Knitted fabrics are created by intermeshing loops of yarns using knitting needles. Depending on the direction in which the loops are formed, knitted fabrics may be broadly categorized into two types—warp knitted fabrics and weft knitted fabrics. By controlling the loop (stitch) geometry and density, a wide variety of knitted fabrics can be produced. Because of the looped structure, the maximum fiber volume fraction of knitted fabric composites is lower than that of the woven or braided fabric composites. Generally, weft knitted fabrics are less stable and, hence, stretch and distort more easily than warp knitted fabrics; thus they are also more formable. Owing to their looped structure, the knitted fabrics are more flexible than the woven or braided fabrics. In order to enhance the mechanical properties, straight yarns can be integrated into the knit loops. In this way, fabric can be tailored for stability in certain directions and conformability in other directions.
