| Abstract [eng] |
The thesis provides a comprehensive analysis of thermoplastics and thermosets, with a focus on how their properties affect machinability indicators when cutting tools are used. It was determined that the cutting edge angles, as well as the radius of the tool edges and corners, have a significant impact on tool wear rate and the surface quality of the workpieces. The importance of materials and coatings used in the production of cutting tools was further discussed. Additionally, the numerical methods applied to solve machining problems for plastics were identified. Based on further theoretical analysis, a cutting tool study was conducted using polyacetal as the material being machined. For this study, cutting tool prototypes manufactured by company X were used. The edges and top radii of the prototypes were measured and later evaluated through numerical analysis. During the numerical analysis, ten different mathematical models were created, each with different front and back angles. To more accurately describe the characteristics of the POM-C material used by company X, tensile tests were performed on the samples, which allowed the determination of the yield strength. After defining the characteristics of both the tool and the workpiece material, a numerical analysis was conducted for each tool geometry model. A smoothed particle hydrodynamics (SPH) model was applied to obtain results, aiming to identify which tool geometry is the most effective when machining POM-C plastic. In the economic analysis, the cost of the improved cutting tool was calculated and compared with a cutting tool from the „HASS“ manufacturer, designed for machining steep angles. It was found that the improved cutting tool developed by company X has the potential to be economically superior to market competitors' products. However, additional experimental studies would be needed to confirm it. Furthermore, in terms of ecological sustainability, plastic recycling methods (mechanical, chemical, energy, and biological) and their significance in the industry were discussed. In conclusion, this thesis provides valuable insights into the potential for improving tool geometry efficiency and the research methods that could help enhance the operational properties of tools and the quality of machined workpieces. |
