Textile Processing

Fabric Calendering

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The fabric passing through the rollers of the calender is subjected to a very uniform pressure all along its width; if the rollers rotate at a different speed, a vigorous friction effect is generated. Steel rollers may be equipped in such a way to be heated from the inside by means of steam, circulating fluids or electrical power.The wavy engraving on the rollers give the effect as shown.

The fabric passing through the rollers of the calender is subjected to a very uniform pressure all along its width;if the rollers rotate at a different speed, a vigorous friction effect is generated. Steel rollers may be equipped in such a way to be heated from the inside by means of steam, circulating fluids or electrical power.The rollers coated with paper/wool, containing 45-50% of wool, feature good elasticity and excellent resistance to wear and are suitable for a wide variety of applications; they can also be used in embossing calendering units.Rollers made of paper/cotton, are used almost in friction calenders and for treating hard fibres. Cotton rollers, featuring higher elasticity than the paperones, are mainly used for cotton and blends finishing and for a final full hand effect.

Fabric Embossing

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Embossing means to create a raised or lowered image on the surface. The embossing machine is made up of a heated and embossed roller made of steel,which is pressed against another roller coated with paper or cotton, its circumference being exactly a whole multiple of the metal roller.

The garment will have to be dry-cleaned.Washing and drying the garment will raise the pile and destroy the embossed image.

Water Proof Finish

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Water proofed fabric has the pores of the fabrics covered with acontinuous surface.The coating being done on the surface, air permeability is non-existent, with nobonding between the fibres and the coated product intended for use in the fabric of rain- and water-resistant clothing.

The type of hydrophobic treatment chosen affects the quality of the garment and its durability during washing or chemical cleaning.Finish is applied by filling the fabric pores witha film-forming compound or by the applying to individual fibres or fabrics of compounds which repel water and have a high surface tension.

Water Repellent Finish

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Specially Durable to washing. Also resistant to dry-cleaning. Easy handling and storage. Improved finish durability,can provide repellency to 30 home laundry washes . Solvent Free and Low foaming. High resistance to yellowing,suitable for colored and white goods.

Typical application fields are

Carpet finishing.Clothing (e.g. sportswear & rain coat.).Umbrella cloth.Table linen, curtains and upholstery fabric.Tarpaulins and tents.Technical fabrics (e.g. protective clothing)

Chintz : Glaze Finish

2011-09-12T00:34:00.001-07:00

Chintz is a closely woven plain weave cotton fabric with a shiny and lustrous finish. It usually has bright figures of large flower,birds, and other such designs.

The fabric is processed with glazed finish to give it a polish look. The wax and starch glaze washes out. It is produced by friction or glazing calendars. It withstands washing or dry cleaning

Fabric Softener Finish

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Fabric softener is a product used while laundering to make clothes soft and eliminate static cling. Depending on the brand of fabric softener one purchases, it can be added at the beginning of the laundry cycle at the same time detergent is dispensed or during the rinse cycle.

Fabric softener can also come in sheets to be placed in the dryer.

Heat Setting Crinkle Finish

2011-09-12T00:32:00.000-07:00

A process of decorating fabric includes the step of imparting wrinkles to the fabric oblique to the warp and weft directions and heat setting the wrinkles into the fabric.

The wrinkle imparting step may include moving the fabric longitudinally and simultaneously moving portions of the fabric from side to side by frictionally engaging the fabric to an oscillating means such as an elastomeric pad or interleaved fingers and oscillating the pad or fingers from side to side.

Disadvantage of Pile Finish

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The process being lengthy and time consuming is very expensive

Advantage of Pile Finish

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Pile Finish is labour friendly. The workers are not exposed to dangerous chemicals like caustic soda, acids, bleaches etc to which they most definitely are in the chemical washing process.

Pile Finish

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The dry finishing process is mechanical and 100% chemical free. Combing the pile very carefullyand thoroughly during the weaving process after each row of knots is tied so that the pile fibres are disentangled and lie parallel to each other,imparting a rare clarity to thedesign.

The finishing is thus very much apart of the weaving process itself.

Coating

2011-06-19T07:08:00.000-07:00

Application of a rubber, (polyvinyl chloride) or PU (Polyurethane) paste on one or both faces of a fabric. As soon as the coating is dry, it is firmly bonded to the fabric. As an example of coated fabrics, one can mention tarpaulin. Several coating processes (in solvant or aqueous medium) are possible.

Chemical Treatments

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Chemical treatment to add particular qualities and characteristics to fabrics. The most commonly used treatments are

Crease-resistant treatment, allowing to avoid the tendency to crease of cotton fabrics.

Shrink-resistant finish limits the tendency to shrink of cotton.

By applying the water repellent and oil repellent finish, one avoids that fabrics absorb water and oil

Other finishes add specific properties to fabrics to starch and reinforce them.

The softening finish improves the touch of the fabric

Aesthetic Finishing

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Aesthetic treatments improve the appearance or touch (sensation) of the fabric. chemical treatments are considered as wet treatments and mechanical treatments as dry treatments.

Finshing Classifications are done by their degree of permanency. These classifications are :

Temporary - The finish is removed by washing or dry-cleaning; e.g. calendaring (similar to pressing).

Renewable - Finishes that may be applied again. Examples of this type of treatment are starch and dirt repellent finishes.

Durable - A treatment that will last the entire life of the product but with decreasing efficiency.

Permanent - Finish remaining entirely the same during the entire life of the product.

Functional Finishing

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Functional finishing improves the product's performance under conditions of specific use

Chemical Finishing

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Chemical) finishing adds qualities to fabrics which they lack; it eliminates certain flaws or improves their touch and aspect.

Stages at which cellulose can be Mercerised

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Mercerisation is possible -

On Greige Goods

After Desizing

After Desizing and Scouring

After Bleaching

After Dyeing

Woven fabrics are mercerized in full width, knitted fabrics in full width or in rope form.

The sodium hydroxide concentration varies from 20% - 30%. The process, done in a continuous way, consists of the following steps: - padding of the textile with the lye - drafting of the textile - washing (under tension) - acidifying, rinsing. The main ecological impact in mercerising is the high concentrated residual dye.

Sodium Hypochlorite (NaClO) Bleaching

2011-06-19T06:53:00.000-07:00

The NaClO bleaching is characterized in that the bleaching is performed at room temperatures without requiring a heating apparatus such as a steamer, and that the chemical cost is low. However, the disadvantages of the NaClO bleaching include relatively low bleaching whiteness and embrittlement of fabrics.

No particular pH adjustment is required in the NaClO bleaching. The NaClO bleaching is usually employed for bleaching fabrics after Kier-scouring, or for bleaching towels. For towels, the two-step bleaching comprising the NaClO bleaching and the H2O2 bleaching is preformed to obtain full whiteness. The NaClO bleaching is also employed for jeans fade adjustment, etc. Note here that a dechlorination process needs to be provided as in the NaClO2 bleaching. Since 'chlorine free' is a recent trend, like PRTR, a method without using chlorine is being examined. The same applies to NaClO.

One-Bath Desizing and Bleaching

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Desizing agent -BIOGEN 300

Bleaching auxiliary -BIOGEN NN

Dechlorination agent -BRITE CL-B

Sodium Chlorite (NaClO2) Bleaching

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The NaClO2 bleaching is performed after pH adjustment to 3.5 with an acid such as a formic acid. It provides soft hand with less embrittlement of cotton. Compared with the H2O2 bleaching, some insist that even bluish whiteness can be achieved with the NaClO2 bleaching.

Also, the NaClO2 bleaching is free from worries about pin-hole generation, as often occurs in the H2O2 bleaching. However, a harmful chlorine dioxide gas is generated during the bleaching process, and therefore, suitable measures including the equipments need to be taken for metallic corrosion problems and dechlorination purposes. After bleaching, a dechlorination process needs to be provided. A trace chlorine which exists in fabrics reacts with nitrogen compound to form chloroamine, or cause yellowing of the fabrics when exposed to light and heat.
Note here that a special reducing agent, sodium thiosulfate (hypo), or hydrogen peroxide (so-called, cosmetic bleaching) is used for the dechlorination purposes.

Sodium chlorite low-temperature activator -BRITE FB CONC

Residual Hydrogen Peroxide Dispersing Agent

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BK-7 -Reduction System

ENZYLON KAT-50 -Catalase

Hydrogen Peroxide Stabilizer

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BRITE NIK -Contains sodium silicate; Effective in dispersing silica scales.

BRITE W -Contains no sodium silicate

APPEAGEN TOP -Improved version of BRITE W

Hydrogen Peroxide (H2O2) Bleaching

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The H2O2 bleaching is the most common bleaching method, and is environmentally friendly (degradable into water and oxygen). The best bleaching whiteness can be obtained at pH 11 adjusted using caustic soda.

However, if metal ions, such as iron ions and copper ions are present in fabrics or in water, catalytic action of these metal ions causes abnormal degradation of H2O2, which may sometimes cause embrittlement of fabrics until holes (pin-holes) are generated due to the excessive degradation.

Usually, the abnormal degradation of H2O2 and the resulting generation of pin-holes are prevented by adding a chelating agent. Also, as a stabilizer for H2O2, sodium silicate has been conventionally employed. The obtained bleaching whiteness is favorable. However, the use of sodium silicate has the following disadvantages. Silica scales are generated due to calcium ions and magnesium ions reacted with silica ions. The generated silica scales are adhered to machinery, damaging fabrics, or undermining hand of the fabrics.This case, however, suffers from a contradiction that complete removal of calcium ions and magnesium ions will undermine the stability of H2O2.

To solve the disadvantages and contradiction, a non-silicate type stabilizer containing no sodium silicate has been developed, although the cost is higher than sodium silicate.

Furthermore, when dyeing is performed without a drying process after the H2O2 bleaching, the problem of residual H2O2 arises. 10ppm of residual H2O2 or more causes dyeing problems, although it depends on a type of dye. To degrade the residual H2O2, a reducing agent or the like, or an enzyme (catalase) can be used. The enzyme appears as a current mainstream.

Lipase

2011-06-19T06:34:00.001-07:00

ENZYLON AKG-2000 - Oil-Degrading Enzyme

Chelating Agents

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CHELATE HC -Chelating Agent

FN-5000 -Chelate Dispersing Agent

FN-6602 - Chelate Dispersing Agent

Scouring Agents

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DESCO SOFT 900 -Soft-type Scouring and Penetrating Agent

DESCO DN-40 -Low-foaming Scouring and Penetrating Agent

DESCO SOFT UC CONC - Soft-type Scouring and Penetrating Agent/ Low-Foaming

DESCO KRA -Scouring Agent/ Alkali-Resistant