PVC used to be the world's largest production of general plastic, the application is very wide.In building materials, industrial products, daily necessities, floor leather, floor tile, artificial leather, pipe, wire and cable, packaging film, bottle, foam materials, sealing materials, fiber and other aspects are widely used.PVC material in the water purification industry has a long history of application, was once replaced by new materials, but PVC alloy ultrafiltration membrane research and development let it in the water purification industry and a firm foothold.At present, there are only a few water purifiers using PVC alloy ultrafiltration membrane technology in China. Among them, the PVC alloy ultrafiltration membrane technology developed by a domestic water purifier brand has been certified by NSF in the United States. It was a great success in the 2010 Shanghai world expo, and it has formed a unique situation in China.
There are many materials that can be used to make ultrafiltration, including polyvinylidene fluoride (PVDF), polyether sulfone (PES), polypropylene (PP), polyethylene (PE), polysulfone (PS), polyacrylonitrile (PAN), etc.In the early 1990s, polyethersulfone materials were applied commercially.In the late 1990s, polyvinylidene fluoride ultrafiltration with better performance began to be widely used in water treatment industry.Therefore, polyvinylidene fluoride and polyether sulfone have become the most widely used ultrafiltration membrane materials.
Ultrafiltration membrane is divided into inorganic membrane and organic membrane according to the different membrane materials, inorganic membrane is mainly ceramic membrane and metal membrane.
Organic membrane is mainly made by polymer materials, such as cellulose acetate, aromatic polyamide, polyether sulfone, polyvinylidene fluoride and so on.According to the different membrane shape, can be divided into flat film, tube film, capillary film, hollow fiber film.The membrane used in household water purifiers on the market is basically hollow fiber membrane.
Among inorganic membrane, ceramic ultrafiltration membrane is widely used in household water purifier.Ceramic film long life, corrosion resistance, but the water has earthy taste, affect the taste.At the same time, ceramic film is easy to plug, cleaning is not easy.Hollow fiber ultrafiltration membrane is widely used in household water purification industry due to its advantages of large filling density, large effective membrane area, high pure water flux, simple operation and easy cleaning.
Under the condition of constant water yield per unit film area, the larger the film area filled by the filter element, the greater the total water yield of the filter element.