1. waterproof and breathable membrane
membrane in long-term storage, must maintain good performance can have the use of value, so the life ofwaterproof breathable membrane is an important issue. Therefore, special attention should be paid to the
actual preservationwaterproof and breathable microfiltration membrane is divided into two ways: wet preservation and drypreservation. In either case, the purpose is to prevent hydrolysis of the film, to prevent growth and erosion
of microorganisms, shrinkage deformation of the film, and the like.

1 wet preservation
wet preservation is to always make the membrane surface with a preservation solution, which is wet.Preserving liquid can use the following formula: water: glycerol: formaldehyde = 79.5:20: 0.5. The role offormaldehyde is to prevent the growth and reproduction of microorganisms on the surface of the membrane.to prevent erosion of the membrane, the purpose of adding glycerol is to reduce the freezing point of thepreservation liquid,to prevent damage to the membrane due to icing. The formaldehyde in the formula canalso be replaced by other fungicides such as copper sulfate, which are not harmful to the film. Thepreservation requirement of cellulose acetate film is temperature 5~40 DEG C, PH = 4.5-5, and thepreservation temperature and PH of non-cellulose acetate film can be wider

2 Dry Preservation
waterproof breathable microfiltration membranes are often offered on the market as dry membranesbecause of their ease of storage and transport. In addition, the wet film to change to dry storage, but alsothe following methods must be used to deal with the film can be carried out. The specific method is asfollows: the cellulose acetate film can be soaked in 50% glycerol aqueous solution or 0.1 sodium dodecyIsulfate aqueous solution for 5 to 6 days, and dried at a relative humidity of 88%. The polysulfone membranecan be dried at room temperature using a 10% solution of glycerol, sulfonated oil. polyethylene glycol, etc.as a dehydrating agent. In addition, the surfactant also has a good effect on the non-deformation of theprotective film.
2. waterproof breathable membrane system maintenance and maintenance should pay attention to theproblem
membrane system should focus on the following issues. According to the different membranes, special attention should be paid to the use of the environment.especially the temperature of the feed liquid, PH value, and even the chlorine content in the feed liquid2 short time to stop the membrane system, should pay attention to the membrane moisture, because themembrane surface once the loss of water, and no remedial measures, waterproof breathable membrane holewill shrink deformation, so that the membrane performance decline.