Development of Biodegradable Filaments Based on Agro-Industrial Waste and Evaluation of Process Parameters in Final Properties

Additive manufacturing, which has become popular in recent years, is the process of joining materials through the deposition of layers to form parts based on data from a 3D model and fused deposition modeling. The search for biodegradable materials for the production of filaments for 3D printing is increasing and opening up possibilities for the development of new sustainable products, including the use of lignocellulosic waste in the formulation. Therefore, the present work aims to develop polymeric filaments based on polybutylene adipate terephthalate and low content (2.5 and 5 wt%) of peanut and soybean shells and evaluate their potential for 3D printing. The charges were characterized in terms of chemical composition. Tensile and dimensional variation tests were performed on samples manufactured from two different filling orientations: -45/45 degrees and 0/90 degrees. The printability of the filament was based on the manufacture of prototypes of agricultural tubes that were also characterized by thermogravimetry and their morphology through scanning electron and optical microscopy. Both natural residues significantly (p < 0.05) affected the sample dimensions and mechanical properties. However, the filling orientation difference was insignificant (p > 0.05). The filaments produced showed good processability, thermal and dimensional stability. The samples produced showed a satisfactory surface finish without exposing load agglomerates. These results demonstrate the feasibility of using lignocellulosic fillers, such as peanut and soybean shells, in additive manufacturing and indicate the possibility of producing parts with varied geometries.