AbstractThe influence of the enzyme addition point on fiber properties was analyzed by treating two industrial recycled pulp samples – with and without industrial refining – with a mixture of cellulases and hemicellulases. The effects of the enzyme treatment variables – enzyme dosage, time, and consistency – on the fiber properties were studied. The aim of this work was to improve the drainability and the recovery of the strength properties of recycled fibers. The properties of the pulps treated enzymatically and refined in a PFI mill were also evaluated. According to the statistical analysis, opposite effects on drainability were obtained by varying pulp consistency, enzyme dosage, and enzyme application point (i.e., before or after the industrial mechanical treatment). Drainability and strength properties increased when the enzymatic treatment was applied to the pulp without industrial refining, whereas no improvement was observed for pulp with industrial refining.