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Research on new chemical agents pursuing improvements in physical properties of paper and cardboard

The aim is to develop an innovative dry strength agent, which will allow for maintaining paper and cardboard properties despite an increased use of recycled material.

Paper and cardboard production is using as the main raw material primary fibre from trees and plants. The use of recycled or secondary fibre has increased significantly over the last years, due to economic and environmental reasons. Therefore, several changes have been introduced in production process in order to maintain the production capacity and efficiency of such processes, as well as the need to minimise the impact produced by secondary fibres on final products, in terms of strength, aspect, whiteness, or even the impact on the process' wastewaters (the lesser fibre size, the more difficult to be retained). Traditionally, the use of recycled fibres implied the use of dry strength agents, mainly starch, including its varieties (corn, potatoes, tapioca plant, etc.), normally derivatives and cationic characteristics. The addition of starch, usually in thick stock, permits the improvement of properties such as tensile strength, burst, traction, stretching and breaks. This improvement also presents several limitations: - It allows for achieving maximum values which can not be overcome despite increasing the addition of starch. - The excess of starch in the production process can result in a deficient retention in paper sheets or cardboards and, in consequence, its spill to the final effluent. Due to the molecular weight of starch, which is significantly low, its presence in wastewater very significantly increases the dissolved organic matter, non-removable by means of physico-chemical treatments. The use of recycled paper and cardboard allows for reducing the use of primary fibre during the production process and will result in cost cutting and significant lower environmental impact. Replacing virgin fibre by recycled fibre implies, however, a direct impact on the final product�s physical properties, which will be recuperated by adding dry strength agents. The new agents to be developed are mainly based on derived copolymers from polyvinyl alcohol, with the optional participation of a second component based on acrylate, as well as the use of different polysaccharides. The project will also analyse the impact of this kind of product on other parameters used in paper production, specially its impact on production efficiency. Keywords: dry strength agent, paper, chemical.
Acronym: 
CALLAWAY
Project ID: 
4 035
Start date: 
01-01-2007
Project Duration: 
24months
Project costs: 
950 000.00€
Technological Area: 
Man made fibres
Market Area: 
Wood / Pulp & paper

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.