method for controlling papierblattwellungen in the dryer section of a paper or pappemaschine

摘要

The invention concerns a method in the dryer section of a paper or board machine for control of the curl of paper, in which method steam treatment and/or moistening of the paper web (W) is/are employed. In the method, the operations carried out in view of controlling the curl of the paper web (W) are carried out in a number of stages and/or when the web (W) temperature is lower than 85 DEG C, preferably lower than 75 DEG C, and/or when the dry solids content of the web (W) is in the range of K1...K2, wherein K1 = ultimate dry solids content - 7 % and K2 = ultimate dry solids content + 3 %. Further, the invention concerns a paper or board machine, which comprises at least a headbox, a former, a press, and a dryer section, in which steam boxes or moistening devices are employed for control of the curl. There are at least two of said curl regulation devices in view of achieving a regulation of the curl in a number of stages, and/or said curl regulation devices have been fitted to operate in an area in which the web temperature is lower than 85 DEG C, preferably lower than 75 DEG C, and/or the dry solids content of the web is in a range of K1...K2, wherein K1 = ultimate dry solids content - 7 % and K2 = ultimate dry solids content + 3 %.