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33-404: Most bowstrings may be described as either simple, reverse-twisted, or looped. Simple strings may be made of any fiber , twisted into a single cord. Such strings have been used in many parts of the world and are still effective and fairly quick to make. However, they tend to be weaker for their weight, and they may also come apart if not kept constantly under tension. They are normally secured to

66-400: A line is to apply a multi-layered protection against chafe and deterioration to standing rigging . It is a technique not usually used on modern small boats, but is found extensively on traditionally-rigged sailing ships. Worming, parcelling and serving —referred to collectively as "service"— is traditionally applied only to traditional twisted rope, either natural fiber or steel wire-rope, not

99-416: A stay , where the chafe on the middle section of the stay precludes complete protection. "Worming" the line is designed to fill in the channels (the contlines ) between the strands in order to keep water out and to allow tighter, smoother wrapping of the next layers by giving the rope a more cylindrical shape. Lengths of "small stuff" or string are led along the lay of the rope between the strands, following

132-488: A fabric. Artificial fibers consist of regenerated fibers and synthetic fibers. Semi-synthetic fibers are made from raw materials with naturally long-chain polymer structure and are only modified and partially degraded by chemical processes, in contrast to completely synthetic fibers such as nylon (polyamide) or dacron (polyester), which the chemist synthesizes from low-molecular weight compounds by polymerization (chain-building) reactions. The earliest semi-synthetic fiber

165-467: A general aspect ratio (defined as the ratio of fiber length to diameter) between 20 and 60, and (ii) long fibers, also known as continuous fibers, the general aspect ratio is between 200 and 500. Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron. Carbon fibers are often based on oxidized and via pyrolysis carbonized polymers like PAN , but

198-695: A low number of surface defects; asbestos is a common one. Invented in Japan in the early 1980s, microfibers are also known as microdenier fibers. Acrylic, nylon, polyester, lyocell and rayon can be produced as microfibers. In 1986, Hoechst A.G. of Germany produced microfiber in Europe. This fiber made it way into the United States in 1990 by DuPont. Microfibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 denier). Denier and Dtex are two measurements of fiber yield based on weight and length. If

231-442: A mixture of tar, varnish and black paint. This needs renewing periodically, and going aloft to paint footropes , shrouds , stays , and other served rigging is one of the regular maintenance tasks on many tall ships . The tar, or "slush" is a mixture of Stockholm tar , boiled linseed oil, and Japan drier. Many "recipes" for slush exist, but the intent is always to allow a penetrating coat of preservative pine tar that then cures to

264-407: A modern recurve bow or compound bow , but are still effective and still used on traditional wooden or composite bows . Sinew and hide strings may be seriously affected by water. The author of Arab Archery suggests the hide of a young, emaciated camel. Njál's saga describes the refusal of a wife, Hallgerður, to cut her hair to make an emergency bowstring for her husband, Gunnar Hámundarson , who

297-417: A number of applications. This is because artificial fibers can be engineered chemically, physically, and mechanically to suit particular technical engineering. In choosing a fiber type, a manufacturer would balance their properties with the technical requirements of the applications. Various fibers are available to select for manufacturing. Here are typical properties of the sample natural fibers as compared to

330-678: A viscous mass and formed into fibers by extrusion through spinnerets. Therefore, the manufacturing process leaves few characteristics distinctive of the natural source material in the finished products. Some examples of this fiber type are: Historically, cellulose diacetate and -triacetate were classified under the term rayon, but are now considered distinct materials. Synthetic come entirely from synthetic materials such as petrochemicals , unlike those artificial fibers derived from such natural substances as cellulose or protein. Fiber classification in reinforced plastics falls into two classes: (i) short fibers, also known as discontinuous fibers, with

363-634: A woven, non woven or knitted structure. Fiber surfaces can also be dull or bright. Dull surfaces reflect more light while bright tends to transmit light and make the fiber more transparent. Very short and/or irregular fibers have been called fibrils. Natural cellulose , such as cotton or bleached kraft , show smaller fibrils jutting out and away from the main fiber structure. Fibers can be divided into natural and artificial (synthetic) substance, their properties can affect their performance in many applications. Synthetic fiber materials are increasingly replacing other conventional materials like glass and wood in

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396-429: Is often omitted from the process. The line is then "parcelled" by wrapping it in a spiral fashion with long overlapping strips of thin canvas. This is wound from bottom to top, the edge of the progressing strip slightly overlapping the previous wrap to create a shingled effect, to prevent water from entering. Often the strips of canvas are either saturated with Stockholm tar as they are applied, or painted with tar after

429-400: Is often used. A serving board or serving mallet can be used to help get the outer twine as tight as possible. Despite the name (arising from its shape) the serving mallet is not used to hit anything; it forms a kind of guide and tensioning lever for applying the twine to the rope. An optional final stage for the permanent protection of "served" rope is to paint the outer layer of twine with

462-412: Is the cellulose regenerated fiber, rayon . Most semi-synthetic fibers are cellulose regenerated fibers. Cellulose fibers are a subset of artificial fibers, regenerated from natural cellulose . The cellulose comes from various sources: rayon from tree wood fiber, bamboo fiber from bamboo, seacell from seaweed , etc. In the production of these fibers, the cellulose is reduced to a fairly pure form as

495-431: Is then killed. Widely used modern materials are stronger for their weight than any natural material, and most are unaffected by water. They include: Dacron (strength per strand = 22.5 kg (50 lb), stretch = 2.6%), a commonly used polyester material. Because of its durability and stretch, Dacron is commonly used on beginners' equipment, wooden bows, and older bows. The relatively high stretch causes less shock to

528-431: The 1990s. They are lighter, therefore faster, than Kevlar—and have a much longer life. Modern strings are often made from composite fibres—such as a mixture of Vectran and Dyneema—to gain the advantages of both. Serving a bowstring refers to the use of an additional thread, commonly wrapped round the main string at the nocking points where abrasion is most likely, and also used on looped strings to keep

561-431: The anchor cable from chafing through. This was not then covered with parcelling and serving, but is included here as a further example of the utility of the technique. On the rigging of modern small craft, where the cuntlines are not so deep as to leave large gaps beneath the parcelling (where moisture can become trapped and corrosion occur), or to create a facetted surface (as opposed to a smooth, round surface), worming

594-408: The bow by a knot /round turn and two half-hitches at each end. Reverse-twisted strings are traditional in Europe and North America for most natural materials. Linen and hemp fiber have been widely used. The form is also used for modern materials. A reverse-twisted string is made of separate bundles, each bundle individually twisted in one direction; the entire group of bundles is then twisted in

627-407: The bow by a knot at each end, usually a timber hitch , also known as the bowyer's knot. The traditional "Flemish" string has a laid-in loop at one end, which is easier than most knots to fit over the nock of the bow when stringing and unstringing. It is more trouble to make; the short length, towards one end, that will form the loop is reverse-twisted first. The ends of each bundle are then laid into

660-604: The bow, which is an important consideration for wooden-handled recurves. Dacron strings are easy to maintain and can last several years. Liquid crystal polymers such as Kevlar and Vectran (strength per strand = 31.8 kg (70 lb), stretch = 0.8%) are polymer materials with a higher density and smaller diameter than Dacron, which results in a faster arrow speed (approximately 2 metres per second (6.6 ft/s) faster). Ultra-high-molecular-weight polyethylenes , such as Spectra and Dyneema (strength per strand = 45.5 kg (100 lb), stretch = 1.0%), have been used since

693-406: The braided line almost exclusively used on modern vessels, but some traditional vessels now use modern high modulus braided lines (like Amsteel or AS-90) in place of wire rope (to save weight aloft) and serve the line to maintain the traditional appearance. It can be applied to the entire length of a line, such as a shroud , or selectively, to specific parts of a line, such as over the spliced ends of

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726-758: The end product is almost pure carbon. Silicon carbide fibers, where the basic polymers are not hydrocarbons but polymers, where about 50% of the carbon atoms are replaced by silicon atoms, so-called poly-carbo- silanes . The pyrolysis yields an amorphous silicon carbide, including mostly other elements like oxygen, titanium, or aluminium, but with mechanical properties very similar to those of carbon fibers. Fiberglass , made from specific glass, and optical fiber , made from purified natural quartz , are also artificial fibers that come from natural raw materials, silica fiber , made from sodium silicate (water glass) and basalt fiber made from melted basalt. Mineral fibers can be particularly strong because they are formed with

759-532: The ends, where wear is most likely; this may be overcome by serving the string. In many parts of Asia, traditional strings have a single loop in the center, with the ends made of separate lengths tied on using a special knot. This design allows extra fiber to be used at the ends, where weight is less important and wear more likely. Traditional materials include linen , hemp , other vegetable fibers, hair , sinew , silk , and rawhide . Almost any fiber may be used in emergency. Natural fibers would be very unusual on

792-572: The fiber density is known, you also have a fiber diameter, otherwise it is simpler to measure diameters in micrometers. Microfibers in technical fibers refer to ultra-fine fibers (glass or meltblown thermoplastics ) often used in filtration. Newer fiber designs include extruding fiber that splits into multiple finer fibers. Most synthetic fibers are round in cross-section, but special designs can be hollow, oval, star-shaped or trilobal . The latter design provides more optically reflective properties. Synthetic textile fibers are often crimped to provide bulk in

825-401: The fiber shape, and include those produced by plants, animals, and geological processes. They can be classified according to their origin: Artificial or chemical fibers are fibers whose chemical composition, structure, and properties are significantly modified during the manufacturing process. In fashion, a fiber is a long and thin strand or thread of material that can be knit or woven into

858-399: The line, each progressive turn of the twine laid as close as possible against the last, covering the line completely. Following the rhyme above, it should have course run against the lay of the rope; this alternation helps prevent sideways chafe from opening up the protection. Traditionally hemp "marline" was and still is used for service; on modern small craft three-strand nylon "seine twine"

891-427: The main length of the bundles, which are reverse-twisted in turn. The Japanese bowstring is made by reverse-twisting in different directions in the core and outer layers of the string. See Kyūdō . Looped strings are made of one or more continuous loops of material. Modern strings are often made as a single continuous loop: this is then served to give the final form. Disadvantages include the lesser amount of fiber at

924-449: The other direction. The result tends to be stronger for its weight than a simple or looped string, and holds together better than a simple string. Unlike some looped strings, the full thickness of the string passes around the nocks on the ends of the bow, where wear is usually greatest. Additional threads may also be laid in at the nocking points for the bow stave and for the arrow, which are sites of likely wear. The string may be secured to

957-469: The parcelling is complete, immediately prior to the process of serving. The tar helps fill any remaining gaps in the cuntlines as well as creating a waterproof seal over the line within. As with worming, parcelling is applied in the same direction as the twist of the line being covered. The rule is "worm and parcel with the lay; turn and serve the other way". When parcelling is used on modern small craft, friction tape or cotton athletic tape can be used for

990-502: The properties of artificial fibers. (in) (Ksi) (Ksi) (%) (%) (Kraft Pulp) b  N/A means properties not readily available or not applicable (0.001 in) (Ksi) (%) (%) (°C) Temp (°C)    Low    High 0.92 0.95 11-17 50-71 25-50 20-30 nil nil 110 135 55 65 b  N/A means properties not readily available or not applicable Worm, parcel and serve#Serving To worm, parcel and serve

1023-404: The purpose. On rare occasions, when parcelling is not to be served (e.g., for short term use to protect a line against chafe), it should be applied against the lay of the line, counter to that guiding rhyme. In these circumstances, the parcelling itself is filling the protective role that serving would do. The outer layer of protection is formed of twine wrapped as tightly as possible around

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1056-409: The twist so that they spiral round the main line. For larger lines, such as the natural (e.g. hemp) fiber rigging used on early vessels, "sister worming" could be built up from several different sizes of "small stuff", as was needed to fill in the typically larger cuntlines of cable-laid hemp rope. In the days of hemp anchor cable, worming of chain was used, when anchoring on a rocky bottom, to protect

1089-723: The two sides of the loop together. Fiber Fiber (also spelled fibre in British English ; from Latin: fibra ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene . Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing natural fibers have some benefits, such as comfort, over their synthetic counterparts. Natural fibers develop or occur in

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