Poly-(lactic acid): PLA; It is a biodegradable synthetic polymer that can be derived from different food sources and is extensively used in the 3D printer industry owing to its ecological degradation and improved manufacturability. Moreover, research on tissue scaffolds with different geometry-features relationships have been commenced in recent years, as the biocompatibility and biodegradability features of PLA, which is preferred in medical applications requiring long-term strength (such as connective tissue, tendon structures and vascular grafts), have attracted more attention. In this study, PLA scaffolds (abbreviated as 40-□, 40-○, 60-□, 60-○, 80-□ and 80-○) was designed with computer-assisted design (CAD) program then printed with a 3D printer and its mechanical properties were investigated. Thus, in addition to the researchers' research on different unit cell geometries, it was aimed to investigate the combined effect with the fill rate. First of all, the total porosity of PLA printed parts have been determined in terms of suitable for scaffolds requirements and then mechanical (compression) tests were carried out. It was noticed that the total porosity reduced with increasing fill rate with cubic and cylindrical scaffolds with theoretical porosity of 62.72% and 52.34%, respectively (from 85.52% to 59.67%, for 40-□ and 80-○, respectively), it was noted that the unit cell geometry was effective in total porosity. As a result of compression tests performed on scaffolds in accordance with ASTM D695 standard, 2.17, 2.60, 4.25, 5.90, 5.79 and 8.24 MPa compression strengths have been calculated for 40-□, 40-○, 60-□, 60-○, 80-□ and 80-○, respectively. It is anticipated that PLA scaffolds produced in line with these results can be used in soft tissue applications that do not require high mechanical rigidity. It has been determined that the compression strengths increase with increasing fill rate, and the unit cell geometry is quite effective on the mechanical features of scaffolds. As a result of the study, it was revealed that the occupancy rate and unit cage geometry can differentiate PLA scaffolds in terms of mechanical properties. Moreover, it is predicted that the physical and mechanical properties may change completely as a result of the design of scaffolds with functional layered pore structure.
Anahtar Kelimeler: Unit cell geometry, Fill rate, Compression test, 3D printing, PLA scaffold