MICROBLASTING CHARACTERISTICS OF JEWELRY MODELS BUILT USING STEREOLITHOGRAPHY APPARATUS (SLA)

This paper describes an investigation of the effect of the microblasti ng process on the surface finish of jewellry models built using stereo lithography apparatus (SLA). The layering process of SLA results in vi sible steps on the model surface. The investigation aims to determine the significant operating parameters of the microblaster deburring pro cess that affect the surface roughness of the SLA jewellry model, to s et a practicable range for these parameters for effective deburring an d establish the optimum parameters for the best surface finish. A ring model based on the British Standards 28653: 1993 is designed using th e Pro-Engineer software. The experimental strategy applies techniques including the full factorial and Yates' method together with the analy sis of variance on the deburred samples. The surface roughness of the ring models before and after the deburring process are then measured w ith a Form Talysurf surface roughness measuring machine. The informati on obtained is used to identify the parameters for further study. Para meters identified are different nozzle types, blasting time and pressu re variation. These parameters are tested for their optimum settings a nd the microblasting process is found to significantly improve the sur face finish by approximately 30% on both the curvature and flat featur es of the ring model.