Finishing (textiles)
Encyclopedia
In textile manufacturing
, finishing refers to any process performed on yarn
or fabric
after weaving
or knitting
to improve the look, performance, or "hand" (feel) of the finished textile or clothing
. Some finishing techniques, such as fulling, have been in use with hand-weaving for centuries; others, such as mercerisation, are byproducts of the Industrial Revolution
.
fabric is necessary to make it crease-free or wrinkle
-free. In a similar way, mercerising, singeing, flame retardant
, water repellent, waterproof, anti-static and peach finishing achieve various fabric properties desired by consumers.
The use of 100% synthetic textiles has increased considerably since the development of textured yarns made of filaments, and the growing production of knit goods. The use of open weave has enabled production of lighter, breathable, fabrics to ensure better wearing comfort.
The properties of plastic
-based synthetic fiber
s, most important among them being polyamide
, polyester
and polyacrylonitrile
, are essentially different from those of natural cellulosic and wool
fibers. Hence the sequence of finishing operations is likely to be different. While cellulosic fabrics require a resin
finishing treatment to impart easy-care properties, synthetic fibers already exhibit these easy-care criteria and require only a heat setting operation.
. Enzymes, such as cellulase
for cotton, selectively remove protruding fibers. These enzymes may be deactivated
by an increase in temperature.
Mercerisation makes woven cotton fabric stronger, more lustrous, to have better dye affinity, and to be less abrasive.
Raising
lifts the surface fibers to improve the softness and warmth, as in flannelette.
Peach Finish subjects the fabric (either cotton or its synthetic blends) to emery wheels, making the surface velvet
-like. This is a special finish used mostly in garments.
Fulling
or waulking adds weight and density and decatising
to bring dimension stability to woolen
fabrics.
Calendering
makes one or both surfaces of the fabric smooth and shiny. The fabric is passed to through hot, fast-moving stainless steel
cylinders.
Sanforizing
or Pre-shrinking prevents a fabric and the produced garment from shrinking after production. This is also a mechanical finish, acquired by feeding the fabric between a roller and rubber blanket, in such a way the rubber blanket compresses the weft
threads and imparts compressive shrinkage.
Crease-Resist finish or "wash-and-wear" or "wrinkle-free" finishes are achieved by the addition of a chemical resin finish that makes the fiber take on a quality similar to that of synthetic fibers.
Anti-microbial finish causes a fabric to inhibit the growth of microbes. The humid and warm environment found in textile fibers encourages the growth of the microbes. Infestation by microbes can cause cross-infection by pathogen
s and the development of odor where the fabric is worn next to skin. In addition, stains and loss of fiber quality of textile substrates can also take place. With an aim to protect the skin of the wearer and the textile substrate itself, an anti-microbial finish is applied to textile materials.
Stiffening and filling process: A stiffening effect is desirable in certain polyamides and polyester materials (e.g. petticoats, collar inner linings), which can be done by reducing the mutual independence of structural elements of fabric by polymer deposition on coating
as a fine film.
Hydrophilic finishes
compensate for lower moisture and water absorption capacity in synthetic fiber materials, which become uncomfortable in contact with skin. Certain products, based on modified (oxy-ethylated) polyamides, make the fabric more pleasant by reducing the cohesion of water so that it spreads over a larger area and thus evaporates more readily.
Anti-pilling finish alleviates pilling
, an unpleasant phenomenon associated with spun yarn fabrics, especially when they contain synthetics. Synthetic fibers are more readily brought to the surface of a fabric due to their smooth surface and circular cross-section
, and due to their higher tensile strength
and abrasion
resistance. With knit
"picking" also occurs: by abrasion, individual fibers work themselves out of yarn loops onto the surface, and the garment catches on a pointed or rough object. Knitting is susceptible to these effects due to the open weave and bulky yarn.
Anti-static finish prevents dust from clinging to the fabric. Anti-static effective chemicals are largely chemically inert
and require Thermasol or heat treatment for fixing on polyester fabrics. Polyether agents have been found to be useful but should not effect the dye-equilibrium on fiber, lest they impair the rubbing fastness. In general, Thermasol anti-static agents also have a good soil release action, which is as permanent as the anti-static effect. Anti-static finishes may also be of polyamide type, being curable at moderate temperatures.
Non-slip finishes give the filaments a rougher surface. Synthetic warp
and weft threads in loosely-woven fabrics are particularly prone to slip because of their surface smoothness when the structure of fabric is disturbed and appearance is no loner attractive. Silica gel
dispersions or silicic acid colloidal solutions are used in combination with latex polymer or acrylate
s dispersions to get more permanent effect, along with simultaneous improvement in resistance to pilling or snagging
. These polymer finishes are also capable of imparting a soft and smooth handle to synthetic fabric without making it water repellent.
Fire Resistant or Flame Retardant finish
: to reduce flammability
.
Anti-microbial finish: with the increasing use of synthetic fibers for carpets and other materials in public places, anti-microbial finishes have gained importance. Products which are commonly applied are brominated phenol
s, quaternary ammonium compounds
, organo-silver
and tin compounds, which can be applied as solutions or dispersions. They can also be incorporated in a polymeric film deposited on the surface to achieve controlled release.
Textile manufacturing
Textile manufacturing is a major industry. It is based in the conversion of three types of fibre into yarn, then fabric, then textiles. These are then fabricated into clothes or other artifacts. Cotton remains the most important natural fibre, so is treated in depth...
, finishing refers to any process performed on yarn
Yarn
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...
or fabric
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...
after weaving
Weaving
Weaving is a method of fabric production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. The other methods are knitting, lace making and felting. The longitudinal threads are called the warp and the lateral threads are the weft or filling...
or knitting
Knitting
Knitting is a method by which thread or yarn may be turned into cloth or other fine crafts. Knitted fabric consists of consecutive rows of loops, called stitches. As each row progresses, a new loop is pulled through an existing loop. The active stitches are held on a needle until another loop can...
to improve the look, performance, or "hand" (feel) of the finished textile or clothing
Clothing
Clothing refers to any covering for the human body that is worn. The wearing of clothing is exclusively a human characteristic and is a feature of nearly all human societies...
. Some finishing techniques, such as fulling, have been in use with hand-weaving for centuries; others, such as mercerisation, are byproducts of the Industrial Revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...
.
Introduction
In order to impart the required functional properties to the fiber or fabric, it is customary to subject the material to different types of physical and chemical treatments. For example, wash and wear finish for a cottonCotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
fabric is necessary to make it crease-free or wrinkle
Wrinkle
A wrinkle is a fold, ridge or crease in the skin. Skin wrinkles typically appear as a result of aging processes such as glycation or, temporarily, as the result of prolonged immersion in water. Wrinkling in the skin is caused by habitual facial expressions, aging, sun damage, smoking, poor...
-free. In a similar way, mercerising, singeing, flame retardant
Flame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
, water repellent, waterproof, anti-static and peach finishing achieve various fabric properties desired by consumers.
The use of 100% synthetic textiles has increased considerably since the development of textured yarns made of filaments, and the growing production of knit goods. The use of open weave has enabled production of lighter, breathable, fabrics to ensure better wearing comfort.
The properties of plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
-based synthetic fiber
Synthetic fiber
Synthetic fibers are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread...
s, most important among them being polyamide
Polyamide
A polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, such as wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids,...
, polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
and polyacrylonitrile
Polyacrylonitrile
Polyacrylonitrile is a synthetic, semicrystalline organic polymer resin, with the linear formula n. Though it is thermoplastic, it does not melt under normal conditions. It degrades before melting. It melts above 300 degrees Celsius only if the heating rates are 50 degrees per minute or above...
, are essentially different from those of natural cellulosic and wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
fibers. Hence the sequence of finishing operations is likely to be different. While cellulosic fabrics require a resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
finishing treatment to impart easy-care properties, synthetic fibers already exhibit these easy-care criteria and require only a heat setting operation.
Quality-oriented
- CalenderingCalenderingCalendering is a finishing process used on cloth where fabric is folded in half and passed under rollers at high temperatures and pressures. Calendering is used on fabrics such as moire to produce its watered effect and also on cambric and some types of sateens.In preparation for calendering, the...
- DecatisingDecatisingDecatising or decatizing, also known as crabbing, blowing, and decating, is the process of making permanent a textile finish on a cloth, so that it does not shrink during garment making. The word comes from the French décatir, which means to remove the cati or finish of the wool...
- DesizingDesizingDesizing is the process of removing the size material from the warp yarns in woven fabrics.-Sizing agents:Sizing agents are selected on the basis of type of fabric, environmental friendliness, ease of removal, cost considerations, effluent treatment, etc.-Natural sizing agents:Natural sizing agents...
for woven fabrics. - Pressing
- ShrinkingShrinkage (fabric)Shrinkage is when a fabric becomes smaller than its original size, usually through the process of laundry. Novice users of modern laundry machines sometimes experience accidental shrinkage of garments, especially when applying heat. Others may intentionally try to shrink a garment in their size...
, SanforizationSanforizationSanforization is a process of treatment used for cotton fabrics mainly and most textiles made from natural or chemical fibres, patented by Sanford Lockwood Cluett in 1930... - ScouringTextile bleachingTextile bleaching is one of the stages in the manufacture of textiles. All raw textile materials, when they are in natural form, are known as 'greige' material. This greige material will be with its natural color, odour and impurities that are not suitable for clothing materials...
with detergents, alkaline solutions, or enzymes removes foreign matter. - Shearing or singeing smooths the fabric by removing the fine protruding fibers on the surface of the fabric. Flame singeing is the standard process: the wet fabric is passed through an array of gas burners at a suitable distance to burn the pillsPill (textile)A pill, colloquially known as a bobble, is a small ball of fibres that forms on a piece of cloth from wear. Pill is also a verb for the formation of such balls....
off of its surface.
Design-oriented
- BleachingTextile bleachingTextile bleaching is one of the stages in the manufacture of textiles. All raw textile materials, when they are in natural form, are known as 'greige' material. This greige material will be with its natural color, odour and impurities that are not suitable for clothing materials...
of woven fabrics removes any prior color in order to obtain a uniform color during the dying process. - DyeingDyeingDyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is normally done in a special solution containing dyes and particular chemical material. After dyeing, dye molecules have uncut Chemical bond with fiber molecules. The temperature and time controlling...
adds color. - PrintingTextile printingTextile printing is the process of applying colour to fabric in definite patterns or designs. In properly printed fabrics the colour is bonded with the fiber, so as to resist washing and friction...
adds color and pattern. - Watering adds moiré patternMoiré patternIn physics, a moiré pattern is an interference pattern created, for example, when two grids are overlaid at an angle, or when they have slightly different mesh sizes.- Etymology :...
s.
Handle-oriented
- FullingFullingFulling or tucking or walking is a step in woolen clothmaking which involves the cleansing of cloth to eliminate oils, dirt, and other impurities, and making it thicker. The worker who does the job is a fuller, tucker, or walker...
or waulking adds weight and density. - Hydrophobic finishing produces a fabric that repels stains or water.
- WeightingWeighted silkThe process of "weighting" silk fabric is the addition of metallic salts during processing for the purpose of increasing the weight of the finished goods.Unlike most fabric/yard goods which are sold by the yard , silk is sold to the wholesaler by weight...
silk with metallic salts or polymer adds weight and improves handle.
Special finishes for natural fibers
Bio-polishing removes the protruding fibers of a fabric through the action of an enzymeEnzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
. Enzymes, such as cellulase
Cellulase
400px|thumb|right|alt = Colored dice with checkered background|Ribbon representation of the Streptomyces lividans beta-1,4-endoglucanase catalytic domain - an example from the family 12 glycoside hydrolases...
for cotton, selectively remove protruding fibers. These enzymes may be deactivated
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
by an increase in temperature.
Mercerisation makes woven cotton fabric stronger, more lustrous, to have better dye affinity, and to be less abrasive.
Raising
Nap (textile)
Primarily, nap is the raised surface on certain kinds of cloth, such as velvet. Nap can refer additionally to other surfaces that look like the surface of a napped cloth, such as the surface of a felt or beaver hat....
lifts the surface fibers to improve the softness and warmth, as in flannelette.
Peach Finish subjects the fabric (either cotton or its synthetic blends) to emery wheels, making the surface velvet
Velvet
Velvet is a type of woven tufted fabric in which the cut threads are evenly distributed,with a short dense pile, giving it a distinctive feel.The word 'velvety' is used as an adjective to mean -"smooth like velvet".-Composition:...
-like. This is a special finish used mostly in garments.
Fulling
Fulling
Fulling or tucking or walking is a step in woolen clothmaking which involves the cleansing of cloth to eliminate oils, dirt, and other impurities, and making it thicker. The worker who does the job is a fuller, tucker, or walker...
or waulking adds weight and density and decatising
Decatising
Decatising or decatizing, also known as crabbing, blowing, and decating, is the process of making permanent a textile finish on a cloth, so that it does not shrink during garment making. The word comes from the French décatir, which means to remove the cati or finish of the wool...
to bring dimension stability to woolen
Woolen
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...
fabrics.
Calendering
Calendering
Calendering is a finishing process used on cloth where fabric is folded in half and passed under rollers at high temperatures and pressures. Calendering is used on fabrics such as moire to produce its watered effect and also on cambric and some types of sateens.In preparation for calendering, the...
makes one or both surfaces of the fabric smooth and shiny. The fabric is passed to through hot, fast-moving stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
cylinders.
Sanforizing
Sanforization
Sanforization is a process of treatment used for cotton fabrics mainly and most textiles made from natural or chemical fibres, patented by Sanford Lockwood Cluett in 1930...
or Pre-shrinking prevents a fabric and the produced garment from shrinking after production. This is also a mechanical finish, acquired by feeding the fabric between a roller and rubber blanket, in such a way the rubber blanket compresses the weft
Weft
In weaving, weft or woof is the yarn which is drawn through the warp yarns to create cloth. In North America, it is sometimes referred to as the "fill" or the "filling yarn"....
threads and imparts compressive shrinkage.
Crease-Resist finish or "wash-and-wear" or "wrinkle-free" finishes are achieved by the addition of a chemical resin finish that makes the fiber take on a quality similar to that of synthetic fibers.
Anti-microbial finish causes a fabric to inhibit the growth of microbes. The humid and warm environment found in textile fibers encourages the growth of the microbes. Infestation by microbes can cause cross-infection by pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s and the development of odor where the fabric is worn next to skin. In addition, stains and loss of fiber quality of textile substrates can also take place. With an aim to protect the skin of the wearer and the textile substrate itself, an anti-microbial finish is applied to textile materials.
Special finishes for synthetic fibers
Heat-setting of synthetic fabrics eliminates the internal tensions within the fiber, generated during manufacturing, and the new state can be fixed by rapid cooling. This heat setting fixes the fabrics in the relaxed state, and thus avoids subsequent shrinkage or creasing of the fabric. Presetting of goods makes it possible to use higher temperature for setting without considering the sublimation properties of dyes and also has a favorable effect on dyeing behavior and the running properties of the fabric. On the other hand, post-setting can be combined with some other operations such as Thermasol dyeing or optical brightening of polyester. Post-setting as a final finish is useful to achieve high dimensional stability, along with desired handle.Stiffening and filling process: A stiffening effect is desirable in certain polyamides and polyester materials (e.g. petticoats, collar inner linings), which can be done by reducing the mutual independence of structural elements of fabric by polymer deposition on coating
Coating
Coating is a covering that is applied to the surface of an object, usually referred to as the substrate. In many cases coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance...
as a fine film.
Hydrophilic finishes
Hydrophile
A hydrophile, from the Greek "water" and φιλια "love," is a molecule or other molecular entity that is attracted to, and tends to be dissolved by water. A hydrophilic molecule or portion of a molecule is one that has a tendency to interact with or be dissolved by, water and other polar substances...
compensate for lower moisture and water absorption capacity in synthetic fiber materials, which become uncomfortable in contact with skin. Certain products, based on modified (oxy-ethylated) polyamides, make the fabric more pleasant by reducing the cohesion of water so that it spreads over a larger area and thus evaporates more readily.
Anti-pilling finish alleviates pilling
Pill (textile)
A pill, colloquially known as a bobble, is a small ball of fibres that forms on a piece of cloth from wear. Pill is also a verb for the formation of such balls....
, an unpleasant phenomenon associated with spun yarn fabrics, especially when they contain synthetics. Synthetic fibers are more readily brought to the surface of a fabric due to their smooth surface and circular cross-section
Cross section (geometry)
In geometry, a cross-section is the intersection of a figure in 2-dimensional space with a line, or of a body in 3-dimensional space with a plane, etc...
, and due to their higher tensile strength
Tensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
and abrasion
Abrasion (mechanical)
Abrasion is the process of scuffing, scratching, wearing down, marring, or rubbing away. It can be intentionally imposed in a controlled process using an abrasive...
resistance. With knit
Knitting
Knitting is a method by which thread or yarn may be turned into cloth or other fine crafts. Knitted fabric consists of consecutive rows of loops, called stitches. As each row progresses, a new loop is pulled through an existing loop. The active stitches are held on a needle until another loop can...
"picking" also occurs: by abrasion, individual fibers work themselves out of yarn loops onto the surface, and the garment catches on a pointed or rough object. Knitting is susceptible to these effects due to the open weave and bulky yarn.
Anti-static finish prevents dust from clinging to the fabric. Anti-static effective chemicals are largely chemically inert
Inert
-Chemistry:In chemistry, the term inert is used to describe a substance that is not chemically reactive.The noble gases were previously known as inert gases because of their perceived lack of participation in any chemical reactions...
and require Thermasol or heat treatment for fixing on polyester fabrics. Polyether agents have been found to be useful but should not effect the dye-equilibrium on fiber, lest they impair the rubbing fastness. In general, Thermasol anti-static agents also have a good soil release action, which is as permanent as the anti-static effect. Anti-static finishes may also be of polyamide type, being curable at moderate temperatures.
Non-slip finishes give the filaments a rougher surface. Synthetic warp
Warp (weaving)
In weaving cloth, the warp is the set of lengthwise yarns that are held in tension on a frame or loom. The yarn that is inserted over-and-under the warp threads is called the weft, woof, or filler. Each individual warp thread in a fabric is called a warp end or end. Warp means "that which is thrown...
and weft threads in loosely-woven fabrics are particularly prone to slip because of their surface smoothness when the structure of fabric is disturbed and appearance is no loner attractive. Silica gel
Silica gel
Silica gel is a granular, vitreous, porous form of silica made synthetically from sodium silicate. Despite its name, silica gel is a solid. It is a naturally occurring mineral that is purified and processed into either granular or beaded form...
dispersions or silicic acid colloidal solutions are used in combination with latex polymer or acrylate
Acrylate
The acrylate ion is the ion of acrylic acid.Acrylates are the salts and esters of acrylic acid. They are also known as propenoates ....
s dispersions to get more permanent effect, along with simultaneous improvement in resistance to pilling or snagging
Snag (textiles)
In textiles, a snag is created when a sharp or rough object pulls, plucks, scratches, or drags a group of fibres, yarn, or a yarn segment from its normal pattern...
. These polymer finishes are also capable of imparting a soft and smooth handle to synthetic fabric without making it water repellent.
Fire Resistant or Flame Retardant finish
Flame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
: to reduce flammability
Flammability
Flammability is defined as how easily something will burn or ignite, causing fire or combustion. The degree of difficulty required to cause the combustion of a substance is quantified through fire testing. Internationally, a variety of test protocols exist to quantify flammability...
.
Anti-microbial finish: with the increasing use of synthetic fibers for carpets and other materials in public places, anti-microbial finishes have gained importance. Products which are commonly applied are brominated phenol
Phenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
s, quaternary ammonium compounds
Quaternary ammonium cation
Quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure NR4+, R being an alkyl group or an aryl group. Unlike the ammonium ion and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged,...
, organo-silver
Organosilver chemistry
Organosilver chemistry in chemistry is the study of organometallic compounds containing a carbon to silver chemical bond and the study of silver as catalyst in organic reactions. In the group 11 elements silver is the element below copper...
and tin compounds, which can be applied as solutions or dispersions. They can also be incorporated in a polymeric film deposited on the surface to achieve controlled release.
See also
- Textile manufacturing, Finishing