Patent ID: 8377260

Claim:
A method of manufacturing a newsprint paper for offset printing in a papermaking plant, consisting of: selecting fillers having an average grain size of 0.5 to 5 μm and being a mixture of fillers having a negative zeta potential and a positive zeta potential, wherein the total of the fillers has a zeta potential of 0 mV or above, said zeta potential being measured in a state dispersed in water, said fillers including precipitated calcium carbonate as produced on-site in the papermaking plant and containing no dispersant; providing a pulp slurry for making a base paper; adding the fillers to the pulp slurry for increasing an ash content of a resultant newsprint paper to more than 15 percent by weight but less than 40 percent by weight; subjecting the resultant slurry to a papermaking machine to obtain the base paper; and making a newsprint paper for offset printing using the base paper.