UD fabrics

The superior performance of UD structure over woven structure has been described in many publications. According to Scott, around 30% improvement in either weight or performance has been observed in both flexible armour and hard composites. Lee et al. ° found that the ballistic limit for angle-phed laminates gives a higher value than the woven fabric-based composites, as the density of the panels increases. It has also been established that a 100% UD fabric panel absorbs 12.5-16.5% more energy than a 100% woven fabric panel. ... 

Stitch bonding can be used to hold together an assembled warp or weft UD fabric. To confer adequate stability, a mat or tissue is usually placed on the fabric prior to stitching. 

Figure 21.4 Non-woven UD fabric with adhesive bonding strips. Source Reprinted from SP Systems, Newport, low, technical data with kind permission.

Figure 23.57 XXsys Technologies corrosion retrofit process (part B). (f) Manual application of UD fabric, (g) Adhesive is applied to concrete prior to UD fabric being applied to lower cap beam with adhesive applied between layers, (h) Robo curing system (55 kWm ), (i) Curing process in operation (2 h), (j) Application complete. Cap beam retrofit and column retrofit. Source Courtesy of XXsys Technologies Inc., San Diego.

Composite forming processes based on woven, braided or UD fabric or by pultrusion, filament winding etcetera. 

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