MECHANICAL-PROPERTIES OF DENSE POLYLACTIC ACID STRUCTURES FABRICATED BY 3-DIMENSIONAL PRINTING

Polylactic acid (PLA) is a bioresorbable polymer that is used in a num ber of clinical situations. Complex shapes of PLA are commonly machine d for bone fixation and reconstruction. Solid free form fabrication me thods, such as 3D printing, can produce complex-shaped articles direct ly from a CAD model. This study reports on the mechanical properties o f 3D-printed PLLA parts. 3D printing is a solid free-form fabrication process which produces components by ink-jet printing a binder into se quential powder layers. Test bars were fabricated from low and high mo lecular weight PLA powders with chloroform used as a binder. The binde r printed per unit line length of the powder was varied to analyze the effects of printing conditions on mechanical and physical properties of the PLA bars. Furthermore, cold isostatic pressing was performed af ter printing to improve the mechanical properties of the printed bars. The maximum measured tensile strength for the low molecular weight PL LA (53 000) is 17.40 +/- 0.71 MPa and for high molecular weight PLLA ( 312 000) is 15.94 +/- 1.50 MPa.