Question 17 (Textile Engineering & Fibre Science)
In bleaching with H2O2 the active oxidizing species is
Frequently Asked Questions | FAQs
What is the bleaching process with H2O2?
The bleaching process with hydrogen peroxide (H2O2) is a common method used in the textile industry to remove color and other impurities from fabrics and yarns. The process involves several steps:
Scouring: The fabric or yarn is first scoured in a solution of alkali and detergent to remove any natural impurities, such as waxes, oils, and pectins.
Bleaching: The fabric or yarn is then treated with a solution of hydrogen peroxide and a catalyst, such as sodium silicate or tetraacetylethylenediamine (TAED). The hydrogen peroxide oxidizes the colorants and other impurities in the fabric, breaking them down into smaller, colorless molecules that can be easily removed.
Neutralization: After the bleaching process, the fabric or yarn is neutralized to remove any residual alkali.
Rinsing: The fabric or yarn is thoroughly rinsed with water to remove any remaining impurities or chemicals.
Stabilization: Finally, the fabric or yarn is stabilized with a solution of hydrogen peroxide and a stabilizing agent, such as sodium silicate or magnesium sulfate. This helps to prevent any remaining hydrogen peroxide from decomposing and damaging the fabric or yarn.
The bleaching process with hydrogen peroxide is generally considered to be a more environmentally friendly alternative to chlorine-based bleaching processes, as it does not produce harmful byproducts such as dioxins and other organochlorines. However, the process requires careful handling and monitoring to ensure that the hydrogen peroxide is used safely and effectively.