According to an example aspect of the present invention, there is provided a cost-effective method of producing cellulose based films by introducing an intense water removal system to the process, and cellulose based films thereof having improved properties.

The invention relates to a Yankee drying hood arrangement (1) which has a first temperature main supply conduit (9, 9′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a first temperature T1 and a second temperature main supply conduits (10, 10′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a second temperature T2 which is not the same as T1, the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) being in communication with the distributor conduits (8) such that a fluid such as hot air can stream from the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) to the distributor conduits (8), wherein at least one distributor conduit (8) is provided with damper means (31) for changing the ratio between amount of fluid at temperature T1 from the first temperature main conduit and the amount of fluid at temperature T2 from the second temperature main conduit that streams into the distributor conduit.

The invention relates to a Yankee drying hood arrangement (1) which has a first temperature main supply conduit (9, 9′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a first temperature T1 and a second temperature main supply conduits (10, 10′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a second temperature T2 which is not the same as T1, the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) being in communication with the distributor conduits (8) such that a fluid such as hot air can stream from the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) to the distributor conduits (8), wherein at least one distributor conduit (8) is provided with damper means (31) for changing the ratio between amount of fluid at temperature T1 from the first temperature main conduit and the amount of fluid at temperature T2 from the second temperature main conduit that streams into the distributor conduit.

According to an example aspect of the present invention, there is provided a cost-effective method of producing cellulose based films by introducing an intense water removal system to the process, and cellulose based films thereof having improved properties.

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.

According to an example aspect of the present invention, there is provided a cost-effective method of producing cellulose based films by introducing an intense water removal system to the process, and cellulose based films thereof having improved properties.

According to an example aspect of the present invention, there is provided a cost-effective method of producing cellulose based films by introducing an intense water removal system to the process, and cellulose based films thereof having improved properties.

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.

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.

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.