| Effects of wood extractives on the production process and paper quality were investigated in this work for two speciality paper grades: grease resistant paper and supercalendered paper.;A method was developed to build a mass balance of fluorochemicals, based on the fluorine content in the paper and process water. When this method was applied to both regular pulp and extractive-free pulp systems, a good recovery of the fluorochemicals applied was observed and the results also showed that the presence of extractives in pulp fibers was detrimental to the retention of fluorochemicals. The presence of extractives in high-extractive pulp had a significant negative effect on the fluorochemical retention during the internal sizing with fluorochemicals. The effect of extractives on the distribution of fluorochemicals was also studied based on the Energy Dispersive X-ray method. The results showed that the addition of cationic polymers, such as poly-DADMAC, cationic PAM, led to positive effect on the performance of fluorochemical retention and grease-resistant development.;The interactions of wood extractives with various metal ions were carried out. The valency of metal cations was found to determine the ability of capturing pitch for the formation of deposits. Trivalent ions, such as Al3+ or Fe3+, had much stronger effects than divalent ions, such as Ca2+, Mg2+. The thermograms from a differential scanning calorimeter (DSC) showed that a higher pH, trivalent metal ions (Al 3+ or Fe3+), and the presence of polymers, for instance, polyDADMAC, CPAM, increased the thermal stability of deposits formed in colloidal pitch solutions. A Confocal Laser Scanning Microscope (CLSM) was used to map the distribution of pitch in the paper sheets and the results showed that polymers can aggregate pitch particles and made them easy to be retained on the paper sheet.;Deposit samples were also analyzed by using a thermogravimetric analyzer (TGA) and the results showed the mass loss due to heating in the temperature range of 50-200°C was less than 5%. The gas chromatography (GC) results showed similar chemistry for the deposit samples before and after the TGA analysis, indicating that fatty and resin acids, rather than volatile components, were the main components in the deposit samples and that the migration of the softened resin and fatty acids may be responsible for the formation of the deposit.;Two control programs, detackification versus fixation, were compared and the detackification chemistry was found to be more effective on reducing the extractives-related deposit formation on the supercalendering stack. |
