The process of producing microfiber leather mainly includes two parts: wet processing and dry finishing. The basic principle of the process is: the main component of superfine fiber is polyamide fiber. According to the data, the composition and structure of polyamide fiber are simpler than protein fiber. There are carboxyl and amino groups only at the end of the molecular chain. In the middle of the molecular chain, there are a large number of carbon chains and amide groups without side chains. The amino content of polyamide fiber is low. The amino content of nylon 66 and nylon 6 is 0.04mol/kg (fiber) and 0.098mol/kg (fiber) respectively, which is about 1 / 20 and 1 / 10 of wool. The carboxyl group content of polyamide fiber is higher than that of amino group. At the isoelectric point, all amino groups exist in the form of – NH3 + ion, while the carboxyl group only partially exists in the form of – COOH – ion.
According to the structure of polyamide fiber, acid hydrolysis and enzymatic hydrolysis were used to chemically modify the superfine fiber, open its amide bond and increase its active group; Then, the retanning, filling, fatliquoring and dyeing technologies of natural leather are used to fill the macromolecular tanning agent between the microfiber, improve its water vapor permeability and other physical properties, and make the hand feel of the microfiber base cloth close to that of the leather blank.
The basic principle of dry finishing is to use the finishing technology of natural leather combined with the surface making technology of synthetic leather for different purposes of finished products, and adopt the process route of back cover, fine grain pressing, buffing, surface making, fine grain pressing, top coating, embossing and softening, so as to form superfine fiber sand hair leather with leather appearance. The wet transfer film is used to form the next layer to give the microfiber base cloth the particle surface similar to the leather blank. The microfiber leather manufacturer said that on this basis, a variety of real leather finishing technologies such as roller coating, spraying, embossing, printing and film pasting can be used to make a variety of fashionable microfiber products similar to the appearance and feel of leather.