LAUSR

Fabrication of functional prototypes from computer-aided design data through joining polymer powders particles is accomplished using selective inhibition sintering (SIS) process. The dimensional accuracy of sintered specimens in SIS process is significantly affected for the materials such as polymer and inhibitor, complex geometry and process parameters. Increasing dimensional accuracy in SIS process improves the quality and functional ability of end-use components. The present work investigates the shrinkage characteristics of SIS parts with reference to various process parameters such as thickness of layer, heater energy and its feedrate, and inhibitor nozzle feedrate. The test specimens are fabricated using the developed SIS system. Experimental study and mathematical modelling is accomplished based on statistical box-behnken response surface methodology. The result of analysis of variance (ANOVA) revealed that the layer thickness followed by printer feedrate and heater feedrate are the dominating variables on shrinkage. The optimal operating conditions of selected process variables to reduce shrinkage is presumed using desirability approach. The results revealed that the settings of low layer thickness and high heater energy with medium heater feedrate and medium printer feedrate is beneficial for improving dimensional stability of sintered specimen. Furthermore, the effect of these parameters on shrinkage are evaluated by conducting sensitivity analysis.