A Review on Melt Flow Index Characteristics of Polylactide (PLA) for Recycle Use in 3-D Printing

Plastic wastage is one of the major environmental pollution problems. The method for manipulating such wastage has become a challenging work in recent decades. This paper reviews the usages of plastic materials and possible recycling methods in the field of additive manufacturing. Recently, fused deposition modeling (FDM), which applies the thermoplastic filaments as the basic material for printing 3-D objects directly without using traditional molding techniques, has been widely adopted, especially in the education industries. The feasibility study of applying recycled polylactide or polylactic acid (PLA) as an alternative feedstock for FDM has been conducted. Melt flow index is one of the important factors that affects the setup of operation parameters of 3-D printers. The objective of this paper is to provide the foundation for possible further studies on the application of recycled polymeric material in 3-D printing. A review of injection characteristics of PLA studies that are related to the melt flow index has been addressed. Methods for improving the printing performance of using recycled PLA filament in 3-D printers are also proposed in this paper.