Applications Of Papermaking Additives In The Production Of High Speed Boxboard Paper Machine

Applications of papermaking additives take on very important roles in the actual production process of papermaking enterprises with waste paper as raw material.In this paper,the use of papermaking additives in the actual production process of PM6 papermaking production line of Anhui Shanying Paper Co.,Ltd.was tracked.Through comparison and analysis,the appropriate papermaking additives were selected and the optimum adding amounts were explored.Mainly applied paper additives are: dryer stripping agent,retention aid,drainage aid,surface sizing agent.Due to the existence of more sticky materials in waste paper,the normal paper machine operation would be impacted.In order to improve the efficiency of paper machine,in the actual papermaking production process,the addition of dryer stripping agent is adopted to solve the sticky cylinder problem in paper machine dryer section.In the case of the same amount of boxboard paper production,the number of paper breakage and the stickies per unit area of the paper were calculated before and after the addition of the dryer stripping agent.When machine production the 90 g/m2 of T-2 boxboard paper,and paper machine speed 1350 m/min or so,the optimum dosage of the stripping agent 5.5 ml/s was confirmed,according to the numbers of cylinders sheet broken times in different dryer stripping agent addition amounts.Study showed that the effect of CPAM(cationic polyacrylamide)monolithic retention and drainage system was better than that of CAPC(polyacrylamide derivative)monolithic retention and drainage system.CPAM + CAPC binary retention and drainage system was much better than the CPAM single system.When use waste paper as raw material basis weight is 90 g/m2 of T-2 boxboard,paper machine speed is controlled 1350 m/min,the dosage of CPAM was around 0.35 kg/t,for the slurry filtration performance.Both of paper machine direction breaking length and tear index improved greatly.As for drainage application,using same dosage of CPAM 0.35 kg/t and adding CAPC as binary retention and drainage system,compared to monolithic retention and drainage system,drainage time decreased greatly due to the mutual synergy of both CPAM and CAPC.For binary retention and drainage system,when the dosage of CPAM was 0.35 kg/t,the optimum adding amount of CAPC range was between 0.25 ~ 0.30 kg/t.When further increase of dosage of CAPC,although drainage time continued to decrease,the decline rate showed slower.With the increase of dosage of CAPC,the machine direction paper breaking length and tear index increased level off.Several surface sizing agents from different manufacturers were applied in the process of practical operation of paper machine.When paper machine speed was about 1050 m/min,and basis weight was 130 g/m2 of T-2 boxboard.According to the effects of different surface sizing agents,compared the paper resistance abilities to water penetration and the relevant costs of the surface sizing agent(styrene acrylic type of surface sizing agent)was the best one in this papermaking process.