Similar to metal-infused filaments but made of small fibers rather than metal, carbon fiber filaments are composite materials created by mixing carbon fiber fragments with a polymer basis. The polymer base can be made from a variety of 3D printing materials, including nylon, PLA, ABS, PETG, and PEEK.
While genuine carbon fiber materials have long continuous fiber strands that increase mechanical resistance, these filaments have smaller particles with an average diameter of 0.01 mm that enable printing. Even if this is sufficient to increase the strength of printed items, keep in mind that these filaments cannot match pure carbon fiber in strength.
Carbon fiber filament offers a reasonably simple substitute for more expensive and difficult materials like polycarbonate (PC) or PEEK for those looking for harder 3D printing materials. Additionally, the added strength that the carbon fiber particles offer promotes greater dimensional stability, preventing warping and shrinking.
However, there are some challenges with printing these materials in 3D. The nozzle does not melt the infused carbon fiber particles during extrusion, which could cause frequent blockage. Additionally, during extrusion, these particles act as abrasives, gradually wearing away the internal bore of a brass nozzle. For printing with composite materials, specialized nozzles like hardened steel are strongly advised.