Executive Summary : | 3D printing based on the FFF technique for producing reinforced polymer composite parts with continuous fiber-reinforcement is a very promising technique but at a premature stage. An initial effort to produce the continuous fiber-reinforced parts has been already made. There exists a lot of challenges in producing industrial-grade 3D printed CFRP composite parts. While fabricating short-fiber reinforced thermoplastic filament, it is rather difficult to homogeneously disperse the carbon fibers. A suitable filament manufacturing printing strategy should be developed. It has been reported in the literature that beyond a certain proportion, the short fibers become problematic, thereby clogging the printer nozzle. Continuous fiber reinforcements, offer much more difficulty in their fabrication using 3D printing. The challenge lies in the correct alignment of the fibers. Improper alignment can lead to a larger void fraction, thereby producing weaker parts. The quality of parts, such as roughness in the direction perpendicular to the printing direction, must be controlled to achieve the desired surface finish, in the vertical direction. The poor adhesion of the fiber-matrix interface is another issue of concern that should be taken care of. A deep understanding of the optimal printing strategy, printing parameters, and their effect on the material, mechanical, and thermal properties of the parts is required and needs to be addressed. A suitable decision-making approach needs to be developed, taking into account the sustainability (social, economic, and environmental) in the manufacturing process. Such a decision-matrix can help the user to identify, that in which scenarios, choosing 3D printing technique over conventional can be more advantageous. The decision matrix can further help the user to determine that based on the desired number of parts if the 3D printing technique is a cost-effective, and environmentally friendly measure. The project aims to bridge the research gap by providing suitable measures to the various challenges listed in the earlier sections. The problem of larger void fraction can be solved by the precise alignment of the reinforced fibers using a dual-nozzle arrangement in the printer. If a nylon filament, pre-infused with short carbon fiber is used as a matrix, the strength of continuous CFRPs can further be enhanced. Thus, for the purpose of this project nylon will be used as a thermoplastic material. This project will open new avenues in the area of 3D printing of polymer-matrix composites reinforced with the continuous carbon fibers. |