Processing of carbon fiber for 3D printed continuous composite structures

This article describes original carbon fiber impregnation procedure. The aim of this research is to determine carbon fiber impregnation process influence on mechanical properties of printed composite structures. 3D printing head and carbon fiber impregnation device were designed and produced. Three different polymer materials (PLA, PC, ABS) and solvent methylene chloride (DCM) were selected and solutions of different concentrations (2-10%) were prepared. 1 and 3K carbon fiber tow were impregnated with solutions (2-10%) and tensile tests of impregnated carbon fiber tow were performed. The correlation analysis revealed a strong relation between the tensile force of impregnated carbon fiber and mass of impregnated carbon fiber tow. For 3D printing 1 and 3K carbon fiber tow impregnated with 8 and 10% solutions were selected. Tensile tests were carried out to evaluate the mechanical properties of 3D printed composite structures. The obtained results revealed the dependency between the solution concentration and tensile strength, i.e. the higher the concentrations in carbon fiber impregnated with solution, the higher the tensile strength. This tendency is strong in PLA and PC impregnated 3K carbon fiber, however when the carbon fiber impregnated with ABS solution, the change in the results was not so significant. The obtained results can be used for the future development of different 3D printed composite structures.