Heat-induced changes in fibre surfaces

摘要

The optical properties of sheets of two mechanical pulps - a spruce groundwood (GW) and a thermomechanical pulp (TMP) - were studied after various thermal treatments. The heat treatments were performed at moderate and high temperatures in either a dry oven or a humidity chamber. The optical changes were followed using UV-VIS reflectance and fluorescence spectroscopy. The kinetics of the yellowing was investigated using both techniques, which reveal changes in the fibre surfaces.