Method for producing paper or board and a product produced by the method

Abstract

A web of paper or paperboard is manufactured by first forming a base web that is dried on the press section of papermaking machine. The base web is further dried on the dryer section of the papermaking machine and a base web speed differential, or draw, is set between the press section and the first dryer cylinder group of the dryer section, whereupon at least one surface of the web is surface sized. The draw is set to 3% maximum, and a surface size furnish is applied having a solids content of at least 15% of the total amount of size components and liquid in the furnish.

Description

CROSS REFERENCES TO RELATED APPLICATIONS [0001] This application is a U.S. national stage application of international application No. PCT / FI2003 / 000745, filed Oct. 8, 2003, the disclosure of which is incorporated by reference herein, and claims priority on FI 20021804 filed Oct. 9, 2002, and on FI 20022161, filed Dec. 5, 2002. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] The present invention relates to a method for manufacturing paper and paperboard products, the method comprising the steps of monitoring web formation during the manufacturing process and surface sizing the web at least on one side. The method also allows the control of curl in the manufactured product. The invention also relates to a product manufactured by virtue of the method. [0004] In paper manufacture, as factors of increasingly higher importance have arisen a precise adaptation of the properties of the p...

AI Technical Summary

Benefits of technology

"The present invention provides a method for making paper products with lower raw material and energy consumption compared to conventional methods. This is achieved by keeping the speed difference between the press section and the dryer section low (15%). The method also allows for better control of curl in the paper and paperboard products, which can be achieved by adjusting the amount of surface size application or the water content of the surface size furnish. The use of different size furnishes on the two sides of the paper can further improve curl control. Overall, the method provides a more efficient and flexible way to produce high-quality paper products."

Problems solved by technology

Due to these basic requirements, the price of copier paper becomes high, because a large amount of fiber is used to obtain a high basis weight and the application of a surface size loads the web with imported surplus water that must be evaporated using a lot of energy.

As a result, a high drying capacity is needed, even further accentuated by the fact that water is the more difficult to remove the deeper the penetration of water into the web.