Some Question and Answer related to Acid washing

 

Acid Wash

Question-1: What is Acid washing in garments?

Answer: Acid washing a process in which a denim garment is treated with a bleach solution containing chlorine-soaked stones so that the color becomes faded and the material is softer.

Question-2: What types of garments can be washed by Acid wash?

Answer: It is normally done on the garments from heavy fabrics like denim, course canvas, sweater & thick twill etc.

Question-3: Describe acid wash process for 50 kg garments.

Answer: A process of Acid wash of 50 kg batch of Denim Trouser is mentioned below:

First Step: Pretreatment/Desizing.

•      Add water @ L : R = 1 : 10 .............. 500 litres.

•      Start Machine.

•      Add desizing agent @ 1 gm/litre .................500 Gms.

•      Add detergent @ 1 gm/litre ........................ 500 Gms.

•      Temperature............................. 60°c.

•      Time........................... 20 mts.

•      Drop the liquor.

•      Rinse one for 3 minutes (cold).

Second Step: Hot wash

•      Add water @ L: R = 1: 10.............. 500 litres.

•      Temperature............................. 60°c.

•      Time........................... 5 mts.

•      Drop the liquor.

      Here hot wash is used to remove the adhering materials from the garment surface.

•      Unload the garments from the washing m/c in the trolley.

•      Load the pre treated garments in the dryer m/c.

•      Dry the garment completely & unload the garments.

The pumic stones used for acid wash need to pre-treat in the following chemical solution:-

•      Water ..................... 100 L

•      Potassium per manganite ( KMnO₄ ).............. 1000 Gms.

•      Phosphoric Acid ( H₃PO₄ ) ............................... 250 Gms.

•      Stire the solution in a stainless steel tub with dry pumic stone.

•      Soak the stones with the chemical solution ......... 10 – 15 minutes.

•      The stones will pick up the solution. Then the soaked stones are dried in the open air for.............. 2 to 3 hrs.

•      Then pre-treated garment 30 – 40 kg per batch load in the dry washing machine.

•      Load the per-treated stones (about 50 kg) in washing machine.

•      Start machine running for each batch ........................ 7 to 10 mts.

•      Stop machine running.

•      Unload the treated garment separately. Pumic stones with P.P. solution hit on garment surface as a result fading will be developed.

•      Then load the stones treated garment in another washing machine.

Third Step: Wash for cleaning

•      Batch wt................................ 50 kg.

•      Add water @ L: R = 1: 8.............. 400 litres.

•      Add detergent @ 1 gm/litre .............400 Gms.

•      Temperature............................. 40°c - 50°c.

•      Time ..................................10 mts.

•      Drop the liquor.

      Here detergent is used to remove the breaking stone dust and chemicals from the garment surface. 

Fourth Step: Whitening/Neutralization.

•      Add water @ L: R = 1: 8.............. 400 litres.

•      Machine running.

•      Add Metabisulphite @ 5 gm/litre..... 2000 Gms.

•      Cold temperature.

•      Time 5 mts.

•      Drop the liquor.

Fifth Step: softening

•      Add water @ L: R = 1: 7.............. 350 litres.

•      Machine running.

•      Add Acetic acid @ 0.6 gm/litre ..................... 210 Gms.

•      Add Softener @ 1 gm/litre ........................ 350 Gms.

•      Then unload the garments.

Sixth Step: Hydro-extractor machine.

      Hydro extractor machine is used to remove excess water from the garments.

Seventh Step: Dryer machine.

      After hydro extraction the garments are sent to drying m/c for complete drying.

Eighth Step: Quality checking & Delivery.

       After drying the garments go to quality checking & rectify washing fault and then good one delivery.

Question-4: What is the ultimate effects of Acid wash?

Answer: During Acid wash, pumic stones are used. By the action of pumic stones, irregular fading affect is developed on the heavy garments like denims, thick canvas/twill, and sweater. The pumic stones act as a brushing action on the garment fabric surface. The area where more brushing action takes place there more discolour or fadding affect is developed and the area where less brushing action takes place less brushing action and takes place less fadding affect will be developed. The multi-layer fabric areas like – collar, calf, pocket, placket, side seam etc area will be brushed more than the single layer areas. As a result irregular fading affect will be developed on the garments fabric surface. Thus in this way fading affect may be developed on the garments by acid wash technique.