Abstract: Dialysis membranes are disclosed, in the shape of hollow fibers composed of cellulose regenerated from copper-ammonia solution, having a continuous hollow cavity and a closed wall, wherein in any cross-section normal to the direction of the fiber axis the difference of the distance to the outer wall surface and the distance to the inner wall surface, each measured from the fiber midpoint, varies along the periphery, the fiber midpoint being the midpoint of the circle circumscribing the fiber cross-section, and the cross-section normal to the direction of the fiber axis possessing the shape of a circle, a deformed circle, an ellipse, a kidney-shaped deformed ellipse, or a deformed quadrangle.

Abstract: Fermented beverages of a reduced alcohol contents are made by causing the fermented beverage having a normal alcohol contents as produced in the fermentation to flow along one face of a dialysis membrane at a pressure differential below 5.0 bar while simultaneously a dialysate liquid which is substantially alcohol-free is passed along the other face of the dialysate membrane. An apparatus for carrying out the process comprises a housing in which two separate chambers are provided. Each chamber has separate inlet and outlet ducts. The inlet ducts are connected to separate feeding devices for liquids. Separate regulating devices are arranged for regulating the flow through each of said two chambers and means are provided for regulating the pressure differential between the two chambers.

Abstract: Dialysis membranes are described in which two or more hollow fibers of cellulose regenerated from cuoxam solution are spun together and connected to each other parallel to the fiber axis. The connection may be in the form of crosspieces, which should be between about 1 and 3 times the thickness of the hollow fiber walls. A novel process for preparation of the dialysis membrane hollow fibers is also disclosed.