Research Results For 'Yarn'

BOBBIN

A bobbin is a reel or other similar contrivance for holding thread. It is often a cylindrical piece of wood or plastic with a head, on which thread is wound for making lace; or a spool with a head at one or both ends, intended to have thread or yarn wound on it, and used in spinning machinery (when it is slipped on a spindle and revolves therewith) and in sewing-machines (applied within the shuttle).
Research Bobbin

COTTON-SPINNING

Cotton-spinning is a term employed to describe in the aggregate all the operations involved in transforming raw cotton into yarn. The word 'spinning' has also a more limited signification, being used to denote the concluding process of the series. The following affords a general notion of the nature and order of the successive operations carried on in the manufacture of cotton yarn:

(1) Mixing, the blending of different varieties of raw cotton, in order to secure economical production, uniform quality and colour, and an even thread in any desired degree.

(2) Cleaning, an operation partly effected in mixing, partly by scutching, the cotton being prepared in the form of a continuous lap or rolled sheet for the next process.

(3) Carding, an operation in which the material is treated in its individual fibres, which are taken from the lap, further cleansed, and laid in a position approximately parallel to each other, forming a thin film, which is afterwards condensed into a sliver - a round, untwisted strand of cotton.

(4) Drawing, the drawing out of several slivers to the dimensions of one, so as to render the new sliver more uniform in thickness, and to place the fibres more perfectly in parallel order.

(5) Stubbing, the further drawing or attenuation of the sliver, and slightly twisting it in order to preserve its cohesion and rounded form.

(6) Intermediate or second stubbing, a repetition of the former operation and further attenuation, not necessary in the production of coarse yarns.

(7) Having, a continuation of the preceding, its principal object being to still further attenuate the sliver, and give it a slight additional twist.

(8) Spinning, which completes the extension and twisting of the yarn. This is accomplished either with the throstle or the mule. By means of the former machine the yarn receives a hard twist, which renders it tough and strong. By means of the latter yarns of less strength are produced, such as warps of light fabrics and wefts of all kind.

Up to the middle of the 18th century the only method of spinning known was that by the hand-wheel, or the still more primitive distaff and spindle. In 1767 a poor weaver of the name of Hargreaves, residing at Stanhill, near Blackburn, in Lancashire, invented a machine for spinning cotton, which he named a spinning-jenny. It consisted at first of eight spindles, turned by a horizontal wheel, but was afterwards greatly extended and improved, so as to have the vertical substituted for the horizontal wheel, and give motion to from fifty to eighty spindles. In 1769 Arkwright, originally a barber's apprentice, took out a patent for spinning by rollers. From the circumstances of the mill erected by Arkwright at Cromford, in Derbyshire, being driven by water-power, his machine received the name of the water-frame, and the thread spun on it that of water-twist. The next important invention in cotton-spinning was that of the mule, introduced by Samuel Crompton, of Bolton, in 1775, and so called from its combining the principle of the spinning-jenny of Hargreaves with the roller-spinning of Arkwright.

Numerous improvements in cotton-spinning have been subsequently introduced up to the present day, but they are all, more or less, modifications of Arkwright's spinning-frame and Crompton's mule-jenny. Among the principal of these may be mentioned the throstle, an extension and simplification of the original spinning-frame, introduced about the year 1810.
Research Cotton-Spinning

DYEING

Dyeing is the art of giving colour to textile and other articles in such a way that the colours are more or less permanent, and not readily affected by the action of light, washing, etc. Like spinning and weaving it was originally a home industry, as it still is in many places. Until about 1850 natural dye-stuffs alone were employed, but the discovery of dyes of all colours that can be obtained from coal-tar products revolutionized dyeing as an industry, and the vegetable dye-stuffs were gradually superseded by the newer colours.

Before dyeing, the materials have generally to be cleansed or bleached to get rid of undesirable colouring matters or impurities; and frequently a textile material is subjected to some subsidiary treatment in order to obtain special effects. For example, cotton yarn may be subjected to the action of strong caustic soda ('mercerizing' process) while in a state of great tension, in order to give it a permanent silky lustre.

Dyeing is not only an art, it is also a branch of applied chemistry. One fundamental principle is, that the colouring matter and other necessary substances must be applied in a state of solution, and while in direct contact with the fibre they must be rendered insoluble, so that they are precipitated within or upon the fibre and thus permanently fixed. The method of effecting this varies greatly according to the fibre and the colouring matter employed. As a rule the vegetable and the animal fibres are dyed by very different methods. The affinity of the animal fibres for certain colouring matters is often so great that they are readily dyed by simple immersion in hot colour solutions;
but this simple process is not generally sufficient. According to the method of their application in dyeing the following groups: of dye-stuffs may be distinguished: Avid Colours, Basic Colours, Direct Colours, Developed Colours, Mordant Colours, Miscellaneous Colours, Reactive Colours.

The acid colours are so called because they are of an acid character and are applied in an acid dye-bath. As a rule, they are only suitable for dyeing the animal fibres, e.g. wool and silk, also leather, horn, feathers, etc. Only a few vegetable dye-stuffs belong to this class, for example, the purple colour orchil and the blue colour indigo extract. On the other hand, the acid colours derived from coal-tar - and increasingly petroleum - are very numerous and yield a great variety of hues - red, orange, yellow, green, blue, violet, brown, and black, each with its particular name.

The basic colours are so called because their essential constituents, to which they owe their dyeing power, are organic bases. The bases themselves are colourless and too insoluble in water to be of use, hence they are employed in the form of their soluble coloured salts, usually the hydrochlorides of the colour-bases. Their solutions are precipitated by tannic acid, because it combines with the colour-bases to form insoluble tannates. Wool, silk, and animal substances generally have a direct attraction for colour-bases, and hence these fibres are readily dyed by simple immersion in hot aqueous solutions of the basic colours. Cotton and linen, on the other hand, are not dyed so readily; they need first to be prepared or impregnated with tannic acid, and thus prepared are said to be mordanted, the tannic acid in this connection being styled the mordant. Most of the colours of this class are fugitive to light, and all but one, barberry root, are derived from coal-tar products.

The direct colours are so called because they dye cotton direct, that is, without the aid of any mordanting process. The first of this class derived from coal-tar was congo red, discovered in 1884; this group includes a very great variety of fast colours, and forms, indeed, one of the most important and valuable series of dye-stuffs employed. Cotton, linen, and the vegetable fibres generally are dyed in the simplest possible manner by merely boiling them in a solution of the dye-stuff, with or without the addition of a little soap, carbonate or sulphate of soda, etc. Wool and silk are frequently dyed in the same manner as cotton. Very few vegetable dye-stuffs belong to the direct colours, e.g. Safflower, Turmeric, Saffron, Annatto. They are all fugitive, and have been of little or no importance to the dyer since the end of the 19th century. The coal-tar colours of this class, on the other hand, are extremely numerous.

The developed colours include a variety of colours which are formed in situ upon the fibre by the successive application of two or more substances. These colours are all of coal-tar origin. A number of them belong to the so-called azo colours, derived from compounds containing nitrogen.

The mordant colours form one of the most important classes of colouring matters, for they include not only most of the vegetable dye-stuffs, e.g. madder, logwood, fustic, etc, but also many valuable fast coal-tar colours, commonly known as the alizarin colours, after their typical representative, alizarin. These mordant colours have by themselves very little colouring power, as a rule, and if employed alone in dyeing give little or no result. If applied, however, in conjunction with metallic salts, notably those of chromium, aluminium, iron, tin, and copper, they each yield a variety of colours, according to the metallic salt employed. In employing them usually two distinct operations are involved: first, that of applying the metallic salt or mordant, called the mordanting process ; and second, that of dyeing proper, in which the mordanted material is boiled in a solution or decoction of the dye-stuff. During the dyeing operation the colouring principle of the dye-stuff combines with the metallic salt already upon the material, and the colour is thus produced and fixed upon the fibre. The method of mordanting varies with the fibre and the metallic salt employed. The vegetable dye-stuffs of this class include Madder, Sapanwood, Camwood, Barwood, Old Fustic, Young Fustic, Quercitron Bark, Persian Berries, Weld, Logwood. Madder was formerly the most important and highly valued of the dye-stuffs of this class, being especially employed to produce the fine 'Turkey-red' dye; but was entirely superseded by the coal-tar colour alizarin towards the end of the 19th century.

Reactive colours combine directly with the fibre being dyed through a chemical reaction and result in a fast colour. The first ranges of reactive dyes for cellulose fibres were introduced in the mid-1950s.

Similarly, the employment of cochineal (an insect dye) has also greatly diminished through the introduction of the cheaper colours. Camwood and barwood are almost entirely used in wool-dyeing, either in conjunction with the indigo-vat or for the purpose of dyeing various shades of brown. Old fustic is the most important of the yellow mordant dye-stuffs, and the colours are fast although not very brilliant. Young fustic yields fugitive colours, and has been little used since 1900. Quercitron bark is an excellent dye-stuff employed by wool-dyers for the production of bright orange and yellow colours. Persian berries and weld, a species of wild mignonette, are both excellent dye-stuffs, but their employment is now limited. Logwood is largely employed by wool, silk, and cotton dyers for dyeing black and dark-blues, which, although fast to washing, are only moderately so towards light. During the 20th century dyewoods were gradually replaced by coal-tar colours.

Among miscellaneous colours are several dye-stuffs applied in a distinct manner. Indigo is a dark-blue powder quite insoluble in water, but can be rendered soluble for dyeing purposes by two methods. The first method converts the indigo into so-called indigo extract, which is sold as a blue paste and applied as an acid colour in dyeing wool and silk. In the second method the indigo-blue is converted into indigo-white, which readily dissolves in the alkali present, the solution thus obtained being called an indigo-vat. If cotton, wool, or silk is steeped for some time in the clear yellow solution of such a vat, and then exposed to the oxidizing influence of the air, they are dyed a permanent blue. The indigo-white absorbed by the fibre loses its acquired hydrogen, and thus insoluble indigo-blue is regenerated within and upon the fibre. Aniline black is a valuable colour, produced direct upon the fibre by the oxidation of aniline, and remarkable for its extreme permanency.

Catechu is a vegetable dye-stuff used in dyeing cotton and woollen brown. On wool, catechu yields khaki browns in single bath by using copper sulphate as the mordant. On silk it is largely employed for weighting purposes in the process of dyeing black. Chrome Yellow, Iron Buff, Prussian Blue, and Manganese Brown, employed in cotton dyeing, are frequently classed as mineral colours. Chrome yellow is obtained by immersing cotton successively in solutions of acetate of lead and bichromate of potash, whereby the yellow precipitate of chromate of lead is fixed upon the fibre. Iron buff is obtained in a similar manner by the successive application of iron sulphate and carbonate of soda, and finally developing the full colour by washing with water and exposure to air. The buff colour is really due to the precipitation of oxide of iron on the cotton. Prussian blue is at once developed by passing the buff-dyed cotton through an acidified solution of potassium ferrocyanide. The production of manganese brown on cotton is similar to that of iron buff. The brown colour ultimately produced upon the fibre is an oxide of manganese. The mineral colours are very useful for certain purposes, and are to be regarded as very fast to light.
Research Dyeing

LOOM

A loom is an apparatus for weaving yarn into a textile by the crossing of vertical (warp) and horizontal (weft) threads.
Research Loom

MILLBOARD

Millboard is a type of cardboard made from paper refuse material. The best quality, used for book bindings, was made from hemp, rope, yarn, cotton or linen rags hand formed in moulds.
Research Millboard

WEAVING

Weaving is the art of interlacing yarn threads or other filaments by means of a loom, so as to form a web of cloth or other woven fabric. Two sets of threads are used which traverse the web at right angles to each other. The first set extends from end to end of the web in parallel lines and is called the warp; while the other set of threads crosses and interlaces with the warp from side to side of the web and is called the weft.
Research Weaving

YARN

Yarn is a fibre, such as cotton, wool, silk or flax which has been spun and prepared for use in weaving or knitting.
Research Yarn

COCONUT

Coconut (formerly Cocoa-nut, or coco-nut), IS a woody fruit of an oval shape, from 7 or 10 to 15 or 20 cm in length, covered with a fibrous husk, and lined internally with a white, firm, and fleshy kernel. The tree (Cocos nucifera) which produces the coconut is a palm, from 12 to 18 metres high. The trunk is straight and naked, and surmounted by a crown of feather-like leaves. The nuts hang from the summit of the tree in clusters of a dozen or more together. The external rind of the nuts has a smooth surface. This encloses an extremely fibrous substance, of considerable thickness, which immediately surrounds the nut. The latter has a thick and hard shell, with three black scars at one end, through one of which the embryo of the future tree pushes its way. This scar may be pierced with a pin; the others are as hard as the rest of the shell. The kernel encloses a considerable quantity of sweet and watery liquid, of a whitish colour, which has the name of milk.

This palm is a native of Africa, the East and West Indies, and South America, and is now grown almost everywhere in tropical countries. Food, clothing, and the means of shelter and protection are all afforded by the coconut tree. The kernels are used as food in various modes of dressing, and yield on pressure an oil which is largely imported into various countries. When dried before the oil is expressed they are known as copra. The fibrous coat of the nut is made into the well-known coconut matting; the coarse yarn obtained from it is called coir, which is also used for cordage. The hard shell of the nut is polished and made into a cup or other domestic utensil. The fronds are wrought into baskets, brooms, mats, sacks, and many other useful articles; the trunks are made into boats or furnish timber for the construction of houses.

By boring the tree a white sweetish liquor called toddy exudes from the wound, and yields by distillation one of the varieties of the spirit called arack. A kind of sugar called jaggery is also obtained from the juice by inspissation.
Research Coconut

THROSTLE-PIECER

Throstle-piecer was the name given to girls aged between thirteen and sixteen who were formerly employed in cotton mills whose duty was to attend to the throstle frames, and to piece up the yarn as it was made in the frame, before it is wound upon bonnins fixed on the spindles to receive it.
Research Throstle-Piecer

ACETATE

Acetate is a man-made cellulose fabric or yarn that was first created in Germany in 1869. Work on the fibre was continued by Swiss chemists Camille and Henri Dreyfus of Basle in the 1900s, but their research was interrupted by the outbreak of the Great War when acetate was used to make waterproof varnishes for French and British fabric-covered aeroplanes. In 1920 British Celanese Ltd made a commercially viable acetate fibre using the Dreyfus method.
Acetate has since been used to make lingerie, blouses, dresses and knitwear as well as other garments requiring lightweight, silky fabrics.
Research Acetate

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