Patent ID: 7191967

Claim:
A refining surface for a refiner intended for defibrating lignocellulose-containing material, the refiner comprising at least two refining surfaces arranged coaxially relative to each other, at least one of which rotates around a central shaft in a rotation direction, and between which the material to be defibrated is fed, and wherein at least one of the refining surfaces comprises grooves and between them ridges, at least part of the refining surface ridges being formed of at least two different ridge parts each defining a length connected to each other in such a way that one ridge part is farther ahead in the rotation direction of the refining surface than the other ridge part and that at least some ridge parts define a wall relative to the rotation direction of the refining surface which defines an inclination relative to the shaft over at least part of its length, wherein the inclination of the wall of the ridge part changes along at least part of the length of the ridge part in such a way that the inclination of the wall closer to the central shaft of the refining surface is smaller than the inclination of the wall farther off from the central shaft of the refining surface.