STUDY ON PULPING OF HIGH WET-STRENGTH PAPER CONTAINING POLYAMIDE EPICHLOROHYDRIN

In this paper, three different kinds of oxidants (sodium hypochlorite, potassium permanganate and hydrogen peroxide) were used in the recycling process of the high-wet strength paper which contained the polyamide epichlorohydrin. With the 13 formation index as the main parameter, the most effective oxidant was selected under the same processing conditions including chemical dosage, reaction temperature, reaction time and pH. Furthermore, the oxidant which was picked up above was used in the treatment of high wet-strength paper and the optimum condition was further investigated. The results showed that the most effective oxidant was sodium hypochlorite. The corresponding optimum conditions were as follows: sodium hypochlorite dosage was 4%, the reaction temperature was 80 degrees C, the reaction time was 80 min (acid treatment was 40 min when the pH was 3, alkali treatment was 40 min when the pH was 12 respectively). Under the optimum conditions, the 13 formation index was 2.59 and increased 0.04 compared to the blank sample.