Multipath rotary disc valve for distributing polymer plastics melts

A method of operating multipath valve for distributing and/or dividing at least one flow of polymer melt, the multipath valve comprising a front plate and a rear plate with surfaces facing each other, wherein the surfaces are ground and hardened, and wherein the front plate and the rear plate are provided with openings for inlets and outlets of the polymer melt, and at least one rotary disc rotatably mounted on an axle bolt between the front plate and the rear plate, the at least one rotary disc having parallel ground and hardened surfaces, wherein the rotary disc has circular segment-shaped ducts having a width and end radii equal to an inner width of the openings of the front plate and the rear plate, wherein center points of the openings are located on a reference circle and center lines of the ducts are located on the reference circle, wherein the at least one rotary disc is configured to be positionable in accordance with a desired flow path of the polymer melt, further comprising clamping bolts and clamping nuts for bracing the front plate and the rear plate against the at least one rotary disc such that the ducts are completely sealed, while the at least one rotary disc remains rotatable, the method comprising automatically carrying out at least slight forward and rearward movements of the at least one rotary disc in a timed sequence, such that any danger of carbonated deposits of melt on the surfaces is eliminated.