Using amylases to optimize the desintegration process

The rising utilization Mixed Office Waste (MOW) as a source of secondry fib er makes necessary to develop news tecnologies to make this secondary fiber grade suitale for the manufacturee of higgh brightness printing paper. Dei nking this kind of paper is necessary to achieve the required properties. B ut the deinking operation is as impotant as the previous desintegration ope ration. This desintegration could be improved by biotechnology. Amylases ar e enzymes which hydrolyze starch and, in this work, they were used to remov e the starch in the paper and, thus, to reduce the cohesion of the sheet, m aking the disintegration easier We have not found studies about this subjec t in the bibliography. For this work, special inkjet printer paper was used because its desintegration is much more difficult than in the case of usin g standard printing paper. Moreover, a method to assess the action of the e nzymee based on the remaining flakes in the pulp after standard lab desinte gration is proposed. The study was split in two different parts in which tw o different statistical plans were carried out. In to first part, a special inkjet printer paper was compared with a standard printing paper, suitable for photocopiers. The results of the first part showed thatt the inkjet pr inter paper was more difficult to desintegrate than the standard one. The e ffect of a commercial amylase was evaluated in the second part. A statistic al plan was used to perform the study in which the variables were the enzim e dose (1,6 to 5%), the treatment time (20 yo 60 min) and number of revolut ions of a standard laboratoy desintedgrator (15.000 to 65.000 revolutions). Two different responses were evaluated: the flakes amount after enzymatic treatment and desintegration and the remaining starch in the pulp after enz ymatic treatment. The results of the second part showed that the enzyme had a significant effect on the final flakes amount in the pulp. The conclusio n is that a previous treatment with amylases makes the desintegration easie r, so it if posible to obtain pulp in better conditions to be deinked.