Research On The Effect Of Bacterial Cellulose On Pulp Wet End Chemistry And AKD Sizing Properties

With the rapid development of the paper industry in our country,the paper has been applied more and more widely in various life and production fields.Bacterial cellulose is a kind of natural renewable cellulose,which has high purity,crystallinity and excellent mechanical properties.And also it is a good additive in Papermaking.Bacterial cellulose is widely used in the paper industry,mainly in improving the performance of the paper,the preparation of functional paper,paper film preparation,electronic paper and aging paper repairing.In order to better guide the application of bacterial cellulose in paper making,the electrochemical properties of bacterial cellulose and its adsorption properties to CPAM was studied in this paper,as well as the effect of adding bacterial fiber on the pulp of electrochemical properties,water filtration performance and the physical properties of filler paper.Meanwhile,the effect of the addition of bacterial fiber on the properties of AKD sizing and the method of improving AKD sizing were studied.The results show that bacterial cellulose has the same chemical structure as plant fiber,and its crystallinity and purity are higher than that of softwood fiber.The bacterial fiber length is 0.25mm and the width is 19.5?m PFI after dispersion of PFI with 30000r.Its cationic demand and Zeta potential are about 11 times and 5 times than that of the softwood fiber respectively.The adsorption saturation time of bacterial cellulose to polymer CPAM was 30min,and the increase of temperature and pH was beneficial to the adsorption of CPAM by bacterial fiber.Trace inorganic salts NaCl is favorable to the adsorption of CPAM by bacterial fibers.It was found that the cationic charge demand and the absolute value of Zeta potential of the pulp increased with the addition of bacterial fiber so as to the filtration time.When the beating degree of the pulp is higher or the content of the fine fraction is higher,the addition of a small amount(2%)of bacterial fiber is beneficial to the filtration of the slurry.Bacterial cellulose is beneficial to PCC filler retention,when under the CS/CPAM dual retention system,3%bacterial fiber can improve the PCC filler retention rate to 95%.Adding 3%bacterial fiber into the pulp,the tearing index,tensile index,burst index of filled paper can increase 15%,19.6%,33.3%respectively,but the paper permeability decreased.A little bacterial cellulose(5%):is able to adsorb as much AKD latex as the whole pulp;therefore the addition of it will reduce the sizing degree of paper sizing with AKD.As retention and sizing enhancement aids,the use of CS,CPAM,PAE and chitosan can improve the sizing degree of the paper with bacterial fibers.The addition of a small amount(0.2%)of PAE and chitosan can improve the sizing degree by about 60%in the best adding position CS?PAE or chitosan?AKD?CPAM.The optimum aging temperature and time of PAE is 125?,90niin.'While to chitosan it.is 85?,30min.