Finishing Process

The whole cycle of finishing consists of mechanical and chemical processes, which are used depending on the kinds and end uses of the fabric. Mechanical processes include drying, calendaring, schreinering, embossing, sueding, raisingetc and chemical processes include in the application of special substances on the fabric, impregnation with size, starch, dextrin and other polymeric substances. 

Some Finishing process of textiles are given below: 

Steaming

A fabric steamer uses steam rather than heat to remove wrinkles. The steam, and slight pressure of the steamer's surface, relaxes the fibers rather than flattening them. Because of this process, using a fabric steamer is gentler on clothing, faster than using an iron, and eliminates scorching.

The fabric steamer is ideal for use on napped fabric, such as velvets and velveteen. A traditional iron will crush the nap, unless used with a needle board, but the fabric steamer doesn't exert pressure, preserving the luxurious look and feel of any material. Even very delicate materials, such as satins and silks, benefit from the gentle care of a fabric steamer.

Sanforizing

It is a process whereby the fabric is run through a sanforizer; a machine that has drums filled with hot steam. This process is done to control the shrinkage of the fabric.
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Calendaring/Embossing/Crabbing

Fabric calendaring is effected in special machines I.e. calendars, the main working organ of which is rolls with smooth surface for normal calendaring engraved surface for emboss calendaring and engraved finer lines for schreinering calendaring or for getting crepe effect. The calendar may be 3 bowl or five bowl and the contacting one bowl is plain steel roller and the other may be covered with rubber otherwise the fabric at nip point will break if both bowls are hard.

Glazing or rolling calendar: This method is not particularly important for nonwoven fabrics, with occasional exceptions. The smooth surface can be obtained usually by selecting an appropriate form of bonding and, especially, for drying a wet-bonded web. Calendaring has not met with much success since it is often accompanied by undesirable compression. The only time a rolling calendar is used is when two steel rollers are paired to break the so-called 'blotches' in spun-bonded fabrics.
Moiré or goffering calender: The calenders are common in nonwoven finishing and are used in the compacting of the webs made of natural and synthetic fibers. This type of calendering can be considered to be both a bonding and finishing process. Webs composed of longitudinally oriented cotton or viscose fibers with a GSM of about 10-30 g/m² can be stiffened and compacted sufficiently by passing them through a goffering calender when slightly damp. Hot embossing of synthetic fiber webs, even when the fibers are longitudinally oriented, produces a product remarkably strong due to the fibers melting at the embossed areas. The patterns can be of grid, webbed or point type. The temperature of the heated rollers is generally 20-30°C above the melting point of the fibers and the nip roll pressure 20-50dN/cm, depending on the volume of the web and the proportion of synthetic fibers it contains. If the web is cross-laid, point embossing results in maximum strength. If the fibers are arranged lengthwise, webbed embossing is employed.

The embossing effect is used to obtain special effects such as leather graining, simulated weave, plaster, brush strokes, cord and mock tiling. Another area in which heated calenders used is in the manufacture of laminates. Here thermoplastic fibers, layers of thread or film are placed between two layers of non-plastic web and are fused together by heat and pressure. Such laminates are used as tablecloths, seat and cushion covers. Calenders are also used in the transfer printing of the bonded webs.

Crabbing is a preliminary treatment for both un-dyed and dyed woven fabrics with differing objectives. In the case of un-dyed woven material the crabbing process serves to fix the fabric so as to avoid too intensive creasing and felting at the subsequent dyeing stage. After being dyed the woven fabric is smoothed and leveled by crabbing. Silicone blankets are used in this process.

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Anti-crease finish

For getting anti crease effect usually melamine formaldehyde, urea formaldehyde and dimethylol dihydroxy ethylene urea (DMDHEU), butane tetra carboxylic acid (BTCA) etc. can be used. At very high temperature, they react with cellulose and give permanent anti crease effect. The following reactions take place between the cellulose macromolecule and DMDHEU
The usual method is Padding with DMDHEU and Catalyst -> Drying at (90-100) degree C for 5 minutes -> Curing at (140-150) degree C 5-3 minutes

The following recipe can be used:

Stabitex FRD/Fixapret CPN (DMDHEU) = 75 g/L
Ploy Vinyl acetate = 20 g/L
Ammonium sulphate = 10 g/L Or Magnesium Cholride = 10 g/L
Sodium perborate = 0.3 g/L
The fabric is padded with the above solution and then dried at 100 degree C following curing at 160 degree C for 3 minutes. Curing can be carried out in the stentering machine or curing chamber.

Antistats

Static electricity tends to build up in nonwovens made of synthetic fibers due to their lack of moisture regain and conductivity. This can cause problems such as clinging and dragging during processing, apparel that clings and crackles, dangerous discharge of static electricity in explosive atmospheres and tendency to attract airborne dirt and soil in processing and use. The antistats work in three basic ways. They improve the conductivity of the fibers, coat the fiber with a thin layer of material that will attract a thin layer of moisture, and finish the fabric such that it holds a charge opposite to that normally accumulated on the fiber to neutralize the static charge. Antistats can be either durable or non-durable. Examples of durable antistats include vapor deposited metals, conductive carbon or metallic particles applied by binders, polyamines, polyethoxylated amine and ammonium salts and carboxylic salts. Non-durable antistats usually consist of inorganic or organic salts or hygroscopic organic materials. Examples are quaternary ammonium salts, imidazoles and fatty amides which are cationic. Anionic antistats include phosphates, phosphate esters, sulfonates, sulfates and phosphonates. Examples of nonionic antistats include glycols, ethoxylated fatty acids, ethoxylated fatty alcohols and sorbitan fatty acid esters.

Antimicrobials

These are used to control populations of bacteria, fungi, algae and viruses on the substrate. The treatment usually prevents the biological degradation of the product or prevents the growth of undesirable organisms. Broadly classed, the antimicrobials are either fixed or leachable. The fixed treatments are durable, but the leachable treatments may transfer to the surrounding environment through migration, solubility or abrasion. A generic list of the treatments include alcohols such as isopropanol or propylene glycol, halogens such as chlorine, hypochlorite, iodine, N-chloramine and hexachlorophene, metals such as silver nitrate, mercuric chloride and tin chloride, various peroxides, phenols quaternary ammonium compounds, pine oil derivatives, aldehydes and phosphoric acid esters. Care should be taken in the application of these compounds to prevent inactivation, loss of durability or masking of the active ingredient with other finishes.

Lubricants

Lubricants or slip agents are generally applied as processing aids to help in stretching or to improve the process ability of nonwovens. They are also applied to aid in sewing, quilting, tufting or other processes where needles penetrate the fabric. Lubricants impart the same properties as softeners but specifically reduce fiber friction. Common chemicals include sulphonated oils, oil emulsions, silicones, esters, polyethylene dispersions and fatty acid soaps. Many surfactants may also be used. Care should be taken to avoid excessive strength loss.

UV absorbers and polymer stabilizers

Ultraviolet light can do great damage to the polymers causing photo-degradation, yellowing, loss in strength and fading of the colors. The damage is generally due to the formation of destructive free radicals in the polymer. The finish can protect the fabric by shielding the fiber or absorbing the light or by chemically quenching the free radicals. The three main classes of products used are, substituted benzotriazoles, benzophenones which are UV absorbers, and hindered amines which are free radical reactants. They are applied from a bath or added to the polymer.

Softening

To impart softness, smoothness and flexibility it is necessary to apply a softening agent. According to ionic nature softener can be classified into:

• Anionic softener
• Cationic softener
• Amphoteric softener
• Non ionic softener
Among them, cationic softeners are mostly used because most of the textile is anionic in nature. Therefore cationic softeners have a god affinity towards textile fibers.

The following recipes can be used:

• Basosoft 8 kg
• Glycerine 1 kg
• Water as required
• Stentering speed 45-60 m/min

Textile Finishing

Textile Finishing is any operation (other than preparation and colouring) 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. Textile finishing usually includes treatments such as scouring, bleaching, dyeing and/or printing, the final mechanical or chemical finishing operations etc.

Aims of Textile Finishing

The final chemical treatments of the fabric which are carried out to impart special characteristics e.g. softening, stiffening, crease resisting, flame retarding, soil release effect etc. is known as textile finishing. The aim of the finishing is to improve the outward appearance and the quality of the fabric, and impart its specific properties.

Cycle of Finishing Process

The whole cycle of finishing consists of mechanical and chemical processes, which are used depending on the kinds and end uses of the fabric. Mechanical processes include drying, calendaring, schreinering, embossing, sueding, raisingetc and chemical processes include in the application of special substances on the fabric, impregnation with size, starch, dextrin and other polymeric substances. Plain fabrics (bleached, dyed and printed) are subjected to finishing and other kinds of treatment. For instance white printed fabrics with a white ground are passed through a padder containing a solution of optical whitening agents for imparting glassy effect to the fabrics to be printed.

Mechanical treatments

• Drying
• Steaming
• Tentering
• Sanforizing
• Raising
• Calendaring/Schereinering/Embossing
• Perforating and slitting
• Shearing

Chemical Treatments

Temporary chemical treatments:

• Hardening
• Softening with non-fabric reactive finishes

Permanent chemical treatments:

• Anti-crease finish
• Anti stats
• Antimicrobials
• Lubricants
• UV absorbers add polymer stabilizers
• Thermoplastic binders, resins and emulsion polymers
• Thermosetting resins and crosslinking agents
• Softening with reactive polymer
• Durable flame retarding
• Durable water repelling etc.

 

Properties Of Textile Fibers

Physical Properties

  

 

Properties essential to make a Fiber

Each fibre has particular properties which help us to decide which particular fibre should be used to suite a particular requirement. Certain fibre properties increase its value and desirability in its intended end-use but are not necessary properties essential to make a fibre. Thus it is very essential to know the individual aspects and specific properties of each kind of fibre.

Basic Textile Fiber Properties:

There are several primary properties necessary for a polymeric material to make an adequate fiber.Certain other fiber properties increase its value and desirability in its intended end-use but are not necessary properties essential to make a fiber. Such secondary properties include moisture absorption characteristics, fiber resiliency, abrasion resistance, density, luster, chemical resistance, thermal characteristics, and flammability.
Some Primary Properties of Textile Fibers are:

• Fiber length to width ratio,
• Fiber uniformity,
• Fiber strength and flexibility,
• Fiber extensibility and elasticity, and
• Fiber cohesiveness.

Fiber Properties for specific requirements

Utility of fibers are broadly catagorized into 2 different uses- one is Apparel or Domestic use and the other is Industrial use.In order to be used in each of these each of these catagories the fiber has to meet some specific requirements.
They are:

Apparel/Domestic Requirements

• Tenacity: 3 - 5 gramddenier
• Elongation at break: 10 - 35%
• Recovery from elongation: 100% at strains up to 5%
• Modulus of elasticity: 30 - 60 gramddenier
• Moisture absorbency: 2 - 5%
• Zero strength temperature (excessive creep and softening point): above 215°C
• High abrasion resistance (varies with type fabric structure)
• Dye-able
• Low flammability
• Insoluble with low swelling in water, in moderately strong acids and bases and conventional organic solvents from room temperature to 100°c
• Ease of care

Industrial Requirements

• Tenacity: 7 - 8 graddenier
• Elongation at break: 8 - 15%
• Modulus of elasticity: 80 graddenier or more conditioned, 50 graddenier wet
• Zero strength temperature: 250° C or above 

 

Classification Of fibre

Basic Fiber Properties:

Fibers are like vitamins in that you are customizing characteristics to get a certain result in your fabric. It sounds complicated, but it is really simple to the consumer. Educate sewers about the basics and they will be much happier with their fabric selections.

Some basic fiber properties, pros, and cons that are applicable to the home sewing consumer include:

• Natural Cellulose Fibers: Cotton and Flax are examples of natural cellulose fibers. These have good absorbency and are a good conductor of heat. They wrinkle easily and pack tightly. They are heavy fibers, very flammable, and printed easily.
• Natural Protein Fibers (Wool): These fibers have an animal origin. They resist wrinkling. They are hygroscopic-comfortable in cool, damp climate but weaker when wet because they shrink. Natural protein fibers are harmed by dry heat. They are flame resistant and dye well.
• Synthetic Fibers: These are fibers made from chemicals. They are heat sensitive and they melt easily. They are resistant to moths and fungi, have low absorbency, and are abrasion-resistant. Synthetic fibers are strong and easy to care for. They are less expensive and readily available.

Fiber

Fiber is the fundamental component required for making textile yarns and fabrics. There are two types - natural and synthetic. Natural fibers come from animals (sheep, goats, camelids, etc.) or vegetable-based fibers (cotton, flax, linen, and other plant fibers). Mineral fibers (asbestos, etc) are also classified as natural fiber. Synthetic fibers are man-made and manufactured from synthetic chemicals – (byproducts of the petrochemical industries) – nylon, polyester, acetates.The characteristics of fibers directly affect the properties of the fabric it is woven into.

The history of fibres is as old as human civilization. Traces of natural fibres have been located to ancient civilizations all over the gobe. For many thousand years, the usage of fiber was limited by natural fibres such as flax, cotton, silk, wool and plant fibres for different applications.

Fibers can be divided into natural fibres and man-made or chemical fibres. Flax is considered to be the oldest and the most used natural fibre since ancient times.

A unit of matter which is capable of being spun into a yarn or made into a fabric by bonding or by interlacing in a variety of methods including weaving, knitting, braiding, felting, twisting, or webbing, and which is the basic structural element of textile products.

It is a smallest textile component which is microscopic hair like substance that may be man made or natural.They have length at least hundred times to that of their diameter or width.

Types Of Fiber :

There are four types of fibers: natural, manufactured, synthetic, and minor miscellaneous types.
Natural fibers include Cotton, Linen, Flax, Wool (any form of animal hair including human hair; not just sheep wool as most associate with wool), and various other minor novelty fibers such as Hemp and Spun Corn. These fibers you can pick up and spin right into a fabric.

Manufactured fibers are types that come from cellulose and protein such as Rayon and Acetate. Rayon was the first manufactured fiber in 1949 and is also known as “artificial silk” since it was developed to mimic the costly silk fabrics of the time. Many people consider Rayon a natural fiber but technically it is not. Rayon is spun from naturally occurring polymers that replicates a natural fiber.

Synthetic man-made fibers could take up a whole book alone with the many styles and varieties. New fibers are developed all the time. Common fibers include Polyester, Microfiber, and Nylon to name a few.

Special use fibers are less common, but people may not realize that they come into contact with them on a daily basis. Surprisingly fibers such as rubber are used in Spandex. Metal such as stainless steel is used in carpets, and other metals such as silver and gold are woven into fabrics. New an innovative uses for fibers are being developed every day.

Causes Of Defects In Carding And Preventive action

Causes for Neps Formation

• Insufficient stripping
• Dirty under casing ( grid bar)
• Uneven flats setting
• Under casing chocked with fly ( waste)
• High roller speed

Causes for Holes or Patches in Card web

• Poor flat stripping
• Hooked or damaged wires on flats
• Damaged cylinder
• Cluster of cotton embedded on cylinder wires

Preventive action in carding process

In order to avoid sliver variation draft calculation should be correct. Testing of sliver must be on time at least 3 times during shift.

• High sliver variation problem may also be due to maintenance problem. So concentrate on maintenance. If our maintenance of machine will be there, then it will get more efficiency and better quality will be achieved. If expiry time of some part of the machine is there, then on time it must be replaced.
• Now a days in advance technology the cards, auto leveler are electronic which adjust the sliver weight automatically. For getting better result with automatic auto leveler, it is also necessary to check sliver weight manually as well.

Preventive action for neps formation

• Over hauling of machine must be on time. During over hauling, setting of every part of the machine has to be checked. Flat setting play very important role for reducing nep formation. So flat setting must not be uneven.
• Suction waste point should be properly working. This point must not be chocked. If there will be chock then neps formation will take place. Suction waste point also to be checked manually as well.
• This problem is also related to maintenance. Over hauling of every machine must be on time. Wire of flats and cylinder have specific time limit of production. After that specific time limit it must be changed. As these play very important role by quality point of view.

 

 

Object Of Combing

Objectives of Combing

Following are the objectives of combing process:

1. To remove the fiber shorter than a predetermined length.
2. To remove remaining impurities in the comber lap.
3. To remove naps in the carded sliver.
4. To make the fiber more parallel and straight.
5. To produce a uniform sliver of required per unit length. 

Necessity of combing
The following quality of fibers can only be obtained by combing

• Clean finer fiber
• Uniformity in length of fiber
• Absence of nap
• More parallel arrangement of fibers
• Straight fibers

Combers Noel: The wastage which is removed from the comber m/c during processing is known as comber’s noel. It is expressed as percentage. It is mainly of short fibers and naps. Noel is used for lower count as raw material.

Combing Process

Combing Machine

For getting high quality of yarn, one extra process is introduced which is called combing process.Combing is an operation in which dirt and short fibers are removed from sliver lap by following ways.

• In a specially designed jaws, a narrow lap of fiber is firmly gripped across its width
• Closely spaced needles are passed through the fiber projecting from jaws.

Short fiber which we remove is called comber noil. The comber noil can be recycled in the production of carded yarn.Yarn which is get from comber sliver is called comber yarn. Carded sliver are combine into comber lap in a single continuous process stage. Flat sheet of fiber which is get from comber lap is fed into the comber in an intermediate.There are different ways by which value of combing is used in the manufacturing of cotton. By spinning point of view combing process makes more uniformity in the yarn. Strength of yarn is also high because in combing process short fiber are removed and only fiber having good strength remains. So it play very important role for increasing the yarn strength. Because of straightened condition of fibers combing makes possible spinning smoother and more lustrous yarn. In combing process length of fiber are strong so it need less twist produced then carded yarn.

Objectives of Combing

Following are the objectives of combing process:

1. To remove the fiber shorter than a predetermined length.
2. To remove remaining impurities in the comber lap.
3. To remove naps in the carded sliver.
4. To make the fiber more parallel and straight.
5. To produce a uniform sliver of required per unit length.

CARDING PROCESS

Carding is a mechanical process that breaks up locks and unorganised clumps of fibre and then aligns the individual fibres so that they are more or less parallel with each other. Carding can also be used to create blends of different fibres or different colours. Carding plays a crucial role in all spinning cycles particularly in the woollen spinning cycle, in which it incorporates different functions, all essential in order to obtain the level of quality required of the product.

The card used in woollen spinning is traditionally the sort with cylinders (covered with clothings that are angled to varying degrees), which rotate at different speeds, effecting the three cardinal actions: carding, stripping and raising. Appropriately combined, these three actions allow opening of the tufts, continuous detachment of the fibres from the card clothing, which would otherwise soon become clogged up, and delivery of the material from the machine at the end of a processing cycle.

Functions of Carding

Carding fulfils a series of precise objectives. They are given below:-

to open the blend fibres fully and definitively

1. To arrange (as far as their length allows) the fibres parallel with one another
2. To remove impurities
3. To blend the raw material further
4. To reduce the blend to a web of fibres and to divide it up into rovings of the required count, suitable for feeding to the spinning machines. 

Carding plays a crucial role in all spinning cycles, and its role is never more central than in the woollen spinning cycle, in which it incorporates different functions, all essential in order to obtain the level of quality required of the product. 

Basically, passing the material over the card undoes tangles of fibres and therefore makes it possible to remove all kinds of impurity. This is achieved thanks to the action of the spikes covering the surfaces of cylinders that rotate around parallel axes.

 

The equipment also fulfils another function, which is both delicate and fundamental: it has to guarantee the accuracy and evenness of the web count and subsequently of the roving count. Indeed, the definitive spinning machines that operate within the woollen spinning cycle can impart only a very low draft, which means that there is practically no possibility, at this stage, of intervening to correct the yarn count.

The carding room equipment thus performs the same operations already carried out in the preparation stage, this time more thoroughly, supplying the divider with rovings of the right count.

Defects In Carding
Causes of high sliver variation

1. Nep formation
2. Holes or patches in card web
3. High sliver variation in due to difference in draft between card
4. Worn clothing and feed roller bearing also create variation in card sliver
5. If auto leveler is not working properly than this will also create high sliver variation. If auto leveler is off then check the wrapping of carding after every 30 minutes.

 

Direct dye

Direct dyes are a class of hot water dyes for use on cellulose fibers, such as cotton. It is one of the two types of dyes that are mixed in 'all purpose dyes' such as Rit, Tintex Hot Water dye, and Dylon Multi-purpose Dye. (The other type in the mixture is an acid dye, which will not stay in any cellulose fiber for long.) Try to find them pure, without the useless (for cotton) and money-wasting acid dyes mixed into the 'all-purpose' dyes.In most cases, better results will be obtained, often with versatile and easier-to-use cool water methods, if you use fiber reactive dye instead of direct dye.
However, there are some cases in which direct dye is preferred.

Duller in color and poorly washfast
The colors of most direct dyes tend to be duller than those provided by fiber reactive dyes, especially after fading in the laundry. The washfastness of direct dyes is poor: expect anything dyed with them to 'bleed' forever. They lack the permanence of the cold water fiber reactive dyes which most hand-dyers prefer for use on cellulose fibers. As a result, clothing dyed with direct dyes should be laundered in cool water only, with closely similar colors. The washfastness problem can be reduced by following dyeing with the use of a cationic after-treatment such as Retayne.  

Inexpensive
The main reason why direct dyes are used is because of cost. Although the widely available all-purpose dyes which contain a mixture of direct and acid dyes are very expensive, per pound of fabric to be dyed, direct dyes sold alone and purchased in bulk are among the cheapest of all dyes.

Single dye bath
Direct dyes are applied in hot water, typically between 175°F and 200°F. They can be applied in the same boiling-water dyebath with acid dyes (whether for same-color effects, as in all-purpose dyes, or contrasting effects, as in the case of AlterEgo brand dyes). 

Lightfastness
Direct dyes are not generally more lightfast than fiber reactive dyes; many direct dyes are less resistant to light than similarly-hued fiber reactive dyes, and both tend to be less lightfast than vat dyes. There are just a few cases in which a particular direct dye may be more lightfast than similar shades of fiber reactive dyes (see About Lightfastness). For example, Colour Index Direct Orange 39 and Direct Blue 86 are quite reasonably lightfast, with a rating of 6 (on a scale of 1 to 8). While some fiber reactive oranges are as lightfast, not all are; the popular Colour Index Reactive Orange 4 rates only 4 on that scale, while the Turquoise Reactive Blue 140 rates 5-6 on that scale.
Unfortunately, the cationic dye fixatives, such as Retayne, that are required to render the washfastness of direct dyes acceptable also reduce lightfastness somewhat.

APPLICATION OF VAT DYES

Aims:
1. To apply a vat dye dispersion to a fabric by padding
2. To apply a vat dye to cotton fabric using a pre-pigmentation method
3. To observe the changes a vat dye undergoes during application to a fabr
4. To determine the effect of soaping on a vat dye
5. To practice pad-bath calculations.

Theory:
The simplest arrangement for dyeing fabric is to pull the textile material through the
dyebath so that the dye can exhaust on to the fabric surface. Low liquor ratios and the
addition of common salt or Glauber's salt both promote such exhaustion. In some cases,
the addition of acid also promotes exhaustion. If the dye is only partially soluble in water
and likely to be exhausted unevenly, the addition of soap or sodium carbonate may
promote leveling. A dyeing is considered to be level if all parts of all fibers have been
penetrated evenly and completely. Machines for this type of dyeing are called batch
machines.

•  Package and beam machines for yarns.
•  Jigs for open width fabrics
•  Winches for woven and knitted fabrics in rope form
•  Jet dyeing machines for knitted fabrics in rope form.
•  Paddle machines for sewn products like bedspreads
•  Smith drums for nylon hosiery or special machines for nylon hosiery

If a dye is not soluble in water, as is the case with vats, it may be applied to the fabric as a
dispersion by a padder. Once the insoluble vat dye has been uniformly applied to the
fabric surface, usually with the aid of special dispersing agents (detergents), it can be
solubilized by reaction with a reducing agent, e.g., sodium hydrosulfite ("hydros",
Na2S2O4) in dilute NaOH. Once it has been converted to its soluble (LEUCO) form, the
vat dye can penetrate into the cotton fibers. After adequate time for penetration to occur,
the fabric is withdrawn from the bath and oxidized by air or an oxidizing agent such as
sodium perborate or hydrogen peroxide. This process is schematically represented below.

                         pad                       hydros
vat dye (insol)  → on fabric surface    →    LEUCO form (soluble)
                                                      NaOH
                                                                         air oxidation
                                                                             vat dye
                                                                  (insolublized inside. fibers)


Before chemical reducing agents were readily available, vat dyes were converted to their
soluble leuco form by fermentation of organic matter in wood tubs called vats. This
method of reduction and application is the source of the name for this class of dyes.
Once the vat dyes have been regenerated inside the fiber, they are very insoluble. This
accounts for their excellent wash fastness.
Because they can be applied as a dispersion by padding, solubilized by reduction, and
finally reoxidized when inside the fibers,  vats are well- suited to continuous dyeing
operations. Such treatments exhibit a number of advantages:

a) very efficient use of the dye. All that is made up can be applied.
b) the insoluble vat is very evenly distributed over the fabric surface, leading
to level dyeings
c) continuous processes are normally more economical processes than batch
processes

Equipment and Chemicals:
Bleached 100% cotton (8" x 24")
C. I. Vat Green 1 (20 g/L) Indanthrene Green FFG
Dispersing agent (10 g/L)
Alginate NVS (sodium alginate, 1 g/L)
Soap solution (50 g/L)
NaOH solution (100 g/L)
Sodium hydrosulfite (hydros) (100 g/L) ..
Sodium chloride solution (100 g/L)
The diagram below illustrates how your fabric is to be labeled and cut for testing.
CAUTION -WEAR SAFETY GLASSES AT ALL TIMES DURING THIS DYEING!

Auxiliaries for Textile

•  AUXILIARIES FOR PRE-TREATMENT

   
1.WETTING AGENTS
• High power non-ionic wetting agent
• An anionic wetting & rewetting cake
• An anionic wetting & rewetting paste
• An anionic wetting liquid
• Auxiliary for drumming and swelling of polyester
• Economical wetting agent with soil suspending & clearing properties
• Versatile wetting agent, stable to alkali and temperature because of its high cloud
point, with scouring action
• Low foaming highly effective mercerizing wetting agent

2.SCOURING & STAIN REMOVING AGENTS
• Solubliser and dispersant for oily & greasy stains with excellent scouring pro
• One bath stain remover, scouring and dyeing auxiliary.
• One bath stain remover and scouring agent for cotton, scouring agent for wo
and stain remover and dyeing auxiliary for polyester.
• A scouring agent stable to high temperature and alkaline conditions
• Desizing & scouring aid for heavily sized polyester & blends.
• All purpose stain remover & scouring Aid for heavily stained goods.

3.SEQUESTERING AGENTS 
• Organic Sequestering agent reduces bleaching & dyeing cost.
• Organic based water-softening agent.
• Water-softening agent.
• An efficient sequestering agent for Calcium, Magnesium, and heavy metal (Ferric &
Copper) ions.
• A unique dispersant and chelating agent for all stages in dyeing of textile.
• An eco friendly, non-foaming, fastness improver sequestering agent to be used in the
dyeing.
• Sequestering agent.

4.BLEACHING AIDS
• Residual peroxide Killer for Bleaching & Dyeing of Reactive Dyes
• Stabilizer for peroxide bleaching
• Organic stabilizer for semi-continuos silicate free alkaline hydrogen peroxide
bleaching of cotton and the cotton component in blends.

• AUXILIARIES FOR WASHING OFF

• A low-foaming high performance detergent, designed for the preparation of cotton,
synthetic, and blended fabrics particularly in high-turbulence equipment such as soft-
flow, jet and package dyeing machines as well as in continuous processing system
• Non-ionic detergent.
• Crypto anionic detergent, washing off agent for reactive prints.
• Crypto anionic detergent for removal of loom oils and other stains, for reduction
cleaning after polyester dyeing & m/c cleaning.
• High power wetting agent and detergent for spongyfication of hydrophobic impurities
oil, wax and other fatty substances.
• Low foaming washing cum stain dissolving auxiliary
• a reduction cleaning agent with detergent action
• A specially washing – off and cleaning auxiliary for rapid & efficient removal of
unfixed disperse dyes from polyester fabrics.

• DYE BATH CONDITIONER  

1.WETTING /DE-AERATING
• Excellent wetting & de-aerating agent for package dyeing with increased antifoam
action at higher temperature
• Penetrating accelerating with markedly strong antifoaming and de-aerating property
in exhaust dyeing.
• A pad dyeing penetration accelerant with high wetting action and durable foam
inhibition property

2.LEVELLING, STRIPPING AGENTS & CARRIES
• Levelling agent for dyeing of polyester and polyester blends with disperse dye.
• Levelling cum striping agent for woolen Dyeing.
• Levelling & stripping agent for disperse dyes.
• Levelling agent for acrylic dyeing
• Levelling agent for Reactive dyeing
• Carrier for dyeing of polyester & Nylon.
• An all in one product for dyeing of cotton in hank form in cabinet system. Has
wetting levelling & dispersing property in addition to foam inhibiting property.  

DYE FIXING AGENT 

• High power dye fixing agent
• Cationic Dye fixing agent for directs & reactive dyes.
• Ecofriendly dye fixing agent free from formaldehyde

Flow Chart of Wet Process Technology

In which way grey fabric is dyed is called wet process technology. Normally wet processing depends on buyer's demand. Suppose your buyer wants the more precised dyed fabric; so in this fact you should mercerize your fabric during the dyeing per-treatment process. Basically if the buyer don’t want that so called particular fabric there is no need to mercerize your fabric .Flow chart of Wet processing technology is given below:

 

Grey Fabric Inspection

↓

Sewing or Stitching

 ↓

Brushing

↓

Croping

↓

Singeing

↓

Desizing

↓

Scouring

↓

Bleaching

↓

Mercerizing

↓

Dyeing

↓

Printing

↓

Finishing

↓

Final Inspection

↓

Delivery

 

Grey Fabric Inspection:  

After manufacturing fabric it is inspected in an inspection Table. It is the process to remove neps, warp end breakage, weft end breakage, hole spot.

Stitching:  

To increase the length of the fabric for making suitable for processing is called stitching. It is done by plain sewing m/c.

Brushing:  

To remove the dirt, dust, loose fibre & loose ends of the warp & weft threads is known as brushing.

Shearing / Cropping: 

The process by which the attached ends of the warp & weft thread is removed by cutting by the knives or blades is called shearing. Shearing is done for cotton & cropping for jute. After Shearing or cropping fabrics goes under singeing process.

Singeing:  

The process by which the protruding / projecting fibres are removed from the fabrics by burning / heat to increase the smoothness of the fabric is called singeing. If required both sides of fabric are singed.

Desizing: 

 The process by which the sizing mtls (starch) are removed from the fabric is known as desizing. This must be done before printing.

Scouring:  

The process by which the natural impurities (oil, wax, fat etc) & added/external/adventitious impurities (dirt, dust etc) are removed from the fabric is called scouring. It is done by strong NaOH.

Souring:  

The process by which the alkali are removed from the scoured fabric with dilute acid solution is known as souring.

Bleaching:  

The process by which the natural colours (nitrogenous substance) are removed from the fabric to make the fabric pure & permanent white is known as
bleaching. It is done by bleaching agent.

Mercerizing:  

The process by which the cellulosic mtls/substance are treated with highly conc.NaOH to impart some properties such as strength, absorbency capacity, lusture is known as mercerizing. It is optional. If the fabrics are 100% export oriented then it is done by highly conc. NaOH (48-52° Tw).

Dyeing :  

A process of coloring fibers, yarns, or fabrics with either natural or synthetic dyes.

Printing:  

A process for producing a pattern on yarns, warp, fabric, or carpet by any of a large number of printing methods. The color or other treating material, usually in the form of a paste, is deposited onto the fabric which is then usually treated with steam, heat, or chemicals for fixation.

Then finishing treatment are done according to buyer requirements and then folding, packaging, and at last delivery.

 

 

What is Lycra? Lycra yarn and its properties.

LYCRA® is a man-made elastic fibre invented and produced only by DuPont® which is also known as estomer or spandex.It’s remarkable properties of stretch and recovery enhance all fabrics and garments in which it is used, adding easy comfort and freedom of movement and improving fit and shape retention. Swimwear and lingerie owe their figure-flattering fit to LYCRA®. All types of hosiery are softer, smoother-fitting and more durable thanks to LYCRA®. In short, a little bit of LYCRA® makes all types of apparel fit better, feel better and look better. Tech-Talk
LYCRA® belongs to the generic elastane classification of man-made fibres(known as spandex in the US and Canada) and is described in technical terms as a segmented polyurethane it is composed of “soft”, or flexible, segments bonded together with “hard”, or rigid, segments. This gives the fibre it’s built-in, lasting elasticity.LYCRA can be stretched four to seven times its initial length, yet springs back to it’s original length once tension is released.While LYCRA® appears to be a single continuous thread, it is in reality a bundle of tiny filaments.

Spandex Fiber Characteristics

• Can be stretched repeatedly and still recover to very near its original length and shape
• Generally, can be stretched more than 500% without breaking
• Stronger, more durable and higher retractive force than rubber
• Lightweight, soft, smooth, supple
• In garments, provides a combination of comfort and fit, prevents bagging and sagging
• Heat-settable — facilitates transforming puckered fabrics into flat fabrics, or flat fabrics into permanent rounded shapes
• Dyeable
• Resistant to deterioration by body oils, perspiration, lotions or detergents
• Abrasion resistant
• When fabrics containing spandex are sewn, the needle causes little or no damage from “needle cutting” compared to the older types of elastic materials
• Available in fiber diameters ranging from 10 denier to 2500 denier
• Available in clear and opaque lusters

How LYCRA® is used
LYCRA® is never used alone; it is always combined with another fiber (or fibers), natural or man-made. Fabrics enhanced with LYCRA® retain the appearance of the majority fibre.

The type of fabric and it’s end use determine the amount and type of LYCRA® required to ensure optimum performance and aesthetics. As little as 2 percent LYCRA® is enough to improve a fabric’s movement, drape and shape retention, while fabrics for high-performance garments such as swimwear and active sportwear may contain as much as 20-30 percent LYCRA®. Weaving or knitting techniques, togheter with fabric type and end use, determine whether LYCRA® is used in a bare or covered yarn form.

Single and double covered LYCRA®










Core-twisted LYCRA®









The material used in the making of the Cotton-Lycra line of Snob underwear consist of:

-90% Cotton
-10% Spandex(Lycra®)

Cotton-Lycra Care

• Hand or machine wash in lukewarm water 
• Do not use chlorine bleach on any fabric containing spandex. Use oxygen or sodium perborate type bleach 
• Rise thoroughly 
• Drip dry. If machine dried, use low temperature 
• Ironing, if required, should be done rapidly. Do not leave the iron too long in one position. Use low temperatures setting. (For specific instructions, refer to garment's sewn-in care label)

Some Major Spandex Fiber Uses

• Garments where comfort and fit are desired: hosiery, swimsuits, aerobic/exercise wear, ski pants, golf jackets, disposable diaper, waist bands, bra straps and bra side panels
• Compression garments: surgical hose, support hose, bicycle pants, foundation garments