## 4 Discussion  
Table 3 displays the ILSS-test data for all the different kinds of sample, along with their processing-pressure settings, FVFs, void contents, processing times, and CNF-z-thread concentrations in the matrix. In terms of the composite-laminate manufacturing-method comparison, the MCFA-AM 3D-printing method delivered laminates with comparable ILSS and void contents to those in the laminates produced by the OOA-VBO process, despite the use of the ZT-CFRP prepreg or the traditional CFRP prepreg. It seems that the localized magnetic compaction pressure and the in situ curing applied during the MCFA-AM 3D-printing process was very effective in ensuring that the void content was similar to that in the OOA-VBO process; hence, both processes resulted in similar ILSS values. On the other hand, as expected, the no-pressure-3 DP samples, representing typical 3D-printing processes (such as the FDM), showed substantially inferior void contents (23.94%) and ILSS values (53.99 MPa) compared with the void content (1.06%) and ILSS (62.60 MPa) of the control CFRP/OOA-VBO samples. The no-pressure-3 DP samples were also substantially inferior to the CFRP samples printed by MCFA-AM, whereas the CFRP/MCFA-AM samples had a void content of 1.36% and an ILSS of 62.83 MPa. Based on Table 4, the use of proven advanced nanomaterials, such as the ZT-CFRP, as the prepreg in the production of composite laminates was found to be a highly effective and consistent method to improve the ILSS. The ZT-CFRP laminates, regardless of the manufacturing methods used, consistently outperformed the traditional CFRP laminates; the improvements in the ILSS due to the use of the ZT-CFRP prepreg to replace the traditional CFRP prepreg, were about 12.8% and 10.97% when manufacturing the laminates with the OOA-VBO process and with the MCFA-AM 3D-printing process, respectively. Furthermore, the ZT-CFRP samples, regardless of whether they were manufactured by OOA-VBO or MCFA-AM, consistently showed tension-failure mode during the short-beam shear (SBS) test, rather than the interlaminar-shear-failure mode. This indicated that the ZT-CFRP was very effective in preventing interlaminar shear failure, and the ILSS value could have been higher if the tension-failure mode had been delayed or prevented, before the interlaminar-shear-failure mode occurred, by using stronger carbon fibers or by modifying the SBS-test fixture and sample dimensions to reduce the local stress concentration near the center of the short-beam sample. Figure 22: Comparison of void contents of all laminate types by different manufacturing methods. Figure 23 depicts the parameters that contributed to the improved ILSS in this study. Using a higher compaction pressure to reduce the void content and applying advanced nanocomposites, such as the ZT-CFRP, when combined appropriately, can provide synergetic effects with which to improve the ILSS of composite laminates. Regarding the convenience, manufacturing speed, and cost, the MCFA-AM 3D-printing process has significant advantages over the OOA-VBO molding process. As shown in Table 4, the time taken to manufacture a composite laminate using the OOA-VBO molding process was about 120 min, and this process also requires the use of aluminum molding, along with many consumables, such as vacuum bags, tubing/vacuum channels, peel plies, distribution media, and sealant tape (see Figure 4). On the other hand, the time taken to print a composite laminate using the MCFA-AM was about 45 min, and this method does not require the use of consumables or molds. The production time saved by using the MCFA-AM process is about 62.5%; the production speed when using the robotic MCFA-AM is about 2.67 times faster than that in the OOA-VBO process. The cost savings in terms of consumables and labor when using the robotic MCFA-AM printing process to replace the commonly used OOA-VBO molding process are also very extensive.