Additive manufacturing of parts with three-dimensional continuous fiber reinforcement

One of the key challenges in additive manufacturing of plastic goods using the Fused Filament Fabrication (FFF) technology is to ensure their strength. The low strength of polymer materials and the distinct anisotropy of their mechanical properties limit the use of 3D printing as an alternative to the traditional small-scale production technologies. The most promising solution to the goal of increasing the strength of printed goods is the application of continuous fiber reinforcement. Several additive manufacturing devices and software products that allow preparing a control program for 3D printing with reinforcement are known, however, having all their advantages, they, like conventional printed products, have a wide spread in strength in various directions (in the plane of a layer and perpendicularly to it, in the direction of growing). In this paper, the authors propose using the continuous fiber reinforcement along the three-dimensional trajectories to smooth out the anisotropy of the products’ properties in the FFF technology and ensure wider possibilities for using them in the production of final goods. In the course of work, a 3D printer with the ability to print using five degrees of freedom and software for preparation of control programs were upgraded for the printing process with laying continuous fiber; printing modes with reinforcement were developed; samples were produced for standard static bending tests. The experiments show that reinforcement improves the printed specimen’s strength, and the proposed three-dimensional reinforcement technique ensures the lower flexing strength compared to standard flat reinforcement with uniaxial laying of fibers, though, the destruction of 3D reinforced specimens occurred without evident delamination.