Production of a liquid separation module

Abstract

Disclosed is a liquid separation module of a spiral type which is produced by a simple apparatus requiring no manual operations, so that a mandrel is provided with a spirally and tightly wound layer arrangement consisting of a plurality of layer elements without any abnormal relative shifting between any layer elements, without occurrence of wrinkles in any layer element and with uniform tightness of the winding along the radius of the wound layer arrangement. The layer arrangement is wound on the mandrel in such way that, while the layer arrangement is being tightly wound on the mandrel by rotating the mandrel with the forward end of the layer arragement fixed to the mandrel, a portion of the layer arrangement which has not yet been tightly wound is forced to bulge just before coming into tight contact with the mandrel or with another portion of the layer arrangement which has been tightly wound, so that at the bulged portion the layer elements are partially separated from each other. A preferable layer arrangement is prepared so that the layer elements are piled one on top of the other and a single sheet of permeable membrane is used as one of the layer elements, which is connected at the ends thereof to form a loop after completion of the winding process.