*4.2.4.3. By 2-step braiding method*

produce thick tubular structures and also has the potential for other geometries with a mandrel. Similar 3D axial braiding machine based on maypole method was also developed by Japan as

**Figure 33.** Schematic view of 3D circular axial braiding based on maypole method [9].

**Figure 34.** (a) 3D circular braiding by maypole method [94] (b) another type 3D axial braiding machine from Japan

Figure 35 shows the required matrix setting for braider carriers and axial yarns so as to form a 3D fabric having 1×1 pattern. The steps involved are the following: The first step is sequential

shown in Figure 34 [95].

108 Non-woven Fabrics

*4.2.4.2. By 4-step braiding method*

[95].

In this method, the cross sectional geometry of the fabric determines the matrix setting of axial yarns. Braider yarns travel diagonally along the matrix arrangement and lock the axial yarns so as to form the required shape. Each braider carrier makes two distinct motions [12, 96]. The process demands relatively fewer braider yarns to impart directional reinforcement. Since the number of braider carriers is reduced, the process can easily be automated. It is possible to produce various shapes such as T, H, TT and bifurcated fabrics [12]. Mc Connell and Popper developed a 3D axial braided fabric [74]. The machine comprises a machine bed, an axial unit, a braider carrier, and a compaction unit. The preform consists of layered and axial yarns. The shape of the cross section determines the positioning of axial yarns. Braider yarns are inter‐ twined and oriented in bias directions along the thickness and the surface of the preform. They travel between the axial layers across the row and column direction. The braid carrier travels about the axial unit depending on a pre-defined path to make two distinct cartesian motions for creating braider type interlacements. The axial unit feeds the axial (0˚) yarns in the machine direction. The final preform is formed by the compaction unit (Figure 36).
