If microfiber leather wants to replace part of genuine leather for shoe materials, it needs to have excellent moisture permeability and waterproof function, otherwise wearing shoes made of microfiber leather will feel uncomfortable.
So how can shoe material microfiber leather have both moisture permeability and waterproof function? The answer is to make a fuss on microfiber leather substrates.
Because moisture permeability is actually two processes of adsorption and transfer, then water vapor (sweat) adsorption points are required on the microfiber leather fabric, so that the water vapor in the shoe can be adsorbed on the microfiber leather fabric, and then gradually transferred to the outside of the shoe. So how to adsorb water vapor at the adsorption point, which can be done in two ways, namely hydrogen bond adsorption and porous adsorption. Since water vapor can easily form hydrogen bonds with the nylon fiber of microfiber leather fabric, it has certain hydrophilic properties, so microfiber leather fabric has certain hydrophilic properties. In addition, microfiber fabrics generally have more pores, so that the larger the surface area, the more water vapor is adsorbed. After adsorption, the water vapor is transferred to the outer layer, so the pore size and opening ratio of the microfiber leather base fabric determine the speed and total amount of transfer.
Of course, shoe material microfiber leather because of the large and uneven aperture of the base fabric, although it has the function of moisture permeability, but rain is also easy to pass through, that is, it cannot reach the waterproof function. Therefore, a special treatment of the microfiber leather substrate is required to make it also have certain hydrophobic properties. How is this done? Since the diameter of water vapor molecules is 4×10-4μm, and the minimum diameter that general rain and fog can pass through micropores is fog is 20μm, light rain is 400~900μm, and moderate rain and heavy rain are more than 2000μm. In layman’s terms, the pore size of the microfiber leather base cloth is designed between the diameter of water vapor molecules and the perforation diameter of rain and mist, which can achieve the function of both moisture and waterproof.
In summary, in the production process of shoe material microfiber leather substrate, reasonable design in the aperture and opening rate of the substrate can make the shoe material microfiber leather have the functions of moisture permeability and waterproof at the same time.