Table of Contents
What is white dyeing?
Dyeing is carried out to change the appearance of the grey yarn or fabric. Generally, dyeing is done with the help of dyes and chemical. Most of the time, raw materials become colorful through the application of dyes. But if we want to get white fabric, we need to pass through the wet processing methods. The methods by which we can get white materials are called white dyeing. Generally white dyeing is carried out with the optical brightening agent during scouring and bleaching process.
Cotton Dyeing With OBA (Optical Brightening Agent)
I have given a flow chart of white dyeing by which we can get a white dyed yarn. The process is as bellow:
Carrier and vessel washed by hydrose and caustic at 1000 C for 20 min
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Load the package in the carrier and feed in the vessel
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Add wetting agent, anti foaming agent, sequestering agent and run at 600 C for 10 min
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Water solution drain
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Add wetting agent, sequestering agent, caustic soda, hydrogen peroxide, optical brightening agent and run at 1100 C for single yarn and 1150 C for double yarn for 40 min
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Drain
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Add peroxide killer and run at 900 C for 10 min
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Peroxide check in the package
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Drain
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Add acetic acid for neutralization and run for 20 min at 500 C
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Drain
So, it is the most practical procedure of white dyeing. If you have better idea about this process let me know.