Non-crimp fabrics (NCFs), especially multi-axial warp-knitted fabrics, are used as reinforcement materials for fiberreinforced composites. The manufacturing of multi-axial warp-knitted fabrics by a conventional stitch bonding process to produce NCF has several disadvantages, such as filament damage, low production speed, yarn disorientation, etc. In order to overcome the existing limitations, the idea of using an adhesive binder to attach the fabric layers is a promising approach, so that the use of stitching yarns can be eliminated. The fundamental investigations presented in this paper show that the selection of the binder material has a major influence on the parameters of the textile products. Whereas the tested hotmelt adhesives offer a short curing time and a small but nevertheless sufficient bonding strength between bonded yarns, the tested reactive adhesives show a bonding strength up to 10 times higher, but at a considerably longer curing time. The reason for the different bonding strength is identified in the different penetration into the yarns. The experiments also show a significant influence of the fiber type and sizing, which needs to be taken into account when selecting fabric binders.

Carbon fiber (CF) must be protected from thermal oxidation for high temperature application because of its low thermo-oxidative stability above 450°C in air. CF is now increasingly being used as a reinforcing material in the construction industry. A thermal and oxidation resistant coating is necessary for CF-reinforced concrete (CFRC) composites in order to satisfy a high level of safety standard in the case of fire. New types of pre-ceramic coatings, such as Tyranno® polymer (Si–Ti based pre-ceramic) and SiO₂ sol–gel, have been deposited on CF filament yarn by means of a wet chemical continuous dip coating method. The results of surface analyses, e.g. scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy, showed the changes in topographical properties of CF caused by the coatings. Thermogravimetric analysis proved that the high temperature (up to 800°C) oxidation stability of CF was considerably improved due to the coatings. Tensile test results indicated that the strength of CF yarn at 20°C was increased by up to 80% with the coatings. Thermo-mechanical properties were also enhanced up to 600°C. CF yarn retains its original strength and elasticity modulus, i.e. the stiffness at 700°C, with a Tyranno® polymer coating.

Three-dimensional (3D) profiled woven fabrics with varying cross-sections along the component parts are needed in a number of industrial applications. One of the main advantages of the ribbon loom weaving technique is the ability to produce highly diverse structures with open or closed edges. The realization of 3D profiled woven fabrics that satisfy the requirements is directly connected to the ability to process high-performance fibers in the weft direction. The processing of high-performance yarns in the weft direction with low fiber damage will open new application areas for shuttle weaving machines. By employing modified mechanical loom elements, the variety of producible structures can be increased significantly.

This contribution will introduce carbon-reinforced concrete components (so-called carbon concrete composites, or C³) with sensor functionalities for innovative building envelopes. For a continuous in situ structural monitoring, these textile-reinforced concrete components are equipped with textile sensor networks consisting of resistive carbon fiber sensors (CFSs), which are integrated into the carbon fiber non-crimp fabrics of the concrete reinforcement by multiaxial warp-knitting. The in situ CFSs, consisting of 1 k or 50 k carbon fiber roving with added staple fiber/multifilament dielectric cladding, are later integral to the load-distributing elements of the concrete component, and elongations within these are easy to record with good correlation to ohmic resistance changes. Gage factors of k = 0.52–1.23 at linearity deviations of ALin=4.0–8.7% are feasible. This allows a monitoring of C³ building envelopes for structural mechanical changes caused by physical changes within the component through mechanical or thermal loads or deformation and cracks.

The new concept of a superconducting magnetic bearing (SMB) system can be implemented as a twisting element instead of the existing one in a ring spinning machine, thus overcoming one of its main frictional limitations. In the SMB, a permanent magnet (PM) ring rotates freely above the superconducting ring due to the levitation forces. The revolution of the PM ring imparts twists similarly to the traveler in the existing twisting system. In this paper, the forces acting on the dynamic yarn path resulting from this new technology are investigated and described with a mathematical model. The equation of yarn movement between the delivery rollers and the PM ring is integrated with the Runge-Kutta method using MATLAB. Thus, the developed model can estimate the yarn tension and balloon form according to different spindle speeds considering the dynamic behavior of the permanent magnet of the SMB system. To validate the model, the important relevant process parameters, such as the yarn tension, are measured at different regions of the yarn path, and the balloon forms are recorded during spinning with the SMB system using a high speed camera.

High-performance yarns such as aramid fibers are nowadays used to reinforce composite materials due to their advantageous physico-chemical properties and their low weight. They are also resistant to heat and fire. Para-aramid filament yarns (p-AFs) wound on a cylindrical dyeing package have been silvered successfully by means of a newly developed wetchemical filament yarn metallization process on a laboratory scale. The surface morphology of untreated and silvered p-AF was determined by means of scanning electron microscopy. The chemical structure of the surfaces (contents of carbon, oxygen, nitrogen and silver) was determined by means of energy-dispersive X-ray spectroscopy (EDX). The eliminated and newly formed groups of p-AF before and after silvering were detected by infrared spectroscopy (Fourier transform—attenuated total reflectance). After metallization, the silver layer thickness, the mass-related silver content and washing and rubbing fastness were assessed. Furthermore, textile-physical examinations concerning Young’s modulus, elongation at break and electrical conductivity were performed. Subsequently, the electrically conductive p-AFs were integrated in thermoset composite materials reinforced by glass fibers and para-aramid.

Structural frames have been established in many technical applications and typically consist of interconnected profiles. The profiles are commonly joined with node elements. For lightweight structures, the use of composite node elements is expedient. Due to the anisotropic mechanical properties of the fibers, high demands are placed on the orientation of the fibers in the textile reinforcement structure. A continuous fiber course around the circumference and at the junctions is necessary for an excellent force transmission. A special binding and forming process was developed based on the weaving technology. It allows the production of near-net-shaped node elements with branches in any spatial direction, which meet the requirements of load-adjusted fiber orientation. The principles by which these three-dimensional (3D) node elements are converted into a suitable geometry for weaving as a net shape multilayer fabric are reported. The intersections of the branches are described mathematically and flattened to a plane. This is the basis for the weave pattern development. Forming simulations on the macro- and meso-scales complement the analyses. A macro-scale model based on the finite element method (FEM) is used to verify the general formability and the accuracy of the flattenings. Since yarns are pulled through the textile structure in the novel forming process, the required tensile forces and the pulling lengths of the individual yarns are analyzed with a meso-scale FEM model. The flattening for two different node structures is realized successfully, and the simulation proves formability. Furthermore, the necessary forming forces are determined. Finally, the developed method for flattening the 3D geometry is suitable for the design of a variety of spatial node structures and the simulation supports the design of automated forming processes.

The integration of shape memory alloys (SMAs) into textile-reinforced composites produces a class of smart materials whose shape can be actively influenced. In this paper, Ni-Ti SMA wires are inserted during the weaving of a glass fiber reinforcement textile. This ‘‘active’’ reinforcement is then combined with an elastomeric matrix to produce a highly flexible composite sheet, which maintains high rigidity in the longitudinal direction. By activating the SMAs, high deflection ratios of up to 35% (relative to the component’s length) are achieved. To adjust the composite’s deflection to defined values, a closed-loop control is set up to adjust the current flow through the SMA wires. A control algorithm is designed and evaluated for several test cases. The high deformability and the controllable behavior show the high potential of these materials for applications such as aerodynamic flow control, automation and architecture.

The increasing need of consistent implementation of lightweight constructions in many technical fields makes the manufacture of near net-shaped node structure to be used in textile-reinforced composites a subject of great interest. The manufacture of the node structure is required to provide a strong node point whilst maintaining the circumference of each adjoining strut. Despite a variety of available methods to produce three-dimensional nodal fabric, the required geometry for the complex nodular connection element has not yet been fully achieved. Furthermore, the available methods have limitations. The developed woven concept in this work allows for maintaining the configuration of the node structure and dimensions of the tubes, especially at the node points. As a result, all tubes positioned at node points are fully open; this is accomplished without distorting the surrounding area once the flat woven node structure is removed from the loom and erected into three-dimensional configuration. In order to produce a three-dimensional structure on a conventional weaving machine, the structure must be flattened in an appropriate way. By using a mathematical algorithm, it is possible to graph the flattened structure precisely. The developed weaving concept and relating calculation are applied to create the weaving plan of the spatial nodal structures, which can be produced on a shuttle weaving loom. The developed concept in this paper will provide repeatable manufacturing of complex node structures by using the conventional weaving loom. The struts of node structures manufactured using this method can be woven at any angle and with spatial arrangements.

The field of articular cartilage tissue engineering has developed rapidly, and chitosan has become a promising material for scaffold fabrication. For this paper, wet-spun biocompatible chitosan filament yarns were converted into short flock fibers and subsequently electrostatically flocked onto a chitosan substrate, resulting in a pure, highly open, porous, and biodegradable chitosan scaffold. Analyzing the wet-spinning of chitosan revealed its advantages and disadvantages with respect to the fabrication of the fiber-based chitosan scaffolds. The scaffolds were prepared using varying processing parameters and were analyzed in regards to their geometrical and mechanical properties. It was found that the pore sizes were adjustable between 65 and 310 µm, and the compressive strength was in the range 13–57 kPa.