Machine for the production of a paper/cardboard/tissue web, with a press nip, has measurement of the web moisture content profile for a control to set water sprays and water extraction and press roller pressure

摘要

The press section of a machine for the production or finishing a web (1), of paper or cardboard or tissue, has a belt (2) to carry the web and at least one meter (6,8) to measure the web and/or belt moisture content profile across the whole width. One or more controlled jets (4) spray water at the belt in zones across the width, before the web passes through a nip between press rollers (3). A further unit with a suction jet or a blower jet extracts water from the belt. A control unit sets the jet actions and the nip pressure to give the required moisture content profile.