3D printing of a continuous fiber-reinforced composite based on a coaxial Kevlar/PLA filament

Abstract

Additive manufacturing has allowed for the production of complex and mass customized geometries, but often at the expense of mechanical performance, a penalty which can be in part mitigated with the fabrication of composite parts. Thermoplastic structures fabricated with material extrusion additive manufacturing stand to be improved in terms of fracture toughness with the integration of continuous fibers. The present research program has investigated the production of a continuously reinforced filament to be used in open-source fused filament fabrication systems. Three different volume fractions of Kevlar fibers were incorporated into a polylactic acid (PLA) thermoplastic filament. It was observed that a 20% fiber volume fraction resulted in a doubling of the tensile strength relative to the unreinforced PLA parts. High-velocity impact tests were also performed on the reinforced printed thermoplastic material, and it was observed that the composite with the highest fiber volume fraction provided an impact energy resistance improved by a factor of four, relative to the plain PLA. The reinforced fibers have shown to restrain the penetration of the projectile at velocities similar to those that perforated the unreinforced PLA. The present work has demonstrated the production of printed composites without the need of modifying the extruding systems of a commercial 3D printer. This approach could represent an alternate and feasible process for producing continuously reinforced 3D-printed thermoplastic parts with utility for high-velocity impact applications.

Failure Prediction in 3D Printed Kevlar/Glass Fiber-Reinforced Nylon Structures with a Hole and Different Fiber Orientations

“…Furthermore, unlike conventional drilling techniques involving structural damage, in 3D printing samples, such damage is not anticipated [ 38 , 39 , 40 , 41 ]. Moreover, 3D printing technology needs to be improved, particularly in the context of enhancing interfacial compatibility between different types of fibers and polymer matrices and maintaining a precise orientation level [ 42 ]. Plasma treatment of fibers [ 43 ], interfacial grafting [ 44 ], and tailoring fiber orientations [ 45 ] are the critical approaches that can be employed to enhance the interfacial interactions between polymer and fiber during 3D printing.…”

Investigation on the Compressive Characteristics and Optimization of Design Parameters of a Novel Functionally Graded Cell Structure

“…PLA filaments reinforced with kevlar fibers were tested for their impact resistance and found that the impact resistance improved with the increased addition of fibers. To produce these continuously reinforced 3D printed components, no modifications are need to be done in the existing printers [27]. A sandwich panel with flexible core and stiff upper and lower surfaces made of filaments reinforced with glass fibers are tested for its energy absorbance.…”

Effects of PLA-Type and Reinforcement Content on the Mechanical Behavior of Additively Manufactured Continuous Ramie Fiber-Filled Biocomposites

“…Composite materials reinforcement using continuous glass fibers through AM has been also investigated with significant mechanical property improvements [31][32][33]. Furthermore, it has been reported that incorporating continuous Kevlar fibers not only enhances the tensile properties of PLA and nylon matrixes, but also effectively improves their impact resistance [34,35].…”