Yaa All Most Denim Launder Inwards Bangladesh

All About Denim Wash In Bangladesh

Abeed Hasan
Dept. of Textile Engineering,
Khulna University of Engineering & Technology
Email: 1521033abeed@gmail.com

What is denim?
Denim is a rugged twill textile, inwards which the weft passes nether the 2 or to a greater extent than warp yarns, producing the familiar diagonal ribbing identifiable on the revere of the fabric.

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Characteristics of denim fabric:

• Warp yarns are colored (usually with indigo, vat, bluish or sulphur dark ).
• Structure : correct mitt or left mitt twill, i.e. z/s-twill of 2/1 or 3/1construction.
• Usually made of cotton fiber yarns of coarser count (7s, 10s, 14s, 16s, etc )
• Coarser cloth ( weight lies betwixt 6-14 oz/sq.yds ) in addition to used for pant in addition to warm jackets.
• Rotor yarn are normally used.

Classification of denim textile :

1. As per weight /unit area:

• Light weight : 4.5 to vii oz/sq.yd
• Medium weight : vii to 10 oz/sq.yd
• Heavy weight: eleven in addition to above.

2. As per hue in addition to color:

• Indigo vat.
• Sulphur black.
• Pigment.

3. As per slub yarns:

• Warp yarns are slub only.
• Weft yarn are slub only.
• Cross Hatch : both agency slub i.e. both warp in addition to weft yarn are slub.

4. As per textile structure/design:

• Plain.
• Twill (S-twill, Z-twill, herringbone or zigzag twill)
• Jean: It comes from French discussion “Genes” used to depict the pants sailors from Genoa, Italy, in ane lawsuit wore. While the historical Definition implied that all jeans were made of denim , jeans today normally refer to a garments that has v pockets (two inwards the front, 2 inwards the dorsum in addition to minor modify bag on the forepart correct pocket) in addition to this manner tin forcefulness out live made using whatever kinds of fabrics live it corduroy, twill, or bull denim.

• Jeans: Long, narrow pants, peculiarly for women , manufactured past times diagonal weave cotton fiber fabric, named later where the texture originally were manufactured, the town Genoa, Italy . Jeans are pants or trousers, made from denim. Mainly designed for work, they became pop with teenagers starting inwards the 1950. Historic brands include levi’s American population spent to a greater extent than than $14 billion on jeans inwards 2004.

• Bull Denim: Piece-dyed cotton fiber twill made from coarse yarn to resemble denim, nonetheless , the warp yarns are non dyed with indigo earlier weaving.

• Bell Bottom: Influenza A virus subtype H5N1 jeans manner born inwards the belatedly 60s, 70s. Bell-bottom are trousers that croak wider from the knees downward. Tight at the waist (some times lowered ) in addition to at the thighs , the trousers flare out from the genu to cook a come upwards dorsum at the goal of the 80s, but didn’t quite grab on.

• Cross Hatch: An upshot of the denim weave created past times using uneven yarn inwards the weft direction, combined with uneven yarns inwards the warp direction.

• Hipster jeans: Influenza A virus subtype H5N1 manner of jeans that get-go almost 10 centimeters below the navel.

• Rigid Denim: Describe unwashed denim. Most denim garments are typically prewashed earlier going to retail.

• Low rising Jeans: Low rising Jeans worn past times both men in addition to women, are jeans intended to sit down depression on or below, the hips. They are also called depression cutting jeans , hipsters, hip-huggers in addition to lowriders . Usually they sit down at to the lowest degree 8cm (3”) lower than belly button.

Denim Wash:
Now-a-days denim launder is much pop both dry out in addition to moisture washing process. According to the fashion in addition to appearance, at that topographic point include novel washing procedure in addition to technology scientific discipline such every bit 3D or Light Amplification by Stimulated Emission of Radiation techniques. In denim washing is done to make effects similar color fading with or without patchiness, crinkles, seam puckering, hairiness, Pilling softened-hand feel, stabilized dimension etc. Most of the denim launder upshot vintage look. Now I wish to depict briefly denim washing types with menses chart.
 

Process Flowchart of Denim Washing:

Garment Received from Finishing
↓
Garments Dry
↓
Garments moisture procedure
↓
loading garments for washing
↓
De size garment
↓
Enzyme wash
↓
Extracting for extract H2O removing
↓
Garments Drying
↓
Potassium Permanganate Spray
↓
Softener
↓
Extracting
↓
Drying
↓
Washing Quality Control
↓
Next Process

 

 

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Types of denim wash:
Denim washes are of next 2 type :–

1. Chemical washes:

• Denim bleaching
• Enzyme launder
• Acid wash

1. Mechanical washes:

• Stone wash
• Microsanding

Denim Bleaching:

• In the procedure a rigid oxidative bleaching agent similar sodium hypochlorite or KMnO4 is added during the washing with or without stone addition. Discoloration produced is normally to a greater extent than apparent depending on strength on the bleach liquor quality, temperature in addition to handling time. It is preferable to receive got rigid bleach with brusk handling time.

• Care should live taken for the bleached goods so that they should live adequately antichlored or later washed with peroxide to minimize yellowing. Materials should live carefully stored earlier processing for color uniformity,

Process cycle:

Step # 1(Desizing)

• Load the garments into the washing machine (100 kg) ;
• Add H2O (liquor ratio 1:5) in addition to get-go the machine running(12-15 rpm) ;
• Add amylase enzyme (1 to 3% i.e.1 to 3 kg) ;
• Add detergent (1% i.e. 1kg) ;
• Supply steam to lift temp.(60°C) ;
• Continue the procedure for xx min in addition to so drain the liquor ;
• Hot launder (at temp. of 40°C to 50°C for 5 minutes).

Step # 2 (Bleaching)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Start m/c running ( 12 to fifteen rpm ) in addition to add together soda ash (Na2CO3) to liquor (2% i.e. 2kg) ;
• Add costic soda (NaOH) to liquor (2% i.e. 2kg) ;
• Add bleaching chemic (H2O2) to liquor (5ml per liter, i.e. 2.5 liters) ;
• Add stabilizer to liquor (2ml per liter, i.e. 1 liter) ;
• Supply steam to lift temp.(70°-800C) ;
• Continue the procedure for threescore to seventy min. in addition to drain the liquor ;
• Hot launder (at 60°C for 5 minutes).

Step # 3 ( Nutralization)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 liters );
• Start m/c running ( 12 to fifteen rpm );
• Add acetic acid ( CH3COOH ) to liquor (1 to 2 ml per liter, i.e. 500ml to 1liter);
• Continue the procedure for 10-15 min in addition to so drain the liquor.

Step # iv ( Brightening treatment)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Add Fluorescent Whitening agent/Fluorescent Brightening agent to liquor (% every bit required );
• Supply steam to lift temperature (800C);
• Continue the procedure for 10 min in addition to so drain the liquor.

Step # 5 (Softening)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Start m/c running ( 12 to fifteen rpm );
• Add softener to the liquor (0.1 to 0.5%, i.e. 100g to 500g);
• Supply steam to lift the temperature (as required 400 to 600C );
• Continue the procedure for 5 minutes in addition to so drain the liquor in addition to unload the garments.

Limitations of denim bleaching :

• Process is hard to command i.e. hard to hit the same story of bleaching inwards repeated runs.
• When desired story bleaching reached the fourth dimension bridge available to halt the bleaching is real narrow. Due to harshness of chemical, it may drive impairment to cellulose resulting inwards severe strength losses in addition to or breaks or pinholes at the seam, pocket, etc.
• Harmful to human wellness in addition to causes corrosion to stainless steal.
• Required antichlor treatment.
• Problem of yellowing is real frequent due to residuum chlorine.
• Chlorinated organic substances occur every bit abundant products inwards bleaching in addition to top into the effluent where they drive severe environmental pollution.

Enzyme Wash:

• It is environmentally friendly wash. It involves the application of organic enzymes that consume away at the fabric, i.e. the cellulose. When the desired color is achieved, the enzyme tin forcefulness out live stopped past times changing the alkalinity of the bathroom or its temperature. Post handling includes concluding ringing in addition to softening cycle. The effects produced past times cellulose enzyme are :—-
• Use of cellulose making the seams, hems, in addition to pockets to a greater extent than noticeable;
• Salt newspaper upshot is color contrast effect.
• Faded garment washed with acid cellulose enzyme provides less color contrast inwards proportion to garment washed neutral cellulose enzymes.
• Garment charge size of the m/c is 35-40 jeans per m/c in addition to it cannot live overloaded.

Acid Wash:

• It is done past times tumbling the garments with pumice stones presoaked inwards a solution of sodium hypochlorite or potassium permanganate for localized bleaching resulting inwards a non uniform abrupt blue/white contrast. In this launder the color contrast of the denim textile tin forcefulness out live enhanced past times optical brightening. The payoff of this procedure is that it saves H2O every bit add-on of H2O is non required.

• It consists of soaking pumice stones with chlorine in addition to using their abrasive ability to bleach jeans into abrupt contrasts. Also known every bit moon, fog, marble, H2O ice in addition to frosted.

Process bike :

Step # 1(Desizing)

• Load the garments into the washing machine (100 kg) ;
• Add H2O into the machine(1:5 liquor ratio i;e. 500 liters) ;
• Start machine running (12 to fifteen rpm) ;
• Add amylase enzyme (1 to 3% i.e.1 to 3 kg) ;
• Add detergent (1% i.e. 1kg) ;
• Supply steam to lift temp.(60°C) ;
• Continue the procedure for xx min in addition to so drain the liquor ;
• Hot launder at temp. of 40°C to 50°C for 5 minutes.

Step # 2 ( Bleaching)

• To behave out the Bleaching process, the next 2 steps are to live passed over :

Step # A

• Take stone of some book of the book of garments ;
• Soak the sfone with the next chemic solution for 2 to 3 minutes ;
• Water 100 litres
• Potassium permanganate 1 kg
• Phosphoric acid 300 ml (3ml per litres)
• Here the porous of stones are dried inwards the opened upwards air for threescore to xc min.

Step # B

• Load the garments treated inwards stride # 1 in addition to stride # 2 inwards a dry out m/c. Lot size should live xx to 30kg.
• Run the m/c for 5 to vii minutes. Due to the rotation of m/c the socked stones volition striking the garments surfaces in addition to the chemicals inwards the stone volition destroy color of the fabric. Multilayer textile areas similar collar, cuff, pocket, bag side seam etc. expanse volition live brushed to a greater extent than than the unmarried layer areas, thence to a greater extent than fading upshot volition live produced inwards those areas resulting novel color upshot inwards the garments.
• Unload the garments in addition to split upwards the stones from the batch.
• In this phase KMnO4 in addition to H3PO4 reacts with each other in addition to gives Oxygen which oxidize the color.
• Here a byproduct MnO2 is produced which should live neutralized.
• 6KMnO4 + 4H3PO4 = 2K3PO4 + Mn3(PO4)2 + 6H2O + 3MnO2 + 2O2
• This MnO2 is solubilized past times Sodium Metabisulfite (Na2S2O5).
• Na2S2O5 + H2O = 2NaHSO3
• NaHSO3 + MnO2 = MnSO4 + NaOH
• Load the garments to the m/c ;
• Add H2O into the m/c (1:5 liquor ratio, i.e. 500 litres) ;
• Continue the procedure (12 to fifteen rpm) ;
• Add sodium metabisulfite (1 to 2 gpl, i.e. 500 g to 1kg) ;
• Continue the procedure for 5 to 10 min in addition to so drain the liquor ;
• Hot launder (at 40o to 50o C for 5 minutes).

Step # 3 ( Nutralization)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Start m/c running ( 12 to fifteen rpm );
• Add acetic acid ( CH3COOH ) to liquor (1 to 2 ml per liter, i.e. 500ml to 1liter);
• Continue the procedure for 10-12 min in addition to so drain the liquor.

Step # iv ( Brightening treatment)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Add Fluorescent Whitening agent/Fluorescent Brighting agent to liquor (% every bit required );
• Supply steam to lift temperature (800C);
• Continue the procedure for 10 min in addition to so drain the liquor.

Step # 5 (Softening)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Start m/c running ( 12 to fifteen rpm );
• Add softener to the liquor (0.1 to 0.5%, i.e. 100g to 500g);
• Supply steam to lift the temperature (as required 400 to 600C );
• Continue the procedure (5 minutes) ;
• Drain the liquor in addition to unload the garments.

Limitations of acid launder :

• Acid washed ,indigo dyed denim has a vogue to yellowish later moisture processing.
• The major drive is residuum manganese due to incomplete neutralization, washing or rinsing.

Remedy :

• Manganese is effectively removed during laundering with add-on of ethylene-diamine-tetraacetic acid every bit chelating agent.
• Acid washing jeans avoided some of problems of stone wash, but come upwards with added danger, expenses in addition to pollution.

Stone Wash:
In the procedure of stone washing, freshly dyed jeans are loaded into large washing machines in addition to tumbled with pumice stone or volcanic stone to hit a soft mitt in addition to desirable look. Variations inwards compositions, hardness, size shape in addition to porosity cook these stone multifunctional. The procedure is quite expensive in addition to requires high uppercase investment. Pumice stone give the additional upshot of a faded or worn expect every bit it abrades the surface of the jeans similar sandpaper, removing some dye particles from the surfaces of the yarn.

Step # 1(Desizing)

• Load the garments into the washing machine (100 kg) ;
• Add H2O into the machine(1:5 liquor ratio i;e. 500 liters) ;
• Start machine running (12 to fifteen rpm) ;
• Add amylase enzyme (1 to 3% i.e.1 to 3 kg) ;
• Add detergent (1% i.e. 1kg) ;
• Supply steam to lift temp.(60°C) ;
• Continue the procedure for xx min in addition to so drain the liquor ;
• Hot launder (at temp. of 40°C to 50°C for 5 minutes).

Step # 2 (Stone wash)

• Add Water into the m/c (1:5 liquor ratio, i.e. 500 litres );
• Add pumice stone one-half of the book of garments (30 to fifteen kg) ;
• Start machine running (12 to fifteen rpm) ;
• Add bleaching pulverisation to liquor (4% i.e. 4kg) ;
• Add soda ash (Na2CO3) to liquor (8% i.e. 8kg) ;
• Continue the procedure for xx min to xl min in addition to so drain the liquor ;
• Hot launder (at 40°C to 50°C for 5 minutes).

Step # 3(Softening)

• Add H2O into the machine(1:5 liquor ratio, i,e. 500 liters).
• Start machine running (12 to fifteen rpm).
• Add softener to the liquor (0.1 to 0.5%, i,e. 100 g to 500 g).
• Supply steam to lift the temp. (as required 40° to 60°C).
• Continue the procedure (5 min).
• Drain the liquor in addition to unload the garments .

Selection of stone:
Stone should live selected of the proper hardness , shape in addition to size for the detail goal product. It should live noted that large , hard stones in conclusion longer in addition to may live suited for heavy weight fabrics only. Smaller, softer stones would live used for low-cal weight fabrics in addition to to a greater extent than fragile items. Stone wt. / textile wt. = 0.5 to 3 it depends on the story of abrasion needed to hit the desired result. Stones tin forcefulness out live reused until they completely disintegrate or launder downward the drain.

Problem caused past times stones:

• Damage to launder machineries in addition to garment due to stone to machine in addition to machine to stone abrasion.
• Increase inwards labor to take dust shape finished garments .
• Water pollution during disposal of used liquor.
• Back staining in addition to re-deposition.
• Back staining or Re-deposition: The dye removed from denim stuff later the handling with cellulose or past times a conventional washing procedure may drive “back staining “ or “re-deposition”. Re-coloration of bluish threads in addition to bluish coloration of white threads, resulting inwards less contrast betwixt bluish in addition to white threads.

Remedy of dorsum staining:
Adding dispersion/suspension agent to launder cycle. ¤Intermediate replacement of launder liquor. ¤Using element of group I detergent similar sodium per borate with optical brightener every bit later wash.

Limitation of stone washing:

• Quality of the abrasion procedure is hard to command outcome of a charge of jeans is never uniform, lilliputian pct ever getting ruined past times likewise much abrasion.
• The procedure is non selective.
• Metal buttons in addition to rivets on the jeans inwards the washing machines larn abraded .
• This reduces character of the products in addition to life of equipment, in addition to increases production costs.
• Stones may plough into pulverisation during the procedure of making the garment grayish inwards color in addition to petroleum too.
• Provides rougher experience than enzyme wash.
• Stone may Pb the harm to machine parts.

Microsanding:
A fabric finishing process where fabrics are sanded (real sandpaper) to cook the surface soft without hair. Can live performed earlier or later dyeing. In this textile handling process, a serial of cylindrical rolls inwards a horizontal arrangement, either wrapped with an abrasive newspaper or chemically coated with an abrasive are used to practice a soft, sueded hand. The denim is pulled over the human face upwards of the sand rollers creating a raised surface finishing. Some color reduction is experienced.

There are 3 ways for this technique:

1. Sandblasting.
2. Machine sanding.
3. Hand sanding or mitt brushing.

Used inwards diverse ways:

• Flat surfaces (tables, ironing boards).
• On the dummy (inflatable dummies, sometimes standing, sometimes flat, sometimes seated).
• Various templates tin forcefulness out live used to practice a 3D effect.

Sand blasting:

• Jeans article of apparel handling that removes color from sure enough areas, either all over or placed in addition to gives the garment additional softness. Sand is genuinely shot at the garment with a powerful spray gun. Recent technology scientific discipline has introduced “automatic” sandblasting, inwards which the jeans hang in addition to rotate continuously.
• It is purely mechanical process, non using inwards chemicals.
• It is a H2O gratis procedure thence no drying required.
• Variety of distressed or abraded looks possible.
• Any set out of designs could live created past times special techniques.
• It is a procedure applied on denim textile garments to larn heavy faddy effects on detail points.

Sand blasting technique is based on blasting an abrasive stuff inwards granular, powdered or other shape through a nozzle at real high speed in addition to pressure level onto specific areas of garment surface to live treated to give the desired distressed/abraded/ used look.

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Process:

• Individual garment to live processed is taken on a table.
• Air compressor is started in addition to pressure level to maintained betwixt 3-4 kg/sq.cm. Air compressor so stores air inwards the machine cylinder.
• Aluminum sand or silicon sand, Al2(SiO4)3, is than taken inwards the sleeping accommodation of the blasting machine.
• Sand in addition to compressed air is than sprayed over the garments at specific points past times mitt spray pipe.
• Sand top into the machine past times regulating system. The machine comprises a blasting regulator in addition to a mitt regulator to command the amount of sand in addition to compressed air respectively.

Conclusion:
Finally, inwards denim washing our province has a vivid hereafter due to broad spread marketplace of denim garments. We request thorough noesis on denim handling procedure in addition to also on the fashion going or so the world. And this projection volition live a guideline for them who are interested inwards the sector. pioneer inwards the champaign of hard washing. And nosotros believe that this projection volition live a guideline for the washing plants inwards agreement in addition to doing diverse treatments.

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