ANALYSIS ON PROCESS PARAMETERS OF SLS RAPID PROTOTYPING PROCESS

This paper shows the final year project regarding the Analysis of Process
Parameters for SLS Rapid Prototyping Process. Selective laser sintering (SLS) is a
layered manufacturing process that builds prototypes by selective sintering of materials
in powder form, like thermoplastic polymer powder, using a C02 laser. Objectives of
this project are to analyze the effect of process parameters on the part accuracy and to
produce the optimal model of process parameters that result in less shrinkage. Prototypes
made by SLS are widely used in product development as they can be used for product
testing. However the wider application of SLS has been limited due to their lack of
accuracy. SLS prototypes should have high accuracy in order to satisfy functional
requirement. Shrinkage is one of the major factors which influence the accuracy of the
SLS parts. Therefore, continuous process improvement is necessary. Improved
understanding of the parameters effects on the process response is expected to lead to
process advances. The relationship between shrinkage and the various process
parameters such as laser power, beam speed, hatch spacing, part bed temperature and
hatch length have been investigated. Optimum shrinkage condition are obtained by
analysis of variance (ANOVA) and linear regression. AN OVA is used to understand the
significance of process parameters affecting shrinkage and energy density analysis is
study to find its relationship with shrinkage effect. Solidworks simulation is also used to
show shrinkage effect for different hatch length.