Laser polishing of thermoplastics fabricated using fused deposition modelling

Fused deposition modelling (FDM) is a technique of additive manufacturing (AM) which is capable of fast construction of plastic prototypes. AM technology has been utilised in orthopaedics and traumatology to fabricate patient-specific models, surgical guides, and implants. However, the layering build-up by FDM usually generates a deleterious rough surface that limits its application to items such as surgical guide and surgical operating guide, because these items require a highly resolved surface quality. The advancement of laser polishing has been offering a cost-effective and fast manufacturing solution for FDM-constructed patient-specific guides and implants. This investigation explores application potential using a contactless laser scanning to improve the surface quality of FDM-fabricated thermoplastics. The results show that a maximum [68%] reduction in surface roughness was achieved at 3 W CO2 laser power, 150 mm/s scan speed, 30 ms scan delay and 0.025 mm line gap. Laser polishing is suitable to treat the surface of polylactic acid (PLA). This study provides data which supports a new approach to the manufacture of AM-fabricated thermoplastics utilising a laser scanning technique to improve the surface quality.