The invention discloses a wet-method production process for a micro-
porous membrane. The process comprises the steps of firstly, preparing a
mixed solution of a DMF
system according to a set ratio andset operating steps,
coating PP or PET release paper with the
mixed solution, dipping the coated PP or PET release paper in a DMF
aqueous solution and clear water, and separating out
silicon dioxidefrom a
coating through a
gel state of PU-DMF-H2O; and carrying out pressurizing through a pressurizing roller, replacing DMF remaining in the
coating in a replacement tank, and carrying out three-stepdrying to completely evaporate the DMF in the coating. The micro-
porous membrane prepared by the process has the air permeability (JIS standard cc) of 0.205 to 0.226 and the
moisture permeability B-1of 21,423 g / m<2> / 24h to 32,769 g / m<2> / 24h. The
water pressure resistance (JIS standard) is higher than 15,000mm and can meet the requirements of a majority of functional clothing on
waterproofing andmoisture permeability. The micro-
porous membrane has a micro-porous structure with uniform
diameter and low wet impedance. The micro-porous membrane has no swelling property and good film
surface strength. A film mentioned in the invention is made from a
polyurethane material, and the material is naturally decomposed in 3 to 5 years due to action of
humidity and microbes when the material is buried in soil.