US Patent 7354011 Refining element

A refiner system is disclosed including a first refiner element and a second refiner element adapted for mounting a refiner for relative rotation with a refining gap between them for processing lignocellulosic material, each of the first and second refiner elements including a refining surface, pins extending upwardly from the refining surfaces whereby the pins on the first refiner surface are disposed in intermediate spaces between the pins on the second refiner surface, each of the first and second refining surfaces further including bars including rounded edges forming a wave-shaped surface thereon.