DMF (Dimethyl Formamide) thickening method for PU (Poly Urethane) synthetic leather wet production line and thickening device adopting DMF thickening method

The invention relates to the field of synthetic leather manufacture, and particularly discloses a DMF (Dimethyl Formamide) thickening method for a PU (Poly Urethane) synthetic leather wet production line and a thickening device adopting the DMF thickening method. The device comprises a first section of rinsing baths and a second section of rinsing baths; the first section comprises eight rinsing baths which are communicated with each other; the second section comprises ten rinsing baths which are communicated with each other; fresh water is replenished to the tenth rinsing bath of the second section; aqueous solution in the first rinsing bath of the second section directly enters a coagulating basin via a pipeline in virtue of hydraulic difference; aqueous solution with about 20 percent DMF concentration in the coagulating basin is pumped into the eighth rinsing bath of the first section through a pump; and aqueous solution in the first rinsing bath of the first section is pumped intoa DMF aqueous solution storage tank through the pump. By changing the fresh water replenishing flow, the method and the device increase the DMF concentration of the rear end of the coagulating basin on the basis that the DMF concentration of the coagulating basin is not changed, and reduce energy consumption.