Classification based on use
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- dress
- floor covering
- yarn
- fibre
- cloth
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- Verviers - Facts
Fabric construction yarns
Almost any textile yarn can be used to produce such interlaced fabrics as woven and knitted types. In weaving, the warp, or lengthwise, yarns are subjected to greater stress and are usually stronger, smoother, and more even and have tighter twist than the weft, or crosswise, yarns. A sizing (stiffening) material such as starch may be applied to warp yarns, increasing their strength to withstand the stresses of fabric construction operations. Weft yarns, subjected to little stress during weaving, may be quite fragile.
Warp and weft threads used in the same fabric may be of differing diameter, producing such special effects as ribbing or cording in the fabric. Special effects may also be obtained by combining warp and weft yarns of fibre from differing origin, or with different degrees of twist, or by introducing metallic threads into weaves composed of other fibres.
Yarns for machine knitting are usually loosely twisted because softness is desired in knit fabrics.
Yarns used in handwork
Yarns used in hand knitting are generally of two or more ply. They include such types as fingering yarns, usually of two or three plys, light to medium in weight and with even diameter, used for various types of apparel; Germantown yarns, soft and thick, usually four-ply and of medium weight, frequently used for sweaters and blankets; Shetland yarns, fine, soft, fluffy, and lightweight, frequently two-ply, used for infants’ and children’s sweaters and for shawls; worsted knitting yarn, highly twisted and heavy, differing from worsted fabric by being soft instead of crisp, and suitable for sweaters; and zephyr yarns, either all wool, or wool blended with other fibres, very fine and soft, with low twist, and used for lightweight garments.
Embroidery floss, used in hand embroidery, generally has low twist, is of the ply or cord type, and is made of such smooth filaments as silk and rayon. Yarn used for crocheting is frequently a loose cotton cord type; and darning yarns are usually loosely spun.
Sewing thread
Sewing threads are tightly twisted ply yarns made with strands having equally balanced twist, producing a circular cross section. Thread for use in commercial or home sewing machines and for hand sewing should allow easy movement when tension is applied and ease in needle threading; should be smooth, to resist friction during sewing; should have sufficient elasticity to avoid the breaking of stitches or puckering of seams; and should have sufficient strength to hold seams during laundering or dry cleaning and in use.
Threads for special uses may require appropriate treatment. Garments made of water-repellent fabrics, for example, may be sewn with thread that has also been made water-repellent. Thread is usually subjected to special treatment after spinning and is then wound on spools. Thread size is frequently indicated on the spool end, and systems for indicating degree of fineness vary according to the textile measurement system used locally.
Silk thread has great elasticity and strength combined with fine diameter. It can be permanently stretched in sewing, and is suitable for silks and wools. Buttonhole twist is a strong, lustrous silk about three times the diameter of normal sewing silk, and is used for hand-worked buttonholes, for sewing on buttons, and for various decorative effects.
Cotton thread is compatible with fabric made from yarn of plant origin, such as cotton and linen, and for rayon (made from a plant substance), because it has similar shrinkage characteristics. It is not suitable for most synthetics, which do not shrink, or for fabrics treated to reduce shrinkage. Its low stretch is useful for woven fabrics, but not for knits, which require more stretch.
Nylon thread is strong, with great stretch and recovery, does not shrink, and is suitable for sheers and for very stretchy knits. Polyester thread has similar characteristics, and is appropriate for various synthetic and preshrunk fabrics, and for knits made of synthetic yarns.
Measurement systems
Yarn measurements are expressed as yarn number, count, or size, and describe the relationship of length and weight (or approximate diameter). Because methods of measurement were developed in various areas of the world, there has been a lack of uniformity in such systems.
Indirect systems
Indirect measuring systems are those employing higher number to describe finer yarns and are based on length per unit weight. Most countries measure yarns made from staple fibres according to the weight of a length of yarn. If one pound is used as a standard unit, for example, a very fine yarn will have to be much longer than a coarser yarn to weigh a pound, so higher counts indicate finer yarns. The size number is an indication of the length of yarn needed to reach a weight of one pound.
In the United States, the system is based on the number of hanks per pound, with a hank of 840 yards for cotton and spun silk, 300 yards (a lea) for linen, 256 yards for woollen yarns, and 560 yards for worsted yarns. A widely used Continental system is based on the number of hanks of 1,000 metres (one kilometre) required to reach a weight of one kilogram.
Denier system
The denier system is a direct-management type, employed internationally to measure the size of silk and synthetic filaments and yarns, and derived from an earlier system for measuring silk filaments (based on the weight in drams of 1,000 yards). Denier number indicates the weight in grams of 9,000 metres of filament or filament yarn. For example, if 9,000 metres of a yarn weigh 15 grams, it is a 15-denier yarn; if 9,000 metres of a yarn weigh 100 grams, it is a 100-denier yarn and much coarser than the 15-denier yarn. Thus, a smaller number indicates a finer yarn. This system is not convenient for measurement of staple yarns because their greater weight would require the use of very large numbers.
Tex system
The tex system, originally devised in 1873, is a universal method developed for the measurement of staple fibre yarns and is also applicable to the measurement of filament yarns. It is based on the weight in grams of one kilometre (3,300 feet) of yarn.
Production of fabric
Fabric construction involves the conversion of yarns, and sometimes fibres, into a fabric having characteristics determined by the materials and methods employed. Most fabrics are presently produced by some method of interlacing, such as weaving or knitting. Weaving, currently the major method of fabric production, includes the basic weaves, plain or tabby, twill, and satin, and the fancy weaves, including pile, Jacquard, dobby, and gauze. Knitted fabrics are rapidly increasing in importance and include weft types and the warp types, raschel and tricot. Other interlaced fabrics include net, lace, and braid. Nonwoven fabrics are gaining importance and include materials produced by felting and bonding. Laminating processes are also increasing in importance, and fairly recent developments include needle weaving and the sewing-knitting process.
Woven fabrics
Woven fabrics are made of yarns interlaced in a regular order called a binding system, or weave. Weaving is the process of combining warp and weft components to make a woven structure. The components need neither be parallel to each other nor cross each other at right angles, but most woven structures are composed of two sets of components, both flexible and crossing at right angles. Weaving is differentiated from warp and weft knitting, braiding, and net making in that these latter processes make use of only one set of elements. In addition, there are geometrical differences, one of the most significant being the small angles through which the components of a woven structure are, in general, bent, in contrast with the components of other structures.
Weaving is a widely used constructional method because it is cheap, basically simple, and adaptable. Woven fabrics have valuable characteristics resulting partly from the geometrical conformation of their components and partly from the fact that the components are held in position not by rigid bonding but by friction set up at the areas where they make contact. Woven fabrics are used in household, apparel, and industrial textiles.
Textile designers can produce a very large variety of cloths by their selection of yarns, finishing processes, and binding systems. Yarns vary in thickness, smoothness, fibre content, twist, and colour, all of which have a profound influence on the finished cloth. Finishing processes range from such simple treatment as brushing up the nap on a woven fabric to such a complicated chemical process as that employed to change opaque cotton fabric to transparent, permanently stiffened organdy.
The binding system, or weave, however, is the basic factor in determining the character of a woven fabric. The three basic systems are plain or tabby, twill, and satin. In complex binding systems, the basic weaves are combined or enriched by hand manipulation or mechanical loom attachments; these include multiple-plane, pile, inlaid, and gauze weaves. Regardless of the binding system, other devices—manipulation of warp spacing, beating in, or tension—can be used to alter the appearance of any weave, to make it looser or more compact, to make it more or less regular.
As musical notation conveys a composer’s ideas, so weave drafts or point paper plans communicate a textile designer’s directions for constructing woven fabrics. The draft is a plan on graph paper showing at least one repeat or weave unit of the fabric to be woven. This information enables the weaver or mill specialist to plot the drawing in of the warp, the tie up of harnesses to the shedding mechanism, and the shedding order.
