Bleach wash or light stone wash refers to light blue shades of denim. The additional step is bleaching to stone wash. This bleaching is usually carried out by strong oxidizing agents. In industry, most widely used chemicals are sodium hypo-chlorite, calcium hypo-chlorite, hydrogen per oxide and potassium permanganate. Other than that many products with different brand names are available in market.
Distinction of Light stone wash to stone wash is the additional extensive oxidation/bleaching process. This gives garment a more used look and brighter complexion. Further more in heavy Bleach wash other effects are more merged and diffused as compare to Medium Stone Wash.
In light wash of denim, strength of fabric is always on risk. Lighter shades are associated with more damage inside fabric. Bleaches/oxidative are very harsh to cotton fiber by nature so light shades in pure cotton denim is not recommended. It is more successful in poly denim articles.
Â Oxidation is always coupled with neutralization. Different neutralizers are used in respect of nature and character of bleaching agent. The choice of neutralizer is very critical it affects the tone color of garment.
It is very important to completely remove the oxidative form garment. In case of partial removal or incomplete neutralization, the remaining quantity of bleach/oxidative will keep on damaging the fabric and it will lose its strength in short period. It also affects the shade of the garment and will change it to yellower from whitish.
General Recipe Steps
Bleach wash generally involves steps
- Stone wash
- Softner Application
It is always recommended to apply bleach in hot bath. High temperature not only increases the penetration of water particles to fabric but also the activity rate of oxidant.
Some time caustic soda is added to avoid the damaging caused by bleach/oxidative. Especially in case of elasticized fabric it is very obvious that bleach/oxidative damage the elastic material so the addition of caustic soda or some other strong alkaline solution will prevent this.
Mostly bleaching agents produce foam in hot bath with agitation. In front lading machines it creates problems in handling. Anti-foaming agents prevent foaming and help in controlling processes.