The invention relates to the technical field of pulping and
papermaking, in particular to a
rosin size preparation process which comprises the following steps: concentrating and screening paper pulp, feeding the pulp into a slushing pump, and injecting 1235T
rosin size at an outlet of the slushing pump according to a proportion of 18kg / t; after the
slurry enters the mixing
pool, aluminum
sulfate is added in three times, the addition amount of the aluminum
sulfate on the
surface layer / the bottom layer is equal to the ratio of the 1235T
rosin size dosage to 0.8, and the pH value of the
slurry is controlled to be stabilized at 5.0 + / -0.5; the fixed addition amount of aluminum
sulfate in a core layer is 45 + / -5kg / t, and the pH value of the
slurry is controlled to be stabilized at 6.1 + / -0.3; 15kg / t of dry strength agent, 5kg / t of talcum
powder and 5kg / t of silica
sol are simultaneously added into the core layer; the mixed slurry enters a buffer
pool, the dispersion particle size is detected, and when the particle size ranges from 25 micrometers to 35 micrometers, the slurry is conveyed to a net part; and carrying out
papermaking, and collecting production
wastewater and
solid waste. The three core problems of large dosage, poor
water resistance and high
environmental protection load in the traditional 1278 type rosin size process can be solved.