Polymaker Fiberon PET-CF17 is a carbon fiber reinforced PET filament engineered for applications demanding high stiffness and dimensional stability. The material combines a PET copolymer base with short carbon fibers, resulting in a filament that exhibits a matte black finish and a slightly textured surface. The carbon fiber content significantly increases the modulus of rigidity, making the printed parts substantially stiffer than standard PET prints while maintaining good impact resistance. The formulation is designed to minimize warping and shrinkage during cooling, enabling reliable printing of large or intricate geometries. In practical use, this filament delivers consistent extrusion and excellent layer adhesion. The carbon fibers contribute to a reduced coefficient of thermal expansion, which helps parts retain their shape under temperature fluctuations. The material’s stiffness makes it particularly suitable for functional applications such as jigs, fixtures, custom tooling, and structural brackets where deflection must be minimized. It also suits end-use components in robotics, automotive interior clips, and industrial prototyping. The 1.75mm diameter is maintained within tight tolerances, ensuring smooth feeding through a wide range of common 3D printers. The printing experience is characterized by a recommended nozzle temperature range of 260–290°C and a bed temperature of 80–100°C for optimal adhesion. A hardened steel nozzle is advised to resist the abrasive nature of carbon fibers. Parts printed with PET-CF17 show a matte, low-gloss appearance that hides fingerprints and minor surface imperfections. The material exhibits strong resistance to chemicals such as oils and solvents, broadening its usability in workshop or industrial environments. It also demonstrates good UV stability compared to unfilled PET, making it viable for semi-outdoor applications. The packaging includes a 1kg spool wound neatly to avoid tangles and is sealed with a moisture barrier bag to preserve print quality. The filament’s stiffness can lead to a slight brittleness in thin features, so appropriately sized radii and wall thicknesses are recommended.

The combination of affordable pricing and high mechanical performance makes this filament an economical choice for engineers and makers seeking a rigid, durable thermoplastic composite without the complexity of exotic materials like PEEK or PEI.