Recent Advances in Enzymatic Pitch Control, 1992 Papermakers Conference Proceedings

The enzymatic pitch control has been continuously applied in the production line for newsprint and wood containing paper at Ishinomaki and Yatsushiro mills, Jujo Paper since May 1990. Better and steady operations and resulting product quality improvement have been achieved by this enzymatic pitch control method. In Yatsushiro mill, increasing unseasoned logs ratio in its wood supply to groundwood pulp production was tried with the help of the enzymatic treatment. It was confirmed that the operation in the trial was as good as that in the conventional run with whole seasoned logs. The cost saving due to less seasoning and less bleaching chemicals consumption was also verified. In Ishinomaki mill, it was observed by the spot detector that the number of paper defects was reduced to one third of the number without the enzymatic treatment. It was also found that the dynamic friction coefficient of paper was increased due to the hydrolysis of TG by lipase and thus costly white carbon addition, which is a routine control to keep a certain friction value, was favorably reduced. Newly discovered thermostable lipase showed good activity up to 80°C. This lipase was directly added to a grinder and it was proved that the thermostable lipase had a high hydrolysis activity of TG under such a severe condition.