Braiding structures

Figure 33. Braided structures (diameter 330 nm, pitch 980 nm) formed by [d08a)4Cu]. Transmission electron micrograph without staining on a formvar-coated copper grid bar, 147 nm. Inset, overview of extended structure. Reproduced from ref. 326 with kind permission.

Tondu B, Emirkhanian R, Mathe S, Ricard A (2009) A pH-activated artificial muscle using the McKibben-type braided structure. Sens Actuators A 150 124... 

A variety of shapes can be fabricated for composite applications, from hollow tubular (with in-laid, non-interlaced yams) to solid sections, including I-beams. Unlike woven fabrics, braided structures can be directly laid on a three-dimensional mandrel by passing it through the braiding ring (Fig. 1.6) and hence producing seamless, near-net shapes. For example, aircraft propeller blades are produced by using this... 

A glass composition which was found particuiarly suitable for these applications [67] contained 52% SiOs, 30% Na20,15% CaO and <3% P2O5 (in mole %). Fiber bundles or tow of up to 5000 filaments were drawn from a melt of this composition and were interwoven with carbon fiber tow into a cylindrically braided sheath/core textile preform. The carbon fibers formed the core of the braided structure and provided the required stiffness and load support, and the bone bioactive fibers formed the sheath and functionality. 

Fujita A, Hamada H, Maekawa Z, Uozumi T, Okauji T, Ohno E, I-beam composites with three-dimensional braiding structure- fabrication and mechanical properties. Proceedings, TexComp-2, Leuven, Belgium, May 17-19, 1994. 

Biaxial braid n. Braided structure with two yarn systems one running in one direction and the other in the opposite direction. 

Triaxial braid n. A braided structure with axial yarns running in the longitudinal direction. 

Illustration of braided structures (a) 1/1, (b) 2/2, (c) circular braid without core, (d) circular braid with core and (e) idealized geometry showing factors, braid angle a and pick spacing x, which affect mechanical properties of braids. 

Rawal A, Potluri P and Steeleand C (2005), Geometrical modelling of the yarn paths in three-dimensional braided structures ,/ Tec/z Text, 35(2), 115-135. 

In principle, woven, knitted or braided structures could also be prepared as natural fiber/PP-composites. But the higher manufacturing costs do not justify the use of these fabrics. The main reason for this is that natural fiber containing composites are low-tech and low-cost products nowadays. 

McConnell, R.F., Popper, P., 1988. Complex shaped braided structures. US Patent 4,719,837. 

Figure 7.1 shows possible applications of the bifurcated braided structure (Chou and Ko, 1989 Chouinard and Peiffer, 2003). 

Figure 7.23 shows solid braids with various solid cross-section geometries. These braid structures have been developed based on a simulation of the Ist-generation braiding process developed at AFML at the University of British Columbia. 

Interlacing density shall be maximized to achieve a stronger dimensional stability of the braided structure (Figure 7.28). Interlacing density of a 2D braid is defined by the intersection repeat. The 2D braid with maximum interlacing draisity is the diamond braid with a 1/1 intersection repeat, that is, the yam continuously passes over one yam and then under one yam Handbook of Industrial Braiding). 

The power assist glove from Okayama University, Japan, comprises six pneumatic mbber (possibly based on braided structures) muscles secured to an ordinary glove (Sasaki et al., 2004). The muscles achieve approximately 20 N, which is sufficient to interact with objects in daily life. Some studies show the possibihty to use PAM to design devices for walking assistance (Kanno et al., 2015) or low back support (Li et al., 2013). Of course, it is possible to propose an entire wearable device like the Muscle Suit from Tokyo University (Kobalob). The main interest in this is that this muscle suit is wearable and does not consist of a metal frame with artificial muscles. The suit is only attached to the body with a belt and Velcro. 

Fig. 3.10 Schematic diagram of braided structures Q ft) SEM photomicrograph of a braided silk suture (right) [7]...

Figure 13.4 (a) Optical images of a coiled fibre made by twist insertion into a 300 xm diameter nylon-6,6 fibre, a two-ply muscle made of the coiled fibres of (a), the braided structure made of 32 two-ply coiled nylon fibres made from a 100 pm diameter precuror fibre, and a 1.55 mm coil made from a 300 pm diameter precursor nylon fibre by twist insertion followed by mandrel coiling, (b) Optical images of coiled nylon-6,6 (300 pm) before and after heating, (c) Tensile actuation of coiled fibres as a function of the temperature. Inset shows the same data for untwisted fibres. 

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