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US 6,712,934 B2Granted
Method for production of paper
AssigneeKemira Chemicals, Inc.
InventorsJonni Ahlgren, Kimmo Strengell
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for the production of paper or board, wherein retention aids are added to the stream of stock. Improved retention and more effective dewatering are achieved by adding to the stream of stock a cationic polymer solution and a suspension-form microparticle mixture composed of a swellable clay of the smectite group and a colloidal synthetic metal silicate in which the prevalent cation is magnesium.
Claims11
A method for the production of paper or board comprising:
- (a) adding retention aids to a stream of stock entering a paper machine headbox,
- (b) directing the stream of stock to a wire,
- (c) dewatering the stock a paper web to form a paper web, and
- (d) drying the paper web,
- wherein the retention aids are (i) a solution of a water-soluble cationic polymer, and (ii) a suspension of a microparticle mixture containing a swellable smectite clay and a colloidal synthetic metal silicate, the prevailing cation of the colloidal synthetic metal silicate being magnesium, and wherein the microparticle mixture contains the swellable smectite clay in an amount of 85-99% by weight, and the colloidal synthetic metal silicate in an amount of 1-15% by weight.
2 more elements
Dependencies are inferred from the claim text.