Process for stabilizing the ph of a pulp suspension and for producing paper from the stabilized pulp
AssigneeAGA Aktiebolag
InventorsHANNU JUHANI LEINO, ANNA LINNEA HOLMBERG
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Abstract
The invention relates to a process for stabilizing the pH of a pulp suspension with buffering agents and to a process for producing paper from a stabilized pulp suspension. The alkalinity of the pulp suspension is increased by a combination of an alkali metal hydroxide feed and a carbon dioxide feed. Said feeds provide a significant buffering effect which stablilizes the pH of said pulp suspension for the paper making process.
Claims12
A process for stabilizing the pH of a pulp suspension in the stock preparation of a paper machine, characterized by increasing the alkalinity of said paper making pulp suspension by adding thereto a combination of an alkali metal hydroxide feed and a carbon dioxide feed which feeds substantially counter each other's pH changing effect, said feeds being provided in an amount sufficient to achieve a significant buffering effect of said pulp suspension while enabling utilization of an excess of said hydroxide or said carbon dioxide for adjusting the pH of said pulp suspension and maintaining the pH at a desired level throughout the paper making.
A process for producing paper comprising
- providing a paper making pulp suspension in the stock preparation of a paper machine;
- increasing the alkalinity of said pulp suspension by adding thereto a combination of an alkali metal hydroxide feed and a carbon dioxide feed which feeds substantially counter each others pH changing effect, said feeds being provided in an amount sufficient to achieve a substantial buffering effect of said pulp suspension while enabling utilization of an excess of said hydroxide or said carbon dioxide for adjusting the pH of said pulp supsension and for maintaining the pH at a desired level throughout the paper making;
- forming said pulp suspension into a web;
- and
- drying said web to form paper.
Process according to claim 14, characterized in that the pH of said pulp suspension is adjusted to a desired value between 7 and 9 by adding an excess of said alkali metal hydroxide or said carbon dioxide.
Dependencies are inferred from the claim text.