Other

Upm-kymmene Corporation

Heikki Pakarinen

Hannu Juhani Leino

Auli Laurila-Lumme

Mika Kosonen

Timo Koskinen

Jouni Huuskonen

Timo Toivanen

The invention relates to coated printing paper which contains mechanical pulp and whose opacity is at least 89%, brightness at least 65% and surface roughness not more than 4.5 &#x3bc;m. The printing paper contains mechanical pulp at least 90 weight-% of the total fiber content of the paper.

Printing paper

A papermaking process wherein calcium carbonate is included in a pulp suspension. The dissolution of the calcium carbonate in the papermaking system is substantially retarded by the introduction of carbon dioxide to said pulp suspension. The invention also provides processes for the production of paper or board in papermaking systems wherein solid calcium carbonate is present as a filler and/or pigment.

Process for producing a paper web having calcium carbonate filler by introducing carbon dioxide to the pulp

The invention relates to papermaking processes wherein calcium carbonate is included in a pulp suspension. The dissolution of the calcium carbonate in the papermaking system is prevented or substantially retarded by the introduction of carbon dioxide to said pulp suspension in connection with subjecting said calcium carbonate in said papermaking system to pH conditions of about 8 or lower. The invention also provides processes for the production of paper or board in papermaking systems wherein solid calcium carbonate is present as a filler and/or pigment.

Process for substantially retarding dissolution of calcium carbonate in a papermaking system

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Valkeakoski, Finland

Heikki Pakarinen