TEXTILE FINISHING

Bultan Sarkar Govt. College of Engg. & Textile Tech. Berhampore

TEXTILE FINISHING

• Any operation (other than preparation and coloring) that improves the appearance and/or usefulness of fabric after it leaves the loom or knitting machine.

Finishing is the final series of operations that produces finished textile fabric from grey goods.

The word "finish" means all the different treatments applied to a fabric to change such things as its Appearance, Feel or hand,Wear ability or care requirements.

Aesthetic Finishes

Classification of Finishes

• Textile Finishes are classified in several ways: According to function

Functional Finishes

Aesthetic Finishes

• Aesthetic Finishes modify the appearance and /or hand or drape of the fabrics.

• Mercerization• Napping And Sueding• Shearing• Softening• Stiffening

Functional Finishes

• Functional Finishes improve the performance properties of the fabric ; like durability, strength etc.

• Antimicrobial/Antiseptic• Antistatic• Crease resistant• Flame Resistant• Mothproof• Shrinkage Control• Soil Release• Water Proof/Repellant

• According to the quality

Temporary Permaanent

Semi Permanent

Temporary Finishes

• A finish which is not stable and goes off after the first wash is known as temporary finish and these finishes disappears during subsequent washing and usage.

• Calendering• Embossing• Starching• Softening

Semi permanent Finishes

• A Finishing on the fabric is said to be semi permanent finish if it is stable to more than 5 to 10 washes and not afterwards.

• Schreiner Calendering.

Permanent Finishes

• If the finishing effect in the fabric does not disappear and remains unaffected through all the conditions of wear and washing treatments, then the finish is said to be permanent finish.

• Sanforising• Resin Finish• Water Proof• Flame Proof

• According to type of machinery

Chemical Finishes

Mechanical Finishes

Chemical Finishes

• Chemical finishes are usually applied to fabric by padding followed by curing and drying. These are also called as wet Finishes.

• Stiff and transparent• Flame Retardant• Soil Release• Water Proof• Crease Resistance• Softening

Mechanical finishes

• Mechanical Finishes usually involved specific physical treatment to a fabric surface to cause a change in fabric appearance. This is also known as dry finish.

• Calendering• Sanforising• Milling

SOME FABRICS AFTER FINISHING OPERATON

Calendering machines

Types of calendering

Finishes enhancing appearanceTreatments enhancing appearance include such

processes as napping and shearing, singeing, tentering, calendering or pressing, embossing, creping, polishing, and optical brightening.

Napping and shearing• Napping is a process that may be applied to woollens,

cottons, spun silks, and spun rayons, including both woven and knitted types, to raise a velvety, soft surface.

• The process involves passing the fabric over revolving cylinders covered with fine wires that lift the short, loose fibres, usually from the weft yarns, to the surface, forming a nap. The process, which increases warmth, is frequently applied to woollens and worsteds and also to blankets.

• Shearing cuts the raised nap to a uniform height and is used for the same purpose on pile fabrics.

The amount of shearing depends upon the desired height of the nap or pile, with such fabrics as gabardine receiving very close shearing.

• Shearing may also be applied to create stripes and other patterns by varying surface height

Singeing

• Also called gassing, singeing is a process applied to both yarns and fabrics to produce an even surface by burning off projecting fibres, yarn ends, and fuzz.

• This is accomplished by passing the fibre or yarn over a gas flame or heated copper plates at a speed sufficient to burn away the protruding material without scorching or burning the yarn or fabric.

• Singeing machines

• Tentering, • These are final processes applied to set the warp and weft of

woven fabrics at right angles to each other, and to stretch and set the fabric to its final dimensions.

• Tentering stretches width under tension by the use of a tenter frame, consisting of chains fitted with pins or clips to hold the selvages of the fabric, and travelling on tracks.

• As the fabric passes through the heated chamber, creases and wrinkles are removed, the weave is straightened, and the fabric is dried to its final size.

• When the process is applied to wet wools it is called crabbing;

Tentering / stentering machines

Creping A crepe effect may be achieved by finishing. In one method,

which is not permanent, the cloth is passed, in the presence of steam, between hot rollers filled with indentations producing waved and puckered areas.

In the more permanent caustic soda method, a caustic soda paste is rolled onto the fabric in a patterned form; or a resist paste may be applied to areas to remain unpuckered and the entire fabric then immersed in caustic soda.

The treated areas shrink, and the untreated areas pucker. If the pattern is applied in the form of stripes, the effect is called plissé; an allover design produces blister crepe.

Crepe effect

Raising

• 1. NappingUsing wire-covered rolls to "dig out" individual fiber endsto the surface

• 2. SuedingUsing abrasive-covered rolls (sandpaper, emery cloth, etc.)to produce shorter pile surface - does cause an apparent shade

change.Special type of raised surface fabric is corduroySueding, sanding- creates softer hand of fabric.

suede

Fire Resistant finishes: With synthetic fiber which melt on igniting by a flame, the

molten moss is itself quite dangerous and a fire resistant treatment is desirable for certain end uses.

Polyester fabrics can be made flame resistant by treatment with an aqueous emulsion of xylene soluble 2,3-dibromopropyl phosphate in a pad-cure sequence.

A semi-permanent effect can be produced by treating with a mixture of ammonium bromide and brominated phosphoric acid esters.

• Stain and Soil Resistant Finishes –• prevent soil and stains from being attracted to fabrics. • Such finishes may be resistant to oil-bourne or water-bourne

soil and stains or both. • Stain and soil resistant finishes can be applied to fabrics used

in clothing and furniture.

• Soil Release Finishes –• These finishes attract water to the surface of fibres during

cleaning and help remove soil.

• Anti-microbial finishes:

• With the increasing use synthetic fibers for carpets and other materials in public places, anti-microbial finishes have assumed importance.

• Anti microbial finish Eco-friendly anti microbial finishing agent for cotton fabrics & Garments.Useful for eliminating bacterial growth due to sweat.

• Products which are commonly applied are brominated phenols, quaternary ammonium compounds, organo-silver and tin compounds which can be applied as solutions or dispersions.

• Mothproofing Finishes protect protein-containing fibres, such as wool, from being attacked by moths, carpet beetles and other insects.

• Waterproof Finishes -Aallows no water to penetrate, but tend to be uncomfortable because they trap moisture next to the body. Recently, fabrics have been developed that are waterproof, yet are also breathable .

• Water-Repellent Finishes - Water-repellent finishes resist wetting. If the fabric becomes very wet, water will eventually pass through. Applied to fabrics found in raincoats, all-weather coats, hats, capes, umbrellas and shower curtains .

• Peach Finish: Subjecting the fabric (either cotton or its synthetic blends) to

emery wheels, makes the surface velvet like. This is a special

finish mostly used in garments.

Finishes for Synthetic fibers

• Heat Setting: Heat setting of synthetic fabrics eliminates the internal tensions within the fiber generated during manufacture 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 fabric. Presetting of goods make 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 running properties of goods.

• On the other hand, post setting can be combined with some other operations such as thermosol dyeing or optical brightening of polyester, post setting as a final finish is useful to get a high dimensional stability along with desired handle.

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