The invention relates to a sealing device (9) for sealing a packing disk (4) with respect to an inner wall (7) of a container (2) of a material exchange column (1), comprising a first sealing tape (10) encircling the packing disk (4), and a second sealing tape (11) encircling the first sealing tape (10). The thermal expansion coefficient (a10) of a material out of which the first sealing tape (10) is made of is different from the thermal expansion coefficient (an) of a material out of which the second sealing tape (11) is made of. The sealing tapes (10, 11) have lateral walls that encircle the packing disk (4), wherein the second sealing tape (11) is arranged between the lateral walls (14, 15) of the first sealing tape (10).
