A Yankee drier including a cylindrical mantle to which two end heads are connected, on each of which a corresponding pin is arranged, wherein the cylindrical mantle has an external surface and an internal surface, and wherein the internal surface of the mantle in cooperation with the lateral heads delimits an internal chamber of the Yankee drier in which steam can be introduced. The internal surface of the mantle is at least partially provided with a surface protective coating, the surface protective coating protecting the internal surface of the mantle from corrosive and/or abrasive agents contained in the steam introduced into said chamber.

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).

A heatable roller suitable for a machine for producing and/or upgrading a web of material, in particular a fibrous material web such as a paper, paperboard or tissue web. The roller has a main element with a metallic and cylindrical roller wall which is heatable by suitable means and on the radially outer side of which there is, at least in sections, a coating. When the roller is used as intended, the coating provides a web contact side which can be brought into contact with the web of material. The coating includes, or is formed by, at least one metallic or metal-carbidic layer with a first layer component providing a matrix and a second layer component distributed in the matrix. The first layer component has a higher abrasion resistance than the second layer component and the second layer component has a greater thermal conductivity than the first layer component.

A contamination preventing agent composition to be applied to a dry part of a papermaking process, wherein the composition is an emulsion comprising a silicone-based oil that is liquid at room temperature, an aqueous medium that is liquid at room temperature, and a dispersant for dispersing the silicone-based oil in the aqueous medium, the aqueous medium comprising water and a polyhydric alcohol dissolved in the water, the boiling point of the polyhydric alcohol being greater than 100 C., the blending ratio of the silicone-based oil to 1 part by mass of the polyhydric alcohol being 0.5 to 50 parts by mass, the blending ratio of the water to 1 part by mass of the polyhydric alcohol being 25 to 300 parts by mass, and the blending ratio of the dispersant to 1 part by mass of the polyhydric alcohol being 0.1 to 50 parts by mass.

The invention relates to steel Yankee cylinders for tissue-making machines and tissue-making machines using such steel Yankee cylinders wherein the outer surface (9) of the cylindrical shell of the steel Yankee cylinder is formed by a steel of the grade P690 as defined in European Standard EN 10028-6:2017 or a similar steel.