3D Printing Cycle Extension of Low-Temperature Curing Composites

During the 3D printing process of low-temperature curing continuous fiber-reinforced thermosetting polymer composites (CFRTPCs), the resin in the print nozzle may be completely cured. The printing cycle will be quite short as the print nozzle is blocked, and hence the printing process will be interrupted. This paper intends to extend the 3D printing cycle of the low-temperature curing CFRTPCs by 3D printing platform design and 3D printing process optimization. F-44/E-20/2E4MZ (FEM) resin was chosen as the matrix phase, and continuous carbon fiber (CCF) as the reinforcement phase of CFRTPCs. The feeding module of the 3D printing platform was designed by adopting the method of pressure extrusion of the resin matrix after heating and melting. According to the power law of non-Newtonian fluid characteristics of FEM matrix resin, a physical prediction model of the flow rate and extrusion volume of FEM matrix resin was established based on the analysis of the simplified model of pressure extrusion process. Therefore, the feeding rate was controlled based on the matched printing speed. Comparison experiments showed that the printing cycle of CCF/FEM was extended from 35.49 to 75.10 min, increased by 111.6%.