The present invention concerns a method for removal of material residues, particularly tissue or similar porous, non-self-supporting materials, from a material-carrying core, which often has relatively large dimensions, e.g. a diameter of approx. 300 mm and a length of approx. 2540 mm, and thereby allow re-use of the core in the same way as new and unused cores a number of times for winding non-self-supporting or porous material, particularly tissue, wherein a cut section is made in the envelope surface of the roll having the material-carrying core from one end or end portion of the roll to the other end or end portion of the roll by means of a driven rotary knife, which is connected to a motor for rotation of the same.