THE EFFECT OF RETANNING AND FILLING OF THE COMPLEX ALUMINUM SULFATE STABILIZED BY TRIMETHYLOL MELAMINE ON THE PROPERTIES OF LEATHER BOOK COVER SAMPLES OF THE MATENADARAN
Keywords:
retanning, filling, ancient leather book covers, semifinished leather, dermis, surface areas, smoothingAbstract
It is known that leather production takes place predominantly from tanning, retanning and filling irrespective of the raw material types.
In previous works, it was shown that aluminum sulfate salts stabilized by ethylenediamine (Al-EDA) was purposely used as retannage of leather book covers of the Matenadaran, which had a positive impact. It gave leather hydrothermal stability and antifungal properties. It should be noted that at present special attention is paid to the issues of leather retanning and filling. It is explained by the fact that many types of leather with the different methods of tanning take place with an artificial surface.
Ancient leather covers are especially fragile and susceptible to shrinkage, as a result of which leather finishing, in particular coating, has undergone significant changes. Experience in the leather industry for the production of leather with synthetic surface has shown that even the use of high-quality finishing materials for topping does not ensure a perfect appearance of the leather unless the surface has not been properly treated. The preparation of the rawhide material for finishing is done through filling the loose peripheral areas of the dermis which improves the buffing property of its surface. In recent years, various synthetic polymers have been applied for the purpose of retanning and filling of leather: nydrophobic polymers in organic solvents, hydrophobic monomers with their subsequent polymerization on the fibers of the dermis, water dispersible polymers, water- soluble polymers.
As a rule, in the first three cises, equalizalion of the leather by topographic sections or an increase in water-resietance, f.e. filling takes place.
This paper shows that the aqueous solution of aluminum sulfate stabilized by trimethylol melamine and injected into leather as a retanning agent also functions as a filler.
