Abstract: In a paper or board machine drying line after the wire section, during dewatering a web's (W) width is affected in a direction crosswise to the web's traveling direction. Starting from an edge, at least one device (20A, 20B) brings about a force effect of a desired magnitude which is directed all the way to a desired arbitrary crosswise web position in order to modify web characteristics. A device in a paper or board machine line after the wire section has means for processing the web and for dewatering. The paper or board machine line after the wire section further has at least one device (20A; 20B) for directing a force effect at a desired partial area (WS) of the web (W) in the cross machine direction in order to modify the web's characteristics profile in the cross machine direction.

Abstract: An applicator device (1) applies surface size to at least one side of a web (W). A pressure effect is applied to the web (W) by subjecting the web (W) to an underpressure and/or to an overpressure such that surface size is forced to penetrate into the pores of the web. Most advantageously, an underpressure is created that sucks applied surface size from the surface of the web (W) into the pores in the inner layers. Surface size is applied to a web first side (W1) and a vacuum effect is applied to the web's opposite side (W2) to cause air to flow through the web (W) such that surface size moves from the first side (W1) in the direction of the second side (W2) into the web (W). Correspondingly, both sides of the web (W) can be treated in successive stages.

Abstract: In a paper or board machine drying line after the wire section, dewatering web's (W) width is affected in a direction crosswise to the web's traveling direction. Starting from an edge, at least one device (20A, 20B) brings about a force effect of a desired magnitude which is directed all the way to a desired arbitrary crosswise web position in order to modify web characteristics. A device in a paper or board machine line after the wire section has means for processing the web and for dewatering. The paper or board machine line after the wire section further has at least one device (20A; 20B) for directing a force effect at a desired partial area (WS) of the web (W) in the cross machine direction in order to modify the web's characteristics profile in the cross machine direction.

Abstract: An applicator device (1) applies surface size to at least one side of a web (W). A pressure effect is applied to the web (W) by subjecting the web (W) to an underpressure and/or to an overpressure such that surface size is forced to penetrate into the pores of the web. Most advantageously, an underpressure is created that sucks applied surface size from the surface of the web (W) into the pores in the inner layers. Surface size is applied to a web first side (W1) and a vacuum effect is applied to the web's opposite side (W2) to cause air to flow through the web (W) such that surface size moves from the first side (W1) in the direction of the second side (W2) into the web (W). Correspondingly, both sides of the web (W) can be treated in successive stages.

Abstract: A web of paper or paperboard is manufactured by first forming a base web that is dried on the press section of papermaking machine. The base web is further dried on the dryer section of the papermaking machine and a base web speed differential, or draw, is set between the press section and the first dryer cylinder group of the dryer section, whereupon at least one surface of the web is surface sized. The draw is set to 3% maximum, and a surface size furnish is applied having a solids content of at least 15% of the total amount of size components and liquid in the furnish.

Abstract: The invention concerns a method for optimizing the degree of flocculation in a headbox. The degree of flocculation is measured continuously from a stock flow (M1)/stock flows by means of a detector (R1) of flocculation, and the detector (R1) transmits a signal to a regulator (H1), which regulates the metering of retention agent (10) and/or fillers (11) and/or auxiliary chemicals (12) into the stock flow (M1)/stock flows continuously on the basis of the signal to an optimal level, which stock flow/flows is/are passed into the headbox (P1).

Abstract: The invention concerns a method for determination of an irreversible stretch and of a dynamic modulus of elasticity from a paper web (W). In the method, the irreversible stretch and the dynamic modulus of elasticity are determined from h paper web (W) by means of on-line measurement. The invention also concerns a method in which the quantities that have been determined are employed in the control of the papermaking process.

Abstract: A method and apparatus for improving forming of a web of paper or paper board employing prepressing during web forming. Forming wires are brought together over at least one roll or alternatively two rolls. The web then passes, sandwiched between two wires through one or more pressure nips which may be one or more roll nips or an extended nips. The pressure nip may be formed as the web travels between the two fabrics, one of them being a forming wire, along a straight path or alternatively as the web travels partially around a roll. The web is then sandwiched between a wire and a fabric, which may be a felt or a belt, and passed through another press nip which may be one or more roll nips or an extended nip.

Abstract: A feedback-connected on-line regulation system for a headbox of a paper or board machine. The headbox includes a flow duct for stock suspension or separate flow ducts placed one above the other, each flow duct extending from an inlet header of the headbox into its slice channel. A stock suspension jet is discharged from the slice opening of the slice channel onto the forming wire or into the forming gap formed between forming wires. The regulation system includes a regulator unit and a set value unit. Measurement values are passed from the headbox system to the regulator unit and from the regulator unit, control values are obtained for controlling the actuators of the headbox system. The regulation system also includes an on-line If arrangement for measurement of the dried paper web or the paper web to be dried, and includes measurement of the distribution of fibers in the plane of the paper web.

Abstract: A method for controlling the curl of paper in which steam treatment and/or moistening of the paper web is/are carried out after the calendering process being performed in the calender. In processes in which calendering is not employed, the curl is controlled in connection with a machine reel-up or in process steps carried out after the machine reel-up. A paper or board machine applying the method includes a headbox, a former, a press, a dryer section and steam boxes, moistening devices, an IR dryer and/or equivalent curl control devices. The steam boxes, moistening devices, IR dryers and/or equivalent curl control devices for the control of the curl are arranged after the calender or, if no calender is employed, in connection with a machine reel-up or a finishing process carried out after the machine reel-up.

Abstract: A method for regulation of the transverse distribution of the fiber orientation of a web produced by means of a paper machine or equivalent, by regulating the transverse profile of the discharge opening (16) of the headbox (10) of the paper machine. The transverse grammage profile of the paper web (W.sub.0 . . . W.sub.1) produced by means of the paper machine is measured, and the measurement signal obtained in this way is used as a feedback signal in the control system. With the machine configuration and parameters present in the paper machine to be controlled, data are collected concerning the relationship between the directional angle of the transverse distribution of fiber orientation and the transverse distribution of grammage of the web (W.sub.0 . . . W.sub.1) that is being produced by, carrying out response runs of the paper machine in its various states of operation (i). The relation data are stored in the memory of the computer (52).

Abstract: A method for continuous overall regulation of a former of a paper or board machine or equivalent in which a physical fluid flow model of the drainage and the flow state of the pulp suspension flow is formed. The model is solved by making use of the data on the geometry of the former and initial and boundary conditions necessary for a solution to the model. The difference between the simulated state, which has been obtained as the solution of the physical flow model, and the state adopted as the target is determined as the cost function, wherein the target state is determined by means of the quality requirements of the paper and possibly by means of the costs of operation and the runnability of the paper machine. The cost function is optimized and, thus, optimal regulation values and set values are obtained for the regulation devices and/or actuators of the former in view of the given cost function.