Comber is small cotton fibre. Cotton contains little or no lignin, but it contains proteins, acids/ketones/aldehydes and sugar.There will be double bonds in these molecules that will contribute to colour. There may be very very few of these types of molecules in the new cotton, but as it ages, the effect of sunlight and biological activity will increase the number of double bonds and therefore the yellowing. The bleaching chemicals will attack and destroy these double bonds, and so remove colour. Think about sugar. Its white, but if we heat it, without burning it, it will change colour, becoming first straw coloured, then more yellow, then darker brown, like caramel, and finally dark brown.. Sunlight and biological activity will cause similar tings to happen to the sugars in cotton.
Very concise, and effective.
Thank you so much dear Sir. Loads of respect for you.
Thanks Mann, very informative and useful for paper guys
Nice info.
Sir comber fiber do not contained conjugate bonds how ever contained aldehyde group what did happen when bleach to comber?
Comber is small cotton fibre. Cotton contains little or no lignin, but it contains proteins, acids/ketones/aldehydes and sugar.There will be double bonds in these molecules that will contribute to colour. There may be very very few of these types of molecules in the new cotton, but as it ages, the effect of sunlight and biological activity will increase the number of double bonds and therefore the yellowing. The bleaching chemicals will attack and destroy these double bonds, and so remove colour.
Think about sugar. Its white, but if we heat it, without burning it, it will change colour, becoming first straw coloured, then more yellow, then darker brown, like caramel, and finally dark brown.. Sunlight and biological activity will cause similar tings to happen to the sugars in cotton.
@@PaperClassroom thank you so much sir
sir i would like to watch the effect of temp and pH in bleaching processes.
I will get round to this once I have finished my Level 2 videos