Nets have been constructed by human beings since at least the Mesolithic period for use in capturing or retaining things. Their open structure provide lightness and flexibility that allow them to be carried and manipulated with relative ease, making them valuable for methodical tasks such as hunting, fishing, sleeping, and carrying.

Definition

A net, in its primary meaning, comprises threads or yarns knotted and twisted into a grid-like structure which blocks the passage of large items, while letting small items and fluids pass. It requires less material than something sheet-like, and provides a degree of transparency, as well as flexibility and lightness.

History

The oldest nets found are from the Mesolithic era, but nets may have existed in the Upper paleolithic era. Nets are typically made of perishable materials and leave little archeological record. Some nets are preserved in ice or bogs, and there are also clay impressions of nets.

Making and repairing nets

Originally, all nets were made by hand. Construction begins from a single point for round nets such as purse nets, net bags, or hair nets, but square nets are usually started from a headrope. A line is tied to the headrope at regular intervals, forming a series of loops. This can be done using slipped overhand knots or other knots, such as clove hitches. Subsequent rows are then worked using

sheet bend The sheet bend (also known as becket bend, weaver's knot and weaver's hitch) is a bend. It is practical for joining lines of different diameter or rigidity. It is quick and easy to tie, and is considered so essential it is the first knot given ...

s, as shown in the diagram, or another knot. Some nets, such as hammocks, may be looped rather than knotted. To avoid hauling a long length of loose twine through each knot, the twine is wound onto a netting shuttle or netting needle. This must be done correctly to prevent it twisting as it is used,Netting instructions
/ref> but makes net production much faster. A gauge – often a smooth stick – is used to keep the loops the same size and the mesh even. The first and last rows are generally made using a half-size gauge, so that the edges of the net will be smooth. There are also knot-free nets. Some nets are still shaped by their end users,Net making
(and repair) guide for commercial fishing nets. although nets are now often knotted by machine. When a hole is ripped in a net, there are fewer holes in it than before the net was ripped. However, the stress concentration at the edges of the hole often causes it to tear further, making timely repairs important. Mending nets by hand is still an important skill for those who work with them.

Materials

Nets may be made using almost any sort of fiber. Traditional net materials varied with what was locally available; early European fishing nets were often made of linen, for instance. Longer-lasting synthetics are now fairly universal.

Nylon Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from pet ...

monofilament nets are transparent, and are therefore often used for fishing and trapping.

Structural properties

Nets, like fabric, stretch less along their constituent strands (the "bars" between knots) than diagonally across the gaps in the mesh. They are, so to speak, made on the bias. The choice of material used also affects the structural properties of the net. Nets are designed and constructed for their specific purpose by modifying the parameters of the weave and the material used. Safety nets, for example, must decelerate the person hitting them gradually, usually by having a concave-upwards stress–strain curve, where the amount of force required to stretch the net increases the further the net is stretched.

Uses

Transport

Examples include

cargo net A cargo net is a type of net. It is usually square or rectangle, but sometimes round, made of thick rope, with cinch ropes extending from the corners, and in some designs, the edges. It is named for its use in transferring cargo to and from sh ...

s and net bags. Some vegetables, like onions, are often shipped in nets.

Sports

Nets are used in sporting goals and in games such as

soccer Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 players who primarily use their feet to propel the ball around a rectangular field called a pitch. The objective of the game is ...

basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (appr ...

, bossaball and

ice hockey Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an ice skating rink with lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two opposing teams use ice ...

. A net separates opponents in various net sports such as

volleyball Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules. It has been a part of the official program of the Sum ...

tennis Tennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball cov ...

badminton Badminton is a racquet sport played using racquets to hit a shuttlecock across a net. Although it may be played with larger teams, the most common forms of the game are "singles" (with one player per side) and "doubles" (with two players p ...

, and

table tennis Table tennis, also known as ping-pong and whiff-whaff, is a sport in which two or four players hit a lightweight ball, also known as the ping-pong ball, back and forth across a table using small solid rackets. It takes place on a hard table div ...

, where the ball or shuttlecock must go over the net to remain in play. A net also may be used for safety during practice, as in

cricket Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by st ...

Capturing animals

Nets for capturing animals include fishing nets, butterfly nets, bird netting, and trapping nets such as purse and long nets. Some, like mist nets,

rocket net Rocket nets and cannon nets are types of animal traps used to trap many live animals, usually birds, but they also have been used to catch large animals such as various species of deer. Rocket nets, cannon nets, and other net launching devices ar ...

s, and netguns, are designed not to harm the animals caught. Camouflage nets may also be used.

Furnishings

Hammocks,

safety net A safety net is a net to protect people from injury after falling from heights by limiting the distance they fall, and deflecting to dissipate the impact energy. The term also refers to devices for arresting falling or flying objects for the ...

s, and mosquito nets are net-based. Some furniture includes a net stretched on a frame. Multihull boats may have net trampolines strung between their hulls.

Clothing

Hair nets, net lace, and net embroidery are sartorial nets.

Armed conflict

Anti-submarine nets and anti-torpedo nets can be laid by net-laying ships.

References

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