A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Build Time <s> Design of experiments (DOE) is a methodology based on statistics and other disciplines for arriving at an efficient and effective planning of experiments with a view to obtain valid conclusions from the analysis of experimental data. Design of Experiments determines the pattern of observations to be made with a minimum of experimental efforts. DOE process is implemented to FDM process to optimize the processing time. In this study three process parameters at three levels are selected. Using full factorial design totally 27 experiments are required. Using design of experiments and orthogonal array the total number of experiments are reduced to 9. Therefore the optimum processing time will be obtained in these 9 experiments. Thus 9 experiments are conducted and the experimental data obtained from the experimental trails are analyzed using S/N ratio and ANOVA analysis. <s> BIB001 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Build Time <s> Fused deposition modeling (FDM) has evolved as one of the fastest growing layer manufacturing (LM) technology because of its capability to build even functional plastic parts with geometrical complexity in a reasonable time period. The quality of the production process depends on various process parameters, the most important of them being layer thickness (h), raster angle (θ), orientation (φ), contour width (c) and part raster width (w). In the present study, the influence of these parameters on two process quality parameters, namely, build time and the support material volume are studied on a rotational part modeled on a FDM 200mc machine. A 25 full factorial Design of Experiments (DOE) methodology was employed and the results for build time and support material volume of the 32 experiments were analyzed using Design Expert®. Analysis of variance (ANOVA) was done and based on the ANOVA results the model equation for the two quality parameters in both coded and original factors has been developed. Comments on the results obtained and interaction effects are included at the end of the paper. <s> BIB002 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Build Time <s> This paper discusses optimization studies on process parameters for fused deposition modelling (FDM). Layer thickness, Orientation angle and fill angle are the process variables considered for optimization. Ultimate tensile strength, surface roughness, dimensional accuracy and manufacturing time were considered as response parameters. Experiments were designed using well known Taguchi's L9 orthogonal array, Taguchi's S/N ratio was used to identify optimum parameter values. Effectiveness of each parameter was investigated using analysis of variance. Furthur, performance of optimum conditions were validated by conducting verification experiment. <s> BIB003 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Build Time <s> Abstract In this research, effect of varying spatial orientations on the build time requirements for fused deposition modelling process is studied. Constructive solid geometry cylindrical primitive is taken as work piece and modeling is accomplished for it. Response surface methodology is used to design the experiments and obtain statistical models for build time requirements corresponding to different orientations of the given primitive in modeller build volume. Contour width, air gap, slice height, raster width, raster angle and angle of orientation are treated as process parameters. Percentage contribution of individual process parameter is found to change for build time corresponding to different spatial orientations. Also, the average of build time requirement changes with spatial orientation. This paper attempts to clearly discuss and describe the observations with an aim to develop a clear understanding of effect of spatial variations on the build time for Fused Deposition Modelling process. This work is an integral part of process layout optimization and these results can effectively aid designers specially while tackling nesting issues. <s> BIB004
To be able to compete with traditional manufacturing processes, the reduction of lead time, as well as production time, is one of the main concerns for additive manufacturing processes to be employed in industrial settings. Therefore, along with part characteristics such as surface roughness, dimensional accuracy, and mechanical properties, build time reduction is an important requirement for functional part production. In addition, the control of "failures" for build time is very important, for example, blocked nozzles can significantly increase build time. Like other part characteristics of FDM parts, build time is also affected by process parameters, and it can be minimized by selecting an optimum combination of process parameters. To know the impact of three process parameters (layer thickness, air gap, and raster orientation) on build time, Nancharaiah BIB001 designed an experiment according to a Taguchi orthogonal array (L9) and produced parts by an FDM machine. Along with a positive air gap, a negative air gap was also considered in their work. Their results indicated that a high layer thickness and a positive air gap reduced build time; the layer thickness was the most significant process parameter, and the raster orientation was insignificant for build time. Kumar et al. BIB002 investigated the impact of layer thickness, raster orientation, raster width, build orientation, and shell width on build time. They applied a full factorial experimental design to determine the required number of experimental runs for two levels of parameters and produced parts using a Stratasys FDM 200 machine. Their conclusion was similar to the conclusion by Nancharaiah BIB001 ; the raster orientation was insignificant for build time. The impact of layer thickness, raster width, raster orientation, number of shells, air gap, STL deviation, and STL orientation on build time was studied by Ali et al.  . In their paper, the first-time impact of STL deviation and STL orientation was analyzed. A multilinear regression model for build time was developed at a 95% confidence level, and results showed that STL deviation and STL orientation were insignificant for build time. To determine an optimum combination of three process parameters (layer thickness, build orientation, and raster orientation) for build time, Nidagundi et al. BIB003 designed an experiment using a Taguchi orthogonal array. Unlike the previously mentioned papers, they showed that raster orientation, layer thickness, and build orientation were all significant for build time. Rhee et al. BIB004 investigated layer thickness, shell width, air gap, raster width, raster orientation, and build orientation to know the importance of those parameters for build time. They developed a quadratic response surface equation using a central composite design (CCD) approach for different spatial orientations (rotation around different axes). The outcome of the study showed the layer thickness was the most significant parameter, and other significant parameters were raster orientation and air gap. One contradiction with other reviewed papers was that they claimed raster width was insignificant, but raster orientation was a significant parameter for build time. Other conclusions were the spatial rotation was significant, and the build time was minimum when the shortest side of an object was placed in the Z-direction. Srivastava et al.  designed an experiment according to CCD, and considered six controllable parameters with three levels each. Among the studied parameters, the layer thickness, shell width, air gap, and raster width were significant parameters, and the insignificant parameters were raster orientation and build orientation. Wu  studied the impact of layer thickness on some part qualities, and one of them was build time; for this, cylindrical PLA parts were manufactured by a Raise3D N2plus FDM machine. Their outcome was the same as other research, whereby build time decreased with an increase in layer thickness. Short discussion and summary: From the outcomes of the reviewed papers on build time, build time was found to be minimum at a high layer thickness, 0 • build orientation, and low infill density. Minimum build time means that it is faster to print a part. The impact of raster orientation and raster angle on build time is still unknown. Thus, further analyses are still needed to draw a more valid conclusion. On a separate note, build time may also be significantly affected by the FDM machine itself. A good FDM machine typically can produce a relatively good-quality part faster than a poor FDM machine. One further research direction is to study the influence of the infill pattern and extrusion temperature on build time.