Design, prototyping and testing of components for incorporating low-temperature plasma sterilizers to 3D printers

This thesis analyses the possibility of improving the cooling system of an FDM-type 3D printer, in this case a third-generation Ender. This work proposes to achieve the aforementioned objective by replacing the two fans that the printer has with devices that use cold plasma. This modification guarantees greater efficiency, better sterilization of the part and also a significant reduction in the noise of the ventilation system. Firstly, through a brief introduction, the aim is to present the technology of additive manufacturing, its main features, the technologies used today and the various problems and challenges to be taken into account when printing in three dimensions. This is followed by a brief description of plasma and then its physical significance, the chemical mechanism that allows it to be generated and its beneficial effects in printing by analyzing and describing the reasons for using it to cool parts and filament. Next, a small digression is devoted to the operation of the device that creates the plasma, i.e. the description of the parts of which it is composed and the mechanism for generating the so-called plasma wind. This section closes with an initial analysis of the solution technique of the project (interlocking of the parts involved, position and number of devices to be used, the necessity or otherwise of catalysis). Then follows the heart of the work with the actual redesign of all the parts making up the extruder modified by the addition of this device. In this section, the problem of space and feasibility was addressed by paying attention to some important constraints that must be considered when designing for additive manufacturing; among others, attention to the use of supports and the importance of the orientation of the part during printing. Lastly, the question of the cooling channel is addressed, which plays the important role of transporting the plasma wind towards the nozzle from which the filament is extruded. In this circumstance, the best configuration was evaluated by means of a fluid-dynamic analysis in order to ensure proper flow homogeneity and minimize aerodynamic losses. To conclude the work, the designed parts are printed out with the final assembly and testing in order to verify that what was realized and simulated with the computer is also feasible and functional in reality.le.