Storage Of Waterproof And Breathable Membrane
When the membrane is stored for a long time, it must maintain good performance and have use value, so the life of the waterproof and breathable membrane is an important issue. Therefore, special attention should be paid to the actual storage.
The preservation of the waterproof and breathable microfiltration membrane is divided into two methods: wet preservation and dry preservation. Either way, the purpose is to prevent the membrane from being hydrolyzed, preventing the growth and erosion of microorganisms, and the shrinkage and deformation of the membrane.
The key to wet preservation is to always keep the membrane surface with the preservation solution in a moist state. The following formula can be used for the preservation solution: water: glycerin: formaldehyde = 79.5:20:0.5. The role of formaldehyde is to prevent the growth and reproduction of microorganisms on the surface of the membrane and to prevent 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 other fungicides such as copper sulfate that are not harmful to the membrane. The storage temperature of cellulose acetate membrane is 5-40°C and PH=4.5~5, while the storage temperature and pH of non-cellulose acetate membrane can be wider.
Waterproof and breathable microfiltration membranes are often provided in the market as dry membranes because they are easy to store and transport. In addition, the wet film must be stored in a dry method, and the following methods must be used to process the film before proceeding. The specific method is: the cellulose acetate membrane can be soaked in a 50% glycerin aqueous solution or a 0.1% sodium lauryl sulfonate aqueous solution for 5 to 6 days, and dried at a relative humidity of 88%. The polysulfone membrane can be dried at room temperature with a solution of 10% glycerin, sulfonated oil, polyethylene glycol, etc. as a dehydrating agent. In addition, surfactants also have a good effect on protecting the pores of the film from deformation.
Second, the maintenance and maintenance of the waterproof and breathable membrane system should be paid attention to
The maintenance and maintenance of the membrane system should focus on the following issues.
① According to the different membranes, special attention should be paid to the use environment, especially the temperature and pH value of the material liquid, and even the chlorine content in the material liquid.
② When the membrane system is stopped for a short time, attention should be paid to the moisture retention of the membrane, because once the membrane surface loses water, there is no remedial measure, the waterproof and breathable membrane pores will shrink and deform, which will reduce the membrane performance.
③When stopping, avoid contact with high-concentration liquids.
④ Wash and maintain the membrane regularly with maintenance liquid to reduce membrane pollution.
⑤ In use, operate in accordance with the operating conditions that the membrane system can withstand to avoid overloading.
Post time: 15-09-21