Improvement of the physical properties of reprocessed paper by using biological treatment with modified cellulase

A primary need for waste paper reprocessing is to preserve optical properti es and the physical strength of the paper fibers. In this study, modified c ellulase with copolymer, polyethylene oxide (PEO) derivatives and maleic an hydride (MA) was applied to the reprocessing of mixed office waste (MOW). M odified cellulase was prepared by a chemical reaction between amino groups of the cellulase and the MA functional groups of the copolymer. In MOW repr ocessing, modified cellulase improved several physical properties of the pa per including freeness, optical properties, and physical strength compared to the conventional process. Even though native cellulase improved the phys ical properties, paper treated with modified cellulase exhibited an increas e in physical properties such as tensile strength and internal bond over th ose of unmodified cellulase. From these results, modified cellulase method is a new biological treatment that will save pulp resources, which are adde d to waste paper reprocessing to maintain the strength of paper. (C) 2001 E lsevier Science Ltd. All rights reserved.