| 摘要 |
A process in which fine paper is made by forming an aqueous cellulosic suspension comprising fibers, a precipitated calcium carbonate filler and a cationic starch strengthening agent, passing the suspension through one or more shear stages, draining the suspension to form a sheet and drying the sheet. The retention and drainage properties of the suspension are substantially improved via the addition of a cationic coagulant having a molecular weight in the range between about 2,000 to about 500,000 to the suspension prior to any of the shear stages, an anionic flocculant having a molecular weight of at least 500,000 to the suspension after the low molecular weight coagulant but before any of the shear stages, and an inorganic material selected from the group consisting of: bentonite, colloidal silica and other inorganic microparticle materials, to the suspension after at least one of the shear stages.
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