Roll for a paper or board machine and method for manufacture of the roll

摘要

The invention concerns a roll for use in the manufacture of paper and board, a press roll, in particular a centre roll in a press, a backup roll for an extended-nip press roll, a hot press roll, or equivalent, which is in direct contact with a wet paper web, or a calender roll, a method for manufacture of the roll. and a composition of coating for the roll. Onto the frame part (1) of the roll, first an adhesion layer (2) is applied, and then a ceramic layer (3) of a thickness of 100...2000 mu m. which contains 50...95 % of Cr2O3 and 3...50 % of TiO2, or Al2O3 and ZrO2, or Al2TiO5, and the roughness Ra of the outer face of the roll is 0.4...2.0 mu m, and the porosity of the outer face of the roll is 1...20 %. Besides, or in stead of, TiO2, the ceramic layer (3) may also contain oxides of aluminum, silicon, zirconium, magnesium, manganese, tin, or tungsten or mixtures of same.