Dear Sir/Madam,
ý am a graduate student and ý am working on my thesis of graduate. My subject is removal of the natural pigments from skins or depigmentation. As you know the pigments, which are occured in the skin, are referred to as melamin. Because of that reason ý need to know the chemicals which are capable of smashing the pigments. I made some trials by using Fe2(so4)3 and H2O2 and ý took very good results in goat skins. This reaction is based on reduction and oxidation. ýf you can advise me some chemicals for smashing the pigments ý will be so glad.
Best Regards,
Barýþ Güzelmeriç
B.S Student
Leather Engineering Department
AEGEAN University,TURKEY
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Sorry I dont feel you need any knowledge from America.
You and your country do not deserve any help for the USA.
You help our soldiers and we will help you.
ABG:
Many people here are indeed very passionate about the 'World' situation but this is a tanning/fur/taxidermy forum so we should leave political views out of discussion. Just my opinion. Anyway news today suggested Turkey would back us...per quote from the top Turkish Military official. Either way that has nothing to do with what we come here for. Right?
Your question ABG:
Depigmentation...aka..Bleaching is a common process in tanning leather. Some skins/hides dont require so much....others a lot.
Iron salts w/ peroxide not safe or widely used.
Most common ways use Sodium Hypochlorite (bleach) with a little acid. Better method uses Potassium Permanganate/ Sodium Metabisulfite oxidation reactions.
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To my knowledge, the natural pigments are located in the epidermis layer. This layer consists of a relatively thin membrane on top of the grain, in which for example the hair follicles and the pigments are located. When making leather, the epidermis layer is always removed together with the hair. A de-haired, raw hide has no pigments in it. Colouring of the skin is depending on the tanning method; if a non-colouring method is used the skin will stay white.
When a do vegatabile (bark) tanning I need to make sure that all the epidermis has come off properly, otherwise it will leave white stains on the skin as it prevents the tanning agents from impregnating the grain.
And John, I can't believe you're such a redneck. The guy is a STUDENT. Was your comment childish or what.
Some types of hides have 'natural pigmentation' that penetrates deeper than the keratin / epidermal layer and into the 'grain'. For example....when u 'lime or de-scale' snake skins ...even though the 'scales / epidermis' are removed...natural markings on the grain (pigmentation) can clearly be seen left behind. This applies to reptile. For bovine / ovine leathers pigmentation is much less and depends upon species, age of animal, etc. In these cases a light retannage with a synthetic bleaching syntan can work nice and strong bleaching can be avoided.