Development and investigation of nonwoven preforms for self-reinforced polylactic acid composites

This work deals with the development and investigation of self-reinforced polylactic acid (SRPLA) composites manufactured from two different nonwoven preforms with two different bicomponent filament architectures. The SRPLA nonwovens prepared via spun bonding technology have two different bicomponent filament architectures, that is, core-sheath, and islands in the sea. For the core-sheath filaments, spunbound nonwovens are compared with the dry-laid SRPLA nonwovens. The SRPLA nonwoven preforms are compression molded at three different mold temperatures to fabricate composite plates. The optimum mold temperature is identified based on the flexural properties and residual void volume fraction of composites. The flexural modulus and strength are about 38% and 50% higher than those of the pure PolyLactic Acid (PLA) matrix, respectively. The influence of bicomponent filament architecture on the mechanical performance of composites is negligible, whereas the nonwoven architecture leads to significant differences both in the residual void volume fraction and in the mechanical properties of composites. Finally, the mechanical properties of the SRPLA composites are compared with those of the conventional composites to prove their applicability to semi-structural parts.