Auswirkung der Materialeigenschaften von ungefüllten und holzgefüllten Biopolymeren für die Anwendung von Fused Filament Fabrication

Research output: ThesisMaster's Thesis

Organisational units

Abstract

Wood Plastic Composites (WPC) form a relatively young material-group that experienced large growth in recent years due to increasing environmental awareness. The environmental friendly material is mainly used as a substitution for expensive tropical woods for outdoor decking and flooring. New processing technologies should open up new fields of application for this material. Thus, in this thesis the suitability of Wood Plastic Composites for generative production methods (FFF/3D printing) is investigated. The aim of this work is to determine the difference between filled and unfilled materials with respect to their material data and consequently the processability on 3D printers. For comparison, filled and unfilled biopolymers (Tecnaro), commercially available WPC filaments (Colorfabb) and highly filled WPC for injection molding (Jelu) were tested. For this purpose, thermal and rheological tests were performed to obtain an understanding of material behaviour. In a simulation with Ansys Polyflow® parameters such as pressure drop, shear- and flow rate in the 3D-printing-nozzle were simulated. Finally, the individual materials were tested on the 3D printer to characterize the influence of the material properties on the processing and strength of the printed components. From the gained knowledge, the requirements for a wood fibre filled filament should be determined. The significantly higher viscosity of the high filled systems compared to the unfilled biopolymers leads to an increased pressure drop in the nozzle of the 3D printer. In practical tests the extrusion of the filaments appeared to be difficult, because highly filled polymers are very brittle and break very easily at a diameter of 1.75 mm. In addition, the surface of the filaments is very rough. The test prints of the biopolymers as well as the commercial WPC filaments (30 wt-%) were successful, whereas the highly filled WPC for injection molding could not be processed with this technology. This high filler content results in a high viscosity and hence in a high pressure required in the nozzle. The filament gets stuck or the wood particles lead to clogging of the nozzle. In addition, conventional polyolefines such as PE and PP are not suitable as a matrix material for 3D printing. This work shows the application limits of processable WPC materials. In further work, additional studies on the filler size and filler content are necessary.

Details

Translated title of the contributionInfluence of material properties of unfilled and wood filled biopolymers on processing with Fused Filament Fabrication
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date1 Jul 2016
Publication statusPublished - 2016