Manufacturing and Characterization of Continuous Carbon Fiber Reinforced Polymer Composites

Additive manufacturing (AM) technology allows designers to create and manufacture complex geometries without being restricted by subtractive manufacturing processes such as turning, drilling and milling. There are several AM techniques but our study focuses on fused deposition modeling (FDM) technique due to its relatively cheaper price tag, robustness, and versatility. Using FDM technique, parts can be manufactured by extruding polymers such as acrylonitrile butadiene styrene (ABS) roads by roads, layer by layer until parts are finished. FDM is great at manufacturing complex geometries, but due to weak layer adhesion, porous inner structure and poor surface finish, the parts produced are weaker compared to the ones manufactured by the traditional techniques. There have been many attempts to overcome the limitations of the technology. One that caught the attention of this study was reinforcement with fibrous materials. In general, there are two type of fibers may be used to reinforce polymers: chopped and continuous fibers. Because chopped fibers may not be easily orientated in certain direction to reinforce the material along the load direction, our research primarily looks into the continuous fiber reinforcement. In this research, the continuous carbon fibers are utilized through an innovative pre- and post-processing technique to generate a composite material with ABS as its resin matrix. A corresponding protocol has been developed to generate a single layer composite material with reinforced carbon fibers.  This technique can be easily expanded to generate a multilayer composite material with different reinforced fiber orientations. In post-processing, optimum conditions for a heat treatment process have been obtained to further enhance the mechanical properties of generated composite sample. Since none of the previous research present standardized manufacturing and post-processing protocol, this study seeks to address this issue by developing and presenting the detailed protocols for both processes.  Then, to fully characterize the created composite material, tensile test experiments have been conducted on multiple samples using 5969 Instron tensile test machine. Experimental results show that the reinforced carbon fiber samples, which generated from our developed protocol, have dramatic increases in various strengths, Young modulus and resilience in comparison with the control samples made only from printed ABS material. Most notably, yield strength and resilience compared to ABS stock sample, increase by whopping 60% and 64%, respectively. Consequently, statistical analyses have been also performed to assure the significance of our findings in this research. After conducting tensile test experiments on multiple samples, ANOVA method with 95% confidence level is applied to determine whether there are statistically significant differences between various characterization parameters compared to control samples.