Printing head for additive manufacturing with continuous filament

For the material extrusion also known as Fused-Deposition-Modeling (FDM) especially unreinforced and short filament reinforced thermoplastics are currently used. For reaching significantly higher mechanical properties it’s possible to incorporate continuous carbon fibers. State of the art is either the use of pre-infiltrated continuous fiber filaments or encasing the fibers with the thermoplastic melt inside the printing head. With the printing head technology presented here it’s possible to construct components with the material extrusion procedure (FDM, FFF) and reinforcing them locally with carbon fibers. Simultaneously the benefits of the procedure are used like low machine and material costs or the simple multi material printing.

The invention presented here enables the infiltration of the carbon fiber roving. Therefore the fiber bundle is led over pins or rounded edges, thus the polymer melt gets pressed into the bundle of fibers by a pressure field. This is facilitated further by the separation of the strand. In comparison to existing technologies of pre-infiltrated continuous fiber reinforced filaments thicker fiber rovings can be used in the presented printing head technology as the minimal bending radii are smaller than for the compound. Additionally the fiber volume content is locally variable or simply various matrix materials are usable.