Importent Terms & Definition Which Are Essential For Dyeing?

Today I will present some 'terms and definitions' which are essential for dyeing.

  

AATCC : American Association of Textile Chemists and Colorists.

Alginate : A thickener used in textile printing for  the paste containing dye.

Affinity : Attraction between the dye and fibres.

Anhydrous : A substance which contains no water or without water. 

Antichlor : A chemical used to neutralize chlorine bleach.

Anti foaming agent : An agent used to protect the dye solution from forming foam. 

Flow process chart for Mercerization

Flow process chart for Mercerization.

Nasrin Sultana Tumpa.

Opex and Sinha Group.

Sr. Production Officer

B. Sc. In Textile Engineering

Bangladesh University of Business and Technology (BUBT)

Mercerizing is done before dyeing. Mercerized fabric is most sophisticated than un-mercerized fabric. This process also depends on the buyer requirement.

Mercerizing is done after bleaching operation. Bleaching is enough for prepared the fabric dyeing. But mercerization is done for adding some advantage to the fabric luster and strength.

Mercerizing makes fabric shinier and more colorful, and it provides the fabric stable shrinkage and fine. It is done for the sophisticated fabric.

Garments Dyeing & Machine Specification

INTRODUCTION

 Textile coloration is combination of same series processes such as scouring, bleaching, dyeing & after treatment which can be carried out at different stages of fiber processing in different forms like staple, yarn, fabric (rope or open-width, piece & garments) Dyeing of staple forms(loose fiber) is better for achieving better colorfastness, maximum penetration and uniform migration of dues over dyeing. Piece (batch) dyeing is carried out open width or rope form in depending on machine type & end-dyes. Usually these materials are dyed in exhaust dyeing method in a single dyeing machine. But lightweight woven fabrics & garments are also possible to dye with same principle in different form

FABRIC PREPARATION PROCESSES : YARN PREPARATION EQUIPMENT

Various types of equipment can be used for preparing fabric. The ultimate goal of any preparation process is to produce fabric that is clean and rid of all impurities that interfere with dyeing and finishing. The preparation steps can be carried out as either batch or continuous processes. The fabric may be transported as a rope or as an open sheet through the equipment. The choice is often predicated on the dyehouse itself. The distinguishing feature of batch equipment is that all of the fabric is simultaneously submerged in the liquor. The fabric is agitated by moving it through the

Fabric preparation for dyeing

The term "Preparation" has two implications in textile processing. In greige manufacturing, it is used to describe the processes which prepare yarns for weaving and knitting. Mostly, it is used to describe slashing operations that ready warp yarns for weaving. In dyeing and finishing, the term is used to describe those processes that ready fabrics for the steps that follow, coloration and finishing. Fabric
preparation is the first of the wet processing steps where greige fabric is converted into finished fabric. The steps that follow, dyeing or printing and finishing, are greatly influenced by how the fabric is prepared. Improper preparation is often the cause of problems encountered in the dyeing and

Define soft water | What is water softening? State the name of method of water softening | Describe the base exchange process for softening hard water?

Define soft water?

The water which does not contain H CO3-, Cl-, SO42- salt of Ca2+, Mg2+, Fe2+, Al3+ & form foam easily by reacting with soap is called soft water e.g. Rain water.

What is water softening? State the name of method of water softening?

WATER SOFTENING: To remove the impurities of hard water by some desirable process is called water softening.

WATER SOFTENING PLANT / METHODS OF WATER SOFTENING:

1.         soda lime process.

2.        Base exchange process (permutit).

3.         Demineralisation.

4.        Soda alum.

5.         Aeration.

6.        Chelation on sequestration.

7.         Calgon process.

Some Impotent Trams About Water Which Is Used In Textile Wet Processing?

##Why water is called universal solvent?

Water is called universal solvent, because the solvency power of water is very high & most of the solute of this world is easily dissolved in the water.

##What do you mean by water hardness?

Hardness is a term applied to water denoting a measurement of its pH & metal salt content. The presence of Ca & Mg salt i.e. Bi-Carbonates, Sulfates, Chlorides in water is called causes of hardness of water. The water which contains these salts is called hard water. Hard water does not easily form lather with soap as the salt of Ca & Mg react with soap to form insoluble organic salts.

Define water? Classification of water ?

Water:

Water is a complex compound. It is very important compound in textile wet processing. The total amount of water in the world is about 75%. Natural water is obtained in 3 steps. They are solid, liquid & vapor. Water has a un-comparable power to dissolve other compound. It is very difficult to obtain pure water in nature. Water is consists of two part Hydrogen & one part Oxygen. Its chemical formula is H2O. Water is converted to ice at 0°C & converted to vapor at 100°C the concentration of water is highest at 4°C.

 

Classification of water:

Classify water on the basis of hardness:

Objects & Advantages of Garments Washing

Objects of garments washing:

• To develop softness in garments: Size materials applied during manufacturing present in the fabric are removed which enhances soft hand feel. Additional softness may be attained by using softener.
• To introduce fading effect: Dyes or pigments are present in the fabric, used during coloration, are washed out locally or partially which result fading or worn out effects in the garments.
• To create new fashion: Washing Process of garments bring different outlook (faded, color tinted etc) thus creating new fashion for the new generation especially for teenagers.

Work procedure of a Garments Dyeing:

1.1  Desizing: This process to remove the size material and increase the absorbency power of the fabric to make the fabric suitable for the next process is called Desizing.

Chemical Types:

 1. Detergent – 200gm

2. Caustic soda – 400gm

3. Water – 400 L

4. Hydrogen Peroxide – 600gm

5. Temperature - 70°c

Flow chart for garments dyeing ( Dark & Light Shade )

Flow chart for garments dyeing (medium / dark shade):

M : L = 1 : 8

Garments Load - 2 kg

↓

Level in water 16 liter

↓

Wetting agent 0.5g/l NOF (70° c × 5’)

↓

Normal Wash

↓

Leveling agent LDR (60° c× 5’)

Fabric dyeing & flow chart

Fabric dyeing is the method after weaving, knitting or non-woven to make fabrics. This is very popular method of dyeing as the dyed fabrics will be processed further to garment industries very easily. Dyeing forms of the fabric dyeing can be used in 2 ways.

1. Open width form using the fabrics to spread without any creases and dye them.

2. Rope form using the fabrics with the form like a rope.

Dyeing work flow chart:

Scouring & bleaching

↓

Per oxide hot with a/acid

↓

Enzymes wash with a/acid

Printing section in Garments & Flow sequence of Rubber Printing???

PRINTING SECTION:

Printing section is playing a vital role in garments section. Garments value can be increased for using printing. Different types of print are given below:
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How to be environment polluted by Textile Industry ?

Textile processing generates many waste streams, including water-based effluent as well as Air emissions, water pollution, and hazardous wastes. The nature of the waste generated Depends on the type of textile facility, the processes and technologies being operated, and the types of fibers and chemicals used.

1 Air Pollutants:

Most processes performed in textile mills produce atmospheric emissions. Gaseous emissions have been identified as the second greatest pollution problem (after effluent quality) for the textile industry.

Speculation concerning the amounts and types of air pollutants emitted from textile operations has been widespread, but, generally, air emissions data for textile manufacturing operations are not

DENIM WASHING OR WET PROCESSES

Introduction 

Today, washing plays an important role in the denim value chain. Lot of customers do not want to wear and tear their jeans themselves, but want the manufacturer to do it for them . To achieve this worn look, a lot of different treatments can be made and different kind of processes and machinery can be used. Some processes are easy and some are complicated and needs to be carefully controlled. Due to poor wet and dry rubbing fastness of the indigo dye, every step in the denim washing process can make a big difference.

STONE WASHING

Stone wash is a traditional washing process where volcanic rocks or pumice stone are added to the garments during wash as abradants. Stone washed products will have a worn look, and are generally a bit puckered at the seams. Usually, stonewashing is made on indigo dyed garments that easily loses colour during abrasion. Often ringdyed yarns are used, which means that only fibres on the surface

Basic difference between dye and pigment?

I will discuss you about difference between dye and pigment which is the most important in dyeing and the students of Textile Engineering and Technology.

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DIFFERENCE BETWEEN THE GARMENTS DYEING AND FABRIC DYEING

Garments Dyeing

1. When garments are made from grey fabric and then the garments are dyed in required color and shade called garments dyeing.

2. Less time is required.

3. Comparatively low cost of production.

4. For direct dyeing M: L ratio maintained between 1: 10

5. Wales per centimeter is not increases after dyeing process.

6. GSM is increase after dyeing

7. Generally Belly machine is used for garments dyeing.

8. Less production than Fabric Dyeing

9. Comparatively lower space is needed.

10. No possibility of shade variation.

11. For direct dye pH is needed 4-7.

12. Sewing thread used for making the garments should be of same fiber like the garments fabric, otherwise color difference may occur between garments fabric and sewing thread.

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What are difference between feeder stripe and engineering stripe?

Yarn  dyed knit fabric is a one of exclusive fabric highly recommended by Buyer.  In knitwear section yarn dyed fabric is very popular and expensive rather than regular solid fabric. 

There are two type of yarn dyed fabric used in knitwear garments:

1. Feeder Stripe yarn dyed fabric

2. Auto Stripe or Engineering Stripe yarn dyed fabric.  

Feeder stripe fabric knitting way is different from engineering stripe. And also dying process is also different from solid color fabric. Solid color fabric being dye after fabric knitting. But in case of yarn dyed fabric first need to dye yarn according required color then fabric dye with colored yarn.

For More Information just Click Here

Feeder Stripe

• Feeder stripe has a small repeating unit approximately 1.9 inch.
• There is no extra device on feeder stripe.
• Production cost is low.

What Is Dye | Dyeing | Pigment?

Dye

A dye or dyestuff is a colored and organic chemical compound which have affinity to substance like textiles, absorbs light strongly in visible region and create physical and chemical bond with the fibres.

Dye must contain chromophore and auxochrome group. In case of organic compounds sometimes they have some molecules with pi-bond e.g. -NO, -NO₂ , -N=N- etc. for which the compounds become colored and  the molecules with pi-bond are called chromophore. Auxochrome is attached to chromophore to modify its absorption of light. –OH, -CHO etc. are auxochrome.

DEFINE & Calcification of SALT? | THE PROPERTIES & USES OF SALT IN WET PROCESSING OF TEXTILE?

SALT:

When Hydrogen atom of acid is fully or partly replaced by the metal or metal like reactive radical, then the compound which is found is known as salt.

Example: NaCl, KNO3, CaCl2 etc.

Classification of SALT: