Production and characterization of bamboo and flax fiber reinforced polylactic acid filaments for fused deposition modeling (FDM)

A new type of fiber reinforced filament materials for Fused Deposition Modeling applications has been developed. Polylactic acid (PLA), compounded with two types of plasticizer, is reinforced with bamboo and flax fibers. The fiber fractions are characterized by measuring their length (l) over diameter (d) before and after compounding so that the effect of the l/d on the final filament properties can be systematically studied. The pre-processing and processing activities, to produce filaments with a diameter of 3 mm, are described. The porosities and the orientation of the fibers in the filament are assessed to predict the theoretical stiffness of the filament via short fiber mechanics which is compared to the experimental results. Reinforcing the PLA filament with short bamboo fibers (l/d = 4-5) increases the modulus with 91-230%, whereas the dust-like fractions only show an increase up till 39%. The glass transition temperature of the produced filaments is also determined to investigate the suitability of the filaments and finally a demonstrator part was printed. POLYM. COMPOS., 40:1951-1963, 2019. (c) 2018 Society of Plastics Engineers