Combined de-inking technology applied on laser printed paper

The combined de-inking technology of ultrasonic, UV irradiation and enzymatic methods was introduced into the de-inking process of HP laser printed paper. The purpose was to reduce the consumption of alkali or even preprocess without alkali absolutely for the purpose of environment protection. The de-inking effects of cellulase, amylase, lipase and their mixture were compared and the experiment results showed that combined enzymes of cellulase and amylase have the best de-inking efficiency which has a 12% increment of brightness. The de-inking efficiencies of several different de-inking technologies were compared, which can provide basis to establish combined de-inking technologies.