Fused Deposition Modeling of Composite Reinforced by Continuous Ultra-High Molecular Weight Polyethylene Fiber

Abstract

Fused Deposition Modeling (FDM) of composites with compliant high-strength fibers couldexpand opportunities for the design and fabrication of complex compliant structures. However, this area of additive manufacturing (AM) is currently not reported in the open literature. This study pursued developing an approach for creating filaments of continuous ultra-high molecular weight polyethylene fiber tow embedded in a matrix of polycaprolactone (Dyneema/PCL) and successful 3D printing. The microstructure and mechanical properties of the filament were evaluated in terms of key parameters including the fiber distribution (dispersed vs. bundled) and printing condition (before and after FDM). At a minimum fiber volume fraction of 18%, the filament exhibited an ultimate tensile strength (UTS) of 588 ± 41 MPa prior to printing, with apparent fiber strength of 3.2 GPa. For the printed condition, the UTS reached 474 ± 62 MPa and with apparent fiber strength of 2.6 GPa. Fiber dispersion in the filament plays an important role in the printed properties and potential for fiber degradation. Nevertheless, the strength of the Dyneema/PCL represents a new performance benchmark for compliant composites produced by FDM. This new material system can support applications where strength and toughness are key performance metrics in addition to flexibility.