Evaluation of the Influence of Amphoteric Synthetic Resins on the Degree of Fiber Holding and Contamination of Pit Water

Background. Waste paper recycling is characterized by deterioration in the content of fiber mass on the fourdrinier wire of a paper-making (cardboard-making) machine, which leads to the fiber content increase in the pit water and to an increase in losses of the source fiber raw material with waste water. Objective. The aim of the paper is to evaluate the influence of amphoteric polymer resins (APR) on the fiber content effectiveness on the fourdrinier wire and the pit water contamination degree. Methods. According to standard techniques, the degree of fiber content and water turbidity, which arises in the paper and cardboard production during the formation on the paper-making machine fourdrinier wire, is determined. Results. The graphs of the dependence of the pit water turbidity on the APR consumption for different milling degree for MS-5B-2 and МС-8В-3 waste paper grades have been constructed. The high efficiency of the APR influence on the fiber content degree on the PPM wire is confirmed. The optimal values of technological parameters (milling degree and APR consumption) for the estimation of the APR impact on the pit water quality have been established. It is shown that the most effective APR among the investigated chemical auxiliaries is UltraRez 200, and the optimum consumption of all APR is 4 kg/ton of paper. The investigated APR are located by the effectiveness increasing of the APR influence on the degree of fiber content and the pit water turbidity reduction in the following series: Luresin KS – Eka WS 325 – Kymene 25X-Cel – UltraRez 200 – Fennostrengt PA21. Conclusions. The use of APR allows achieving a high degree of fiber retention on the wire up to 97 % and reduces 50–85 % of the pit water turbidity, reduces the loss of the source fibrous raw material, reduces the fresh water consumption and increases the efficiency of paper and paperboard production from waste paper.