How waterproof vents are stored

①Wet preservation: The key to wet preservation is to always keep the membrane surface with preservation solution in a moist state. The following formula can be used for the preservation solution: 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 storage requirements of cellulose acetate film are temperature 5-40°C, PH= 4.5-5, while the storage temperature and pH of non-cellulose acetate film can be wider.

②Dry preservation: Waterproof vents are often provided in the market in dry film, because it is convenient for storage and transportation. In addition, the wet film should be replaced by the dry method, and the following methods must be used to treat the film before proceeding. The specific method is as follows: 50% glycerol aqueous solution or 0.1% sodium dodecyl sulfonate aqueous solution can be used to soak the cellulose acetate membrane for 6 d of membrane 5, and then it is 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.