Machinability of PLA obtained by injection molding under a dry milling process

Abstract

Abstract. This paper is part of a study focusing on the elaboration of accurate component with complex geometries using bio-sourced as an alternative to petrochemical polymer. The bio-sourced and biodegradable in this study is composed of a Poly Lactic Acid (PLA) matrix and hemp fibers. The final component is obtained by injection followed by a machining operation. the final component is obtained by injection followed by a machining finishing operation. Injection molding will be carried out to be compared with 3D printing on economic, environmental, production and workpiece quality criteria. This paper focuses only on the combination of two processes, injection molding followed by machining on poly (L-lactic acid) or PLLA which is biobased and biodegradable. After injecting the workpiece, thermo-physical characterization tests are realized on PLLA polymer. Rheology, thermal and mechanical tests are carried out in order to study thermomechanical behavior and to understand material flow phenomena at different temperatures and shear rates. The objective of this paper is to overcome the technical challenges of milling this material without any lubricant. In an upcoming project, various machining operations will be carried out such as turning to study continuous cutting, or milling to study discontinuous cutting on workpieces reinforced with bio-sourced fibers as hemp.