What are the preservation methods of waterproof breathable membrane

① Wet preservation: The key to wet preservation is to always keep the membrane surface with preservation solution in a moist state. Preservation solution can be used in the following formula: water: glycerol: formaldehyde = 79.5: 20: 0.5. The function of formaldehyde is to prevent the growth and reproduction of microorganisms on the surface of the membrane and prevent the erosion of the membrane. The purpose of adding glycerin is to reduce the freezing point of the preservation solution and prevent the membrane from being damaged by freezing. The formaldehyde in the formula can also be replaced by copper sulfate and other fungicides that are not harmful to the membrane. The preservation requirements of cellulose acetate film are temperature 5~40℃, PH=4.5~5, and the temperature and pH of non-cellulose acetate film can be wider.

② Dry storage: Waterproof and breathable membranes are often supplied to the market as dry membranes, because this is convenient for storage and transportation. In addition, if the wet film is to be replaced by a dry method, the film must also be treated by the following methods before proceeding. The specific method is as follows: the cellulose acetate film can be soaked in a 50% glycerin aqueous solution or a 0.1% sodium dodecyl sulfonate aqueous solution for 5 to 6 d, and dried at a relative humidity of 88%. Polysulfone membranes can be dried at room temperature with 10% glycerol, sulfonated oil, polyethylene glycol and other solutions as dehydrating agents. In addition, the surfactant also has a good effect on the deformation of the protective film pores.