## 3 Results
### Study of X-ray Diffraction (XRD)  
Figure 10 shows the XRD spectrum for ABS. This material has a characteristic peak of around 19.92 degrees. The appearance of this peak indicates that it is an amorphous material [29]. In the tested sample, there was an additive in the form of titanium oxide (peaks 27.36\({}^{\circ}\), 36.00\({}^{\circ}\), 39.07\({}^{\circ}\), 41.17\({}^{\circ}\), 43.95\({}^{\circ}\), 54.25\({}^{\circ}\), 56.56\({}^{\circ}\), 62.68\({}^{\circ}\), 63.96\({}^{\circ}\), 68.93\({}^{\circ}\), 69.74\({}^{\circ}\), 82.27\({}^{\circ}\)), which is used in dyes applied in polymers [29; 30; 31; 32; 33]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Test Number** & **MFR** & **MVR** & **Density** \\
**[g/10 min]** & **[cm\({}^{3}\)/10 min]** & **[g/cm\({}^{3}\)]** \\ \hline
1 & 3.41 & 3.52 & 0.97 \\
2 & 3.43 & 3.47 & 0.99 \\
3 & 4.12 & 4.20 & 0.98 \\
4 & 3.78 & 3.78 & 1.00 \\
5 & 4.42 & 4.44 & 1.00 \\ \hline STANDARD DEVIATION & 0.44 & 0.43 & 0.01 \\ \hline AVERAGE & 3.83 & 3.88 & 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Test results obtained using the plastometer for the HIPS flakes. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Test Number** & **MFR** & **MVR** & **Density** \\
**[g/10 min]** & **[cm\({}^{3}\)/10 min]** & **[g/cm\({}^{3}\)]** \\ \hline
1 & 32.52 & 32.45 & 1.00 \\
2 & 30.48 & 29.89 & 1.02 \\
3 & 33.12 & 33.30 & 0.99 \\
4 & 32.04 & 31.59 & 1.01 \\
5 & 30.48 & 29.03 & 1.05 \\ \hline STANDARD DEVIATION & 1.20 & 1.77 & 0.02 \\ \hline AVERAGE & 31.73 & 31.25 & 1.02 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Test results obtained using the plastometer for ABS flakes. Figure 11 presents the XRD spectrum of plastic PS. The XRD spectrum of polystyrene has two characteristic peaks (9.58\({}^{\circ}\) and 19.19\({}^{\circ}\)). Polystyrene is also an amorphous material; hence, the specific appearance of peaks is observed. In the spectrum for polystyrene, a peak for titanium oxide, also derived from the addition of dye (36.00\({}^{\circ}\), 39.07\({}^{\circ}\), 41.17\({}^{\circ}\), 43.95\({}^{\circ}\), 54.25\({}^{\circ}\), 56.56\({}^{\circ}\), 62.68\({}^{\circ}\), 63.96\({}^{\circ}\), 68.93\({}^{\circ}\), 69.74\({}^{\circ}\), 82.27\({}^{\circ}\)), and a peak derived from calcium carbonate (29.35\({}^{\circ}\)) were observed [29; 30; 31; 32; 34; 35; 36]. Figure 11: XRD spectrum for HIPS along with its interpretation. Figure 10: XRD spectrum made for ABS along with its interpretation. The Theoretical Number of the Bubbles That Should Attach to the Surface of HIPS and ABS Flakes to Have a Density Lower than That of Tap Water  
Table 6 presents the selected research results along with the calculated averages for the obtained results. The standard deviation for \(>\)8 mm HIPS flakes is 0.104 g, for \(>\)8 mm ABS flakes is 0.295 g, for 4-8 mm HIPS is 0.084 g and for 4-8 mm ABS is 0.034 g.  
The results of the density test for the HIPS and ABS flakes are presented in Table 7.  
The density of the HIPS flakes is lower by approximately 30 g/dm\({}^{3}\) than that of ABS. This may be due to the additives. All flakes have a density higher than that of demineralized water. The standard deviation for HIPS density is 0.014 g/cm\({}^{3}\) and for ABS density is 0.028 g/cm\({}^{3}\). In the paper [3], the densities of ABS and HIPS are 1.045 and 1.034 g/cm\({}^{3}\), respectively. In the study [4], the ABS and PS samples have average densities of 1.050 g/cm\({}^{3}\) and 1.040 g/cm\({}^{3}\). The differences in densities are in the second decimal place and may be due to the differences in the materials used for the studies. The PS and ABS in papers [1; 2; 3; 4] were obtained from WEEE, and the HIPS and ABS used in this study are from waste refrigeration equipment. Even if in all cases these plastics came from used refrigerators, the differences in the manufacturers, years of manufacture and used additives may be the reason for differences in densities. It can be noticed that is ABS has a density lower than that of PS in each of these studies.