How can Shoe Material Microfiber Leather be Breathable and Waterproof?

Microfiber leather wants to replace part of real 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 functions? The answer is to make a fuss on the microfiber leather base fabric.

Because moisture permeability is actually the two processes of adsorption and transfer, it is required to have water vapor (sweat) adsorption points on the microfiber leather base fabric, so that the water vapor in the shoes can be absorbed on the microfiber leather base fabric. Then gradually shift to the outside of the shoe. So how does the adsorption point adsorb water vapor? There are two ways: hydrogen bond adsorption and porous adsorption. Since water vapor can easily form hydrogen bonds with the nylon fibers of the microfiber leather base fabric, and has a certain degree of water absorption, the microfiber leather base cloth has a certain degree of water absorption. Furthermore, the microfiber base fabric generally has more pores, so that the larger the surface area, it helps to absorb more water vapor. After being absorbed, the water vapor must be transferred to the outer layer. Then the pore size and opening rate of the microfiber leather base fabric determine the speed and total amount of transfer.

　　Of course, because the base fabric has a large and uneven pore size, the microfiber leather has a moisture permeability function, but rainwater can easily pass through, that is, it cannot achieve the waterproof function. Therefore, special treatment is required for the microfiber leather base fabric to make it also have a certain hydrophobicity. How is this done? Since the diameter of water vapor molecules is 4×10-4μm, the minimum diameter for rain and fog to pass through the micropores is 20μm for fog, 400～900μm for light rain, and more than 2000μm for moderate rain and heavy rain. Generally speaking, the pore size of the microfiber leather base cloth is designed to be between the diameter of the water vapor molecule and the diameter of the rain and fog perforation, which can achieve the function of both moisture permeability and waterproof.

　　 To sum up, in the production process of super fiber leather base fabric for shoe material, reasonable design on the pore size and opening rate of the base fabric can make the super fiber leather of shoe material have the functions of moisture permeability and waterproof at the same time.

WINIW Microfiber leather