In connection with papermaking by Japanese traditional hand process, the filterability of mucin solution, sedimentation velocity of rayon pulp and stripping quality of wet paper prepared by this process were studied.
The effect of tororo-aoi mucin (TM) on papermaking property decreased by aging or by heating the mucin solution under the mild conditions. Close correlation was also confirmed between filterablity, sedimentation velocity or stripping quality decribed above and relative viscosity of TM solution. The effect of noriutsugi mucin (NM) and Pachira macrocarpa mucin (PM) on papermaking property was almost similary with the effect of TM.
From the results of measuring relative viscosity of TM solution, UV absorption spectrum of TM complex with toluidine blue and X-ray diffractogram of TM, it was assumed that a network structure of the mucin molecules is slowly broken by aging or by heating under the mild conditions.
From these facts, it was finaly discussed that a decrease in the effect of TM, NM or PM on papermaking property under the mild conditions occurs due to the initial conformational transition of an ordered, weak structure of these mucin molecules.