| Summary: | Studies on the use of rapid prototyping pattern built from the conventional FDM machine are reported quite
extensively, however less focus was given on pattern from portable FDM machine which has ability to be used
in direct investment casting. This study presents an analysis of collapsibility behaviour during the burnout
process of ARS P400 patterns built form a portable FDM machine. The internal design structure consisted of
square 90° and polygon structures respectively. The patterns were constructed in a semi cylindrical geometry
which are wrapped with 4 mm of ceramic shell. Experiments were conducted with varying temperatures
starting from 30°C until 150°C with increment rate of 5°C per minutes. Meanwhile for the numerical
simulation, the temperature chosen was between 30°C to 120°C with 10°C increment per minutes.
Observation was made at glass transition temperature (Tg) near ll0°C. It was found that shell cracking
occurred on the ceramic shell. In addition, the polygon pattern tends to collapse inwardly which did not
occurred on the square pattern during the burnout process. Results also shows that, there is a significant
amount of stress reduction on both square and polygon amounting to 45% respectively. Besides that, the
amount of strain on pattern itself showed an approximate of 9% reduction. Moreover, there was a greater
difference in terms of ceramic shell strain reduction which was 38% for square as compared to polygon
patterns. Last but not least, there is 11% reduction of strain when comparing the square against the polygon
patterns in terms of axial main on ceramic shell
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