Moisture effects on the ABS used for Fused Deposition Modeling rapid prototyping machine

User experience and many machine breakdown records of FDM rapid prototyping indicated that moisture effects on Acrylonitrile Butadiene Styrene (ABS) which consequently causes physical, morphological and thermal stability changes to the polymer, is the major cause of problem. These reports claim that these changes may have caused nozzle blockage on the liquefier of the Fused Deposition Modeling (FDM) machine although no thorough investigation were done. Experiments are therefore conducted to verify these assumptions. It has been observed that physical changes do not cause nozzle clogging. The clogging is due to the morphological and thermal stability changes of ABS when the material is exposed to moisture.