Abstract: A membrane bag, a winding module and a method of making the membrane bag and winding module. The membrane bag and winding module comprise two separation membranes interconnected at their rims and having supply and drain conduits. The membrane bag and winding module are pressure tight and operationally safe at high pressures and temperatures. The rims of the separation membranes are flanged-in at least twice and glue layers are provided between superposed flange rims.

Abstract: A membrane separation arrangement includes a plurality of plate modules adjacently arranged in a housing, the plate modules being formed by two separation membranes each, which are interconnected at their rim regions so as to be tight all around, inner spacers formed by a layer of fibrous material being provided between said separation membranes.To reliably obtain tightness of the individual plate modules, with no high forces required for tightness acting on the separation membranes, while allowing the separation membranes to move without becoming damaged, outer spacers contacting the separation membranes and formed by a layer of fibrous material, such as a woven fabric, a knitted fabric or a nonwoven fabric, of organic or inorganic fibres, are provided between the individual plate modules, and the individual plate modules are interconnected via connection pieces sealingly inserted in openings of the separation membranes.