ISO 2

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S-twist and Z-twist Yarn twist S-Left Z-Right.png
S-twist and Z-twist

ISO 2 is an international standard for direction of twist designation for yarns, complex yarns, slivers, slubbings, rovings, cordage, and related products. [1]

The standard uses capital letters S and Z to indicate the direction of twist, [2] as suggested by the direction of slant of the central portions of these two letters. The handedness of the twist is the direction of the twists as they progress away from an observer. Thus Z-twist is said to be right-handed, and S-twist to be left-handed. The convention of using these two letters to unambiguously designate twist direction was already used in the cordage industry by 1957. [3]

Related Research Articles

Spinning is a twisting technique to form yarn from fibers. The fiber intended is drawn out, twisted, and wound onto a bobbin. A few popular fibers that are spun into yarn other than cotton, which is the most popular, are bamboo, and synthetic polyester. Originally done by hand using a spindle whorl, starting in the 500s AD the spinning wheel became the predominant spinning tool across Asia and Europe. The spinning jenny and spinning mule, invented in the late 1700s, made mechanical spinning far more efficient than spinning by hand, and especially made cotton manufacturing one of the most important industries of the Industrial Revolution.

Textile Flexible interlocking network of fibres

Textile is an umbrella term that covers a wide variety of materials, such as fibers, yarns, and fabrics, in addition to other related goods. The manufacturing of textiles is the oldest industrial art. The textile industry involves the production and processing of various fibers, yarns, fabrics, as well as a variety of textile-based goods such as clothing, household and industrial goods. Fiber is the smallest component of a fabric; fibers are typically spun into yarn, and yarns are used to manufacture fabrics.

Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery, or ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework.

Spinning wheel Device for spinning thread, yarn, or silk from natural or synthetic fibers

A spinning wheel is a device for spinning thread or yarn from fibres. It was fundamental to the cotton textile industry prior to the Industrial Revolution. It laid the foundations for later machinery such as the spinning jenny and spinning frame, which displaced the spinning wheel during the Industrial Revolution.

Worsted is a high-quality type of wool yarn, the fabric made from this yarn, and a yarn weight category. The name derives from Worstead, a village in the English county of Norfolk. That village, together with North Walsham and Aylsham, formed a manufacturing centre for yarn and cloth in the 12th century, when pasture enclosure and liming rendered the East Anglian soil too rich for the older agrarian sheep breeds. In the same period, many weavers from the County of Flanders moved to Norfolk. "Worsted" yarns/fabrics are distinct from woollens : the former is considered stronger, finer, smoother, and harder than the latter.

Carding Process that disentangles, cleans and intermixes fibres

Carding is a mechanical process that disentangles, cleans and intermixes fibres to produce a continuous web or sliver suitable for subsequent processing. This is achieved by passing the fibres between differentially moving surfaces covered with "card clothing", a firm flexible material embedded with metal pins. It breaks up locks and unorganised clumps of fibre and then aligns the individual fibres to be parallel with each other. In preparing wool fibre for spinning, carding is the step that comes after teasing.

Rope Linear combination of plies, yarns or strands which are twisted or braided together

A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine.

Woolen or woollen is a type of yarn made from carded wool. Woolen yarn is soft, light, stretchy, and full of air. It is thus a good insulator, and makes a good knitting yarn. Woolen yarn is in contrast to worsted yarn, in which the fibers are combed to lie parallel rather than carded, producing a hard, strong yarn.

In the textile arts, plying is a process of twisting one or more strings of yarn together to create a stronger yarn. Strands are twisted together in the direction opposite that in which they were spun. Plied yarns will not unravel, break, or degrade as easily as unplied yarns. When enough twist is added to the plies to counter the initial twist of each strand, the resulting yarn is "balanced", having no tendency to twist upon itself.

Twine Cord composed of two or more thinner strands twisted together

Twine is a strong thread, light string or cord composed of two or more thinner strands twisted, and then twisted together (plied). The strands are plied in the opposite direction to that of their twist, which adds torsional strength to the cord and keeps it from unravelling. This process is sometimes called reverse wrap. The same technique used for making twine is also used to make thread, which is thinner, yarn, and rope, which is stronger and thicker, generally with three or more strands.

Textile manufacturing The industry which produces textiles

Textile manufacturing is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful goods such as clothing, household items, upholstery and various industrial products. Overall, many things can be made with cotton, not just clothing.

Hand spinning Method of turning fiber into yarn or thread using a spinning wheel or drop spindle

Spinning is an ancient textile art in which plant, animal or synthetic fibres are drawn out and twisted together to form yarn. For thousands of years, fibre was spun by hand using simple tools, the spindle and distaff. It was only with the invention of the spinning wheel in the Islamic world circa 1030, and its subsequent introduction to China, India and Europe in the High Middle Ages, that the output of individual spinners dramatically increased. Mass production later arose in the 18th century with the beginnings of the Industrial Revolution. Hand-spinning remains a popular handicraft.

Units of textile measurement Systems for measuring textiles

Textile fibers, threads, yarns and fabrics are measured in a multiplicity of units.

Staple refers to textile fibers of discrete length. The opposite is a filament fiber, which comes in continuous lengths. Staple length is a characteristic fiber length of a sample of staple fibers. It is an essential criterion in yarn spinning aids in cohesion and twisting. Compared to synthetic fibers, natural fibers tend to have different and shorter lengths. The quality of natural fibers like cotton is categorized on staple length such as short, medium, long-staple and, extra long. Gossypium barbadense, one of several cotton species, produces extra-long staple fibers. The staple fibers may be obtained from natural and synthetic sources. In the case of synthetics and blends, the filament yarns are cut to a predetermined length.

A sliver is a long bundle of fibre that is generally used to spin yarn. A sliver is created by carding or combing the fibre, which is then drawn into long strips where the fibre is parallel. When sliver is drawn further and given a slight twist, it becomes roving.

An S number on the label of wool suits or other tailored apparel, wool fabric, or yarn, indicates the fineness of the wool fiber used in the making of the apparel, as measured by its maximum diameter in micrometres. Fiber fineness is one of the factors determining the quality and performance of a wool product. In recent years it has also become an important marketing device used by many mills, garment makers, and retailers. The S number appears as a plural with an s or 's following the number, such as 100s or 100's.

Textile manufacturing is one of the oldest human activities. The oldest known textiles date back to about 5000 B.C. In order to make textiles, the first requirement is a source of fibre from which a yarn can be made, primarily by spinning. The yarn is processed by knitting or weaving to create cloth. The machine used for weaving is the loom. Cloth is finished by what are described as wet process to become fabric. The fabric may be dyed, printed or decorated by embroidering with coloured yarns.

DREF friction spinning

Friction Spinning or Dref Spinning is a textile technology that suitable for spinning coarse counts of yarns and technical core-wrapped yarns. Dref yarns are bulky, with low tensile strength making them suitable for blankets and mop yarns, they can be spun from asbestos, carbon fibres and makes filters was water systems. Yarns such as Rayon and Kevlar can be spun using this method. The technology was developed around 1975 by Dr. Ernst Fehrer.

Dimensional stability is the change of dimensions in textile products when they are washed or relaxed. The change is always expressed relative to the dimensions before the exposure of washing or relaxing. Shrinkage is also called residual shrinkage and measured in percentage. The major cause of shrinkages is the release of stresses and strains introduced in manufacturing processes. Textile manufacturing is based on the conversion of fiber into yarn, yarn into fabric, includes spinning, weaving, or knitting, etc. The fabric passes through many inevitable changes and mechanical forces during this journey. When the products are immersed in water, the water acts as a relaxing medium, and all stresses and strains are relaxed and the fabric tries to come back to its original state. The dimensional stability of textile materials is an important quality parameter. Failing and unstable materials can cause deforming of the garments or products. Shrinkage is tested at various stages, but most importantly before cutting the fabric into further sewn products and after cutting and sewing prior to supplying the products to buyers and consumers. It is a required parameter of quality control to ensure the sizes of the products to avoid any complaints regarding deformation or change in dimensions after domestic laundry. The tests are conducted with provided specifications of buyers imitating the same conditions like washing cycle time, temperature and water ratio and fabric load and sometimes top loading and front loading washing machines are chosen to authenticate the test and assurance of the results. This procedure provides standard and alternate home laundering conditions using an automatic washing machine. While the procedure includes several options, it is not possible to include every existing combination of laundering parameters. The test is applicable to all fabrics and end products suitable for home laundering.

References

  1. International Organization for Standardization (1973), ISO 2:1973 Textiles — Designation of the direction of twist in yarns and related products , retrieved 2013-08-04
  2. The International Bureau For The Standardisation of Man-Made Fibres (BISFA) (2009), Terminology of man-made fibres (PDF), p. 49, archived from the original (PDF) on 2015-11-23, retrieved 2013-08-04
  3. Himmelfarb, David (1957). The Technology of Cordage Fibres and Rope. London: Leonard Hill. p. 116.