Acid Wash Process on Denim Jeans Garment

What is Acid Wash?
The technology which is used to modify or change the appearance, outlook, comfort ability and fashion of the garments is called garment washing. It is done on the garments from heavy fabrics like denim and jeans. Today fashion is incomplete without denim. To change the look of denim or jeans different types of washing process are done. Among various washing process of denim, acid wash is the most popular. In this article I will discuss all procedure of acid wash on jeans.

Acid wash on denim jeans has become popular owing to its significant contrasts and attractive appearance in color. Acid wash can be carried out on indigo- and sulphur- based fabric garments. Acid wash is a chemical wash process on denim which strips the top layer of color and makes a white surface while the color remain seen the lower layers of the material, giving it a faded look.

This is also a kind of stone wash, which is accomplished with pumice stones. Due to severe abrasive action, surface fiber damage occurs. In some instances the pumice is impregnated with potassium permanganate (an oxidative bleaching agent), this chemical being less damaging to the cotton fiber than sodium or calcium hypochlorite.

Acid was first launched in the 1980s as an innovative finish on denim garments. This wash is carried out by soaking stones in bleach, followed by neutralization.

Purposes of Acid Wash on Denim Jeans:

• To get regular fading effect on jeans.
• To increase softness of the denim or jeans.
• “Wash look” appearance is developed.

Equipments:

1. Washing machine
2. Hydro extractor
3. Tumble dryer
4. Iron
5. Packing machine

Raw Materials:

1. Jeans garments
2. Peumic stone
3. Desizing agent
4. Detergent
5. Potassium permanganate
6. Phosphoric acid
7. Softener

Recipe:

• Jeans garment —————————————— Xpcs
• Desizing agent —————————————— 1.5%
• Potassium permanganate ————————— 2 Kg/L
• Phosphoric acid ————————————— 350 ml/L
• Detergent ———————————————— 1.5%
• Softener ————————————————— 1.5%
• M:L ——————————————————–1:10
• Temperature ——————————————- 60^oC

Procedure of Acid Wash:

1. Desize with α-amylase enzyme and detergent. The liquor ratio is approximately 5–8:1. After 10–15 min, the material is washed, squeezed and taken out of the machine.
2. The stones are saturated with chlorine/PP, excess water is removed from stones or towel and porous stones are dried in the open air for 60–90 min.
3. The stones followed by the jeans are put in a dry washing machine and treated for about 20 min. Make sure machine does not have single drop of water in it. Open the drain over the complete process.
4. At this time, the jeans are checked to ensure that they look acceptable. Too long a time in the first machine can totally bleach or ruin the jeans; too little time may not produce the desired results or can create a patchy appearance. Check on the jeans once every 10 min or so during the second wash neutralization process to ensure that the desired look is achieved.
5. Move them to another washing machine for a regular washing process.
6. Antichlor or neutralize with sodium bisulphate.
7. Cool by adding water.
8. Dry tumble.
9. Use optical brightening.
10. Use softener.

Step by step acid wash process of denim jeans are given below:

1st step:

1. A process of acid wash on denim trouser is discussed of a batch X pcs.
2. Add water liquor ratio @1:5 ———–500 L
3. Start machine running.
4. Add desizing agent @g/l —————– 1 Kg
5. Start steam supply to raise liquor temp at 60^oC
6. Continue washing for 20 mins.
7. Then drop the liquor

2nd step:

1. Add liquor ratio @1:5 —————– 500 L
2. Start machine running.
3. Start steam supply to raise temp at 50^oC
4. Continue treatment for 5 mins.
5. Drop the liquor.
6. Then unload the garments from the machine trolley.
7. Load the pretreated garments in the drying machine.
8. Dry the garments completely.
9. Then unload the garments from garment drying machine.
10. Keep the pretreated and dried garments separately.

Now, the pretreatment of peumic stone is to be done separately.

Make a stoke solutions as follows-

• Water —————————————100 L
• Potassium permanganate —————-1.2 Kg
• Phosphoric acid —————————0.3 Kg

Mix the solution by stirring into a stainless steel or ceramic tube.

Soak the peumic stone in the chemical solution for 2 to 3 mins, suck the stones from the solution and keep the stones separately for air drying for new hours.

Again,

1. Load the pretreated garments in the another washing machine ——— 30-40 Kg per.
2. Load the pretreated stones in the washing m/c.
3. Start machine running for each batch ———- 5 to 7 mins.
4. Stop the machine running.
5. Unload the treated jeans separately.

Then,
Load the stone treated jeans in another washing machine.

• Batch size ————————————- 100 Kg
• Liquor ratio @1:5 ———————— 500 L
• Detergent 1% —————————– 1Kg
• Temp ————————————— 40^oC
• Time ————————————— 10 mins.

→ Drop the liquor.

Then, make a solution to treat with the stone treated garments.

• Batch size ——————————————– 100 Kg.
• Liquor ratio @ 1:5 ——————————— 500 L
• Softener ———————————————– ½ Kg
• FWA/FBA @0.5 —————————————— ½ Kg

→ Continue treatment for 10 mins.
→ Drop the liquor.
→ Unload the garments.
→ Dry the garments.
→ Deliver the garments.

Precaution:
Acid-washed denim fabric sometimes become yellowish after washing. This is the result of incomplete neutralization, washing or rinsing, so that manganese is not removed from the garment. However the manganese can be removed by washing additional ethylenediamine-tetra-acetic acid as a chelating agent.

Other precautions are taken during acid wash:

1. Maintain properly stock solution and stock solution consistency.
2. Count the garments when enter the machine and count the garments when washing is finished.
3. Addition of stone carefully.

Conclusion:
Acid wash is done to get irregular fading effect on the denim trouser. By this experiment we can achieve knowledge about how to wash the jeans with acid wash. This will help us in our professional life.

You may also like:

1. Different Types of Denim Jeans Washing Process
2. Diversification and Uses of Denim Fabric

Jahanara Rony

Editor of Fashion2Apparel. She is a fashion designer and ex-lecturer in Fashion Designing. She wants to spread fashion knowledge throughout the world.

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