## 1 Introduction  
Additive manufacturing (AM), often known as 3D printing, has experienced tremendous growth in nearly every engineering sector, especially in the aerospace and automobile industries [1, 2, 3, 4]. According to ISO/ASTM 52900 [5], AM technologies are classified into seven classes. Fused filament fabrication (FFF), a sub-class of the material extrusion processes, is one of the most widely used AM technologies owing to its low energy usage, ease of manufacturing complex geometries with fewer tool changes and production times, and lessened waste [6, 7]. FFF is based on the production of components by extruding material from a heated nozzle. The printing process parameters greatly affect the mechanical strength of the printed component. Therefore, a significant amount of work has been done to study the effect of printing temperature, printing speed, layer height, bed temperature, and infill density on the mechanical properties of printed components using FFF [8; 9; 10; 11]. Apart from the aforementioned parameters, raster angle and infill pattern can also affect the mechanical properties of printed components. Raster angle is the angle between the beads being printed with the primary axis of the printer bed, which is mostly an x-axis, as depicted in Figure 1a [12]. While the path along which material is extruded inside the perimeter is called an infill pattern, as illustrated in Figure 1b. Flexural properties are of great importance for composite and sandwich structures. The flexural strength of a structure is its ability to resist bending deflection whenever the load is applied to it [13]. Therefore, these properties are of great interest in the fields where the primary loading condition is flexural such as aerospace and structural applications. The literature has shown various studies regarding the impact of two highly influential process parameters, i.e., raster angle and infill pattern, on the flexural properties. For instance, [PERSON] et al. [14] experimentally examined flexural properties for 3D printed ULTEM at raster angles of \(0^{\circ}\), \(45/-45^{\circ}\), and \(90^{\circ}\). It was concluded the samples printed at \(0^{\circ}\) raster had the highest flexural modulus among the tested samples. [PERSON] et al. [15] suggested that among the samples printed at a \(0^{\circ}\), \(45^{\circ}\), and \(90^{\circ}\), the \(0^{\circ}\) raster angle samples exhibited the highest tensile and fatigue strength. [PERSON] et al. [16] and [PERSON] et al. [17] investigated the flexural properties of ULTEM 9085 and ULTEM 1010, respectively. The coupons were fabricated at two raster angles of \(0/90^{\circ}\) and \(45/-45^{\circ}\). The results revealed that \(0/90^{\circ}\) raster angle with vertical orientation produced samples with a higher flexural strength of about 105 MPa compared to 95 MPa for \(45/-45^{\circ}\) raster [16]. [PERSON] et al. [18] investigated the bending strengths at three different raster angles, i.e., \(0/90^{\circ}\), \(30/-60^{\circ}\), and \(45/-45^{\circ}\). Figure 1: Schematic representations (**a**) raster angle (**b**) infill pattern (Line) and perimeter. It was concluded that samples with \(0/90^{\circ}\) raster showed the highest tensile and bending strengths. In addition, flexural and tensile properties for five different singular raster angles in different printing orientations were evaluated by [PERSON] and [PERSON] [19]. It was observed that the samples fabricated in the edgewise direction resulted in higher flexural strength, whereas samples printed in the in-plane direction showed higher tensile strength. Regarding the effect of infill patterns, [PERSON] et al. [20] observed that the grid pattern outperformed other infill patterns such as line, triangular, cubic, honeycomb, concentric, rectilinear, rectangular, octet, and Wiggle under the tensile load. In another study by [PERSON] et al. [21], it was revealed that the rectilinear pattern outperformed the honeycomb and collinear infill patterns in terms of tensile properties. [PERSON] et al.