Development and characterisation of 3D printed short bamboo fibre-reinforced polyethylene terephthalate glycol (PETG) with added charred coconut shell additive

Purpose This paper aims to create a high-performance, lightweight and environmentally friendly composite filament for use in additive manufacturing for automotive and aircraft parts. By adding chopped short bamboo fibre and pulverised charred coconut shell powder in both micro and nanoforms, the effort aims to improve the mechanical properties of polyethylene terephthalate glycol (PETG). The objective is to create 3D-printable composite filaments that may be used in place of traditional materials to fabricate functional prototypes and lightweight structural components, ultimately enhancing performance while lowering material weight and attaining environmental sustainability. Design/methodology/approach Because of its superior printability, thermal stability and compatibility with natural reinforcements, PETG was chosen as the matrix material. Using a twin-screw extruder, chopped bamboo fibres and powdered burnt coconut shell were combined with PETG. A filament extruder was then used to turn the composite into a consistent 2-mm filament. Fused deposition modelling (FDM) was utilised to 3D print the test specimens, which were then assessed in accordance with the ASTM guidelines. Tensile, flexural, impact, hardness and fatigue tests were used for mechanical characterisation, and scanning electron microscopy (SEM) was used to examine the fracture surfaces morphologically. To evaluate performance gains, the outcomes of the reinforced specimens were contrasted with those of clean PETG. Findings The mechanical performance of the printed composites was significantly improved by the addition of short bamboo fibres and powdered burnt coconut shell. Micro-sized coconut shell powder reinforced specimens (Specimen C) performed the best among the tested formulations, obtaining around 25% more tensile strength, 18% more flexural strength and 22% more hardness than pure PETG. Better load transmission and failure resistance are facilitated by enhanced fibre–matrix interfacial bonding and decreased void formation, as demonstrated by SEM investigation. According to the findings, the created bio-composite filament shows promise for lightweight engineering uses, especially in components for automobiles and aeroplanes that require strength-to-weight efficiency. Research limitations/implications This work presents a new, environmentally friendly PETG-based bio-composite filament that may be used in 3D printing. It is made from powdered coconut shell and bamboo fibre, two naturally occurring agricultural wastes. This work illustrates the synergistic impact of dual natural reinforcements in a PETG matrix for advanced additive manufacturing, in contrast to the majority of previous research that investigate either single natural fillers or non-sustainable reinforcements. The results offer a feasible route for producing lightweight, economical and environmentally friendly parts for the automotive and aerospace industries, where mechanical dependability and weight reduction are essential. Practical implications The development of affordable, environmentally friendly composite 3D printing filaments for use in consumer goods, automotive and aerospace industries is supported by this study. These composites’ enhanced mechanical qualities make them appropriate for structural and semi-structural components where strength and light weight are crucial. Social implications The study encourages sustainable material usage and trash reduction by using agricultural waste materials like bamboo and coconut shell. Additionally, it supports green technology and the use of biomass in rural areas by promoting the use of environmentally friendly composite alternatives in manufacturing. Originality/value In this study, a novel PETG blend with bio-fillers and natural short fibres specifically designed for 3D printing is presented. The work is new since it shows compatibility with additive manufacturing and uses sustainable reinforcements to improve material performance, which benefits both business and research.