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Lightweight panels are of high relevance for various applications, such as automotive, aerospace, civil engineering, and achieve high stiffnesses and strengths at low self-weight. The sandwich principle is commonly used to manufacture the panels, although conventional materials and reinforcement structures often limit the design and application of the panels in a wide range of possible applications. The reason for this is that lightweight panels fail either under combined compressive/shear loading or as a result of delamination of the individual layers. In this article, novel fabric structures are presented as a basis for the fabrication of lightweight panels that effectively overcome these deficiencies. These fabrics have a spatial truss-like structure, with the core and top layer being connected by continuously running reinforcing fibers. This results in high panel stability and high delamination resistance, which are evaluated in this article using mechanical tests in compression, flexure and combined tension-shear. The results are related to sample panels with conventional honeycomb core as reference. The high potential and excellent delamination resistance of the new fabric-based lightweight panels is shown in the result of the tests. [ABSTRACT FROM AUTHOR]

Three-dimensional fabrics have an enormous potential for the manufacturing of semi-finished products in a direct preforming procedure for fiber-reinforced materials. The production of these three-dimensional fabrics involves the processing of coarse reinforcing yarns with high warp density. However, conventional weaving looms have not been designed for such applications, and their maximal achievable warp yarn density is therefore severely limited. Friction and clamping between warp yarns impede the shedding process, and fragments of damaged or fibrillated fibers interfere with the weaving process. Most of the solutions for these issues, which has been presented so far, are based on noncommercial technologies or require extensive modification on standard weaving machines. Hence this paper proposes a new shedding method based on double flat steel heddles, which is suitable for the use in conventional weaving looms. The paper gives a detailed description of the new shedding method including the required materials and the technological framework. Furthermore, a suitable algorithm for the fast pattern conversion under consideration of the special technological framework and requirements of the shedding is presented. [ABSTRACT FROM AUTHOR]

Woven spacer fabrics are used as reinforcing materials for fiber-reinforced plastics. These fabrics consist of mostly pliable textile fibers, which still require defined rigidity for different crash applications. In this regard, multi-material woven spacer fabrics present a promising approach. This paper presents the development of multi-material woven spacer fabrics using steel wire and carbon rovings. For the development of such woven spacer fabrics, a systematic structure realization based on the weave pattern was performed. Selected structures were produced on a modified weaving machine. [ABSTRACT FROM AUTHOR]

Manufacturing of thermoplastic composite based on textile preforms made from hybrid yarns is well suited for the production of fiber-reinforced plastic (FRP) in medium- and large-scale production runs. Especially, the consolidation of thermoplastic FRP is currently complicated by the high viscosity of molten material. Woven multilayered and z-reinforced NCF-preforms are very interesting for FRP supposed to withstand three-dimensional loading and impact stress. These preforms with z-directional reinforcement improve the FRP delamination behavior and out-of-plane characteristics. The well-known composite parameters are essential to ensure the use of these materials in a wide range of applications. [ABSTRACT FROM PUBLISHER]

Weaving technique offers a large potential for the highly productive manufacture of woven 3D-preform structures in lightweight applications. This research work reports on the technological modification to the construction of a double-rapier weaving machine for the low damage production of double-walled shell structures made from glass/polypropylene hybrid yarn multilayered woven fabrics. On this basis, 3D-woven preform structures with integrated stiffeners in the longitudinal and transverse directions for high composite strength and rigidity within a single weaving process were developed and implemented.Furthermore, textile engineering solutions were acquired for the required reinforcement of the gusset area between the stiffener and the skin. This broadens the range of uses for large-scale fiber-reinforced plastics with integrated stiffeners made from 3D-woven preform structures. [ABSTRACT FROM PUBLISHER]

Abstract: An innovative weaving technology for the manufacturing of 3D woven double-walled spacer fabrics from high performance hybrid yarns was developed and implemented. Based on the gained technical and technological experience the woven multi-layered structures with load-oriented non-crimp fiber arrangement are realized and improved for high preform stiffness and a reproducible manufacturing. The article provides an overview of the technology for weaving of 3D spacer preforms in one production step with the required machine modifications. Furthermore the advantages of multi-layered woven fabric as well as the development of special pattern to forming and stiffening of the critical areas (joint areas) will be presented. [Copyright &y& Elsevier]

This article focuses on the improved strength and stiffness of woven three-dimensional (3D) spacer fabrics used in fiber-reinforced plastics. The spacer fabrics were manufactured using E-glass/polypropylene (GF/PP) hybrid yarns and are intended for lightweight engineering applications. The two-dimensional (2D) woven fabrics used for the outer layers of 3D spacer fabrics were produced from GF/PP hybrid yarns with different yarn alignments and weft densities. Furthermore, the implemented hybrid yarns and the 2D composites constructed of multi-layer fabrics were tested for mechanical properties. The processing of the GF/PP hybrid yarn, as well as the geometry of the woven fabrics, is proven to strongly influence the mechanical properties of the end composites. Multi-layer fabrics can be used for manufacturing woven 3D spacer fabrics with minimal yarn damage and high mechanical properties. [ABSTRACT FROM PUBLISHER]

In this article, the development of the two spacer fabrics on flat knitting machine is described. These fabrics have two outer surfaces connected together with U and V shaped knitted cross-links which are particularly developed for the light weight applications. [ABSTRACT FROM AUTHOR]

The ORW weaving technology by Lindauer Dornier GmbH, Lindau/Germany, offers new perspectives for the manufacture of grid-like as well as thick non-crimp woven reinforcement fabrics from coarse high-performance yarns. Thanks to the adjusted warp-guiding system modified at the Institute of Textile Machinery and High Performance Material Technology (ITM) at TU Dresden/Germany, the damage to the heavy tow carbon fiber during the weaving process could be significantly reduced, while the range of processable different yarn counts was increased. This opens up the possibility to weave a wide variety of reinforcement structures for construction or synthetic materials at reduced damage. At the ITM a reliable processing of assembled carbon fibers with up to 6,600 tex for woven reinforcement fabrics was established. [ABSTRACT FROM AUTHOR]