The control of sticky contaminant with enzymes in the recycling of wastepaper

As paper mills have increased the use of recycled fiber, the potential occurrence of sticky deposits and quality problems caused by sticky contaminants has increased. Enzymatic technology has been applied to the papermaking process of tissue and machine glazed paper on a plant scale to control sticky contaminant. The content of sticky compounds in the white water and pulp slurry was determined by solvent extraction and the physical properties of final products were measured. This paper shows that the amount of sticky contaminants in screen rejects increased with the enzyme treatment and the content of toluene extract in the final product decreased on a mill scale. In addition to the effect of reducing potential sticky compounds, the burst strength and water absorbency of tissue paper treated with enzymes were enhanced to 110% of the controlled paper.