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Changes in web tension profiles and paper properties during repeated rewinding

Eriksson, L. G.
Hellentin, P.
Johnson, P.

Newsprint rolls with a diameter of about 125 cm have been run six times through a rewinder. The changes in the CD web tension profile have been recorded during the rewindings. The roll hardness has been measured before and after each rewinding. Paper samples have been taken out and measured in order to determine the change in paper properties such as surface roughness, surface compressibility, thickness, air permeance, and friction coefficient. Tensile testing has also been made and values of tensile stiffness, tensile strength, tensile energy absorption, and strain to failure have been derived.

The CD web tension profile remained almost the same. The tensile properties changed also very little. The roll hardness increased after the first rewinding, but in the following rewindings it did not change very much. The thickness, surface roughness, and surface compressibility declined significantly.

Significant changes of the paper properties are recorded after the first rewinding. Thereafter very small changes take place when the roll is repeatedly rewound.