Thermoplastic composites from curvilinear 3D multi-layer spacer fabrics

This article reports on the development of thermoplastic composites using innovative curvilinear 3D multi-layer flat knitted spacer fabrics produced by single stage manufacturing. Thermoplastic composites from textile-based, complex-shaped sandwich preforms, for instance, curvilinear-shaped 3D multi-layer spacer fabrics show great potential for lightweight applications. Faster production time and reduction of waste can be achieved by single stage manufacturing of such 3D textile preforms. Spacer-shaped 3D textile preforms were developed using commingled hybrid yarns made of GF and PP filaments. This 3D spacer fabric was consolidated to 3D composite using the developed mechanical tools. In order to predict the mechanical performance of 3D composites, mechanical properties of reinforcement yarns unraveled from 3D spacer fabrics, 2D knit fabrics, and 2D composites using the 2D knit fabrics produced in the same manner as the individual layers of 3D spacer fabrics were studied. The results are promising for applications in high-performance composites.