The invention discloses a multi-layer co-
extrusion cast film with a one-way
moisture guiding function and a preparation method of the multi-layer co-
extrusion cast film, and belongs to the technical field of layered film materials, the key point of the technical scheme is that the multi-layer co-
extrusion cast film is composed of an outer hydrophilic layer, a middle
transition layer and an inner hydrophobic layer, and the pore diameters of the outer hydrophilic layer, the middle
transition layer and the inner hydrophobic layer are sequentially decreased from the outer layer to the inner layer, the inner-layer mixture is prepared from LDPE, LLDPE, modified
calcium carbonate, nano
calcium carbonate and a
processing aid; the middle layer mixture is HDPE, POE and modified
calcium carbonate, the outer layer mixture is mLLDPE, PP, PEG, modified
calcium carbonate and an anti-blocking agent, the three kinds of mixtures are fed into three different feeding ports respectively, and the multi-layer co-extrusion cast film with the one-way
moisture guiding function is obtained through extrusion of an extruder, stretching, cooling, aftertreatment or functionalization. A hydrophobic-hydrophilic wet gradient and a
pore diameter gradient are constructed through a multi-layer co-extrusion method, the process is simple, and excellent
moisture transfer rate and durability are achieved.