A NOVEL PROCESS FOR THE ELIMINATION OF FREE FOR MALDEHYDE PRESENT IN LEATHER

摘要

A process for elimination of formaldehyde from leather has been developed wherein leather which is to be subjected to the treatment of formaldehyde or its derivatives during post tanning operations is rehydrated by conventional method and is then taken in 200 - 350% by volume of water based on the weight of the leather under consideration, pH of the bathe is adjusted in the range of 4 - 6.5 by known method and 8-16 times w/w of deformaldehyde agent on the total potential presence of free formaldehyde in the leather considering the present content of free formaldehyde as well as the formaldehyde derivatives, which are going to be added, during the subsequent operations, is added to the leather in dynamic condition either in the absence or presence of syntan or dye. Leather is treated with the deformaldehyde agent preferably in the presence of conventional fatliquor, the addition which may be either simultaneous with or preceding or succeeding the addition of the said agent. Finally the acidification is done by adjusting pH in the range of 2 - 4 and the resulting leather is washed in water by conventional method before it is taken out of the processing bath.