Abstract: A packing container of the non-returnable type is frequently manufactured from laminated material which comprises a central carrier layer of paper with thermoplastic layers applied to both sides. As an opening arrangement, a pre-punched pouring opening is used which is covered on the one hand by a tear-off cover strip located outside the packing container and, on the other hand, by an inner protective strip. A method for sealing an emptying opening in accordance with the invention ensures that a part of the inner protective strip corresponding to the shape and size of the pouring opening accompanies the cover strip since the strips are heat-sealed to each other at the same time as they are pressed against each other by means of pressure fluid. An arrangement for carrying out the method comprises a heating device with a heatable zone and an outlet for pressure fluid.