Bleaching Process in Textile Industry | Texhour.com

Before a greige (unbleached) fabric is dyed or printed, it has to be bleached. Bleaching is the removal of all natural color from a fiber, yarn or fabric, resulting in a white color. The chemicals used in the bleaching process depends on the type of fiber (protein, cellulosic, synthetic).

Bleaching Process in Textile Industry | Texhour.com
Bleaching Process in Textile Industry

 

Bleaching Process

• Before a greige (unbleached) fabric is dyed or printed, it has to be bleached.

• Bleaching is the removal of all natural color from a fiber, yarn or fabric, resulting in a white color.

• The chemicals used in the bleaching process depends on the type of fiber (protein, cellulosic, synthetic).

• For cotton, the first type of bleach is "chlorine based" and is usually made of sodium hypochlorite. This is strong bleach and is not recommend for colors, as it cuts and lightens the colors. That is why most garment care labels specify: “Only non-chlorine bleach when needed”

• Chlorine bleach kills many types of germs, viruses, mold, and mildew. This is the reason hotels and hospitals use white towels & bed-linen. White towels can be laundered with chlorine-based bleach and will not be carriers of germs.

• The second type of bleach is "oxygen based". These can be made of hydrogen peroxide or other oxygen releasing compounds. The so-called ‘color-safe’ bleaches are generally in this category.

• Oxalic acid is another oxygenating bleach that is especially good at removing yellow "iron" stains from fabric.

• All bleaching processes reduce the strength of the fiber.

• In a fabric dye house the process usually followed is:

 

Greige fabric

arrow button

Bleaching

arrow button

The fabric is ready for dyeing

 

• When the white fabric is required, process houses usually use optical bleaches or optical whiteners.

• These are actually fluorescent white chemicals and give off a bluish-white light, hiding the otherwise yellowish hue.

 

Greige fabric

arrow button

Bleaching

arrow button

Optical Whitener

arrow button

White fabric is ready for dispatch