Investigation of extrusion based additive manufacturing conditions of recycled thermoplastic PET materials

Additive manufacturing is a manufacturing technology that can produce complex geometries that are difficult to manufacture with traditional methods in a short time and at low cost. Additive manufacturing creates parts by adding materials to each other in the form of wedges. Additive manufacturing has a wide range of applications in industries such as aerospace, automotive, architecture, medical and defense. In this thesis, an experimental study was carried out to examine the mechanical properties of recycled polymer materials. For this reason, by using PET and recycled PET (rPET) materials, samples in accordance with ASTM D638 standards were produced with a material extrusion-based additive manufacturing system. The dimensional measurements of the samples produced with the Taguchi L9 experimental design were made and the deviation values from the planned dimensions were calculated. Additively manufactured samples from both PET and rPET materials were subjected to tensile tests and their mechanical properties were examined. By comparing the results obtained, the difference between the mechanical performances of normal polymers and polymers obtained by recycling is discussed. As a result, the mechanical properties of the samples produced with different production parameters were compared and the most suitable production parameters for the rPET material were determined.