Optimization of the Filling-Greasing Process of the Leather Semi-Finished Products with the use of Nano-Silica

The optimization of the ingredients` expenses of the filling-greasing composition with the use of nano-silica in the manufacture of light-colored leather from the chrome tanning semi-finished product was carried out. A second-order mathematical model was developed using a central composite rotatable plan for the three input variable components of the filling-greasing composition, namely, the expenses of aerosil A-300, acrylic dispersion 2037 and the trupol RA greasing material and three physico-chemical indexes of the obtained leather quality. The multicriteria optimization of the filling-greasing process of leather semi-finished product with the use of the desirability function and the limitations of the values of the indicators taking into account their desirable values was carried out. The optimal values of the expenses of the ingredients of the filling-greasing composition for the production of light-colored leather in the processing of leather semi-finished products of chrome tanning using aerosil A-300 and acrylic dispersion were established. To investigate the effectiveness of the factors` influence on the physico-chemical properties of leather, the semifinished product of chrome tanning of the plant was used after its planing to a thickness of 1.5-1.6 mm. 20 parts of the samples were stacked from the sheltered area using the asymmetric fringe method. For approbation of the optimized process of the filling-greasing technology of the leather semi-finished product in the semi-manufactured conditions the alternating halves of the plant were used. The developed technology of the filling-greasing process with the use of nano-silica in the formation of light-colored leather was tested in the semi-productive conditions of PJSC "Chinbar". This technology provides the production of material of the high elasticity and durability with an increase of the exit area on 2.6% compared with the production technology, which involves the formation of leather materials using a colored tannin filler. The obtained light-colored leather meets the requirements for elastic leather for sewing products according to DSTU 3115-95 and the requirements of the international standard of quality management systems "ISO 9001: 2008". The availability of the developed filling-greasing process is stipulated due to the possibility of its use in the technologies of chrome tanning of semi-finished products in the manufacture of light-colored leather of wide use.