The Isoflux membrane, a patented manufacturing technique developed by Tami Industries, represents the third generation in membrane design and is, according to GEA , a viable alternative to the fouling and inefficiencies caused by gel layer formation.
GEa Filtration, which is marketing the product, claims that cross-flow microfiltration separations that are sensitive to variations in trans-membrane pressure (TMP) are more efficient, more economical, and much easier to control than technologies used to date.
In conventional microfiltration, as the product flows down the tubular element, there is a natural hydrodynamic pressure drop from the inlet to the outlet of the flow channel.
The uneven permeate flux distribution along the length of the flow channel can be very significant due to the resulting concentration polarisation effect particularly at the higher pressure inlet, and decreasing toward the outlet end. This fouling interferes with the product transmission through the membrane, decreasing the quality of the separation, shortening running time, and increasing costs.
A second generation of membrane processes has attempted to solve this problem and create a uniform TMP over the length of the element by creating a pressure gradient on the permeate side of the membrane. This has been used in some dairy applications but suffers from significant problems such as the requirement for extra piping and pumps, an increased risk of contamination and a long residence time that affects the quality of the final product.
To overcome the disadvantages of the second-generation technologies, Tami Industries of France invented and patented the Isoflux membrane for consistent trans-membrane pressure. The Isoflux membrane controls the permeate flux with a variable thickness active membrane layer that produces a uniform permeate flux along the entire length of the element extending run times, maximising separation efficiency, and minimising both capital and operating costs.
The membrane has been tested and according to GEA proven superior to other attempts to overcome the problem. The product is in commercial use for several difficult separations of fluid dairy products, and tests show similar results in specific biopharmaceutical applications, as well as other sensitive food and beverage separations.
Current working applications for Isoflux membrane technology are mostly in the dairy industry particularly for the removal of heat-resistant bacteria and spores from all types of dairy products and many juices without altering the protein content or other properties, the reduction of fat in whey protein isolates to increase clarity while still retaining important subfractions and maintaining biological activity and the fractionation of casein and whey proteins from skim milk for use as protein supplements and to add nutritional value to sports drinks.
Other food applications include the clarification of raw fruit and vegetable juices, the clarification and concentration of dextrose and maltodextrins and the concentration of vegetable and plant proteins.