Braided reinforcement

Reprinted from Naik, et al. J Composite Mater 1994 28 656-681, with permission from Technomic Publishing Co., Inc, copyright, 1994.  

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 

The potential complexity of the braided shucture, particularly the three-dimensional architectures, is such that the characterisation of the structures is often taken to be a major first step in modelling the behaviour of the reinforced material. The desired outcome of this work is to present a three-dimensional visualisation of the structure (e.g. Pandey and Hahtf ) or to develop models to describe the structural geometry (e.g. Du et aV ). Analytical models for predicting properties are frequently developments 

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Machine-made hose with braided reinforcement, vulcanised in a lead sheath. It is available in lengths up to 500 ft, compared to the comparatively short lengths of hand-made hose. See Braided Hose and Lead Moulded Hose. 

Braiding is another old textile technique and is a very good choice for tubular structures [14]. Braids are commercially available in diameters up to about 300 mm and with different types of fibers. The price of braided reinforcements is higher than would be expected based on the potential for automation. The most probable cause for the high price is the present low production volume. 

New materials and manufacturing techniques have been used to minimize the problem of drag and friction that occurs with heavy umbilicals. Tufflite, a surface diving umbilical, combines the strength of its rope-like cabled lay-up with kink resistance and neutral buoyancy that allows improved maneuverability and lower drag. Tufflite is based on textile braid reinforced polyurethane (PU) hoses for gas and air supply and has a color-coded outer sheath of abrasion-resistant PU. 

Brabender plasticorder flow See test, Brabender plasticorder rheometer melt-flow, brackish water See water, brackish, braiding See fiber braided reinforced-plastic pul-trusion, braided. 

Fiber braided/directional Weaving fibers into a tubular shape. As an example, A8cP Technology, Cincinnati, OH, specializes in developing braided reinforcements using a variety of material types, braid forms, and braid architectures for applications ranging from prostheses to... 

Eurocarbon BV, Sittard, Netherlands—manufacture carbon fiber woven tapes, fabrics and braided reinforcements. 

Four-dimensional braid n. A type of braided reinforcement used to achieve specially directed strength and resistance to interlaminar shear, often involving mixed fibers of different materials. 

Nylobrade, Braid reinforced PVC hose. New Age Industries Inc., Plastics Technology... 

Urebrade, Braid reinforced polyurethane hose, NewAge Industries Inc., Plastics Technology Group... 

In addition to the common roving strands, raw material is available in many other forms, such as preimpregnated (prepreg) and wet systems, mats (paper and nonwovens), woven specialties with knit and braided reinforcement, multiple-ply broad goods, core materials as they apply to automation, fillers, extenders, and additives (films, coatings, plating, etc). The characteristics of the reinforcement must be familiar to the machine designer. 

With respect to the laminates as a structural material, regardless of the type of reinforcement, there are known some behaviour characteristics during the mechanical loading of laminates. Composites with woven reinforcement demonstrate (Dauda et al. 2009) a linear relationship between stress and deformation. Whereas the reinforcement of laminates in the form braided reinforcement show a non-linear dependence is determined by an angle of orientation of the fibre bundles with respect to the axis of symmetry. The increase in flexural strength and modulus values affects the volume fraction of fibres in the composite volume, and the surface density of the strengthening. 

NOTE Thermoplastic nylon tube may have braid reinforcement or color difference between cover and inner tube. Exposure of second color is an out-of-service condition. 

So far, the bulk of literature has concentrated on characterizing the mechanical properties of both thermosetting- - - and thermoplastic-based - knitted composite materials. The modeling of the mechanical properties (mainly stiffness and tensile) has also been popular. However, limited literature exists on the forming property characteristics of knitted fabric-reinforced thermoplastics - and their processing properties are still poorly understood. In fact, most of the literature on forming properties deals with unidirectional, - mostly woven and, to a lesser extent, braided reinforcements, rather than knitted reinforcements. 

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