Wednesday, September 26, 2012

Potassium permanganate spray is done on jeans to take a bright effect on sand blast area. One important thing about potassium permanganate spray is, this is usually a sporting process to increase the effect of sand blast. Potassium permanganate solution is sprayed on blasted area of jeans garment with the help of normal spray gun. This potassium permanganate spray appears pink on garment when fresh and turns to muddy brown on drying. The garment is hanged in open to dry after potassium permanganate spray and when the potassium permanganate turns its colors completely then it is considered to ready for next process.
It is always followed by neutralization process. Sodium Meta bisulphate is most commonly used neutralizer. A number of products are available in market for neutralization process like sodium meta bisulfate selected on the bases of effect required on blasted area.

Potassium permanganate spray in best is done in specific spray booths, where rubber dummies are installed for holding garments. Garments are mounted on the dummies and air is filled so the garment is full fit exposed. Specific dummies are used for different sizes and styles, like for kids, men’s, trousers, jackets, shirts etc. The booths are fitted with proper air exhaust system. This system leads the spray to treatment room where the chemical mixed air is usually passed through the water showers. Potassium permanganate is dissolved in water and the clean air is blown to open. Shower water is further treated with mild quantities of neutralizer before adding to main drain. But where the potassium permanganate spray is used in low concentrations then there is now need to treat shower water. This mild potassium permanganate mixed water is rather useful for water reservoirs to keep the water clean and germs free.

Potassium permanganate spray concentrations ranges form .25 gm per liter to 15.00 grams per liter depending to required results and fabric types. Usually indigo died fabrics are treated with low concentrations whereas Black Sulfur Fabric requires high concentrations to treat with. Sulfur is not much affected with potassium permanganate and hence requires high concentrations and even sometime multiple spray operations. It is more effective to add potassium permanganate brushing to aid the spray effect. It is very important to equip the operator with gloves, gas mask and gaggles. Long time breathing in potassium permanganate spray may cause health complications so proper preventive measures are to be taken for this department.

Garments are mounted on air filled rubber dummies and chemical is sprayed on blasted areas. The variables in spray process are as follow]

1.    Distance of spray gun to garment- less distance will give more defined and sharp effect where as distant spray will result to more mild and merged effect. Distance ranges form one foot to two and a half foot.

2.    Air to Water Ratio of Gun- this is to be set very carefully. Low air pressure possibly will through KMnO4 drops on garment resulting to bright white spots whereas high pressure will produce very low bright effect spray effect to areas where it is not required.

3.    Potassium Permanganate Solution Concentration- of course, this will control the extent to brightness.

KMnO4 Brushing

In KMnO4 Paint, solution of potassium permanganate is applied to garment with paint brush rather to spray with gun. The effect is quite different to spray as we discussed in last that spray is only to aid the sand blasting effect and is done in addition whereas the potassium permanganate paint is itself a process to give its own effect. The solution of potassium permanganate ranging from 0.10 gm per liter to 5.00 gm per liter is used in normal productions.

In usual, it is done with regular paint brushes or the brushes are modified by cutting hairs in different shapes to produce new styles. Rather towels, sponges, straw bunches or other objects are also used to create effects. What it is seen, is that most merging and beautiful effects are created with towel. Towel dipped in solution are drawn over the garment very lightly. This produces random effect and looks great with dark washes in contrast.

 Courtesy: Denim Help