Proper Use of Potassium Permanganate: Chlorine Bleach Alternative for Dyes, Inks, and Mold Stains

For laundry shops, though, potassium permanganate is an effective bleach, especially for some stains that cannot be removed by chlorine bleach. Though it has an excellent stain removal and bleaching ability, many laundry workers haven’t truly mastered its correct usage. When handling dyes, ink, tannin, mold, and other stubborn stains, potassium permanganate can not only replace the sodium hypochlorite but also can be applied to wool, silk, and other delicate fabrics to avoid fiber damage. It should be noted that potassium permanganate may have an impact on the optical brighteners. When treating white clothes, people should test on the inconspicuous parts of the clothes first.

Characteristics of Potassium Permanganate

● It belongs to the oxidants and can release oxygen molecules to dissolve the stains.

● It is alkaline, but it is relatively safe for wool, silk, and other protein fibers.

● It can accelerate bleaching by virtue of acid substances. ( not recommended )

● After use, there are brown stains that need to be removed by the reducing agents. Common reducing agents include a hydrogen peroxide + acetic acid mixture, oxalic acid, or sodium sulfite.

The Application Scenarios and Principles

● It is recommended to only use it on the residual stains that haven’t been completely removed.

● It has a good effect for removing molds on the wool or silk.

● Heating can accelerate the reaction. However, it is recommended not to do so for safety. 

Operation Steps

● Use cold water to dissolve a small amount of potassium permanganate crystals. If the solution is a deep purple, then it can effectively remove stains.

● Use a cotton swab, dip it in the solution, and apply it to the stained areas. Wait for it to turn brown.

● Let it stand for about 20 seconds and then rinse and do not heat.

● Use a hydrogen peroxide + acetic acid mixture, oxalic acid, or sodium sulfite to remove discoloration.

● Completely rinse.

● There is no need to neutralize because the stain remover itself is acidic.

Immersion Treatment Methods

● Add cold water to the plastic containers.

● Add potassium permanganate and dissolve until the water turns a medium purple color.

● Soak the clothes for about 5 minutes. 

● Completely rinse.

● Add 7 grams to 15 grams of sodium bisulfite or oxalic acid per liter of water to reduce.

● Rinse again.

The Principles for Bleaching Agents

● Every increase of 10 degrees Celsius can double the reaction speed.

However, people should consider the fabrics of the clothes because the rising temperature does good to the stain removal and increases the risk as well.

● The bleaching agents can only bleach the washed clothes and cannot remove dirt. 

● There should be sufficient rinses between different bleaching steps.

● Control the quantity of the soaked clothes to avoid the uneven effects.

● Put the clothes after the bleaching agents have completely dissolved.

● Do not use the medal containers.

● Real-time monitoring is needed during the strong bleaching process.

● Rinsing and neutralization are needed after bleaching.

Conclusion

When facing dyes, ink, tannin, mold, and other stains that cannot be removed completely, people can consider using potassium permanganate, especially when facing clothes that are made of silk or wool. As long as the operations are correct, the potassium permanganate can be a safe bleaching agent.