CHESTNUT EXTRACTS

CHESTNUT EXTRACTS

(Astringent and sweetened, Normal and special)

chesnut

PROPERTIES AND CHARACTERISTICS

The tannis obtained from CHESTNUT wood are of pyrogallol nature and belong to that Group of glucoside tannins which are easily hydrolozable .CHESNUT extract contains a convenient quantity of acid groups and of natural organic acids,which determine its Considerable astringency and the property to fix in large amount to the hide substance.These properties make CHESNUT extract especially suitable for the tannage of heavy Hides and of sole leather in particular ,as byb its use it is possible to obtain a high weight Yield ,a firm,compact yet flexible,elastic leather of good colour,lightfast ans a low water absorption. After all ,astringency is the characteristic which determines the practical tanning properties of the different types of extract and since the astringency depends upon a Number of factors which can be varied to a fairly large extent , it is evident how it can be possible to obtain “Sweetened” CHESNUT extracts with a lower degree of astringency and consequently. With a different behaviour in tanning .CHESNUT extracts can be classified in to two groups :

  1. “Astringent “ Chesnut Extracts (N-N2)

The main properties of these extracts are a marked astringency , a balanced tannin Non tannin ratio ,a remarkable capacity to combine with the hide fibres ensuring a particularly tight and elastic grain.They also have an excellent light fastness .Because Hydrolizable tannins are practically not subject to oxidation .

Product specifications (filter method):

                Tannins%                  76 + 1

                Humiditity %             8 Maximum

                Ph (6,9°B)                  3,5+ 0 , 3

  1. “Sweetend “ Chesnut Extracts (Dulcotan RN – SPECIAL)

The astringent extracts are appropriately treated to vary some of their characteristics.The sweetened extracts thereby obtained, with a higher Ph , are less astringent and Therefore penetrate more easily and rapidly .Although the Sweetened extracts for some properties are completely different from the astringent types, they have the same Light fastness and capacity to became fixed to the hide substance, while giving leathers

More mildly tanned.

Product specifications ( filter method) :

                  Tannins%                  72 + 1

                  Humiditity %             8 Maximum

                  Ph (6,9°Be)                4,5+ 0 ,2