The invention relates to a system (1) and a method for collecting and handling dust in a paper-making environment. The system (1) comprises a source of underpressure (2) and an elongated collector (4) that extends along a longitudinal axis and which elongated collector (4) is connected to the source of underpressure (2) through at least one suction duct (7) such that underpressure can be generated inside the elongated collector (4). The elongated collector (4) has an inlet (5) through which dust-laden air can enter the elongated collector (4) and an exit opening (6) leading to the suction duct (7) through which exit opening (6) dust-laden air can be evacuated from the elongated collector (4). A source of water (8) is connected by at least one water supply duct (10) to the elongated collector (4) such that water from the source of water (8) can be introduced into the elongated collector so that dust in the dust-laden air can be exposed to and mix with the water introduced into the elongated collector (4). A flow meter (12) is functionally connected to the system (1) to measure at least one of a flow of water from the source of water (8) to the elongated collector (4) or a flow of water exiting from the elongated collector (4) through the exit opening (6) of the elongated collector (4) and arranged to send a signal indicating a numerical value for a flow of water that reaches or leaves the elongated collector (4) such that this value can be compared to a predetermined minimum value. The system is used to carry out the inventive method.

A method of forming a fibrous web including the steps of providing a fiber slurry, depositing the fiber slurry between an inner forming wire and an outer forming wire, wherein the outer forming wire comprises a structured fabric and the inner forming wire contacts a segment of a forming roll, and rotating the forming roll so that the fiber slurry moves into contact with the structured fabric.

A drying hood for drying a fibrous web, such as a tissue paper web, includes a plurality of nozzle boxes for supplying or discharging air and a housing that at least partially surrounds the nozzle boxes. The nozzle boxes are each individually mounted on the housing by a first bearing and a second bearing. The two bearings allow at least one movement of the nozzle box relative to the housing along a longitudinal axis of the nozzle box and/or at least one movement in a direction transverse thereto, along a transverse axis of the nozzle box. The two bearings have translational degrees of freedom differing by one. A drying arrangement having a drying cylinder and the drying hood is also provided.

A method of forming a fibrous web including the steps of providing a fiber slurry, depositing the fiber slurry between an inner forming wire and an outer forming wire, wherein the outer forming wire comprises a structured fabric and the inner forming wire contacts a segment of a forming roll, and rotating the forming roll so that the fiber slurry moves into contact with the structured fabric.

The invention relates to a forming section (2) for forming a fibrous web (W). The forming section (2) comprises a first forming fabric (3) arranged to run in a loop supported by guide elements (4) and a second forming fabric (5) arranged to run in a loop supported by guide elements (4). The second forming fabric (5) is arranged so in 5 relation to the first forming fabric (3) that the two forming fabrics (3, 5) converge towards each other to form an inlet gap (6) into which stock can be injected. A forming roll (7) is arranged within the loop of the second forming fabric (5) to guide the second forming fabric (5) into the inlet gap (6) and to guide the first and the second forming fabric (3, 5) along a part of their path which is common to both the first and the second 10 forming fabric (3, 5) and which begins at the inlet gap. The forming roll (7) comprises a flexible tubular jacket (8) which is arranged to run in a loop around an axis of rotation (A) that extends in a direction perpendicular to the direction in which the first and second forming fabric (3, 5) are arranged to run and the forming roll further (7) comprises a support ledge (9) located inside the loop of the flexible tubular jacket (8) 15 and extending in a direction parallel to the axis of rotation (A) of the flexible tubular jacket (8). The support ledge (9) can press the flexible tubular jacket (8) in a direction outwards away from the axis of rotation (A) such that, in the area in which the flexible tubular jacket (8) is pressed outwards by the support ledge (9), the flexible tubular jacket (8) is caused to follow a path with a radius of curvature which is smaller than the 20 radius of curvature of the flexible tubular jacket (8) outside this area. The invention also relates to a method of forming a fibrous web.

A method of forming a fibrous web including the steps of providing a fiber slurry, depositing the fiber slurry between an inner forming wire and an outer forming wire, wherein the outer forming wire comprises a structured fabric and the inner forming wire contacts a segment of a forming roll, and rotating the forming roll so that the fiber slurry moves into contact with the structured fabric.

The invention relates to a system (1) and a method for collecting and handling dust in a paper-making environment. The system (1) comprises a source of underpressure (2) and an elongated collector (4) that extends along a longitudinal axis and which elongated collector (4) is connected to the source of underpressure (2) through at least one suction duct (7) such that underpressure can be generated inside the elongated collector (4). The elongated collector (4) has an inlet (5) through which dust-laden air can enter the elongated collector (4) and an exit opening (6) leading to the suction duct (7) through which exit opening (6) dust-laden air can be evacuated from the elongated collector (4). A source of water (8) is connected by at least one water supply duct (10) to the elongated collector (4) such that water from the source of water (8) can be introduced into the elongated collector so that dust in the dust-laden air can be exposed to and mix with the water introduced into the elongated collector (4). A flow meter (12) is functionally connected to the system (1) to measure at least one of a flow of water from the source of water (8) to the elongated collector (4) or a flow of water exiting from the elongated collector (4) through the exit opening (6) of the elongated collector (4) and arranged to send a signal indicating a numerical value for a flow of water that reaches or leaves the elongated collector (4) such that this value can be compared to a predetermined minimum value. The system is used to carry out the inventive method.

The present invention relates to a method for the production of a film comprising microfibrillated cellulose, wherein the method comprises the steps of; providing a suspension comprising between 70 weight-% to 100 weight-% of microfibrillated cellulose based on total dry weight, forming a fibrous web of said suspension, drying the web in a drying equipment wherein the web is at least partly dried at a drying rate above 75 kg(H.sub.2O)/m.sup.2/h by use of hot air whereby a film is formed. The invention also relates to a film produce according to the method and a paper or paperboard substrate comprising said film.

To provide a contamination-preventing agent composition and a contamination preventing method which even if the composition is imparted only to a dryer on the upstream side, a sufficient amount of the composition can be imparted to a dryer on the downstream side via a wet paper, and pitch contamination of a plurality of dryers can be prevented sufficiently as a whole.

The present invention is a contamination-preventing agent composition imparted to dryers D1 to D8 in a dry part D of a paper machine and comprising an emulsion, a re-transfer agent and water, wherein the re-transfer agent has a cloud point of 55 C. or higher and an HLB value of 8 to 15, and preferably a contamination-preventing agent composition wherein the dynamic surface tension value at a lifetime of 100 ms by a maximum bubble pressure method is 65 mN/m or less.

A convective hood for transverse installation in a system for continuous heat treatment of moving strip material comprises blowing nozzles for blowing hot gas against the moving strip in an arrangement transverse to the direction of movement of the strip material; and a first transverse suction zone for the suction of hot gas. The first transverse suction zone comprises a first transverse section and a second transverse section. The first transverse section and the second transverse section are provided at the same side downstream or upstream of the movement of the strip material from the blowing nozzles when the convective hood is installed in a system for continuous heat treatment of moving strip material. The second transverse section is provided along the line for movement of the continuous strip material between the first transverse section and the blowing nozzles. The first transverse section comprises suction openings for suction of hot gas directly from outside the convective hood into the convective hood; the suction openings being in closed gas flow connection to a first manifold for recirculation of at least part of this hot gas to the blowing nozzles for blowing the hot gas onto the continuous strip material. The second transverse section comprises suction openings for suction of hot gas directly from outside the convective hood into the convective hood; the suction openings being in closed gas flow connection to a second manifold for exhausting 100% of this hot gas outside of the convective hood.