Papermaking process

US4980025A · kind A · utility

Assignee

• Eka Nobel AB · SE

Inventors

• Kjell Andersson · Bissenkamp, SE
• Pavol Barla · Gothenburg, SE
• Johnny Yrjans · Kungälv, SE

Key dates

• Filing date: Jul 17, 1989
• Grant date: Dec 25, 1990
• Expiry date: Jul 17, 2009

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D21H17/455
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

In a process for making paper from an aqueous paper pulp, especially a pulp containing bleached/unbleached mechanical pulps or unbleached chemical pulps, a combination of chemicals is added for improving drainage and retention. As drainage-and retention-improving aids are added a cationic polyacrylamide and a sol of colloidal inorganic particles having at least one surface layer of aluminium silicate or aluminum-modified silicic acid.