Patent ID: 8857370

Claim:
Coated paper making apparatus comprising: a transport path along which a web to be formed into coated paper is transported; a liquid-form coating material coating unit arranged on said transport path to apply a liquid-form coating material to one side of the web; a pre-dryer arranged downstream of said liquid-form coating material coating unit to dry the web; a water coating unit arranged downstream of said pre-dryer to apply water to the web, all over a surface thereof; a post-dryer arranged downstream of said water coating unit to dry the web; a smoothing roller rotatably arranged between said water coating unit and said post-dryer to flatten wrinkles in the web passing around said smoothing roller; a measurement device for measuring wrinkles possibly remaining in the web having passed through said post-dryer and supplying measurements, the measurement device including: a displacement sensor arranged at a predetermined distance from the transport path to measure a distance between the sensor and the web moving on the transport path, and a backing roller arranged along the transport path in a position opposite to the displacement sensor, the transport path being between the backing roller and the displacement sensor, the backing roller guiding the web by supporting the web moving beneath the backing roller on a side of the web opposite to a side on which the coating material is applied; wherein the displacement sensor measures distance between the sensor and the web on the backing roller in a direction perpendicular to the surface of the web, to determine a size of the wrinkles in the web; and the apparatus further comprising: a quality controller for managing the measurements received from said measurement device.