by Giorgio Belletti
The classification of the fibres Natural fibres: wool, other fine fibres, cotton, silk, linen
"Man made" fibres: artificial (or cellulosic) and synthetic The textile chain: an overview of the T/A line The process: combing, from the fibre to the yarn and yarn's glossary
The concept of thread count (linear density) The process of spinning of the fibre The productive process from yarn to fabric and fabric's small glossary Textile finishing: dying, printing, coating and bonding ...
FIBRES CLASSIFICATION [the basic information]
NATURAL (available in nature: cotton, wool, silk, linen) ARTIFICIAL
by transformation of natural polymers
MAN MADE (or chemical)
from syntethic polymers
[in the next page you can find the complete classification]
Natural Vegetable Cotton Linen Hamp Jute
Organic CO by transformation of natural polymers
Acetate Alginate Cupro Elastodiene Lyocell Modal Triacetate Viscose
CA ALG CUP ED CLY CMD CTA CV
from synthetic polymers Acrylic Aramid Chlorofibre Elastane Elastodiene Fluorofibre Melamine Modacrylic Plyamide Polyester Polyethylene Polyimide Polypropylene Vinylal
PAN AR CLF EL ED PTFE MF MAC PA PES PE PI PP PVAL
Carbon Ceramic Glass Metal
CF CEF GF MTF
WOOL It is the fur that covers the skin of the sheep, isolates it from the cold and heat, keeping its body temperature constant. There are many varieties of ovine breeds which produce wool with fibres differing for their fineness, length, shininess and resistance. The ovine breed that supplies the best type of wool is certainly the Merino one. The largest farms of this breed, originally from Spain, are in Australia. Merino wool has a not too long fibre with a very fine diameter, which determines its superiority with respect to other types of wools. It is very soft and light, tightly undulated and is used for the production of the finest clothes. Other ovine breeds that produce less precious wools are mixed or local breeds. The mixed breeds, i.e. deriving from crosses between merino sheep and local breeds, supply wool with medium length fibres, less fine and less undulated, aimed at the production of rough fabrics such as tweed. The local breeds produce ordinary wool, with rather long and bristly fibres aimed at the production of craftsman carpets and mattresses.
After shearing the animal, the finer, more regular wool flock from the back, sides and neck is separated from the less precious wool of the stomach and legs. The flock is beaten and opened to remove superficial impurities and then washed. After drying, the flock is controlled, carded, spun and woven. The kind of fabric depends on the yarn used, carded or combed. The carded yarn has long and short fibres laid out unevenly in all directions, for which reason it is softer and swollen. Combed yarn has fibres of an even length, arranged side by side in a homogenous manner, twisted in such a manner as to form a regular yarn, smooth and resistant. The carded cloth is soft, swollen, but also a little rough, whilst the combed one is soft, smooth and compact. Merino wools are aimed at combed spinning, whilst the mixed wools are used more in carded spinning. The fabric obtained from the weaving needs a series of finishing operations, called finishing (or ennobling), which are required in order to improve the yield and aspect. The anti-static, antifelting, hydro repellent, or anti-crease treatments increase the original quality of the fabric, making it even more suitable to current needs.
Properties of wool. Wool fibre is composed of keratin, a substance similar to that of hair. Wool has a very high isolating property, thanks to the air cushions formed by the undulations of the fibres. The finer and more undulated is the wool, the greater is its thermal isolation power. Wool is the most hygroscopic fibre, as it absorbs an amount of humidity equal to 30% of its own weight, without appearing wet. It absorbs aqueous steam avoiding contact between the body and the wet garment and is resistant to dirt with its hydro repellent surface. Wool fibre is elastic, uncreasable, and therefore very resistant to wear-and-tear. How to treat wool articles. Wool suits should always be dry cleaned at least once every season, before storing them in the wardrobe, or even more often if light coloured or worn frequently. Some items, above all, knitwear, can also be washed in water, using neutral soap and following the instructions specified on the label. They should not be bleached or wrung. Ironing should be deep, i.e. completely drying the fabric dampened by steam from the iron or a damp cloth, as the wool absorbs humidity and the fibres swell and become elastic once again.
SPECIAL WOOLS These are the hairs of animals belonging to the camelidae and caprinae families. These animals normally are not sheared but their hair is collected by combing: this is the reason behind the high cost of these fibres. The parts used are above all the under hair as it is much finer, soft and swollen. They are mixed with ovine wool or used alone to obtain very valuable special fabrics. The alpaca and llama are two camelidae who live on the Andes in Peru, Bolivia and Argentina at altitudes of around 4,000 metres. Their fur is ordinary, thick, tallowy, of different colours: reddish, black, grey, light and dark brown, whilst the under fur is much finer and softer. The camel is an animal originating from North America, which escaped to Asia during the ice age through the Bering straits. The regions in which examples are found which supply an optimal wool are Siberia, Mongolia and China; the African camels give a less fine wool, suitable for the production of carpets. Camel hair, collected when it falls and with combing, is very highly esteemed for its lightness, softness and thermal power.
Amongst the special wools, the most esteemed is that produced by the vicuna, the smallest of the south American camelidae, which lives on the Cordillera of the Andes at altitudes between 4,000 and 6,000 metres. In this very cold climate, the animal develops a long and bristly fleece and a very thick under hair composed of fine fibres, short and very soft. The fibres of the under hair are finer than any other textile material. Second in fineness only to the vicuna is the cashmere: the fibre is produced by a goat that lives on the tablelands of Tibet, Mongolia and Iran. The fleece of this goat is composed of long and rough hairs, but in winter is covered with a mantle of short and soft down, which protects the animal from the cold. This under hair, collected in spring with a comb, supplies the prime material for the textile industry.
Mohair is the fibre of the angora goat, an ovine which lives in the Turkish region around Ankara, after which it is named. This animal is also bred in the United States and in South Africa, where very esteemed varieties come from. Mohair, less curly than merino wool, is shiny and of a transparent white and, like merino wool, is a thermal insulator, elastic and resistant. The cloth is made by its dry and nervous hand. The kid mohair, obtained from the fleece of the kid, is the fibre used for finer cloths. It has a high degree of brightness and softness and a marvellous silky aspect which distinguishes it from normal mohair. Lastly, amongst the animals that supply special hair we have the angora rabbit, whose origin is not known. China is the largest producer of angora hair. The animal is toasted or combed about every three months. The fibres of its fleece are white and silky, aimed at the manufacture of particularly soft and warm products, above all in the knitwear sector.
Properties of Special Wools. The special wools have the same properties as ovine wool, but differ from this for their major fineness, softness and thermal isolation capacities. All these wools are extremely light and warm, but must be treated with much more care as, being finer, they are less resistant. Given the high cost of these wools, they are often combined with other natural fibres, such as cotton or silk, obtaining more robust but equally warm, soft and elegant fabrics. How to treat Special Wools items. Special wool items should always be dry cleaned. Some garments, above all knitwear, can be hand-washed, using neutral soaps and following the manufacturer's instructions on the label. They must not be bleached, nor wrung. This kind of item should be ironed at medium heat.
COTTON It is a vegetable fibre obtained from the mature capsule of the cotton plant, a shrub about 40 cm high, with leaves and flowers of a red or yellow colour. When the flower is fecundated it loses its petals and within 25 days a capsule surrounded by a leaf called bract grows. The capsule is sustained by a cup and has a drop shape rounded at the bottom. Inside the capsule there are from five to eight seeds on which the fibre developed. When the capsule is mature it opens into four parts showing the cotton ball. In the same plant the maturation of the capsules does not occur simultaneously, therefore more passages are required for the harvest of the cotton. The harvest is carried out a week after maturation. The first operation after harvesting is husking, which enables the removal of the fibres from the seeds. Then the cotton is carded and combed so as to eliminate all the impurities. The criteria for judging the quality of cotton are: the grade the colour the length of the fibres the character.
The grade is given by the external appearance of the cotton and is determined on the basis of the brightness of the fibres, by its more or less white colour, the presence of particles on the leaf or other foreign substances. The colour is another important element in the evaluation of cotton. Thus, the whiteness of cotton determines the ease with which later workings are carried out and the possibility of obtaining good yarns. The colour of cotton fibres differs greatly: that of cultivated cotton is generally white, more or less candid or tending towards grey; but there are also reddish, tawny, chamois, etc. coloured varieties. The length is the most important attribute of the fibre. In this regard, cotton is divided into two large categories: long fibre cotton (long stapled), which measures more than 28 mms and amongst which Sea Island in the United States holds the record and the Egyptian MakĂ˛ and Sakellaridis which arrive at and sometimes exceed 50 mms, and short fibre cotton (short-stapled), that does not reach the length of 18 mms and originates from Asian regions; there is also an intermediate category of cottons whose fibre length is included between 18 and 28 mms, such as those from the United States Uplands and which comprise the majority of the world production, 60% and more. The character is the attribute that is determined with the most difficulty. It is in part connected with the origin, variety and maturity, but in the end a cotton of good character is that whose fibres are the strongest and most robust, so as to resist traction and breakage, homogenous and uniform, so as to produce few losses in working, and have a complete physical-chemical constitution, so as to give the cotton mass notable solidity and compactness, smoothness and silkiness. The biggest cultivations of cotton are to be found in America, India, China, Egypt, Pakistan, Sudan and Eastern Europe. In Italy there are cotton cultivations in Sicily.
Properties of cotton. 95% composed of cellulose, cotton is the material with which more than 90% of men's shirts are manufactured. It has properties that make it particularly suitable to be worn in contact with the skin. Soft and light, cotton allows the skin to breathe and has good absorption capabilities; unlike wool it does not felt in washing, but, on the contrary, tends to become softer. It is a very resistant fibre that does not wear, but rips; it is dyed easily and the colour holds in washings, which are tolerated even at high temperatures. How to treat cotton items White cotton items should be washed in the washing machine at 600 째C, whilst coloured clothes, especially if dark, should be washed at lower temperatures. Normally they should be ironed on the right side. Dark items should be first ironed on the inside and then on the outside, with a cloth, to prevent the heat of the iron from shining the cloth. White items can be starched to give more consistency to the fabric and avoid it creasing easily.
LINEN The fibre is obtained from the stalk of a plant (Linum Usitatissimum) which is from 80 to 120 cm high, with few branches and small flowers, of a colour which varies from white to intense blue, which flowers only for one day. The linen plant is uprooted in such a way as to obtain the maximum length of the fibres. The stalks are left to macerate so that the fibres can rid themselves of the rubber like substances that cover them tying them into bundles. After the maceration, separation of the textile fibres from the woody residues occurs and then the carding which eliminates the shorter fibres and impurities. At this point the fibre is ready for spinning, which can be dry or humid, i.e. with the passage of the fibres in water. Humid spinning produces a finer, more regular and resistant thread, above all suitable for the production of fabrics for clothing.
Linen properties 70% composed of cellulose, it cannot provoke allergies, absorbs humidity and allows the skin to breathe: therefore it is very indicated in the manufacture of summer items. Very resistant, above all if wet it can be washed many times without being altered, rather it becomes softer, which is very important for items of clothing and for daily use which requires frequent washing such as shirts. Having very low elasticity, linen fabrics are not subject to deformations. How to treat inen items. White items should be washed in the washing machine at 60째C, whilst coloured ones at a lower temperature. White items should be ironed damp with a very hot iron, even steam, first on the inside, then on the outside. Coloured items, especially if dark, should be ironed only on the inside. Starching is not needed as with ironing linen becomes stiff. If you hang the items folded in a suitcase over a bath of hot water, they will return to their original state: the steam will help soften the folds.
Animal fibre produced by the silkworm (Bombyx Mori). The newly born silkworm only eats mulberry leaves. Within 3/4 weeks it becomes adult and begins to seek a place to prepare its cocoon. From an opening under its mouth, the silkworm secretes a very fine filament which, upon contact with the air, solidifies and, guided by eight movements of the head, is arranged in layers forming the cocoon. The silkworm takes three or four days to prepare the cocoon, formed by about 20 to 39 concentric layers made up of a single thread. Inside the cocoon the silkworm transforms itself into a chrysalis and then into a butterfly. In nature, the butterfly leaves the cocoon, lives only the time necessary for fecundation and laying of eggs and then dies. In the cultivation of silkworms, in order not to damage the continuity of the thread, the cocoons are placed in boiling water to kill the chrysalis. A spatula removes the outside layers of the cocoon, then, having found the end of the single cocoons, the silk thread is rolled on reels.
There are three different types of silk thread: treated farmed silk, which is more regular and mostly used; Tussah silk obtained from cocoons which live in natural state, with large and irregular threads; Shantung silk obtained from the natural phenomenon of two silkworms who spin together the same cocoon, whose thread presents typical "flaming". Properties of silk. Silk reflects the light with an inimitable splendor and easily absorbs tints with a great richness of shades. The elasticity of the silk thread gives fabrics a particular resistance and the sheer contact with air maintains its freshness even without ironing. It is not resistant to sunlight and is easily stained by sweat. It is antiallergenic and maintains body heat. Real silk is recognizable to the touch and by its weight, but in case of uncertainty it is enough to burn a thread to be certain. If it is silk it will burn slowly emanating an odor of horn typical of animal fibres. How to treat silk items. It is preferable to dry clean silk items. If washed in water, before submerging the item entirely, it is appropriate to check the solidity of the colours by only wetting a corner. The items should be washed in warm water and neutral soap; they should not be rubbed and wrung. They should be rinsed in warm water and hung to dry in a ventilated place and far away from heat sources. Finally they should be ironed with a warm iron. Crepe-de-Chine is a silk cloth that shrinks with washing, but returns to its original shape after ironing.
ARTIFICIAL FIBRES Artificial fibres are obtained from natural products, such as cellulose. These substances, through chemical procedures, are made soluble and the solutions obtained, filtered through very small holes, are collected in a bath that coagulates the original substance under the form of more or less long filaments, or staple fibre. The beginning of the artificial fibre industry dates to about 1884, and the process were patented in France by Hilaire De Chardonnet. These filaments were also called artificial silks as, notwithstanding the different nature, they had the same brightness as silk. Later attempts were made to produce artificial fibres departing from animal proteins (milk) or vegetable (soya). Amongst the artificial fibres the most widely used are: rayon viscose rayon acetate cupro lyocell
THE MOST IMPORTANT ARTIFICIAL FIBRES
VISCOSE (CV) FIBRES
MAN MADE ORGANIC
Cellulose fibre obtained by the viscose process
Cellulose fibre having a high breaking force (BF) and a high wet modulus (Bw). The breaking force (BFc) in the conditioned state and the wet modulus (Fw) required to produce an elongation of 5 % are: BS > 1,3 LD + 2 LD FW > 0,5 LD
CUPRO (CUP) FIBRES
MAN MADE ORGANIC ARTIFICIAL
Fibra di acetato di cellulosa di cui meno del 92% ma almeno il 74% dei gruppi ossidrilici Cellulose fibre obtained by the Ă¨ acetilato cuprammonium process
ACETATE (CA) FIBRES
MAN MADE ORGANIC ARTIFICIAL
Cellulose acetate fibre in which less than 92 %, but at least 74%, of the hydroxyl groups are acetylated.
TRIACETATE (CTA): Cellulose acetate fibre in which at least 92 % of the hydroxyl groups are acetylated.
LYOCELL (CLY) FIBRES
MAN MADE ORGANIC ARTIFICIAL
Cellulosic fibre obtained by an organic solvent spinning process. It is understood that: 1) an “organic solvent” means essentially a mixture of organic chemicals and water 2) “solvent spinning” means dissolving and spinning without the formation of a derivative.
SYNTHETIC FIBRES These fibres are obtained from chemical synthetic compositions deriving from petroleum and reduced in more or less long filaments or staples. They are distinguished on the basis of the departing prime materials, organic or inorganic, and manufacture processes. Synthetic fibres entered the market after 1940 and immediately affirmed themselves due to the possibility of giving products with a vast range of properties, able to satisfy any need. Amongst the most used we remember polyester, polyamide (or nylon), acrylic, polypropylene and elastane (lycra). In general, for the manufacture of clothes, these fibres are used in 100%, or mixed with natural ones, obtaining soft, uncreasable and very resistant fabrics for many different end uses: apparel, furnishing, shoes, automotive, medical and technical uses.
THE MOST IMPORTANT SYNTHETIC FIBRES
Fibre composed of linear macromolecules having in the chain at least 85% by mass of acrylonitrile repeating units.
Fibre composed of linear macromolecules made up of aromatic groups joined by amide or imide linkages, at least 85% of the amide or imide linkages being joined directly to two aromatic rings and the number of imide linkage, if the latter are present, not exceeding the number of aramide linkages.
Fibre composed of linear macromolecules having in the chain more than 50% by mass of vinyl chloride or vinylidene chloride units (more then 65% in the case in which the rest of the chains is made up of acrylonitrile, the modacrylic fibres being thus excluded). The fibre is intrinsecally flame retardant.
MAN MADE ORGANIC SYNTHETIC
Fibre composed of at least 85% by mass of a segmented polyurethane and which, if stretched to three times its unstretched length, rapidly reverts substantially to the unstretched length when the tension is removed.
Fibre composed of linear macromolecules having in the chain at least 50% and less than 85% by mass of acrylonitrile. The fibre is intrinsecally flame retardant and is mainly used in safety upholstery fabrics and ecological furs.
POLYAMIDE (PA) FIBRES
MAN MADE ORGANIC SYNTHETIC
Fibre composed of linear macromolecules having in the chain recurring amide linkages,at least 85% of which are joined to aliphatic cycloaliphatic units.
MAN MADE ORGANIC SYNTHETIC
Fibre composed of linear macromolecules having in the chain at least 85% by mass of an ester of a diol and terephthalic acid.
MAN MADE ORGANIC SYNTHETIC
Fibre composed of linear macromolecules made up of saturated aliphatic hydrocarbon units in which one carbon atom in two carries a methyl side group, generally in an isotactic configuration and without further substitution.
The "textile chain" From the fibre to the end product: a global outlook of the textile industry
THE THEORETICAL PATTERN OF A TEXTILE CHAIN TEXTILE MACHINERY PRODUCTION INDUSTRY
FINAL PRODUCT MANUFA CTURING
STAPLE MAN MADE silk
CREATIVITY AND MARKETING A GOOD RELATIONSHIP WITH THE MAN MADE FIBRE INDUSTRY IS ANOTHER STRONG POINT FOR EVERY TEXTILE CHAIN
THE SPINNING OF STAPLE FIBRES
SPINNING DEFINITION The process of drawing and twisting fibers together to produce a thread or a yarn.
THE PRODUCTION PROCESS FROM FIBRE TO YARN FIBRE BALES
OPENING SORTING AND SCOURING
SLIVER DRAFT ROVING FRAME
COMBING TECHNOLOGICAL CYCLE
Combing is the first processing phase of the fibre, that is a mass of packed material in the same conditions as it has been collected. Aim of the combing is to order this material and to prepare it for the further processing step, that is the spinning.
SORTING Fibre sorting is necessary to obtain the maximum homogeneity possible among them. Itâ€™s important because the higher is their homogeneity during the first processing, the higher will be the quality of yarns and fabrics obtained from them. Similar fibres in colour, length, fineness and quality are grouped and processed and, thanks to the blending, mixed further together to reduce any difference among them at the lowest level.
This process is necessary to eliminate any impurity from fibres, it is carried out by passing the material through a series of bowls containing water at different temperatures. Regarding animal fibres (wool in particular) immersion is in water mixed with soap and soda-hash. In this way, fibres are cleaned, even if not completely: in fact, it is important that they maintain a percentage of their grease (about 0.5-0.6%) that will make further operations easier, spinning in particular, where fibers are submitted to tension and twisting. Grease lets them maintain a certain elasticity and manageability that will avoid excessive breaks and the risk of creating static electricity due to fibres crakling among each other and on machineries. Out from the washing bowls, fibres are squeezed and dried in drying machines.
CARDING It is the process thanks to whom fibres, from a shapeless mass are arranged for the first time and are cleaned from all the extraneous vegetable part that they may contain. The operation is carried out by machineries called cards that open carefully fibres; the result is a stretched fibres continuous ribbon.
PREPARING It consists of three passages into hackle drawing frames, then into doubling and ironing machines. The aim is to give major distribution and regularity to ribbons.
It is the phase when fibre ribbons are combed by metal-tooth combs, more or less fine, that make them smoother and homogeneous. Tufts are united to each other, discarding the shortest and obtaining ribbons with longer fibres.
It is the last combing process. Fibre ribbons are pulled through an ironing machine that further joins fibres, then they are treated in the back washing machine, made of a new bath in soapy water and, if necessary, whitener agents, followed by rinse and drying. Finally, ribbons go through the finishes drawing frame that reduces their weight to the optimal measure for spinning.
From wool combing lanolin is obtained, it is the wax normally produced by sheep's skin to protected and to maintain its characteristics. It is a completely natural grease and it is often used by pharmaceutical and cosmetic industries for its moisturizing properties.
THE YARN Yarn is understood as a collection of fibres placed together more or less homogeneously or regularly, to form one thread. This is stretched, that is, lengthened, twisting together the individual fibres in order to keep them together to form the thread, which resists traction. The fundamental division of the yarn is: carded yarn, in which the individual fibres are freely mixed, arranged in all directions and less twisted among them combed yarn, in which the fibres are arranged much more homogenously and regularly, arranged in parallel, stretched and twisted much more closely Another important element of classification of the yarn is the count, indicating the degree of fineness and is expressed with the relationship between weight and length. There is also the twist that is, the number of turns given to the yarn per linear metre, a factor that determines important characteristics, such as more or less soft texture, resistance to breakage, elasticity etc. To obtain colour or fancy effects, yarns of different colours are joined (mouline, jaspe) or added to threads with irregularities in form or structure (slubby, buttoned, bouclĂŠ, wavy) that give movement and a more varied appearance to fabric.
The first step: opening and feeding
Steel cylinder chromium plated or ceramic coated
Drowing roll scheme Roving bar for short staple processing
Roller for fibre up to 80 mm long
Draft of the full machine
1. Feed plate 2. Feeler roll 3. Draw rolls 4. Delivery rolls 5. Drawing sliver 6. Sliver coiling
Roving frame scheme Front feeding
Symmetrical spindle position in regard to the drawing
Costant speed flyers
Variable angular velicity spindles
Scheme of a ring spinnig frame
WINDER (OR CONER) DESCRIPTION 01. Unwinding speed up unit 02. Yarn end scissors 03. Preliminary slub catcher 04. Yarn tension device 05. Splicer 06. Electronic slub catcher 07. Cutting and stopping device 08. Waxing device 09. Retaining nozzle 10. Revolving pirn change
THE YARN COUNT
According with BISFA, count and titre, although widely used, are "deprecated terms" and should be replaced with linear density
The yarn count expresses the thickness of the yarn, and must be known before calculating the quantity of yarns for a known length of fabric. The yarn count number indicates the length of yarn in relation to the weight.
the yarn count
Three systems of yarn count are currently in use: the fixed weight the fixed length the Tex systems.
1. The fixed weight system The fixed weight yarn count system is used for numbering spun yarns. It is based on the length of the yarn per Kg. weight. The greater the length of the yarn weighting 1 Kg., the finer it is, and the higher the count number. Nm 1 = L (1.000 m) / P (1.000 gr) Nm 20 = a hank of yarn 20.000 m long, weigthing 1.000 gr
the yarn count
Plied Yarns When a yarn is plied, that is, when two yarns of identical count are twisted together, the yarn is twice as thick, and therefore the length of yarn per Kg is halved. The numbering of the yarn states both the count of the single component and the number of components that make up the ply.
the yarn count
2. The fixed length system This system in used to number continuous filament yarns, ie: reeled silk and man-made yarns such as nylon. It is based on a fixed yarn length to a variable weight and is measured in deniers. The denier count of a yarn states the weight in grams per 9000 meters. The coarser the yarn, the higher the denier count number becomes. Thus: 9000 meters of 30 denier yarn weighs 30 grams.
the yarn count
3. The Tex system. The Tex system is also based on the fixed length system. Ie: Weight per unit length. The Tex count represents the weight in grams per 1 kilometre (1000 meters) of yarn. For example, a yarn numbered 10 Tex weighs 10 grams per kilometre. The Tex number increases with the size of the yarn. The yarns are labelled according to an international code. The yarn count number is followed by "Tex". The term "folded" is used in preference to "plied" yarn when two or more yarns are twisted together, and the direction of the twist is included in the formation.
the yarn count
small glossary of yarns BOUCLE' - this is an irregularly curled yarn, which forms small rings or knots, used in knits and woollen fabrics, which gives it a fancy surface BOUTONNE' - yarn with the effect of knops and slubs also in various colours, used both in knits and fabrics such as Donegal and tweed CHINE' - literally means mottled, faded, or striped by printing or dying. This is also said of yarn printed in hanks to create this effect on the fabrics. CHENILLE - very fluffy twisted yarn, with thick, voluminous wisps of fur, for fabrics with an appearance similar to velvet, but softer and more open SLUBBY YARNS - slubs are irregular enlargements that usually constitutes a defect in the yarn. Deliberately taking advantage of this effect, threads are created that present enlargements at deliberate intervals, with which fancy knits or fabrics such as shantung (slubby fabrics) are produced JASPE' - yarn in which fibres of various colours are mixed homogeneously, with a mottled and fused effect, without contrasts in tone ONDE' - fancy yarn obtained by twisting, with wave spiral effects
from yarn to fabric
THE PRODUCTION PROCESS FROM YARN TO FABRIC
WARPING SIZING WEAVING
from yarn to fabric
DEFINITIONS WARPING The process of producing the parallel lengthways threads winded on the beam, to weave a fabric
SIZING The application of a gelatinous film to the warps prior to weaving. Used to protect the yarn from abrasion. Substances used include starch and polyvinyl alcohol. WEAVING The method or process of interlacing two yarns of similar materials so that they cross each other at right angles to produce a woven fabric.
from yarn to fabric
THE WEAVE CYCLE The weave cycle is quite similar, as a procedure, for all types of fabric produced. The methods vary however, according to the weave and the type of loom, and so production speed and characteristics also vary. In the area of automatic mechanical looms, we have found the super fast shuttleless models, while for certain valuable productions, jacquard looms are still used, which are very complex and slow. The preparation for the weave, that is, the warp, means placing the threads that form the warp chain according to an order preestablished by designers, and which, being raised and lowered in the loom, form the weaving. The loom moves the various warp threads alternately up and down, and the shuttle is "shot" between these, carrying the spool from which the weft is unwound, forming the weaving.
from yarn to fabric
sizing machine scheme
from yarn to fabric
1. Warp beam 2. Warp 3. Heddle (heald) 4. Comb (reed) 5. Shuttle 6. Weft 7. Cloth roller
from yarn to fabric
THE MOST IMPORTANT WEAVES
from yarn to fabric
FUNDAMENTAL WEAVES The yarn composes the fabric according to certain interlacing or weave; that is, the way in which wefts and warps are linked and interwoven. The weave indirectly influences not only the aesthetics but also the structural characteristics of the fabric. An infinite number of existing weaves derive from three fundamental types: plain weave saia weave satin weave
from yarn to fabric
PLAIN WEAVE Also called "taffeta," it is the simplest and most widespread. Every thread of the weft is woven (that is, it passes over and under) to every warp thread, for every intersection of the threads. The plain weaves have equal forward and reverse lines, are very resistant, and present a regular surface. Among the variants, the following are worthy of note: natte or panama weave, which uses two or more threads in parallel in weft and chain oxford weave, used primarily in light fabrics for shirts, is obtained with two warp threads and oneweft thread rep or ribbed weave increases different weft and warp threads in number and proportions, obtaining an edge effect
from yarn to fabric
SAIA WEAVE Also called "batavia," this weave is the basis for the clothing fabric and is characterised by a very regular diagonal ribbing, from lower left to upper right. In the saia weave, the intersection of the warp and weft threads is repeated at regular intervals, but offset diagonally. The saias are more elastic than plain fabrics, very resistant, and allow a great combination of designs, among which are the twills, in which the twill weave is used, which is obtained by alternatively inverting the diagonal direction of the saia at brief intervals.
from yarn to fabric
SATIN WEAVE Also called "sateen", it brings together points of intersection, or tying, very wide-spaced and far apart, giving the surface of the fabric a smooth and uniform appearance, shiny and soft. Satins, however, are not "tight" and so are less resistant and easier to fray. Five- and eight-count satins are very widespread, in which the warp is woven every 5 or 8 wefts. Other variants are Turkish or Duchess satin.
from yarn to fabric
CLASSIFICATION OF FABRICS WITH SURFACE EFFECTS
SIMPLE those obtained from a warp and from a weft on normal looms
COMPOSITE those obtained with several warps and several wefts on special looms
WITH DESIGN OR COLOUR EFFECTS
satins gauzes or felts pile fabrics plain dyed (dyed in the piece) patterns (by coloured threads) figured (background designs) printed fabrics embroidered
double fabrics (two series of threads in chain and in weft) multiple fabrics (with three or more series of warps and wefts) double face (the two wefts and warps give different colours or design) terry (a thread from a additional warp forms curled rings)
little glossary of fabrics BROCADE- a heavy and very rich fabric, generally of pure silk, with relief effects on the embroidery, often on a gold- or silver-coloured background CADY - combed fabric of cotton, wool or other fibre, used for elegant clothing CALENDERED - fabric passed through the "rollers," or rotating cylinders that stretch it to give it a smooth and flattened appearance, or to make designs in it RIBBED - said of the fabrics with "ribbing," with distanced edges, usually strong and compact CASENTINO - wool cloth originating from the Tuscan area of the same name, rustic but soft, with pile of medium height, slightly ruffled CHIFFON - a very fine and light fabric (gr. 40 or 50 per metre), of silk or other fibre, in soft and twisted thread, transparent as a veil SELVEDGE - also called "chain selvage", this is the lateral border of the material, in general thicker and more resistant, in which the brand or the trademark of the manufacturer or other text is sometimes woven ("speaking" selvage) CORDUROY- a particular textile weave to obtain design effects
little glossary of fabrics CREPE - generic name of the fabrics with characteristic nubby, crepe, wavy or mobile appearance, obtained from weave effects, or more often using the high-torsion yarn of the same name DAMASK - is a jacquard fabric of oriental origin initially woven on hand looms, with closer and more rigid warp and weft than brocade. Often it is produced in a single colour, with brilliant yarns that create designs with chiaroscuro relief DAMIER -design with alternating and contrasting checks or squares, small or medium, like a checkerboard DECATIZING - the final operation with which fabrics are treated to eliminate distortions from pressing, dampening the fabric to fix its stable dimensions DONEGAL - an originally Irish tweed made by hand. Today, in addition to being carded, it is also found in semi-combed. The appearance is rugged and sporty, with soft texture; the surface has many coloured nubs FELT - woven cloth, but also nonwoven, which is obtained using the felt property of the wool. Felts are also wools or rabbit fur
little glossary of fabrics FLANNEL - this is a classic for clothing, of medium or light weight, with a rather compact structure, soft and warm texture, felted or gauze. Combed flannel is more resistant and finer; carded flannel, also called vicuna, is soft and delicate. FUSTAIN - robust cotton fabric, made with very resistant thread, gauzed on the front to resemble a more or less sueded velvet GABARDINE - this is a basic fabric for clothing, elastic and resistant, with a diagonal weave and a close and smooth structure, closely shaved. The warp is of double density compared to the weft and the weights are variable from summer types to heavier ones GAUZED - this is any fabric from which the pile has been removed after having been felted, running in contact with rotating cylinders provided with metallic points (gauze) or vegetal burrs LENO WEAVE - special weave with a double warp thread, which "turns" around the weft threads avoiding running and gives the fabric more stability EMBOSSED - beehive fabric with relief and groove effects forming geometric designs, made by a weave effect or engraved with a calendar
little glossary of fabrics GRISAILLE - this is a classic male fabric design, with a subtle diagonal outline effect, excellent in different weaves and weights GROSGRAIN - fabric with a course grain, with pronounced warp ribs, also used as trim MERCERIZED - cotton or linen that has undergone mercerizing treatment with a chemical bath that gives luster, elasticity and substance to the thread and fabrics NATTE - also called "panama" or "stitch," this is a cloth weave in which several threads work in tandem, in weft and warp, creating heavy but loosely woven fabrics, with marked designs, similar to mats, used in woolen ORGANZA - a fine and light cotton muslin, (from 30 to 40 gr and more) very transparent, made with very highcount thread, reinforced by a rigid polish OTTOMAN - combed medium-weight fiber with a close structure and well delineated edges horizontal, obtained with course weft threads that are covered by a soft warp thread CLOTH - generically, for very dense and felted woolen fabrics
little glossary of fabrics SHEARED - this is non-gauzed combed fabric, well sheared, without fuzz TWILL - also called "herring bone," this is a basic design, obtained from saia weave by inverting the direction of the diagonals at intervals TAFFETA - generic term indicating woven fabrics of silk or cotton TWEED - carded fabric of medium or winter weight with a coarse grain a bit rough, with fantasy designs in two or three nubby colours or (Harris Tweed) VELVET - in general, all the fabrics having a surface with a thick nap perpendicular to the weave, smooth, lustrous and compact. One variant is velvet with edges for a woven effect or for other procedures ZEPHIR - fine and light cotton fabric (but also wool), twisted in two layers, especially for shirts ZIBELINE - from the name of a small furry animal, in woolens, it indicates a cloth with oriented nap or a fabric carded to a nap, with silky reflections similar to that of fur, obtained with strong felting, gauzed and stretched, and then trimmed in dip
DEFINITION OF KNITTED FABRIC While in what is called "shuttle" weave, the fabric is formed by different interwoven warp and weft threads, always crossing at right angles, the knit is formed by a single thread, which has a curved lines, and that is linked by the needles in a series of interlocked rings, called knits. This makes production simpler and more economical and is noted for speed and flexibility, greater than that of traditional fabrics illustration of a weft knit
illustration of a warp knit production of warp knit
flat knitting machine
circular knitting machine
A manufactured sheet, web or batt of directionally or randomly orientated fibres, bonded by friction, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted, tufted, stitchbonded, incorporating bonding yarns or filaments, or felted by wet-milling wether or not additionally needled. The fibres may be of natural or man-made origin. They may be staple or continuous filaments, or be formed in situ.
TEXTILE FINISHING The goal of finishing fabrics is to provide to the market a valid product both from the aesthetic and functional point of view, meeting the technical requirements of the sewing industry and the consumers' comfort and performance requirements. This is obtained by promoting the intrinsic properties of the macromolecular fibres of the fabric, or enhancing them with the appropriate process Finishing, in fact, is often also called "refining." On rough fabric, just removed from the loom, there are essentially three treatments to undergo: to eliminate the foreign substances to develop the "finish," to confer on the finished fabric its fundamental components of texture and appearance to give proprieties that ensure optimal behaviour during sewing and use.
FUNDAMENTAL OPERATIONS During the finishing, the fabric undergoes a complex series of operations, rather variable according to the article, grouped in two fundamental subcycles: damp finishing (that can also include the dying)
dry finishing In short, it can be said that the former is the basis for the quality and the touch of the fabric; the latter develops and perfects it. The figure on the side shows the diagram of the finishing process.
DAMP FINISHING WASHING - This has the goal of eliminating the impurities accumulated in the course of the previous work and to cause the relaxation of internal tensions, with an effect on the texture. FULLING - Taking advantage of the felting phenomenon, typical of wool, gives the fabric, when required, a particular degree of compactness and mass per surface unit. SETTING - With numerous variations, it causes a "fixation" phenomenon, with effects both on the texture, and on the stability of later treatments, which can alter the structure of the fabric. CARBONIZATION - Through treatment with sulfuric acid, vegetal particles possibly present in the fabric are eliminated. GAUZING - If required for special finishing, this operation extracts the pile from the surface of the fabric, then orienting it in various ways through "scrubbing." The operation may be done on damp or dry fabric, on machines with vegetal or metallic raising teasel.
DRY FINISHING SHEARING - This has the goal of shaving or equalizing the pile to a specific height, in relation to the article being worked. A variant of the operation is "singeing." PRESSING - This operation gives the surface of the fabric a flatter and more lustrous aspect, and also provides moderate "setting." It can be continuous (calender) or discontinuous STEAMING - This is a treatment for relaxing the internal tensions, provoked by the action of the steam on fabric free from mechanical bonds. This causes a reduction of the dimensions of the fabric (shrinking), and better stability. DECATIZING - This is the fundamental operation for the purposes of touch and workability of the fabric: this is a "setting" action from the effect of the steam on a fabric subject to mechanical intervention. The effects that can be obtained are extremely varied, based on the process regulations: temperature of the steam, duration, nature of the mechanical intervention, operating mode and amount of humidity present in the fabric.
PRINCIPLE FINISHING TYPES They can be classified in three major categories: sheared finishing: this is typical of combed fabrics, in particular lightweight ones (for summer) and is characterized by the absence of felting, by deep shearing and the neat appearance, which brings out the design. felted finishing: felting leads to a compact fabric with a more fused appearence, with a less evident weave and light superficial fuzz. It is applied primarily to carded fabrics. nap finishing: normally reserved for carded fabrics (previously felted), is characterized by the gauzing operation. According to the means of working and based on the appearance of the nap (short or long, lying down or not...), it is divided into numerous subcategories: velour, loden, drape, etc...
THE DYEING PROCESS The dyeing process is aimed at giving woven or knitted fabric its intended colour, crucial to its end use. It can be carried out at different stages of fibre processing, i.e. in different forms: staple, yarn, fabric (rope or open-width), and piece. When the dyeing process is carried out during the first processing stages, for example on staple fibres, a better colour fastness can be achieved; Yarn dyeing is carried out after the fibre has been spun into yarn. Yarn dyeing is preferred for manufacturing Jacquard or striped fabrics; this dyeing method grants a good colour fastness since the dye penetrates the fibres and reaches the yarn core. Skeins are dyed in hanks, spools are dyed in autoclaves and warp yarns are dyed in perforated beams loaded in autoclaves. Piece dyeing is carried out on several types of machines and the material can be open-width or rope dyed. The most important processes for piece dyeing are: jigger system jet (or rope) system beam system
The drawings of these equipments for piece dyeing are in the following pages
These machines have been used for a long time to treat medium-size lots of woven with an open-width exhaust dyeing process. The fabric moves while the liquor stands still, except for the very latest machines, which are also equipped with a circulation pump.
Drawing of a jigger system
These machines, where both liquor and material move, are used for rope dyeing and preparation; the fabric is carried over and driven through the machine only by the fluid force. These systems run with high temperatures (maximum temperature ranges between 135 and 140째C).
8 9 4
Drawing of a jet system
1. jet 2. guide roller 3. transport tube 4. heat exchanger 5. liquor circulating pump
6. auxiliary pump 7. vat for adding liquor 8. fabric and dwelling vat 9. magnet signal system 10. by-pass valve
The diffusion of polyester - a material requiring very high dyeing temperatures (up to 140째C) - led to the extensive application of beam dyeing machines; they essentially included a dyeing autoclave with circulating liquor, with the open-width fabric lying on a perforated beam provided with plates.
Drawing of a beam dyeing machine
Printing could be referred to as a sort of selective dyeing that makes an important contribution to fabric decoration thanks to the combination of colours and dyeing methods. To obtain sharply defined, precise and reproducible patterns, the dyebaths traditionally used are not sufficient, because of the capillarity and/or hygroscopicity of fibres and migration of dyes that cannot grant sharp and well-defined colour patterns. It is therefore necessary to use special liquids, conventionally called "printing pastes", whose main characteristic is a high degree of viscosity. As a consequence, the dyestuff applied on the fabric in well-defined areas to reproduce the desired pattern cannot migrate to other areas of the fabric. The application of the print dye on the fabric is carried out by forcing it through the gray fabric on special printing blocks or perforated hollow rollers applied onto the fabric; the dye is then fixed by a steaming process.
The three main technologies are: screen printing roller printing transfer printing
THE PRINTIG PROCESS
conveyor belt Flat screen printing machine screen
roller doctor knife fabric
Revolving cylinder screen printing machine
Drawing of a screen printing machine
Drawing of a roller printing machine
fabric feed rolling device
rubberized fabric pressure roll
Detail of a print head engraved print roll doctor knife (cleaning blade) dyestuff feeder roll dyestuff bowl
printed paper roll
Drawing of a transfer printing machine
cylinder warmed up to 170/180째 C
After the launch and diffusion of synthetic resins, the so called "coating and bondingl" applications have been experiencing an extraordinary growth, above all in Italy. Coated and bonded fabrics are now simply classified, according to their end use, i.e. for garments, upholstery, draperies and tapestries, footwear, leather goods and technical articles. Generally the process starts from a fabric or from a nonwoven fabric as a "backing". All fibres can be used, from light silk to linen and hemp, from synthetic fibres to glass fibres. As regards the resins used for the coating layer, manufacturers once employed only natural substances, but are now using almost exclusively synthetic polymers of high molecular weight. These coating polymers are bonded to the fabric backing by means of calenders, in the form of thin sheets or are mainly spread in the form of aqueous dispersions or solutions in solvents. The characteristics and properties of coated fabrics depend on the chemical structure of the coating resins applied and the type of backing fabric used.
COATING AND BONDING
bonding zone drying oven
bonding zone coating frame
MEMBRANE LAMINATING A process for transferring a thin polymeric film (membrane) to a woven fabric. The thin layer applied on the fabric imparts the desired properties of good breathability and waterproofness, while maintaining the soft feel and drape of the fabric.
Gore-Tex, a registered trademark of W.L. Gore & Associates, is the best known membrane on the market, for its use in relation to waterproof and breathable fabrics. Gore-Tex materials are typically based on thermo-mechanically expanded polytetrafluoroethylene PTFE, and other Fluoropolymer products. They are used in a wide variety of applications such as high performance fabrics, medical implants, filter media, insulation for wires and cables, gaskets and sealants. Gore-Tex based fabric material is composed of a thin, porous fluoropolymer membrane with a urethane coating that is bonded to a fabric, usually nylon or polyester. The membrane has about 9 billion pores per square inch, each of which is approximately 20,000 times smaller than a water droplet, making it impenetrable to liquid water, while still allowing the smaller sized water vapour to pass through. The result is a material that is breathable, yet waterproof and also windproof. The best known application for Gore-Tex is in outdoor activity clothing and shoes. In this context, it helps keep the wearer 1. Wind and water are bocked protected from the wind and rain, while 2. Body moisture vapour passes through PTFE micropores 3. Outer shell nonetheless allowing sweat 4. GORE-TEX PTFE membrane 5. Inner layer to evaporate and escape. 6. Oleophobic (oil repelling) coating
QUESTA PUBBLICAZIONE E’ DISPONIBILE ANCHE IN ITALIANO CLICCANDO QUI