## 3 Results and Discussion  
In order not to adversely affect the deformation zone, the beginnings and ends of the individual layers were placed in the corners of the blades of the test sample, so that they varied layer by layer, not forming a single weakened or raised corner. The results of samples printed without adjusting the start of the printing are shown in Figure 9.  
By changing the settings in the postprocessor, the starting point for the printing has been adjusted to achieve the most objective result possible and to prevent the accumulation of defects in the test area. That is, the printhead does not begin its motion at a random location, such as the arc of the printing pattern, but at its corners, as shown in Figure 10. All the beginnings of the transitions for the peripheral layers (Figure 11), as well as the body's infill, were located in the areas intended for clamping the sample to the jaws of the measuring device. The body of the sample is then produced by a continuous passage of the tip of the extruder without interruption in the monitored part. Figure 8: Imperfections are caused by the start and end of the working motion. Figure 10: Test results are affected by the default starting point of the printing process. Figure 9: Improperly chosen starting points. As mentioned at the beginning of the paper, the starting sample for comparison and evaluation of the measurement results is a sample of pure PLA, free from dyes and additives. Other studied materials are composites composed of PLA plastic with different percentages of admixtures. To determine the effect of the orientation of the infill in the sample to be torn, when applying the FDM technology, a series of samples is created from materials gradually containing an admixture of dust particles of copper, steel, and iron. For the given models, 10 samples of pure PLA material have been made for all five orientations. Composite samples were produced only in the 0\({}^{\circ}\) orientation. The result of the measurements is a document with individual values obtained in course of the measurement. The measurement is repeated for each test sample and finally evaluated using tables and graphs. The measured and calculated values obtained in the static tensile test are given in Figure 12. The values of the tensile force Fm show the maximum values of the applied force recorded during the experiment (forces at the peak of the load force). The subsequent graph of dependence indicates the values of the \(\Delta\)L elongation under the maximum tensile force (Figure 13). Figure 11: Beginnings of working motion outside the monitored zone. Figure 12: Average maximum tensile force values [kN] for pure PLA plastic. The measured values make it possible to determine the tensile strength Rm [MPa]. During a static tensile test (Figure 14), there is a graphical (or digital) dependence between elongation and stress. Through measurements based on the results, it is possible to claim that the selected material is brittle, with a small yield strength. Due to the layered nature of the filament, there is no significant formation of a narrowed neck. Breaking zones occur randomly in the space between the grips. The cause may be defects in interlayer mesostructural properties such as pore size. When working with materials containing additives defects can cause the abnormal size of particles and their weak mutual adherence weakening the polymer matrix. Various defects also may occur during printing pure material of the specimens which can lead to the final rupture. The most common causes are uneven material flow, unsuitable thermal conditions, and degraded material. The wet material in the printhead heats up very quickly above the boiling temperature, where the accumulated steam splashes through the nozzle, and the escaping gas damages the produced walls. Figure 14: Set of samples (orientation 22.5\({}^{\circ}\)) before and after the test. Figure 13: Examples of individual waveforms of PLA material printed with different orientations.