Abstract: To address the issue of significantly higher resin content in the lower layer than in the upper layer during vacuum-assisted molding of three-dimensional hollow fabrics, a resin sustained-release technology was designed. A resin sustained-release layer was placed above the fabric and the release cloth, and carbon fiber hollow fabric composites with heights of 5 mm and 8 mm were prepared respectively. The resin content and mechanical properties of the upper and lower layers of the composites were tested and analyzed. The results show that the resin sustained-release technology can effectively alleviate the problem of uneven resin content between the upper and lower layers of carbon fiber hollow fabrics. For the 5 mm sample, the difference in resin content between the upper and lower layers was reduced from 6.9% to 2.5%; for the 8 mm sample, the difference was reduced from 6.4% to 3.3%, and the uniformity of resin content distribution in the upper layer was simultaneously improved. Concurrently,as the difference in resin content decreased, the tensile, bending, and impact mechanical properties of the composites all improved.

Key words: carbon fiber hollow fabric composite, resin content, vacuum assisted molding process, resin sustained-release process