Abstract: The invention relates to a method for manufacturing a printing paper product, in which method natural fibres are introduced into a system which includes a paper machine. In the method, calcium hydroxide and carbon dioxide are admixed to natural fibres, for precipitating calcium carbonate onto the surfaces of the natural fibres, and said printing machine is used for manufacturing a printing paper product which includes at least said natural fibres, with calcium carbonate precipitated on their surfaces, as a filler for said printing paper product. The invention also relates to a system for manufacturing a printing paper product. Further, the invention relates to a calendered printing paper product which has not been coated with a pigment.

Abstract: The invention relates to a method for manufacturing a printing paper product, in which method natural fibres are introduced into a system which includes a paper machine. In the method, calcium hydroxide and carbon dioxide are admixed to natural fibres, for precipitating calcium carbonate onto the surfaces of the natural fibres, and said printing machine is used for manufacturing a printing paper product which includes at least said natural fibres, with calcium carbonate precipitated on their surfaces, as a filler for said printing paper product. The invention also relates to a system for manufacturing a printing paper product. Further, the invention relates to a calendered printing paper product which has not been coated with a pigment.

Abstract: A procedure and arrangement to control the lamella of a headbox's lip channel, when the mass flow goes in the headbox (3) through the lip channel (2), in which case single mass flows are held separate from each other with the lamella (1) before the flows are united after the lamella. The lamella's dimensions, mechanical characteristics and/or dynamic characteristics are changed at least in the lamella's border area with an active structure, which is active and/or passive active tool and/or active and/or passive active material.

Abstract: A procedure and arrangement to control the lamella of a headbox's lip channel, when the mass flow goes in the headbox (3) through the lip channel (2), in which case single mass flows are held separate from each other with the lamella (1) before the flows are united after the lamella. The lamella's dimensions, mechanical characteristics and/or dynamic characteristics are changed at least in the lamella's border area with an active structure, which is active and/or passive active tool and/or active and/or passive active material.

Abstract: A headbox (10) of a paper machine or such includes a bypass manifold (J1), from which the pulp is conducted by way of pipes (11a1.1, 11a1.2 . . . 11a2.1, 11a2.2 . . . ) of pipe rows in a set of pipes (11) and an intermediate chamber (E) into a turbulence generator (12), or from the bypass manifold (J1) directly into the turbulence generator and by way of the pipes (12a1.1, 12a1.2, . . . ; 12a2.1, 12a2.2 . . . ) of the turbulence generator's (12) pipe rows into a lip cone (K) and further out from the headbox on to a formation wire. The turbulence generator (12) of the headbox includes a fluidization element (14), wherein fluidization is carried out in one stage only and in which structure as little disturbance as possible is then caused to the fluidised flow.

Abstract: A method for fluidisation of a pulp flow in the headbox of a paper machine or such. The characteristics of the pulp flow are affected in the headbox's fluidiser (14) in one step only, whereby the height (h1) of the step is at least equal to the average fibre length, and after the fluidiser (14) the biggest permissible step expression in the flow channel in direction z is smaller than the average fibre length.

Abstract: In the short circulation of a paper machine, a chemicals flow (F1) is fed into a fibre suspension flow in connection with a pipe expansion comprising a first pipe (1) and a second pipe (2) having a larger diameter than the first pipe, which pipes are connected to each other by means of an expansion step (3) perpendicular to the direction of flow. The chemicals flow (F1) can be passed so as to be mixed with the fibre suspension flow either in the second pipe (2) in an ideal mixing zone situated after the expansion step (3) or in the first pipe (1) so close to the expansion step (3) that the chemicals which are added have no time to react with the fibre suspension before the flow enters the expansion step (3).

Abstract: A paper/board machine headbox (10) has a stock inlet header (J), a tube bank (11), a turbulence generator (13) and a slice opening (14) which is provided with a profile bar. The headbox (10) is provided with cross direction measuring sensors (D1, D2; Dmn), by means of which the flow rate profile of the headbox (10) is determined, and the profile bar of the slice opening (14) of the headbox (10) is adjusted in the cross direction on the basis of the thus determined flow rate profile. The headbox (10) is provided with measuring sensors (D1, D2; Dmn) for determining the cross direction flow rate profile of the headbox (10) and with means for adjusting the profile bar on the basis of the flow rate profile.

Abstract: The invention concerns a headbox (10) of a paper machine or such. It includes a bypass manifold (J1), from which the pulp is conducted by way of pipes (11a1.1, 11a1.2, . . . ; 11a2.1, 11a2.2, . . . ) of pipe rows in a set of pipes (11) and an intermediate chamber (E) into a turbulence generator (12), or from the bypass manifold (J1) directly into the turbulence generator and by way of the pipes (12a1.1, 12a1.2, . . . ; 12a2.1, 12a2.2, . . . ) of the turbulence generator's (12) pipe rows into a lip cone (K) and further out from the headbox on to a formation wire. The turbulence generator (12) of the headbox includes a fluidisation element (14), wherein fluidisation is carried out in one stage only and in which structure as little disturbance as possible is then caused to the fluidised flow.

Abstract: The invention concerns a method for fluidisation of a pulp flow in the headbox of a paper machine or such. The characteristics of the pulp flow are affected in the headbox's fluidiser (14) in one step only, whereby the height (h1) of the step is at least equal to the average fibre length, and after the fluidiser (14) the biggest permissible step expansion in the flow channel in direction z is smaller than the average fibre length.

Abstract: In the short circulation of a paper machine, a chemicals flow (F1) is fed into a fibre suspension flow in connection with a pipe expansion comprising a first pipe (1) and a second pipe (2) having a larger diameter than the first pipe, which pipes are connected to each other by means of an expansion step (3) perpendicular to the direction of flow. The chemicals flow (F1) can be passed so as to be mixed with the fibre suspension flow either in the second pipe (2) in an ideal mixing zone situated after the expansion step (3) or in the first pipe (1) so close to the expansion step (3) that the chemicals which are added have no time to react with the fibre suspension before the flow enters the expansion step (3).

Abstract: A headbox (10) has a stock inlet header, a tube bank, a tubulence generator and a slice channel. Measurement targets (PA, PB, PC, P, PE) are provided with means for making measurements of the fiber mobility of the fiber suspension, then controlling the flow state of the suspension. Sensors on the width of the headbox (10) or traversing sensors are positioned on different width points of the headbox (10) and arranged to measure the fiber mobility profile, with means for changing the flow state on the basis of the measurements. Apparatus for diluting the thick stock into headbox consistency and units for cleaning the stock to be fed into the headbox may be provided. Sensors may be disposed in the short circulation pipes or cleaning units arranged to measure the fiber mobility of the fiber suspension with means for changing the flow state on the basis of the measurement data.

Abstract: A paper/board machine headbox (10) has a stock inlet header (J), a tube bank (11), a turbulence generator (13) and a slice opening (14) which is provided with a profile bar. The headbox (10) is provided with cross direction measuring sensors (D1, D2; Dmn), by means of which the flow rate profile of the headbox (10) is determined, and the profile bar of the slice opening (14) of the headbox (10) is adjusted in the cross direction on the basis of the thus determined flow rate profile. The headbox (10) is provided with measuring sensors (D1, D2; Dmn) for determining the cross direction flow rate profile of the headbox (10) and with means for adjusting the profile bar on the basis of the flow rate profile.