Characteristic studies of collapsibility of ABS patterns produced from FDM for investment casting

A study was made of the collapsibility phenomenon of acrylonitrile butadiene styrene (ABS) P400 patterns tabulated using fused deposition modelling technique that will be used for investment casting process. There are two types of specimens: hollow ( or hatching) and solid H shape ABS patterns. Results showed that the hollow patterns offered better results than the solid patterns in terms of mould cracking and internal mould cleanliness at temperature 300-500 degrees C. However, all patterns demonstrated similar behaviour at temperatures of 550 and 600 degrees C whereby no cracks were present and total decomposition of ABS was recognised. The results were strongly related to a fluidity phenomenon of the ABS material in conjunction with elevated temperature.