Finishing

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Finishing

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85Bureau Veritas Consumer Products Services

Finishing is a general term for a magnitude ofprocesses and treatments that a fabric may undergoafter it has been made (woven or knitted) and colored(dyed or printed).

It is the final processing of the cloth. Its purpose isto make the fabric more suitable for its intended enduse.

Textile finishes can be classified as aestheticfinishes and functional finishes.

They are also categorized as chemical finishes andmechanical finishes.

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These are finishes which change the appearance,drapability and hand (feel) of fabrics includingparchmentizing, softeners, and stiffeningfinishes.

Finishes that alter or create texture include burn-out designs, embossing, plissé, raised fibersurfaces (brushing, gigging, napping, sueding,and flocking).

Finishes that alter fabric luster include beetling,calendering (simple, glazed, moiré, schreinering),optical finishes (delusterants, and opticalbrighteners).

Finishing Aesthetic Finishes6


These are finishes which improve the performanceproperties of fabrics.Finishes that enhance care properties include durablepress, soil-release, stain- and soil-resistant finishes.Finishes that provide comfort and safety includeantistatic, chemical-protective, absorbent, flameresistance, water-repellent and waterproof finishes.Finishes that alter durability include abrasion-resistant, slip resistant, and shrinkage control.Finishes that provide environmental protectioninclude antimicrobial finishes, fume fading inhibitors,metallic and plastic coatings, and mothproofing.

Finishing6 Functional Finishes


Finishing that Changes Appearance, Drapability and Hand� Parchmentizing» A finishing process to give cellulosic fabrics such

characteristics as transparency, linen-like hand, and texture.The fabric is immersed briefly in an acid bath undercontrolled conditions and then quickly neutralized. Thisfinish is most effective on mercerized cotton.

� Softening» Softening agents are frequently used to improve the hand and

drape of fabric. The most commonly used softeners are oils,fats, wax emulsions, soaps and synthetic detergents, andsilicone compounds. Silicone compounds produce relativelydurable softening.

� Stiffening» Some fabrics need to be made stiffer and more crisp than

they would otherwise be in order to meet an intended enduse. Stiffening may be done by any of several chemicalfinishes, all applied by pad and either dried or cured. Starchis widely used but starch finishes are temporary.



Finishes that Alter or Create Texture� Plissé» This is a permanent finish, produced on cotton by the

treatment of sodium hydroxide to produce a puckered orcrinkled fabric. Sodium hydroxide is printed on the fabric inthe form of paste and the fabric shrinks only where thepaste is applied. Acetate, rayon, and manufactured fabricswith a puckered effect can be produced by chemicaltreatment or heat setting.

� Embossing» This is a process to produce a raised design or pattern in

relief on fabrics by passing the cloth between hot engravedrollers that press the design into the fabric. In thermoplasticfabrics (polyester, nylon) embossing is permanent. In otherfabrics, resin finishes are used to create a durable effect.



Finishes that Alter or Create Texture� Diagram of Embossing Rolls




Finishes that Alter or Create Texture� Raised Fiber Surface

» Fabric surfaces can be raised by brushing,gigging, napping, and sueding. Fabrics must bemade of staple-fiber yarns with low twist andlubricated to ease the extraction of fiber ends fromthe cloth.


Finishes that Alter or Create Texture� Napping» Napping uses a series of 24-30 cylinders covered with

fine metal wires bent into small hooks, to produce athick, raised fiber surface on fabrics produced fromloosely twisted staple-fiber yarns. A fabric can benapped on a single side or both. The nap maybebrushed and/or sheared to make it even. Napping isused on broadcloth, flannel, and blankets

� Sueding» A process similar to napping, it is a mechanical finish

that produces a soft, suede-like surface on the fabric.Instead of rotating, bristled wire covered brushes usedin napping, the rotating cylinders used for suedingconsist of a sandpaper-like material.



Finishes that Alter or Create Texture� Diagram of Napping Process



Finishing that Alter Fabric Luster� Calendering» A finishing process producing a flat, glossy, and

smooth surface by passing the fabric under pressurebetween cylinders. The greater the heat and pressure,the higher the luster. Calender finishes include ciré,glazing, moiré, and schreinering.

� Ciré» Ciré is a highly polished fabric produced by

impregnating the fabric with wax or a thermoplasticmaterial and then passing it through friction rollers.The resultant fabric is highly lustrous and takes on apopular �wet look.� When thermoplastic fiber fabricsare ciré finished, the fabric becomes moderately waterrepellent due to flattening and partial fusing of fibers.



Finishing that Alter Fabric Luster� Glazing» A process that produces a smooth, high polish on the

surface of the fabric. The material is treated with variousmaterials including starch, paraffin, and shellac. Threerollers are used; the center roll is cotton-padded or paper,and the other two are metal. The metal rolls operate at avery high speed, and the other roll turns more slowly. Thepolish is created by the friction of the rolls.

� Moiré» A moiré finish is characterized by a soft luster and an

optical effect, which is created by interference between lightrays reflected from the crushed and uncrushed parts of thefabric. Two layers of identical fabric are placed face to faceand then subjected to heat and pressure whereby a patternof parallel lines formed by the weft yarns of each fabric isimpressed upon the weft yarns of the opposing fabric.



Finishing that Alter Fabric Luster� Schreinering

» A finishing process where the fabric is passed underpressure between an engraved steel calender rollerand a smooth roller. The engraved roller has 180-360 fine lines embossed. This process flattens thefabric and produces fine lines on the surface whichincreases the light reflection to create a soft silk-likeluster.



Finishing that Alter Fabric Luster Optical Finishes� Delusterants» A process of dulling the luster of manufactured fibers,

yarns, or fabrics with pigments or chemical treatment. Inmost manufactured fibers, pigment is introduced in thespinning solution to reduce luster. Delusterants such asbarium salts, zinc oxide, aluminum oxide and china clay canalso be applied to yarns and fabrics.

� Optical Brighteners» Optical brighteners are used in finishing to maintain white

and bright fabrics. They adhere to the fabric and create anappearance of whiteness or brightness by the way theyreflect light; they absorb ultraviolet light and reflect it asvisible blue light.



Finishing that Enhance Care Properties� Durable Press

» This finish provides garments with shape retention,durable pleats and pressed creases, durably smoothseams, and wrinkle resistance.

» There are two methods:1) post-cure technique in which the garment rather than

the fabric is cured and heat-set after construction or

2) flat or precured technique in which the piece goodsare finished and cured. Almost all fabrics for durablepress are blends of cellulosic fibers and polyester.



Finishing that Enhance Care Properties� Soil Release» A finish that increases the absorbency of a fabric, and

which makes it easier to remove soil and stains inwashing. This finish (1) allows the stain to leave thefabric faster; (2) increases wicking action for greatercomfort; (3) makes fabric dry-cleanable; and (4)maintains brightness after repeated laundering.

� Stain- and Soil-resistant Finishes» Stain- and soil-resistant finishes resist staining. Stain-

and soil-resistant finishes reduce the rate of soildeposition on a fabric either by creating an electriccharge that repels the soil or by producing a smoothsurface to which soil will not adhere. Fabrics treatedwith such finishes are therefore easily cleaned.



Finishing that Alter Durability� Abrasion-resistant Finish» Abrasion resistance can be imparted by an acrylic resin;

however, some resins are too soft to be effective andsome are too hard and introduce brittleness to the fabric.These resins bind the fibers more firmly to the yarns.Some fiber such as nylon have inherent resistance toabrasion. Abrasion-resistant finishes are used on fabricssubject to prolonged abrasive wear such as pockets,waistband lining, and hatbands.

� Slip-resistant Finishes» Finishes applied to a fabric to reduce or eliminate yarn

slippage and reduce seam fraying are called antislip, slip-resistant, or nonslip finishes. Products such as rosins(they have poor washfastness), colloidal dispersions ofsilica (they reduce surface smoothness but are notdurable), and formaldehyde resins (they are durable) arecommonly used.



Finishing that Alter Durability Shrinkage Control� There are Two Kinds of Fabric Shrinkage:

» Relaxation ShrinkageThis occurs because the fibers and yarns are under tensionwhen the fabrics are made. Later when the fabric is wet in atensionless condition, relaxation occurs.

» Progressive ShrinkageThis occurs each time a fabric is laundered. Unlikerelaxation shrinkage which occurs only once, progressiveshrinkage continues and the fabric shrinks a bit more witheach laundering. Of the major fibers, only wool and viscoserayon are subject to progressive shrinkage.



The factors that control shrinkage in fabrics orgarments are:� Construction: A tighter fabric construction reduces

potential shrinkage� Yarn twist: Optimum twist (based on yarn size) is very

important for controlling shrinkage and torque.� Type of Weave or Knit: Pain weave of Jersey knit show

more resistance to shrinkage than other types.� Tension During Sewing of Garments: Uneven or too much

sewing tension can lead to differential shrinkage causingpuckering in the seam areas.� Stability of Fiber and Yarns: Improper stabilization could

lead to excessive shrinkage especially in blends wheresynthetic fiber shrinks differentially than the cellulosicfibers.

?? Shrinkage Control


Illustration of Shrinkage on Woven Fabric Causedby Fiber and Yarn Swelling

Loomstate Fabrics

Fabric After Washing

?? Shrinkage Control


Finishing that Alter Durability Shrinkage Control� Compressive Shrinkage (Relaxation Method)

» Used for woven cotton, tubular knit cotton, linen and rayon;the method consists of mechanically compressing thefabric lengthwise by overfeeding onto a large roller withdamp blankets. Sanforized is a well known trade mark forfabrics treated by this method.

� Heat Set (Relaxation Method)» Used for fabrics from thermoplastic fibers such as nylon,

polyester and acrylic; it is based on the principle thatthermoplastic materials will become stabilized in theirconfiguration in which they happen to be when heated totheir softening temperature.



Finishing that Alter Durability Shrinkage Control� Sponging (Relaxation Method)» Used for woolen and worsted fabrics; it consists of

thoroughly wetting the fabric with water or steam andallowing the material to dry slowly in a relaxed tensionlessstate. This does not make wool washable or shrink-proof;it permits wool to be steam pressed or caught in rainwithout severe shrinking.

� Resin Treatments (Relaxation Method)» Used for fabrics of rayon and cotton; it involves

impregnating rayon and cotton with resins and then curingwhich stabilizes the fabric and thus reduces its tendencyto distort. Resins also provide crease resistance. It ispreferable to hand wash resin treated rayon fabrics.



Felt Blanket Principle

Compressive Shrinkage

Illustration of the Felt Blanket Machine Principle

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Rubber Belt Principle

Compressive Shrinkage

Diagram of the Rubber Belt Principle

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Shrinkage Controlof Knit Fabrics

Belt Principle for Imparting Mechanical Shrinkage for Knits

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For open-width knit fabricsbased on cavity typeoverfeeding

Shrinkage Controlof Knit Fabrics

The Micrex Process

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Finishing that Provide Comfort and Safety� Antistatic» A finish that helps reduce or eliminate static buildup in

fabrics. They are chemical compounds that, whenapplied to a fabric, reduces or eliminates theaccumulation of static electricity. This may be added tothe fiber lubricant or to yarn during spinning, byspraying, or in a final rinse, or in pad dyeing. Fabricsofteners used in home laundering also reduce static.

� Chemical-protective Finishes» These are finishes that prevent penetration of herbicide

or pesticide through clothing and prevent easy removalby laundering of any pesticide on the surface of clothing.All cotton fabrics are better than polyester becausepesticides are absorbed by polyester but not cotton.



Finishing that Provide Comfort and Safety� Flame Retardant Finish» For most part, fabrics treated with these finishes burn in

the direct path of flame but self-extinguish when the sourceof flame is removed.

» Unfortunately, use of these finishes result in stiffening andloss of fabric drapability, strength loss, loss of finish inlaundering (nondurable), and ineffectiveness whenlaundered in household bleach, soaps, or water softeners.

» Some of the commonly used flame-retardant treatmentsinclude Pyrovatex CP (for cellulose and its blends), THPC(used extensively for children�s sleepwear), Firestop(trademarked by Cotton Incorporated; used in cellulose andits blends), Fyrol 76, TM-DABT (for 100% cotton and poly-cotton blends), Proban (cellulose blends), Spartan,Flamegard, Glotard, Fireway, Caliban, and Protogard.



Finishing that Provide Comfort and Safety� Water and Stain Repellent Finishes

» They are chemical finishes that resist the penetration ofwater through the fabric but permit the passage of air ormoisture. The principle behind this ability is that yarnsrather than fabric are coated with repellent chemicals.Water repellent finishes can be non-durable, durable, andrenewable.The principle types include wax emulsions,resins (renewable), silicone compounds (durable), andzirconium compounds (non-durable).

� Waterproof Finishes» These are finishes that resist wetting and the penetration

of water. Waterproof fabrics are generally woven tightlyand coated with rubber, plastic (usually vinyl), linseedoil, cellulose esters, or other compounds. Fabrics arenon-permeable to air, possess a firm non-drapable handand are not comfortable as wearing apparel.



Finishing that Provide Environmental Protection� Antimicrobial Finish» They are applied to fabrics to prevent growth of

microorganisms. They thereby control the spread ofdisease and reduce the danger of infection; help to inhibitthe development of unpleasant odors from perspiration andother soils; and reduce damage to fabrics from mildew-producing fungi and rot-producing bacteria. These finishesmay be durable or renewable. Pacificate and Sanitizedare two well known trademarks for this finish.

� Fume Fading Inhibitors» Some colors fade, particularly disperse dyes on acetate,

caused by exposure to oxides of nitrogen in theatmosphere. Simple alkaline substances such as borax aresometimes used as after-treatments, but they are notpermanent.



Finishing that Provide Environmental Protection� Metallic and Plastic Coatings» Metallic and plastic coatings are applied to the back of

fabrics. Aluminum coatings, modify the warmth andcoolness of fabrics, are used for drapery lining. Plasticcoatings help reduce the amount of soil that penetratesthe fabric and delay the passage of heat through thefabric. One problem with coatings are they may peel orcrack off the substrate.

� Mothproofing Finish» Moth larvae and carpet beetles are known to attack

animal-fiber fabrics. Mothproofing is a chemical that isadded to the dyebath during dyeing of wool fabrics.Treated wool fabrics and silk fabrics are less susceptibleto damage by moths and other insects. Finishes basedon pyrethroids and pyrimidines are among the mostsuccessful products used for mothproofing.



The principles of nanotechnology are utilized to createexceptional performance in everyday items: apparel,home furnishings, commercial interiors, industrialfabrics.Nanotechnology provides the ability to work on a nanoor submicron scale to create intelligent structures thatare stronger and have fundamentally different,performance-enhancing molecular organizations.NANO-CARE® fabric protection imparts arevolutionary, carefree quality to wrinkle resistantfabric that minimizes stains, offers superior liquidrepellency and maintains wrinkle resistance. NANO-CARE® enhanced fabrics cause water and oil spills tobead up and roll off fabric without penetrating thefibers.

Finishing6 Nano-Care


Key Features� Superior Stain, Water, And Oil Repellency

� Resists Wrinkles

� Breathable Fabric

� Preserves Original Hand

� Easy Care

� Durable Performance

Finishing6 Nano-Care

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