an energy‑efficient additive manufacturing route for lightweight, biobased fibre‑reinforced composites. The research was carried out by the Deutsche Institute für Textil‑ und Faserforschung Denkendorf (DITF) with close collaboration from the industrial partner Arburg and the technology provider InnovatiQ. The project ran from early 2021 through 2023, with key milestones including two internships at Arburg (October 2021 and August 2022) and a series of workshops and conferences to disseminate results.
Technically, the project focused on integrating continuous cellulose fibres into a cellulose‑based matrix during the 3D‑printing process. A solution‑based approach was developed that operates at ambient temperature, mirroring natural composite formation such as in bone or wood. The research team formulated a polymer solution containing cellulose acetate butyrate (CAB) at a concentration of 40 % (w/v). Viscosity measurements of this solution were performed to ensure suitable flow characteristics for extrusion. The team also investigated the mechanical behaviour of the resulting filaments, measuring bending stiffness and other relevant properties to confirm that the filaments could be handled by the printer without degradation.
A custom printhead was designed to co‑extrude the polymer solution and continuous cellulose strands. The printhead architecture was optimized for precise fibre placement, allowing the reinforcement to follow the load paths of the printed part. Process development involved fine‑tuning extrusion rates, temperature control, and fibre tension to achieve consistent deposition. The resulting printed specimens were subjected to mechanical testing, including tensile and flexural tests, to evaluate the strength and stiffness of the composite. While the report does not provide explicit numerical values, the tests demonstrated that the printed parts exhibit mechanical performance comparable to conventional glass‑fibre composites, with the added benefit of a more favourable fracture behaviour due to the chemical similarity between the matrix and the reinforcement.
Optical inspection of the printed parts confirmed good surface quality and fibre alignment, indicating that the process can produce parts suitable for functional applications. The technology was further validated on the Freeformer, a commercial 3D printer, where the full printing chain—from filament preparation to part fabrication—was demonstrated. This proof‑of‑concept stage confirmed that the process can be scaled to industrial settings and that the material and energy consumption are significantly lower than traditional composite manufacturing routes.
Beyond the technical achievements, the project produced a comprehensive technology‑transfer plan. The DITF and Arburg coordinated the publication of results in specialist journals and presented findings at national conferences such as JEC World 2023 and the DITF Innovation Day. The team also explored patenting opportunities and outlined a commercialization strategy that includes potential integration of the printhead technology into InnovatiQ’s LiQ‑series printers. The collaboration model, with DITF providing research expertise, Arburg supplying equipment and practical training, and InnovatiQ offering a pathway to market, exemplifies a successful partnership between academia and industry aimed at advancing sustainable composite manufacturing.