Design and verification of enhanced CFRTPCs fabrication technique using fused deposition modeling

Research shows that mechanical properties of parts produced using fused deposition modeling (FDM) are inferior when compared to parts produced using conventional techniques such as injection molding. Efforts have been made in recent years to improve mechanical properties by reinforcing the parts with high strength fibers. This has been achieved by either modifying FDM setups to extrude fibers with thermoplastics and fabricate continuous fiber reinforced thermoplastic composites (CFRTPCs) or employing manual techniques subsequent to part production. Existing CFRTPCs fabrication procedures have limitations of fiber exposure to environment, no direct control method for volume fraction, and poor surface finish. This research work is focused on improving the process of producing CFRTPCs by addressing these limitations using a dual extruder FDM setup. The process developed was tested for its feasibility using Kevlar fiber as reinforcement for commercially available ABS, PLA, PLA-C, and PLA-Cu thermoplastic fibers. Taguchi L₁₆ orthogonal array was used to design experiments, while tensile and flexural testing was performed to determine mechanical properties achieved. Tensile strength was improved up to 3 times the baseline value of thermoplastics, while flexural strength was improved up to 1.6 times. This technique can further the goal of developing CFRTPCs, on industrial level, using FDM with better control over volume fraction and fiber layup.