Effects Of Coated Art Paper Broke Recycling On Retention Of Slurry And Physical Properties Of The Base Paper

During the production of art coated paper, a lot of broke will be produced, and the broke will be reused as the raw material for art coated paper. The broke contends a lot of pigments, coating binder, coating starch and other additives as well as fibers, so the paper making system will be affected by the recycling of broke. In presence work, the effects of broke ratio and cationic polymers charge on the stock retention and physical properties of base paper was studied by orthogonal test. As a main coating binder of art coated paper, butyl benzene latex was used as a model substance of anionic trash formed during the recycling of coated broke, and the effects of butyl benzene latex on the stock retention and physical properties of base paper was studied.A small amount of coated broke pulp addition caused the slight increase of the evenness and tearing strength of the base paper. But the evenness and strength properties of the base paper decreased as the coated broke pulp ratio exceeded 20%. Compared to the uncoated broke, the negative effects of coated broke on the tensile strength and tearing strength were more obvious, especially at high broke ratio.The effects of coated broke ratio, cationic starch and cationic polyacrylamide (CPAM) on the properties of the base paper of art coated paper were studied by orthogonal test, and the results showed that, during the recycling of coated broke, the primary factors affecting the evenness of the base paper were broke ratio and interaction between broke ratio and cationic starch dosage. The primary factors affecting the strength properties including tensile strength and tearing strength of base paper was both cationic starch dosage. During the recycling of broke, the satisfied physical properties of the base paper could be obtained by adjustment of cationic starch dosage and CPAM dosage in paper making process.The effects of broke recycling on the stock retention and drainage in a CPAM/bentonite retention system were investigated. The results showed that, the recycling of coated broke negatively affected the stock retention and drainage. With the increase of coated broke pulp, the zeta potential, the first pass retention, filler retention and drainage of the stock all decreased obviously. In the process of coated broke recycling, the primary factor affecting the stock retention was CPAM dosage. As the recycled coated broke increased, and the stock retention could be improved by increased CPAM and PAC dosage. The recycling of uncoated broke also negatively affected the retention and drainage of the stock, but its effects were much less than that of coated broke.Butyl benzene latex (BBL) was used as a model substance of anionic trash from the coated broke, and the effects of butyl benzene latex on the stock retention and physical properties of base paper were studied. The results showed that, the addition of BBL resulted in the decrease of the stock retention and physical strengths of the base paper. During coated paper recycling, the introducing of coating binder from the broke was an important reason caused the decreasing of stock retention and physical strengths of base paper. The BBL particles were adsorbed on the fibers in presence of cationic polymers, which would negatively affect the binding strength of the fibers and thus the physical strengths of base paper, as well as the efficiency of cationic polymers.