braid (also called plait) is a complex structure or pattern formed by intertwining three or more strands of flexible material such as textile fibres, wire, or human hair. Compared to the process ofweaving a wide sheet of cloth from two separate, perpendicular groups of strands (warp and weft), a braid is usually long and narrow, with each component strand functionally equivalent in zigzagging forward through the overlapping mass of the others.
The simplest possible braid is a flat, solid, three-strand structure in some countries/cases called a plait. More complex braids can be constructed from an arbitrary (but usually odd) number of strands to create a wider range of structures: wider ribbon-like bands, hollow or solid cylindrical cords, or broad mats which resemble a rudimentary perpendicular weave.
Braids are commonly used to make rope, decorative objects, and hairstyles (also see pigtails, French braid). Complex braids have been used to create hanging fibre artworks.
Braiding is also used to prepare horses' manes and tails for showing, polo and polocrosse
Braiding creates a composite rope that is thicker and stronger than the non-interlaced strands of yarn. Braided ropes are preferred by arborists, rock climbers and in sport sailing because they do not twist under load, as does an ordinary twisted-strand rope. These ropes consist of one or more concentrictubular braided jackets surrounding either several small twisted fibre cords, or a single untwisted yarn of straight fibres, and are known as Kernmantle ropes.
In electrical and electronic cables, braid is a tubular sheath made of braided strands of metal placed around a central cable for shielding againstelectromagnetic interference. The braid is grounded while the central conductor(s) carry the signal.
Another use is for litz wire which uses braids of thin insulated wires to carry high frequency signals with much lower losses from skin effect or to minimiseproximity effect in transformers.
Flat braids made of many copper wires are also sometimes used for flexible electrical connections between large components. The numerous smaller wires comprising the braid are much more resistant to breaking under repeated motion and vibration than is a cable of larger wires.
Similar braiding is used on pressurized rubber hoses, such as in plumbing and hydraulic brake systems in automobiles. Braiding is also used for fibres for composite reinforcements.
A property of the basic braid is that removing one strand unlinks the other two, as they are not twisted around each other. Mathematically, a braid with that property is called a Brunnian braid.
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