There are two types of reverse osmosis filtering membranes. Thin film composite membranes (PA) are made from polymide, polysulfone and a fabric support sheet.
An asymmetric membrane (CA) is composed of cellulose acetate in a single dense layer supported by a secondary spongy layer.
The table below compares the two.
|Parameters||PA Membrane||CA Membrane|
|Operating pH range||2~12||4~6|
|Operating Pressure (Kg/cm2 )||15||30|
|Salt Rejection (%) TDS||99+||98|
|Salt Rejection Change after 3years||99%→98.7%||98%→96%|
|Chlorine Tolerance||<0.1 ppm||1 ppm|