Evaluation of ABS hollow & solid pattern for the production of long stem hemi

Abstract

Orthopedic implants can be defined as medical devices used to replace or provide fixation of bone or to replace articulating surfaces of a joint. Many trauma cases require almost immediate/short lead time surgery. Thus rapid respond from the manufacture is very crucial. The manufacture of surgical implant often requires the use of machining process. Current trend shows that preform either from casting or forging is preferred to reduce machining cost and time. It is expected that by employing rapid manufacture using rapid prototyping and investment casting process could expedite the manufacturer to surgery time. This objective of this project was to evaluate the effect of dewaxing time on collapsibility characteristic of solid and hollow constructed rapid prototyped Long Stem Hemi (LSH) ABS pattern. Wax pattern casting is used as reference for this ABS pattern process.FDM2000 machine was used to build the ABS patterns. Acrylonitrile Butadiene Styrene (ABS) P400 was used for pattern material in this study. Only shell investment casting mould is involved in this study. Output responses investigated were collapsibility, expansion defects. ABS Hollow and Solid mould are prepared and they are subjected to dewaxing time. The ABS Hollow and Solid shell are compared based on the dewaxing process results, ceramic shell defects, FESEM analysis etc. The best pattern material is chosen based on the results and compared with the reference process