Development of a highly various warp yarn manipulation system for the fabrication of 2D net-shape non-crimp-fabrics for highly material efficient concrete reinforcements

Textile reinforcements have revolutionized many industries, most of all aerospace, automotive and building. Due to its high performance and the significant increased lightweight potential, they have established themselves as an efficient and sustainable alternative to conventional materials. However, in view of the increasing demand of an ever growing population in contrast to a scarcity of resources and urge of material efficiency in the face of climate change, novel technologies for highly material efficient products in large-scale productions are required. In this regard, a major research field involves the multiaxial warp-knitting technique for the production of high performance textile preforms. In several steps, this technology has been further developed to enable the production of application-specific and bionic-inspired textile preforms, which are characterized by a force compliant and multi-material design. Yet the structural possibilities are still limited. This article presents a novel developed warp yarn manipulation system for multiaxial warp-knitting machines. The system enables the fabrication of 2D net-shape non-crimp-fabrics (NCF) made of up to 16 single warp yarns that specify by an alternating diagonally offset and overlapping edge-strand. This structure is suitable for the use as textile lattice girder for reinforcing concrete slab structures Hereby the developed warp yarn manipulation system allows highly various structural parameters of the 2D net-shape NCF for highest material efficiency and product variety. The technological development is discussed in means of the constructive and electronic control design as well as a specific application example for new net-shape reinforcement structures.