Abstract: A coater for coating a running paper or carboard web comprises a coating chamber having one side open against the web and means for filling the coating chamber with pressurized coating substance. The coating chamber is limited in the longitudinal direction of the web by a web entrance wall, and opposite thereof, a back wall in the form of a doctor member for forming a coating layer on the web. The distance between the walls is so short that, at normal web running speed, the web moves from the web entrance wall to the back wall in a time of at the most 0.3 s, preferably at the most 0.03 s. Coating substance is supplied by means of positive pressure to the coating chamber at a position close to the web entrance wall.

Abstract: A short-dwell coater comprises of a backing roll (1) used for guiding a paper web (1), with an upper lip (28) and a lower lip (28) forming a nozzle apparatus. This nozzle apparatus can apply the coating mix on the paper web while the web is backed by the surface of the backing roll. A doctoring member with which the excess mix applied with the nozzle apparatus can be doctored is also provided as well as a mounting fixture, to which the doctoring member is mounted, and a support structure, with which the fixture is supported. In the short-dwell further comprises an actuator, to which the nozzle apparatus is attached so that the apparatus is movable in relation to the doctoring member in order to adjust the dwell length between the doctoring member and the nozzle apparatus.

Abstract: An appliance for a double-sided coating of a moving web by means of two coating substance applicators and a smoothing nip comprising a back-up roll on one side of the web and a adjustable levelling blade or the like on the other side of the web. The coating substance is supplied on the web directly on the side facing the levelling blade and on the surface of the back-up roll or the web on the other side of the web. The smoothing nip and the both applicators are located within a 30 degrees sector of the back-up roll, preferably within a 20 degrees sector.

Abstract: A coater for coating a running paper or cardboard web comprises a coating chamber having one side open against the web and means for filling the coating chamber with pressurized coating substance. The coating chamber is limited in the longitudinal direction of the web by a web entrance wall, and opposite thereof, a back wall in the form of a doctor member for forming a coating layer on the web. The distance between the walls is so short that, at normal web running speed, the web moves from the web entrance wall to the back wall in a time of at the most 0.3 s, preferably at the most 0.03 s. Coating substance is supplied by means of positive pressure to the coating chamber at a position close to the web entrance wall.

Abstract: A system for two-sided coating of a running paper web. The device comprises an application device for spreading the coating material over both sides of the web running through a first nip formed by a rotating counter roll and a levelling member.According to the invention, the device includes an auxiliary roll, which is, in the direction of progress of the web, fitted at a certain distance from the first nip and which, together with the counter roll, forms a second nip for the web which has followed along with the said roll over the distance. The diameter of the auxiliary roll is substantially smaller than the diameter of the counter roll, and the face of the auxiliary roll is substantially harder than that of the counter roll. By means of the invention, the risk of damaging the coating at the side of the web facing the roll can be reduced by the web being detached from the second nip formed between the rolls.