The effect of in-situ fiberglass reinforcements on the mechanical and tribological properties of 3D printed parts

Abstract

Fused filament fabrication (FFF) has been a widely used manufacturing method in the past decade. It operates through additive manufacturing (AM), where thermoplastic material is melted layer by layer to create a product, competing with traditional methods like injection moulding or subtractive techniques such as milling, drilling, and turning, Nevertheless, thermoplastic products produced through FFF often exhibit inferior mechanical properties when compared to their injection moulded counterparts. This research addresses these limitations by employing fibre-reinforced thermoplastics to enhance the mechanical strength of printed parts, improving interlaminar bonds and reducing voids between layers. A prototype fibre-doser was developed and optimized to deposit in-situ short fibre reinforcement during the FFF process, enabling the fabrication of fibre-reinforced thermoplastic composite parts. The fibre-doser was constructed using high strength materials to ensure precision and durability. It is able to produce composites with varying fibre contents, offering adaptability for diverse applications. Specimens prepared following ASTM standards underwent thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical tests, including tensile, flexural, impact, and tribological assessment. Results showed that the inclusion of glass fibre enhanced tensile strength by up to 45% and impact resistance by approximately 60%, with a modest 15% improvement in flexural strength. Tribological test revealed a 35% reduction in wear rate due to the reinforcing effect of the fibres. SEM analysis confirmed uniform fibre distribution and improved interlaminar bonding, while TGA indicated enhanced thermal stability. These findings demonstrate that the fibre-doser effectively produces high-strength composite materials using FFF, overcoming the limitations of traditional FFF parts. The advancements achieved in mechanical and tribological properties expand the potential of 3D-printed components for demanding engineering applications such as prostheses, gears, bearings, and linkages, thus extending the capabilities of FFF technology.