To produce sealing plates (1) consisting of a plurality of sealing rings (3) connected by radial webs (2) by injection molding, wall-type guide elements (5) are arranged obliquely to the direction of flow in the mold channel (6) which is therefore initially largely constricted in the region of weld lines (15) formed by the convergence of the fronts of the divided plastic melt streams, said guide elements being moved out of the mold channel (6) during the further filling of same so that the strength is significantly improved in the region of the weld lines (15).