New nozzle cap to improve interlaminar strength of 3D-printed continuous carbon fiber composites

Abstract

A new 3D printer hardware with coaxially arranged twin nozzles was developed to print continuous and short-fiber filaments. The short-fiber nozzle used a screw and pellets instead of filaments, and a hole was drilled at the center of the screw to print continuous fibers. The new coaxial 3D printer showed a 7% void area and low strength in the lay-up direction. Thus, in this study, a novel nozzle cap was designed to improve the performance of the aforementioned 3D printer. The nozzle cap transferred heat from the heat block to the printed path by extending the rim area of the nozzle edge. Printing tests were performed, and the void ratio was reduced to 2%. Interlaminar shear test results indicated that the interlaminar strength improved by 2.3 times.