The Ice wash or Snow wash process is a unique finishing method for denim garments. This technique is popular for producing white patches or a mottled effect that gives the denim a snow-like or frosted appearance due to uneven dye removal. Here, stones are used similarly to stone washing, which is employed specifically to deposit chemicals unevenly onto the denim fabric, creating a distinct colored stripe. It often uses sodium hypochlorite or other bleaching agents that react with the fabric, resulting in a faded effect. Indigo and selected sulfur dyes are the popular practice for this technique. The technique has been popular since 1986 and is in high demand in the fashion industry today. It significantly improves the visual appeal and adds a vintage appearance.
Wash Procedure of Ice Wash Denim:
- Desizing (10-15 min)
- Soak stones in Potassium permanganate solution of Conc. 1.5-5% or Sodium hypochlorite of conc. 5-10% for 1-2 hours
- Drain excess liquor.
- Place stones and garments in the machine
- Tumble for 10-30 min
- Add reducing agents.
Sodium bisulfite, hydroxylamine sulfate, or acidified hydrogen peroxide while potassium permanganate is used/ Sodium bisulfite or hydrogen peroxide while sodium hypochlorite is used. - Rinse well
- Repeat step 6 if necessary
- Apply softener
- Tumble dry
Excess liquid from stones can be removed in several ways, such as using mesh fabric before soaking, tumbling the stones with waste fabric in a rotary tumble machine, or using pre-soaked stones or materials from suppliers. Depending on their porosity, the stones can also be reused for another load before resoaking. Moreover, the selection of potassium permanganate and sodium hypochlorite can be determined based on the dyestuff and the desired effect needed. Safety considerations must be taken while handling either of these chemicals.
Ice wash or snow wash is an important method in finishing denim that uses both mechanical and chemical processes to create unique effects. This technique is sometimes termed acid washing, but it can be a misleading term as mineral acids are not used in this process. However, these traditional methods can waste a lot of water and chemicals, which can be harmful to the environment. As the denim industry seeks greener solutions, there is a push for more eco-friendly options that lower chemical use and reduce waste water.