Development and mechanical properties of three-dimensional flat-knitted fabrics with reinforcement yarns

Abstract

Three-dimensional (3D) flat-knitted fabrics have become a topic of interest in the field of composites in recent years because of the growing need for rapid preparation of complicated shape preforms. In order to improve the mechanical properties of 3D flat-knitted fabrics, two types of 3D flat-knitted fabrics with reinforcement yarn (FKFR) were developed using ultra-high molecular weight polyethylene (UHMWPE) yarn. Their basic structures were composed of plain structure and interlock structure with tuck stitch, respectively, and the reinforcement yarn was integrated into the fabric as the weft inlay. The tensile, bending, drape, and bursting properties of the two fabrics were characterized. Results showed that the basic structure of the fabric has impacted on the mechanical properties of the fabric significantly. The tensile and bending properties of the fabric with interlock structure were better than that of the fabric with plain structure. During the transverse stretching process, the surface structure of the fabric with interlock structure was more stable. Moreover, transverse yarn strength utilization of the fabric with interlock structure was 1.05, which reached the level of ordinary woven fabric. In addition, the bursting force of the fabric with excellent tensile properties was lower than that of the fabric with a plain structure because the latter has better extensibility.