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 formation detection system comprising: one or more sensors located above a sheet of paper, located below the sheet of paper, or both and one or more lights that illuminate all or a portion of the sheet of paper passing by the one or more sensors so that the one or more sensors monitor formation of the paper comprising: orientation of fibers within the sheet of paper, wherein the formation detection system is configured to monitor the sheet of paper before a press section, within the press section, before a dryer section, within the dryer section, after the dryer section, or a combination thereof of a paper machine; and wherein the one or more sensors are movable in a cross-machine direction across the sheet of paper within the paper machine.

A formation detection system comprising: one or more sensors located above a sheet of paper, located below the sheet of paper, or both and one or more lights that illuminate all or a portion of the sheet of paper passing by the one or more sensors so that the one or more sensors monitor formation of the paper comprising: orientation of fibers within the sheet of paper, wherein the formation detection system is configured to monitor the sheet of paper before a press section, within the press section, before a dryer section, within the dryer section, after the dryer section, or a combination thereof of a paper machine; and wherein the one or more sensors are movable in a cross-machine direction across the sheet of paper within the paper machine.

The invention relates to a Yankee drying hood arrangement (1) which is shaped to be fitted over a Yankee drying cylinder (2) such that the drying hood arrangement (1) can cover a part (4) of the circular cylindrical surface (3) of a Yankee drying cylinder (2). The Yankee drying hood arrangement (1) comprises a plurality of nozzle boxes (5) distributed equidistantly around an imaginary axis (X) such that, when the Yankee drying hood arrangement (1) is fitted over a Yankee drying cylinder (2), the nozzle boxes (5) are spaced from the circular cylindrical surface (3) of the Yankee drying cylinder (2) but form a curved structure (6) that follows the outer contour of the circular cylindrical surface (3) of the Yankee drying cylinder (2). Each nozzle box (5) has a longitudinal extension in a direction parallel to the axial extension of the Yankee drying cylinder (2) and each nozzle box (5) has openings (7) distributed along the longitudinal extension of the nozzle box (5) through which openings (7) a fluid such as hot air can exit the nozzle boxes (5) and stream towards the circular cylindrical surface (3) of the Yankee drying cylinder (2) at different points at different points along the axial extension of the Yankee drying cylinder (2). The Yankee drying arrangement further comprises a plurality of distributor conduits (8) for a fluid such as hot air and the distributor conduits (8) extend in the circumferential direction around the curved structure (6) formed by the nozzle boxes (5). Each distributor conduit (8) is in communication with several nozzle boxes (5) such that a fluid such as hot air can stream from each distributor conduit (8) to several different nozzle boxes (5). At least one main supply conduit (9, 10) for a fluid such as hot air is in communication with the distributor conduits (8) such that a fluid such as hot air can stream to the distributor conduits (8). The distributor conduits (8) are oriented around the curved structure (6) of the nozzle boxes (5) in such a pattern that, when one and the same distributor conduit (8) communicates with different nozzle boxes (5), it does so at different points along the longitudinal extension of the different nozzle boxes (5). The invention also relates to a Yankee drying cylinder fitted with the inventive Yankee drying hood arrangement and to a method of drying a fibrous web.

A machine for dewatering and drying a paper, cardboard or other fibrous web, to which machine a fibrous stock suspension is fed which is formed at least partially from waste paper. The machine includes at least two press nips which are formed in each case by two press rolls, wherein a fibrous web runs through first press nip with a water absorbing dewatering belt on both sides. The fibrous web then runs through a second press nip with at least one other dewatering belt and a smooth impermeable transfer belt on both sides. A transfer belt transfers the fibrous web after second press nip to a belt in a downstream machine unit, e.g. dryer group. The dryer group allows the fibrous web to be guided in a serpentine manner alternatively over heated dryer cylinders and vacuum equipped guide rolls.

Unlike conventional through-air drying processes the instant invention utilizes at least two through-air driers where the first dyer is at least partially encircled by a first through-air drying fabric and the second dyer is at least partially encircled by a second through-air drying fabric. By providing each through-air dryer with its own fabric the overall drying performance may be increased. Additionally, in certain embodiments, the first and second fabrics may be different to optimize both the drying performance and/or tissue product properties.

A fibrous structure. The structure may include a plurality of continuous or semi-continuous knuckles extending from portions of the surface of the fibrous structure in a parallel path, wherein the plurality of knuckles may be separated by adjacent continuous or semi-continuous pillows. Each knuckle may comprise a plurality of discrete pillows, the plurality of discrete pillows may be arranged in a spaced configuration along the path of each knuckle; alternatively, each pillow may comprise a plurality of discrete knuckles, the plurality of discrete knuckles may be arranged in a spaced configuration along the path of each pillow.

Unlike conventional through-air drying processes the instant invention utilizes at least two through-air driers where the first dyer is at least partially encircled by a first through-air drying fabric and the second dyer is at least partially encircled by a second through-air drying fabric. By providing each through-air dryer with its own fabric the overall drying performance may be increased. Additionally, in certain embodiments, the first and second fabrics may be different to optimize both the drying performance and/or tissue product properties.

A method for operating a heating group subsystem of a machine for the production or treatment of a fibrous web. The heating group subsystem includes a first heating group and a last heating group and at least one additional heating group; in each case having at least one device that is heated with pressurized heating steam. Viewed in a direction of travel, the fibrous web is fed first through the first heating group, then through the at least one additional heating group, and thereafter through last heating group. The steam pressure of the heating steam of the at least one additional heating group is adjusted lower than the respective steam pressure of the heating steam of first heating group and of last heating group.

A method for operating a heating group subsystem of a machine for the production or treatment of a fibrous web. The heating group subsystem includes a first heating group and a last heating group and at least one additional heating group; in each case having at least one device that is heated with pressurized heating steam. Viewed in a direction of travel, the fibrous web is fed first through the first heating group, then through the at least one additional heating group, and thereafter through last heating group. The steam pressure of the heating steam of the at least one additional heating group is adjusted lower than the respective steam pressure of the heating steam of first heating group and of last heating group.