Degrading starch or starch derivs. in paper prodn. - by treating with amylase to reduce viscosity and simplify coating process

摘要

Amylases are used to degrade starch (derivs.) used in paper prodn. By partial degradation, the viscosity can be controlled to a desired value and the coating process simplified. For example, an aq. 7.5% soln. of a starch ether (e.g. 'Solvitose H') has a viscosity of 35 cP and pH 6.5. By adding 0.05% of an alpha-amylase (e.g. 'Biolase PC 90') the viscosity is reduced, the process being stopped by adjusting the pH to 3.5. This can be carried out, e.g. by adding acetic acid. The viscosity can be adjusted to any value between 35 and 2 cP, by varying temp., enzyme concn. and time.