Intended for the manufacturing of complex geometries, structures and physical models at low fabrication cost additive manufacturing (AM) or three dimensional (3D) printing is a quick growing engineering tool. In comparison to the outmoded engineering processes (casting, welding and machining) AM fabricate the part in multiple layers printing manner [1]. The ability of AM in the manufacturing of complex compound parts make it suitable for mechanical engineering [2], biomedical sciences [3], construction (civil engineering) [4], aerospace (aeronautics) [5], and food processing industries [6] as well as in educational sector for research. On the basics of 3D printing AM can be classified as seven different fundamental processing methods, namely, vat photo polymerization, sheet lamination, powder bed fusion, material extrusion, material jetting, direct energy deposition and binder jetting [7–8]. Among all these, multi jet 3D printing (MJP) is the material jetting oriented mode used to manufacture polymer-based parts and models [9–10]. Raw material for MJP technology is in the form of liquid. During printing the liquid is injected through nozzle that travels according to the guidelines specified as a result of the slicing software. The layer by layer deposition of hot material from the nozzles is remain sustained, till the model is completed [11–12]. The process of MJP is shown in Fig. 1. Many researchers have given significant contribution in the 3D printing. Shanmugam et al [14] explored the effect of the FDM process controls on the fatigue behavior of polymeric materials and provided their recommendations, also advocated further investigation in this area. Dai et al [15] emphasized the compression properties of (HP nylon PA12) open-cell hollow-sphere parts experimentally and mathematically. The parts were fabricated by multi-jet melting (MJF) printing technology. Rosso et al [16] examined the mechanical properties of polyamide powder (pA12). Specimens are fabricated using both the SLS (selective laser sintering) and MJF technologies. It was reported that MJF had less surface roughness then the SLS. SLS and MJF exhibited the single peak for the melting temperature. More over the SLS part had more porosity then the MJF. SLS gave good tensile strength then the MJF. SLS fracture was the brittle and the MJF fracture was ductile. Mirzaali et al [17] studied the fracture mechanism, Young’s moduli, ultimate strengths of the soft-hard polymeric composites, functionally graded materials (FGM) by means of image relationship, digital microscopy and SEM. The Parts were fabricated by voxel-based multiple-material AM technology. They achieved that from the micro-mechanical characterization point of view elastic modulus of FGM part fabricated through bitmap3D-printing did not obey the rule of blends. Although the chemical configuration had the significant effect on mechanical properties. Zhu et al [18] explored the outcome of different energy inputs on porosity and mechanical properties of polyamide (p-12) mechanical parts. The parts were fabricated by powder bed fusion (AM) technique. It was reported that the high energy input caused less porosity and provided improved density, ultimate tensile strength and percentage increase in elongation. Dana et al [19] investigated that the outcome of the printing orientation and the build direction on the compressive properties of the printed specimen on 3D sand printing process (3DSP). It was found that at 90° to the X-Y plane mechanical properties were excellent as compared to other directions. Khabia et al [20] compared the three different kind of FDM printers for three different kinds of Acrylonitrile butadiene styrene (ABS) material at the constant parameters. It was reported that the printer-1 (Arya UNO Printer, low cost ABS filament, Ultimaker Cura3.6-Slicing Software) exhibited the good tensile strength (35MPA). Bilkar et al [21] considered the effect of the carbon nanofiber (CNF)(1–2%wt) added to ABS on mechanical properties (tensile test, dimensional accuracy and surface roughness. It was reported that ABS + 2 wt % CNF enhanced the mechanical properties of the ABS polymer. Liu et al [22] exhibited the outcome of orientation and the layer thickness of the two type of materials (rigid polymer material and soft rubber). The parts were fabricated by multi material poly jet AM 3D printing. They stated that the orientation and coat thickness had the significant effect on the tensile behavior and stiffness. Valean et al [23] studied the effect of part orientation and layer thickness. The parts of PLA were fabricated on FDM 3D printer. The results stated that the object orientation had less effect on the modulus of elasticity and high effect on stretchable tensile strength. Increase in quantity of layer lead to decrease in the Young’s modulus and tensile strength. Mele et al [24] introduced the new analytical model for the Multi jet fusion process (MJF) and for polymeric material (Pa-12). This reduced the capillarity effect (edges of part gets deformed), causeing the reduction in dimensional accuracy and increase in surface roughness. Maurya et al [25] investigated the effect of the process parameters (raster angle and orientation) for the poly jet process. Parts fabricated of RGD 840 were investigated for mechanical properties (Young’s elastic modulus, tensile strength at peak load, true stress-strain and plastic strain). The optimized results were found at raster angle (90°), horizontal orientation and glossy surface finish. Ali et al [26] compared the two mid soles of helical spring with variable dimensions (VDS) and uniform-dimension helical spring (UDS) mechanical-structure and the commercially available wave spring midsole fabricated on multi jet fusion. Experimental and numerical methods were used to improve energy absorption and strength. It was deduced that VDS has higher strength, better flexibility and better stability as compare to UDS. Kuo et al [27] optimized the process parameters (laser power, layer thickness, scanning speed and hatching space,) for the direct metal laser sintering of the mold fabricated from maraging stainless steel powder. The optimization tool used was Taguchi and analysis of variance (ANOVA). The results stated that permeability of gas and the thickness of layers were the important parameters that effected the mechanical properties of the material. Yang et al [28] considered the effect of different speed ranges (30, 50 and 70 m/s) on the density, flexural strength and compressive behavior of wood fiber/polylactic acid composite (WPC). The results indicated that density of the part improved as the speed of the FDM feeder was reduced. Tensile and flexural strength remained unaffected with the travel speed. Whereas with the increase in travel speed compressive strength of the part decreased. Dejaki et al [29] deliberated the effect of the infill pattern (solid, honeycomb, wiggle, grid, and rectilinear) on the tensile strength. PLA was used on the FDM for the fabrication of part. Honey comb and grid have highest strength. Samples at 0° gave the strongest layer adhesion and 60° and 75° showed the weakest layer’s adhesion. Yadav et al [30] explored the effect of different type of infill patters (Hilbert curve, honeycomb, line, rectilinear, Archimedean curve and actogram spiral) for the PLA base parts fabricated on FDM. The compressive strength was studied at the different in fill densities (20 to 80%) is 20 steps. The results stated that Hilbert curves exhibited maximum compressive strength. It was concluded that with the increase in in fill density the compressive strength also increased. With the increase in the infill density the roughness also increased and rectilinear paternal exhibited the lowest roughness.
An extensive range of research has been conducted on the effect of the parametric variation on the mechanical behavior of FDM part. However, there is less work about the effect of part orientations on the mechanical properties in case of multijet printer. So due to this reason in the current study the impact of part orientation on the mechanical behavior is investigated. The methodology adopted to study is schematically represented in Fig. 2.