Development of New Retention Aid and Paper Quality Evaluation

Abstract

Recently the waste paper is noticed a reduction in quality, as strong demand for export of high quality waste paper, and slowdown in domestic paper spending. Furthermore, the basis weight of paper has been become lighter and ash content in paper has been become higher, in an effort to cut cost. Therefore, it is the issue that the lower retention rate, caused by variation of such papermaking surroundings, should be solved.

In order to develop new retention aid, which will solve the issue above mentioned, we focused on the distribution in existing polymer. In this section, we report the concept of new technology ‘Selection: control of polymer distribution’ and high-performance retention aid developed by this new technology.

In general, polymers have certain distribution in the molecular weight, the structure, and the electric charge. We established ‘Selection-technology’ which enable us to select active components for retention and to remove disadvantageous components for paper quality, from the distribution of polymers.

By this technology, we succeeded to develop the new retention aid that have high abilities of both macromolecule bridging and charge neutralization, which were the main mechanism of flocculation of fibers and fillers. Because the new retention aid is superior in the flocculation of fiber and ash, it showed not only high retention but also improvement of paper quality, for different properties on fiber length and amount of ash.

These results supported that the new retention aid exerted a beneficial impact on the best performance under the changing of papermaking surroundings.