# An Analysis of the Process of Applying Technical Lubricating Coatings
## 3 Results
Figure 7 shows a graphical comparison of the spray angle (\(\alpha\)) for the sprayed lubricant in the different measurement series. There is a visible downward trend for the value of the spray angle with increasing atomization pressure. In Figure 8, the changes in the spray angle depending on the atomization pressure are presented. The analysis of the obtained experimental data showed that for systems AI and AII, the obtained spray angle values decreased from 100-120\({}^{\circ}\) at a pressure of 20-40 psi to around 70\({}^{\circ}\) at a pressure of 80 psi. For system BI, the trend of decreasing spray angle values is similar, with the difference being that, at pressures >60 psi, the angle values are around 40\({}^{\circ}\). For system BII, the spray angle values decrease much faster, as, at pressures of 30-40 psi, the observed spray angles are already around 30\({}^{\circ}\), and further increasing pressure does not cause significant change. When spraying lubricants, this value showed a downward trend. This is due to, for example, the fact that at low atomization pressures, there was a significant dusting of the material. As a result, the analyzed photograph showed a fairly wide spray angle. With the increase of the atomization pressure, the spray disappeared, so that at such pressure values, lower and lower values of the spray angle can be noted. However, it should be remembered that the measurement error at the spray angle can be up to \(\pm\)4\({}^{\circ}\). It can be concluded that higher values of the spray angle could be recorded using lubricant No. I and for a fan-flat atomizer. However, these values may be slightly overestimated due to the previously mentioned dust spray, especially at the initial points. Figure 7: Graphical comparison of spray angle of sprayed lubricant coatings (**A**) = nozzle with flat spray, (**B**) = nozzle with full cone spray, I = lubricant No I, II = lubricant No II. The results of the experimental tests and analysis revealed that when atomization pressures are low, the edge of the spray is uneven and there is a significant amount of dusting. However, as the atomization pressures increase, the edge of the spray becomes more defined and there is no dusting present. The material layer appears to be more uniform, but at pressures above 70 psi, the spray takes on a wave-like appearance. Additionally, during dusting, inhomogeneities in the material layer are visible in the form of drops of varying volumes and shapes. When using round nozzles, the material is more uniform and the edge of the spray is clearer. On the other hand, when using a flat nozzle, the uniformity of the material and the edge are not as good as with a round nozzle. However, a flat nozzle allows for a wider width of the material path compared to a round nozzle. The width of the material path decreases with a flat nozzle, but increases with a round nozzle. Additionally, it was also observed that the spray angle decreases as the atomization pressure increases. This study aimed to assess a test method that would enable an objective qualitative analysis of the interactions between grease applied with spray nozzles and the working surface. The conducted research allowed us to propose a method for the evaluation of sprayed lubricant coatings. The atomization of grease was the initial stage. Afterwards, the coatings were photographed, and the obtained image was subjected to computer processing using Image-Pro Plus in accordance with the formulated algorithm. The study used test grease samples, which were enriched with commercial additives. The study results showed a correlation between the pressure and nozzle type and the size of the surface area covered with the tested product.