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. 

anti-migrant : An additive used to prevent undesired movement or spread  the wet dye on fabric.

Binder : A material like gum or glue  nearly colorless, that is used to attach a pigment to fabric.

Carbonizing : Treatment of wool with acid and heat to remove vegetable, burrs, other  materials.

cloud point :  The temperature at and above which a water soluble  component will precipitate from solution.

crocking : Transfer of color from dyed or pigmented fabric onto other white fast fabric by rubbing.

Defibrillation : Process to remove fibrils from the surface of a fabric.

Diluent : Deluent or dilutant is a solid or liquid chemical used to carry or  dilute anything. 

Electrolyte : A substance that makes an electrically conductive solution when it is dissolved in water.

Etchant : In textile terms, a chemical that is used to break down fibres so that they can be removed for purposes of patterning.

Exhaustion :  The transfer of dye from dye bath to fibre.

Fastness : The resistance of a textile material to specific chemical agencies.

Fixation :  Build up the “final” bond between the dye and fibre

hydration number : A value indicating how many water molecules are associated with each molecule of some other compound in a crystal of that compound.

Hygroscopic :  Having a tendency to absorb water or moisture from air.

Indigo : A natural or synthetic Vat dye derived from the plant Indigofera tinctoria.

leveling agent :  An ionic, non-ionic surfactant used to promote level dyeing.

Mercerization : treatment of cotton yarn or fabric with a strong solution of NaOH to increase its strength.

Mordant : A chemical that helps the binding of dye or dyestuff  to the fibers for both fiber and dye.

Owf : On weight of fibre, normally expressed in percentage.

  

Omf : On  mass of fibre

Padding : A dyeing method with very low liquor to good ratio, where typically only enough strong dye solution is used to saturate the fabric

Pigment dyeing : Coloring fabric with  ground pigments mixed with a binder rather than a true dye.

Soaping or soaping off : A process of washing the dyed fabric with hot water with surfactants or cleaning agents, soap, detergent to remove the fixed dye. 

Softener (fabric softener) : A chemical or chemical mixture like lubricant stands for to give fabric a soft hand.

Softener (water softener) : Chemicals used to water to prevent hardness ions from interfering with other solutes.

Stripping : The process to remove  uneven dye from fabric before redyeing it.

Stock solution: A solution of known strength, made up with the intent of dilution or mixing before final use. Stocked will  be discussed future.

Substantive(ity) : The rate of dye to transfer from solute to solution. 

Subtractive : With reference to color, removal of colors from light reflected from a surface.

Surfactant : Surface active agent.

Syntan : Synthetic tanning agent.

Wetting agent: An agent helps to increase the uptake of the dye by the fibre or to penetrate solution by wetting it.

W/w : Abbreviation of weight/weight.

W/v : Abbreviation for weight/volume. 

বিস্তারিত পড়ুন

• Share
• Tweet

Flow process chart for Mercerization

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.

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)

বিস্তারিত পড়ুন

• Share
• Tweet

Garments Dyeing & Machine Specification

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 of dyeing machine such as jet dyeing machine. During garment dye process, some dyeing parameter should be adjusted according to form of products-righty weaved and heavy garments need the dyes with better migration properties, higher dyeing temperature, lower liquor ration & careful circulation of goods.

 Usually, textile coloration is carried out impart attracting of textiles & pretreatment is first stage of textile coloration process, plats very role on coloring on textiles. Generally loose fiber, yarn, knit fabric, garment & very lightweight synthetic woven fabric are dyed batch wise in single machine. So the batch preparation is the early step of pretreatment in coloration process.

GARMENTS DYEING

This method is the best process of the dyeing of goods. However, the penetration of the dye solution may not be completely passed to the fibers such as between the seams, buttons, zippers etc. Normally, it is used for lingerie, socks, sweater dyeing etc.

In woven fabric processing generally various types of dying process is used. Those are:

i. Pad Dry Steam (PDS)

ii. Pad Dry Cure (PDC)

iii. Cold Pad Steam (CPS)

Machine required for those process:

i. Cold pad batch

ii. Thermosol

iii. Pad steam

 Cold pad batch: It is the simple & easiest way of woven fabric dyeing. In this process only dark shade can be produced successfully & economically. But limitation is medium or light shade is difficult to match. It takes a long time because after dyeing it required a rotation of 8 to 12 hours.

Thermosol: It is a dyeing machine but it cannot produce the color as finally required or permanent. But in PDS process it can be provide finished product. By this machine only color is migrated from liquor to fabric. The it is dried on pre dryer & followed by hot air flow drying in thermosol unit. After this process color is developed in pad steam by chemical padding.

Pad stream: Thermosol run fabric must pass through pad steam for the development of color when CPS process is carried out. Here chemical padding is done through which color is fixed on the fabric. CPB run fabric does not require pad steam process. Here based on requirement additional dye can also added.

Garments Dyeing Machine Specification:

No. of machine: 01: Belly  Machine

Brand Name: Nagai Shina

Origin: China Capacity: 250 kg

Model No: NS-2260

RPM: 28

Temperature- 100° c

No. of machine: 02: Front Loading Machine/Computer Machine.

 Brand Name: DANIS Origin: Turkey

Capacity: 450 kg

Model No: MKM-525

RPM: 30(Fixed)

No. of machine: 03: Hydro Machine

Brand Name: DANIS Origin: Turkey

Capacity: 250 kg

Model No: D-2233

RPM: 800N-1000N

No. of machine: 04: Dryer Machine (Steam Dryer)

 Brand Name: DANIS Origin: Turkey

Capacity: 180 kg

Model No: D-2218

RPM: 30

No. of machine: 05: Dryer Machine (Gas Dryer)

Brand Name: DANIS Origin: Turkey

Capacity: 180 kg

Model No: D-2218

RPM: 30

বিস্তারিত পড়ুন

• Share
• Tweet

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

finishing steps. Wet processing technical conferences nearly always have sessions that stress the importance of fabric preparation, seldom is there a conference without topics on how to prepare specific fabrics.

There are many different fabrics, many different plant set-ups and many different machines used in wet processing. There is no universally accepted best method for each of the wet processing steps. Nonetheless every set-up is expected to, and more often than not, accomplish the same goals. To deal with this seemingly infinite number of permutations, a fundamental understanding of what happens at each step and how to control the chemical and physical parameters becomes paramount.

The discussions that follows will deal with all of the specific steps that encompass fabric preparation. Fundamental chemical and physical concepts will be stressed. It is important for the reader to understand that not all fabrics undergo each of the steps: however, a specific fabric will be routed through those steps that are necessary to end up with a thoroughly prepared fabric. Chapter 1 will discuss the equipment used to prepare warp yarns, and the equipment used to prepare fabrics for dyeing and finishing, Chapter 2. will cover the chemistry. In wet processing it is generally recognized that the steps encompassing preparation are:

Singeing: A process where loose fibers and fuzz is burned away to yield a clear and clean fabric surface.

Desizing: A process where warp size is removed.

Scouring: A process where mill and natural dirt, waxes and grease are removed

Bleaching: A process where color bodies are destroyed and the fabric is whitened.

Mercerizing: Caustic treatment of cellulosic fabrics improving luster, water absorbance, dye yield and fiber strength.

Carbonizing: Acid treatment of wool for removing vegetable matter.

Heat Setting: Heat treatment of fabrics containing thermoplastic synthetic fibers. Stabilizes fabric by reducing shrinkage and distortion.

বিস্তারিত পড়ুন

• Share
• Tweet

Working procedure of Dyeing in Textile Industries?

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

At first mixed the chemical then run the machine 10 minutes at 70°c. After this process to proper clean the machine with 800 L water.

1.2 Neutral: Neutral is done to control the pH of this process pH must be checked. Some chemical are use for the process. At first Acetic Acid (100gm) with water 400 L to run the machine 5 minutes at 45°c. Then after this process to proper clean the machine with 800 L water for the next process.

1.3 Dyeing: This process by which is a textile material is to be changed physically or chemically, so that it looks mono uniform colored is called Dyeing.

Alfatex + Anticrease = 45°c – 5min

Dye Chemical = 55°c – 5min + Salt after 20min

Fixing Agent

 Softening Agent

 Rinsing Wash

Dain

1.4 Objects of dyeing:

1. The textile goods are dyed uniformly with single color.

2. To increase the attractiveness of the textile goods.

3. To make the fabric suitable for various usage.

4. To make textile goods suitable for decorative purposes.

Some necessary chemicals are needed for this process. Such as

1. Alfatex – 500gm

2. Anticrease – 500gm

Anticrease removes crease mark. The Belly Machine run 5 minute with chemical and water at 80°c temperature then add dyestuff.

 Indosol Scarlet BL – 350GM

 Rose RR – 66.25gm

 Red BA – 153.5gm

 Salt – 15kg

Those chemical are mixed in a bath. Those chemical are taken in a Belly Mache with 800 L water to run the machine 5 minute at 80°c temperature then check garments to match the shade.

1.5 Fixing: This is a very important process because it helps to carry dye in garments. It increases durability dye in the garments. For this process fixing agent such as hydrocol sun (300gm) and water is needed to run machine 5 minute at 40°c. Then after this process to proper clean the machine with 800 L water for the next process.

1.6 Enzyme: This process is done when the garments carry excess dye than the buyer requirement. But when garments carry light that time enzyme process is not necessary. For enzyme process Jak powder (150gm) and pocket clear (100gm) are needed with water to run the machine 5 minute at 40°c temperature. After this process to proper clean the machine with 800 L water.

1.7 Softener: Softener is used to soft the garments. For this process IMA and Acetic Acid are needed with water to run the machine 5 minute at 40°c temperature then garments out. After Finishing those process garments are taken out for finish dry process. Time, Temperature, Liquor Ratio must be controlled.

1.8 Garments dyeing process with vat dyes: The following process is suitable specially for garment dyeing. Typical recipe: Wetting agent = 0.5 – 1.0 g/l Sequestering agent = 1.0 - 2.0 g/l Leveling agent = 1.0 - 2.0 g/l Retarding agent – 5 - 7 g/l (If necessary use in hot dyes) Dyes = 7% (owf) Caustic soda = 5 %(according to vender recommendation) Hydros (sodium hydrosulfite) = 5%( according to vender recommendation) Temperature = 70°c - 80°c Time = 30 – 50 min M: L = 1:10

Procedure:

1. First, settle dye bath with substrate at 40°c and wetting, sequestering agent, leveling, retarding agent (if necessary) and then run for 5 – 10 min.

2. Add dyes according to substrate weight and run the bath for 5 min.

3. Add 2/3 of caustic soda requirements and run for 5 min.

4. Raise the temperature to 70 – 80 at 2-3c/min and run for 5 min.

5. Add Sodium hydrosulfite (hydroz) to the bath with rest 1/3 amount of caustic requirements.

6. Run the bath for 30 min and maintain reduction by checking with vat reduction paper.

7. Overflow rinse until with cold water.

1.9 Oxidation: After dyeing cycle penetrated and distributed dye molecules are oxidized to convert insoluble form into the fiber. The oxidation process can be done in contact of air or other oxidizing agent. For example, the oxidation process can be carried out treating the dyed goods with 0.5 – 1.0 g/l hydrogen 35% at 30 – 35 for 10 min.

1.9.1 Soaping:

Detergent = 1.0 – 2.0 g/l

Soda ash = 1- 2 g/l

Glucose = 95 – 100c

Time = 15 – 30 min

M: L = 1: 10 – 1: 20

The rinse the goods with cold-hot-cold water successively.

1.9.2 Softening:

1. That the good with 1.0 – 2.0% softening agent at 10 min.

2. Drop

3. Finally dry the goods uses.

বিস্তারিত পড়ুন

• Share
• Tweet

Flow chart for garments dyeing (light shade)

Flow chart for garments dyeing (light shade):

 Level in Raise temp. (70° c × 5min)

↓

 Wetting + Detergent (NOF)

 ↓

Leveling agent (LDR) 60° c × 5min)

 ↓

Color dosing {60° c × (10 +10)} {CIBA Yellow FNR - 0.048% CIBA Red FNR – 0.048% CIBA Blue FNR – 0.048%}

↓

 Salt dosing (24g/l){60° c × (10+10)}

 ↓

 Soda dosing {(8g/l) (60° c × 10’)}

 ↓

Run time 35 min (sample check)

↓

 Normal Wash

 ↓

Acetic Acid (1 g/l)

 ↓

 Cold wash

↓

 Fixing agent (E.C) (1 g/l) – (40° c × 5 min)

↓

 Raise temp. 50° c

 ↓

 Run time 5 min

↓

Drain

 ↓

Level in

 ↓

 Cold wash (27° c × 2 min)

বিস্তারিত পড়ুন

• Share
• Tweet

Flow chart for garments dyeing (medium / dark 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’)

↓

Color dosing (60° c× 10’) RG Yellow RGB - (0.44%) RG Red RGB - (0.254%) RG Blue RR - (0.898%) Run 10’

↓

Salt dosing {(50g/l) 60° c × (10’ + 10’}

↓

Soda dosing {(16g/l) (60° c × 10’)}

↓

Run Time 35’ (sample check)

↓

A – Acid (1 g/l × 5’)

↓

Fixing agent (E.C) (1g/l) – (40° c × 5 min)

↓

Raise temp. 50° c

↓

Run time 5

↓

Drain

↓

Level in

↓

Cold wash (27° c × 2min)

বিস্তারিত পড়ুন

• Share
• Tweet

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

↓

Leveling with sequestering

↓

Dyeing dosing

↓

Salt dosing

↓

Soda dosing

↓

Sample

↓

Drain

↓

Washing off

↓

A/acid

↓

Softener

↓

Unload

Dyeing machine:

Name of the m/c: Dyeing machine

Brand Name: Dilmenlar

Manufacturing Company: Turkey

Year of Manufacturing: 2004 Machine

capacity: 150 kg

No. of nozzle: 02 Maximum

Temperature: 135°c

Motor: 01

Winch Motor: 01

Pump Motor: 01

The controlled Parameters for dyeing procedure:

pH:

- During H2O2 bleaching Ph: 10.50 – 12

- During neutralization : 6.50 – 7.0

- During Enzyme : 4.50 – 7.0

- During reactive dyeing pH: 9.5 – 11.50

- During Soda dosing : 10.0 – 11.0

- Soaping : 4.50 – 6.0

- During disperse dyeing pH : 4.50 – 5.0

Temperature:

- For cotton scouring : 98°c

- For cotton enzyme : 55°c - 60°c

- For cotton dyeing : 98°c (For hot brand)

- For salt, Soda : 60°c

- Polyester dyeing : 135°c

- For cotton cold wash : 30°c - 40°c

- For cotton hot wash : 80°c - 90°c

- For cotton acid wash : 50°c - 60°c

- OBA application : 98°c

Time:

- For scouring & bleaching : 60 minute (when temp. 98°c) If 110°c, time 30min.

- For cotton enzyme : 60 minute

- For reactive dyeing : 30 minute

- For disperse dyeing : 30 minute

- For salt dosing : 30 minute

- For soda dosing : 45 – 60 min

M: L ratio:

- For reactive dyeing M: L ratio maintained between 1: 8

- For disperse dyeing M: L ratio maintained between 1: 10

The calculated formula followed in production:

01. Color (%) – Required dye (gm)= Total fabric × Recipe / 100

02. Chemical + Auxilaries (gm/l) - Required chemical (gm)= Total liquor × chemical(gm/l) / 1000

Working Procedure:

Firstly the detergent, Anti-creasing agent, Anti-foaming agent and Stabilizer are mixed in mixing tank, then load to machine at 50°c

 ↓

The temperature is risen to 60°c. Now the Caustic Soda is given to bath

↓

The Hydrogen Peroxide is given at 70°c

 ↓

Raise the temperature at 98°c and run for 60 minutes. Here the Ph = 11-12

↓

 Rinse the fabric

 ↓

Hot wash is done at 80°c × 10 → Drain → Normal wash → Drain

 ↓

Peroxide is applied at 60°c and run for 15 minutes → Hot wash

 ↓

 Add Acetic Acid at same temperature and run 10 minutes

↓

 pH checked (pH=6.5) → Normal wash

 ↓

 Now Acetic Acid applied at 55°c for pH control (pH= 4.50) and then Enzyme is given to bath at same temperature with 60 minute

↓

 Raise the temperature (Grade rate → 2 C/min) at 80°c and run 6 minute

 ↓

 Cold wash is done 2 times and the drained out.

বিস্তারিত পড়ুন

• Share
• Tweet