METHOD AND DEVICE FOR FINISHING NATURAL LEATHER Russian patent published in 2023 - IPC C14C11/00 C14B1/34 C09D175/04 C09D183/04 

FIELD: leather industry.

SUBSTANCE: method for finishing natural leather includes placing a semi-finished leather product on a worktable and moving the semi-finished leather product with the following operations in succession: applying one layer of coating based on polyurethane resin on the surface of the semi-finished leather product, drying the coating layer with partial polymerization of the resin, simultaneous sequential application of two single-layer coatings based on polyurethane resin on the surface of the transfer paper tape with a thickness of 15-35 mcm each, drying coatings on the surface of the transfer paper tape at a temperature of 80-120°C, contact of the coating on the surface of the semi-finished leather product and on the surface of the transfer paper tape with simultaneous compression at a pressure of 60-90 bar and subsequent heat treatment of the resulting coating at a temperature of 90-140°C to complete polymerization. Next, the finished leather is removed with separation of the transfer paper tape from the coating, the transfer paper tape is cleaned and wound onto a drum. Before applying the coating based on polyurethane resin, a primer layer 4-6 mcm thick is applied to the surface of the semi-finished leather in the method, which is dried at a temperature of 80-110°C. To implement the natural leather finishing method, a natural leather finishing device is used, which consists of a leather moving and processing device and a transfer paper tape moving and processing device. The device for moving and processing leather includes a feeding conveyor, a roller machine for applying a coating layer based on polyurethane resin to a semi-finished leather product, a coating layer drying chamber, a rotopress in the form of two rotating shafts: an upper one for feeding a transfer paper tape and a lower pressing one, a chamber for heat treatment of compressed coatings. The device for moving and processing the transfer paper tape includes a means for moving the transfer paper tape, the first roller machine for applying the first coating based on polyurethane resin on the surface of the tape, the first drying chamber for the first coating, the second roller machine for applying the second coating based on polyurethane resin on the surface of the tape, the second chamber drying of the applied layers, a roller for tensioning and moving the transfer paper tape, an upper shaft feeding the transfer paper tape for connecting and compressing the coating layer on the surface of the transfer paper with the coating layer on the skin surface, a transfer paper tape supply module located at the inlet to the transfer device and processing the transfer paper tape, the transfer paper tape accumulator located between the tape supply module and the first roller machine, the means for applying a primer layer on the semi-finished leather located between the work table and the roller machine for applying the coating layer on the basis of polyurethane resin to the semi-finished leather, as well as the transfer paper tape cleaning module containing a shaft for separating the transfer paper tape from the coating layer, which the transfer paper tape enters after the finished skin removal table, and a drum for winding the cleaned transfer paper tape.

EFFECT: expansion of the range of natural leather finishing products, reduction in labour-intensity of the process of finishing natural leather, quality improvement by eliminating gusts and swelling of the coatings on the surface of the skin and increasing hiding power.

6 cl, 1 dwg, 3 ex