Spreading system for producing a spreading material mat and method for operating such a spreading system

Spreading system for producing a spreading material mat， which is formed on an endlessly rotating forming belt (70) arranged under a spreading head (30) in the direction of falling of a spreading material a metering bunker (10) for at least temporarily receiving grit with an output device (20) for metered discharge of the grit to the spreading head (30) and a spreading head (30) for spreading the spreading material onto the forming belt (70) arranged under the spreading head (30) for producing at least part of the spreading material mat (80)， wherein the spreading head (30) has a dissolving device (34) in the upper region (31) and a spreading device (36) in the lower region (32) on the molding tape and in the dissolving device (34) and the spreading device (36) in or against the production direction ( P) rotatable rollers are arranged， characterized in that to adjust the spreading properties of the spreading head (30) and / or the structure of the spreading material mat (80)， the opening device (34) of the upper area (31) and the spreading device (36) of the lower area (32) to one another， preferably parallel to the plane of the forming belt (70) is arranged to be displaceable in or against the production direction (P).