The manufacturing method of low pressure membrane is a key technology in the field of raw materials for chemical production. Low-pressure membrane has excellent filtration performance and high transmittance rate, which is widely used in the fields of water treatment, chemical industry, food and medicine. In this paper, the manufacturing method of low-pressure membrane will be introduced in detail, including raw material selection, preparation process, structural design and other aspects.
I. Raw material selection
1. Polymer materials: commonly used polymer materials include polyethylene, polypropylene, polyvinyl chloride, polyester, polyamide and so on. These materials have excellent mechanical properties, chemical stability and thermal stability, and are suitable for manufacturing low-pressure films.
2. Additives: In order to improve the performance of the membrane, some functional additives can be added, such as antioxidants, ultraviolet absorbers, hydrophilic agents and so on. These additives can effectively improve the performance of the membrane such as antioxidant, UV resistance, hydrophilicity and so on.
II. Preparation process
1. Melt extrusion method: the polymer materials and additives are mixed in a certain proportion, and then extruded into a film by melt extruder. This method has the advantages of high production efficiency and low cost, and is suitable for large-scale production.
2. Solution casting method: dissolve the polymer material in solvent to make a certain concentration of solution, then cast the solution on a flat substrate, and when the solvent evaporates, a dense film is formed. This method can prepare a low-pressure film with uniform structure and controllable thickness.
3. Phase Transformation Method: By controlling factors such as temperature, concentration and solvent type of the polymer solution, phase separation of the solution occurs, resulting in the formation of low-pressure films with a porous structure. This method can prepare low-pressure membranes with high porosity and good filtration performance. Structural design
The structural design of low-pressure membrane has an important influence on its filtration performance and service life. Usually, low-pressure membrane has a multi-layer structure, including support layer, filter layer and protection layer.
1. Support layer: Provide the mechanical strength and stability of the membrane, usually made of materials with high strength. The filter layer has a porous structure and is responsible for filtering and separating substances. The pore size and structure of the filter layer determines the filtration performance and selectivity of the membrane.
3. Protective layer: protects the filter layer from external environmental damage and improves the service life of the membrane.
4. Performance optimization
In order to further improve the performance of low-pressure membrane, the following measures can be taken:
1. Optimize the mechanical properties and chemical stability of the membrane by changing the type and molecular weight of polymer materials.
2. Adjust the type and content of additives to improve the membrane's antioxidant, UV resistance, hydrophilicity and other properties.
3. Optimize the preparation process parameters, such as temperature, pressure, solution concentration, etc., to obtain the best membrane structure and properties.
4. Post-treatment of the membrane, such as heat treatment, chemical modification, etc., to improve the durability and filtration performance of the membrane.
In short, the manufacturing method of low-pressure membrane involves many aspects such as raw material selection, preparation process, structure design and performance optimization. Through reasonable formulation design and preparation process optimization, low-pressure membranes with excellent performance can be manufactured to provide important technical support in the field of raw materials for chemical production.
