Analysis of processing and environmental impact of polymer compounds reinforced with banana fiber in an injection molding process

The global consumption of thermoplastic materials of fossil origin continues to grow, generating high environmental impacts mainly due to the energy consumed during their production and processing. The use of natural materials, such as banana fiber (BF), present a sustainable alternative for the gradual replacement of these thermoplastic materials, potentially reducing the environmental impact and improving their mechanical performance. This work presents the development of HDPE compounds reinforced with BF for injection molding of components with lower environmental impact. To this end, the processing and treatment of the banana pseudostem fiber have been analyzed, and compounds with fiber percentages of up to 20 wt %, with and without chemical treatment, have been developed and characterized thermal and mechanically. Finally, thickness optimizations of a case study component have been carried out through finite element simulation, with fiber percentages up to 30 wt %, maintaining the stiffness of the original HDPE component. A Life Cycle Assessment was also carried out to assess the influence of the different processing scenarios. The results showed, on the one hand, that the fibers without chemical treatment and with mechanical combing allow improvements in the mechanical properties of HDPE compounds similar to those obtained with chemically treated fibers but considerably reducing the impacts due to the suppression of the fiber treatment (chemical products, subsequent drying, etc.). On the other hand, the environmental impact analysis showed that compounds with percentages of untreated fiber greater than 20 wt % reduce the impact of the components produced compared to pure HDPE. Finally, the incorporation of the BF also allowed the design optimization of the study component, reducing its thickness but maintaining the same original stiffness, further improving its environmental impact.