Resistance and Strength of Conductive PLA Processed by FDM Additive Manufacturing

Abstract

There is a large number of materials that can be used for FDM additive manufacturing technology. These materials have different strength properties, they are designed for different purposes. They can be highly strong or flexible, abrasion-resistant, or designed for example for environments with higher thermal loads. However recently new innovative and progressive materials have come to the practice, which include nano-composite particles, bringing new added value. One such material is the Conductive PLA material, which is capable of conducting electric current. The aim of this article is to present the material properties of this material. The article describes the design of the experiment, the process of measuring the resistance of samples printed by FDM device, measuring the maximum tensile strength of samples. The article includes a statistical evaluation of the measured data, with the determination of the significance of individual factors of the experiment as well as the evaluation of the overall result of the experiments.

The Influence of the Printing Temperature and the Filament Color on the Dimensional Accuracy, Tensile Strength, and Friction Performance of FFF-Printed PLA Specimens

“…This was not the case upon a further increase in the printing temperature, as the UTS of the black-colored specimens continued to decrease, while that of the natural PLA samples increased. Low values of the UTS of black PLA were also reported by other researchers [ 17 , 18 , 29 ] for temperatures situated in the same range. Considering the fact that coloring agents added to natural PLA may act as nucleating agents for the crystalline regions of the semi-crystalline polymers, as previously demonstrated by other authors [ 19 , 27 ], one might assume that the printed black PLA has higher crystallinity than that of the printed natural PLA.…”

“…The variable parameters were the printing temperature (ranging from 200 °C to 240 °C) and the filament color (natural PLA and black PLA). The natural PLA filament was selected as the reference material, whereas the black-colored PLA was chosen considering the fact that black dyes enhance the thermal conductivity of the PLA and modify its friction behavior, as shown by previous research [ 3 , 17 , 18 , 28 , 29 , 34 , 35 ].…”

“…Sometimes, the intrinsic properties of pure PLA cannot ensure certain properties needed for specific products, such as, for example, products with high electrical and thermal conductivity. For the improvement of such properties, additives are mixed with PLA, leading to PLA-based composites [ 16 , 17 , 18 , 19 ].…”

“…Regarding the color of the PLA filament, previous research showed that its influence on the dimensional accuracy [ 1 , 34 ] and the tensile strength [ 17 , 18 , 27 , 29 ] of FDM-printed samples cannot be neglected, and that also the same color PLA filaments manufactured by different producers, may not have the same printing properties [ 24 ]. The reasons behind this are considered to be the color-dependent in-process crystallinity and/or the different thermal behavior [ 17 , 34 ] in the case of PLA filaments containing coloring additives.…”

“…Regarding the color of the PLA filament, previous research showed that its influence on the dimensional accuracy [ 1 , 34 ] and the tensile strength [ 17 , 18 , 27 , 29 ] of FDM-printed samples cannot be neglected, and that also the same color PLA filaments manufactured by different producers, may not have the same printing properties [ 24 ]. The reasons behind this are considered to be the color-dependent in-process crystallinity and/or the different thermal behavior [ 17 , 34 ] in the case of PLA filaments containing coloring additives. Some researchers also more precisely explained the reasons for the abovementioned effects, indicating that the coloring agents may act as crystallization rate modifiers [ 27 ] or nucleation agents [ 19 ] and may restrict the material flow during the printing process [ 27 ].…”