Three-dimensional composite manufacturing processes

Abstract There are several definitions of 3D fabrics. Most common is the definition of Roye: “A fabric can be called 3D fabric, when the textile structure features three dimensions in space, independently of the manufacturing technique” ( Roye et al., 2005 ). Overbraiding and 3D braiding technology offer diverse opportunities to manufacture near net-shape preforms. The radial overbraiding machine consists of a braiding ring and a robot support for the take-up of the braid and the handling of mandrels that are to be overbraided. The 3D rotary braiding technology enables a flexible production of 3D braids. Moved by horn gears, the bobbins can be directed to every position on the machine plate guided by tracks and switches. Therefore, a huge range of different yarn architectures can be realised on this 3D braiding machine. The second topic of the chapter deals with 3D woven structures. Generally, one can differentiate between fabrics woven on a 3D-weaving loom and 3D fabrics woven on a conventional weaving loom, which have fibre orientations in three directions. 3D woven fabrics are produced near–net-shaped and can be grouped into multilayer and profile shaped fabrics. The advantages of 3D fabrics are high delamination and crack propagation resistance, which leads to good impact and fatigue properties. Today’s research focuses on enhancing production technologies to increase fibre volume fraction and mechanical properties. Nonwovens can be also defined as 3D structures when they have properties and functionalities in three dimensions: namely, x, y, and z. The chapter explains in detail the various 3D structures and their manufacturing. Based on their manufacturing process and the final structure obtained, 3D nonwovens are classified as layer-based structures and free-form structures. Furthermore, the application areas of the 3D nonwovens are illustrated.