Study on Continuous Fiber-reinforced Composites 3D printing

• Main Authors: Cheng-Hua Liu, 劉承樺
• Other Authors: Yih-Lin Cheng
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/2nuc79

碩士 === 國立臺灣科技大學 === 機械工程系 === 107 === The demand for composite material such as carbon fiber increases these years. However, the mechanical performance of 3D printing composite material nowadays isn’t still satisfied in industry. Therefore, in this study, the continuous carbon fiber and epoxy double solidifying resin are applied to develop the process of 3D printing composite material. It can be divided into two stages. The first stage is continuous carbon fiber wire preparation and the other stage is carbon fiber print head design and printing. The main purpose of this study is to develop a continuous carbon fiber composite material 3D printer. Furthermore, the pros and cons in composite material printing with none tilting, tilting and flattening printing method is also discussed. In this study, the OM(optical microscope) is adopted to observe the lamination quality of the composite material printing and make the improvement with the observation results. Meanwhile, the composite material 3D printing system is developed to discuss the fiber distribution by using three common printing methods. As the results of the experiments, for none tilting printing method, it has to choose a larger nozzle and layer thickness to prevent the friction between the nozzle and the carbon fiber causes some problems such as fiber breakage bifurcation. Moreover, the proportion of matrix in the product with none tilting method is up to 70.12%. The tilting printing method has many voids in the product due to the interference of the nozzle on adjacent materials as well as no pressure is applied to the extruded material. These voids reduce the mechanical performance of the product. Thus, it needs a great amount of resin to solidify. These cause the proportion of matrix in the product increased to 74.58%. Flattening method combines the advantages of tilting printing methods such as smooth discharge and flattening of the scraper to achieve voids reduced and layer thickness ensured. As a result, the proportion of matrix in the product significantly reduced to 54.67%. According to the distribution of carbon fiber and matrix in the product, the flattening method is the better one compared to the other tested methods.