Investigation of 3D printing strategy on the mechanical performance of coextruded continuous carbon fiber reinforced PETG

Fused filament fabrication (FFF) has been used to create prototypes and functional parts for various applications using plastic filaments. It has also been extended to the use of continuous fibers for reinforcing thermoplastic polymers. This study aims to optimize the deposition design of a coextruded continuous carbon fiber (CCF) composite filament with a polyethylene terephthalate glycol‐modified (PETG) filament. The characterizations on the raw materials revealed that the matrix polymer in CCF composite filament had similar physicochemical properties as PETG, and carbon fibers were homogeneously distributed in CCF filament. The effect of raster orientation and shells number on the mechanical properties of non‐reinforced and coextruded CCF‐reinforced PETG was investigated. The highest mechanical properties were obtained at a raster orientation of 0° for both reinforced and non‐reinforced materials. With the increase of raster orientation, Young's modulus and ultimate tensile strength decreased. The presence of shells improved the tensile strength of non‐reinforced PETG. For composite samples printed with unreinforced shells, Young's modulus decreased due to decrease in fibers content, and elongation at break and ultimate tensile strength increased. Tomographic observations showed that the mechanical behavior of printed specimens depended on the anisotropy of porosity in printed specimens