Abstract: A method for producing a Yankee dryer cylinder, or Yankee cylinder, includes the steps of executing a cylindrical tubular semifinished product made of steel and having a side wall provided with an internal surface and an external surface. A forging step of the cylindrical tubular semifinished product follows for obtaining predetermined thicknesses at the central portion and at the terminal portions of the side wall where the enlarged terminal portions are made. The cylindrical shell is completed executing a plurality of grooves at the internal surface of the cylindrical tubular semifinished product. Then a plurality of longitudinal blind holes are executed at the external surfaces of the enlarged terminal portions of the cylindrical shell. Then, the heads are positioned at each of enlarged terminal portion of the cylindrical shell to which they are fixed by means of studs that pass the blind holes of the shell and respective through holes of which the heads are provided.

Abstract: A method for producing a Yankee dryer cylinder, or Yankee cylinder, comprises the steps of disposing of a first and of at least a second cylindrical portion of shell. These are made of steel, have the same diameter and are provided with a plurality of grooves at an internal surface. In particular, the portions of shell, at a respective end, are provided of respective flange portions. The method provides to coaxially position the portions of shell up to arrange respective coupling surfaces of the flange portions adjacent one to the other. Then the engagement of the portions of shell is provided by means of a plurality of clamping members, each of which arranged to clamp the adjacent flange portions. Then, it is provided the circumferential welding of the cylindrical portion of the shell that are opposite to the flange portions, and the removal of the clamping members and of the flange portions.

Abstract: A Yankee dryer cylinder (1) having a cylindrical shell (10) having a central portion (11), a first and a second end portion (12, 13) and a longitudinal axis (101). At an internal surface (14), the cylindrical shell (10) includes a plurality of circumferential grooves (15). The cylinder (1) includes a first and a second head (20, 30) fixed, respectively, to the end portions (12, 13) of the cylindrical shell (10). The shell (10) includes a first and a second group of circumferential end grooves (15a, 15b, 15?a, 15?b) positioned respectively at the first and the second end portion (12, 13) and a third group of circumferential grooves positioned at the central portion (11). The grooves of the first and of the second group have a width that is greater than the width of the circumferential grooves positioned at the central portion, to uniformly distribute the loads in operating conditions.

Abstract: Yankee dryer cylinder (1) having a cylindrical shell made of steel (10), having a first and a second end opposite each other (11, 12) and provided with a plurality of circumferential grooves (15). The cylinder (1) includes a first and a second head (20, 30) made of cast iron and fixed respectively to the first and to the second end (11, 12) of the cylindrical shell made of steel (10). It is, furthermore, provided a hollow shaft (40) mounted inside the cylindrical shell (10) and connected to the first and to the second head (20, 30) at a first and a second end (41, 42), respectively. The cylinder is also provided with a first and a second bearing journal (50,60) fixed to the hollow shaft (40) at a respective end (41, 42).

Abstract: A Yankee dryer cylinder comprising a fixed hollow shaft provided with an inlet mouth through which a flow of hot air is fed into the cavity, and an outlet mouth through which the flow of hot air exits the dryer cylinder. The Yankee dryer cylinder provides, furthermore, a cylindrical shell having an internal surface and rotatably mounted about the fixed hollow shaft. Into the cavity a partition wall is provided which divides the fixed hollow shaft in a feeding portion and in a discharging portion.

Abstract: A method for producing a Yankee dryer cylinder, or Yankee cylinder, comprises the steps of disposing of a first and of at least a second cylindrical portion of shell. These are made of steel, have the same diameter and are provided with a plurality of grooves at an internal surface. In particular, the portions of shell, at a respective end, are provided of respective flange portions. The method provides to coaxially position the portions of shell up to arrange respective coupling surfaces of the flange portions adjacent one to the other. Then the engagement of the portions of shell is provided by means of a plurality of clamping members, each of which arranged to clamp the adjacent flange portions. Then, it is provided the circumferential welding of the cylindrical portion of the shell that are opposite to the flange portions, and the removal of the clamping members and of the flange portions.

Abstract: A method for producing a Yankee dryer cylinder, or Yankee cylinder, includes the steps of executing a cylindrical tubular semifinished product made of steel and having a side wall provided with an internal surface and an external surface. A forging step of the cylindrical tubular semifinished product follows for obtaining predetermined thicknesses at the central portion and at the terminal portions of the side wall where the enlarged terminal portions are made. The cylindrical shell is completed executing a plurality of grooves at the internal surface of the cylindrical tubular semifinished product. Then a plurality of longitudinal blind holes are executed at the external surfaces of the enlarged terminal portions of the cylindrical shell. Then, the heads are positioned at each of enlarged terminal portion of the cylindrical shell to which they are fixed by means of studs that pass the blind holes of the shell and respective through holes of which the heads are provided.

Abstract: Yankee dryer cylinder (1) having a cylindrical shell made of steel (10), having a first and a second end opposite each other (11, 12) and provided with a plurality of circumferential grooves (15). The cylinder (1) includes a first and a second head (20, 30) made of cast iron and fixed respectively to the first and to the second end (11, 12) of the cylindrical shell made of steel (10). It is, furthermore, provided a hollow shaft (40) mounted inside the cylindrical shell (10) and connected to the first and to the second head (20, 30) at a first and a second end (41, 42), respectively. The cylinder is also provided with a first and a second bearing journal (50,60) fixed to the hollow shaft (40) at a respective end (41, 42).

Abstract: A Yankee dryer cylinder (1) having a cylindrical shell (10) having a central portion (11), a first and a second end portion (12, 13) and a longitudinal axis (101). At an internal surface (14), the cylindrical shell (10) includes a plurality of circumferential grooves (15). The cylinder (1) includes a first and a second head (20, 30) fixed, respectively, to the end portions (12, 13) of the cylindrical shell (10). The shell (10) includes a first and a second group of circumferential end grooves (15a, 15b, 15?a, 15?b) positioned respectively at the first and the second end portion (12, 13) and a third group of circumferential grooves positioned at the central portion (11). The grooves of the first and of the second group have a width that is greater than the width of the circumferential grooves positioned at the central portion, to uniformly distribute the loads in operating conditions.

Abstract: The cylinder (1; 111) comprises: a shell (3; 113) and two heads (5, 7; 115, 117), defining an inner hollow space (9), inside which a heat-transfer fluid flows. Support and rotation journals (15, 17; 121, 123) are also provided, fixed to said heads; and a thermal insulation system (23, 25; 125, 125) for the heads (5, 7, 117, 119). The thermal insulation system comprises, for each head, a plurality of thermal insulation panels (27; 127), each of which comprises a closed space (10) defined in a shell, inside which there is housed a thermal insulating material (35).

Abstract: The air hood (3) for Yankee rolls (1) comprises at least one supply circuit (5, 6, 7) to supply dry hot air towards outlets (7A) to a working area, and at least one suction circuit (11) to suck wet air from the working area. The hood comprises a thermal insulation insulating at least partially the supply circuit from the suction circuit.

Abstract: The invention relates to a method for the production of a web of tissue paper, including the steps of: depositing a layer of an aqueous suspension of papermaking fibers on at least one forming fabric; reducing the water content of the layer until the amount in weight of the fibers in the layer is brought up to a first value; wet-embossing the layer in a nip between a pair of embossing rollers; and drying the embossed layer using a drying system to form a web of tissue paper.

Abstract: The invention relates to a method for the production of a web of tissue paper, including the steps of: depositing a layer of an aqueous suspension of papermaking fibers on at least one forming fabric; reducing the water content of the layer until the weight percentage of fiber in the layer is brought up to a first value; wet-embossing the layer in a nip between a pair of embossing rollers; and drying the layer to form a web of tissue paper.

Abstract: The invention relates to a method for the production of a web of tissue paper, comprising the steps of: depositing a layer of an aqueous suspension of papermaking fibers on at least one forming fabric; reducing the water content of said layer until the amount in weight of the fibers in said layer is brought up to a first value; wet-embossing said layer in a nip between a pair of embossing rollers; and drying said embossed layer using a drying system to form a web of tissue paper.

Abstract: The invention relates to a method for the production of a web of tissue paper, comprising the steps of: depositing a layer of an aqueous suspension of papermaking fibers on at least one forming fabric; reducing the water content of said layer until the weight percentage of fiber in said layer is brought up to a first value; wet-embossing said layer in a nip between a pair of embossing rollers; and drying said layer to form a web of tissue paper.