1. Preservation of waterproof vent breathable membrane.

When the vent membrane is stored for a long time, it must keep good performance and external performance, so the service life of the waterproof breathable vent membrane is an important issue. Therefore, special attention should be paid to the actual preservation.

The preservation of waterproof and breathable microfiltration vent membrane is divided into two ways: wet storage and dry preservation. Either way, the aim is to prevent vent membrane hydrolysis, microbial growth and erosion, shrinkage and deformation of the membrane, etc.

Wet preservation

The key to wet storage is to keep the preservation solution on the membrane surface moist. Preservation solution can be formulated as follows: water: Glycerin: formaldehyde =79.5:20: 0.5. The function of formaldehyde is to prevent the growth and reproduction of microorganisms on the surface of the vent membrane and to prevent the erosion of the film. The purpose of adding glycerol is to reduce the freezing point of the preservation solution and prevent the film from being damaged by freezing. The formaldehyde in the formula can also be replaced by copper sulfate and other fungicides which are harmless to the membrane. The preservation requirements of cellulose acetate membrane are temperature 5 40 and PH = 4.5 5. The preservation temperature and PH of non-cellulose acetate membrane can be wider.

2. Dry preservation

Waterproof and breathable microfiltration vent membranes are often provided in the dry film market because they are easy to store and transport. In addition, if the wet film is to be preserved by dry method, the following methods must be adopted before the wet film can be preserved. Specific methods are as follows: cellulose acetate membrane can be immersed in 50% glycerol aqueous solution or 0.1% sodium dodecyl sulfonate aqueous solution for 5 to 6 days, and dried at 88% relative humidity. The polysulfone membrane can be dried at room temperature with 10% glycerol, sulfonated oil and polyethylene glycol as dehydrating agent. In addition, surfactants also play a good role in protecting film holes from deformation.

Two, attention should be paid to the maintenance and maintenance of waterproof breathable membrane systems.

Attention should be paid to the following problems in the maintenance and maintenance of membrane systems.

According to the different membranes, special attention should be paid to the use of the environment, especially the temperature, PH value of the feed, and even the chlorine content in the feed.

(2) When the vent membrane system is shut down for a short time, attention should be paid to the moisture retention of the vent membrane, because once the surface of the vent membrane loses water and there is no remedial measures, the shrinkage and deformation of the pore of the waterproof and breathable vent membrane will occur, which will degrade the performance of the vent membrane.

3. When discontinued, avoid contact with high concentration liquid.

Fourth, regularly use the maintenance liquid to wash and maintain the vent membrane, so as to reduce membrane pollution.

In use, the vent membrane system should be operated in accordance with the operating conditions that the vent membrane system can withstand, so as to avoid long-term overload operation, so as to avoid irreversible damage to the vent membrane.