Modifying xyloglucan and guar gum for improved paper making efficiency and paper quality

Polysaccharides have found an extensive use as additives in paper production. They have been shown to increase the strength, and surface properties of dry paper, improve retention of smaller particles and other chemicals. Their applicability arises from their ability to modify fibre surface properties and intensify the surface interactions at fibre-fibre contact areas. In this paper we will examine potential of xyloglucan and guar gum and modified xyloglucan as papermaking additive when the application takes place by spraying on wet web. Downtime minimisation is the key determinant of paper machine efficiency.The high width and speed of modern paper machines sets pressure on process stability and furnish quality. The probability of web breaks is known to be closely related to the wet web strength and web tension profiles. There are many additives, such as starch, known to improve the strength of the dry paper, but only a few additives that can improve the strength of wet web before drying. The spray application of non-charged plant based low cost polysaccharides, such as xyloglucan, offers interesting potential for influencing both the properties of wet and dry web without disturbing the white water recycling system. The results suggest that the strength of fibre-fibre connections in both wet and dry webs were improved by guar gum and xyloglucan, but they was substantially strengthened further by elemental cross-linking using borate . The wet web strength was also enhanced by introducing aldehyde groups to xyloglucan The galactose oxidase selectively catalyzed the oxidation of galactose units without degrading the polymer chain compared to conventional chemical oxidation. However, reducing the molecular weight of xyloglucan was found to decrease the positive wet and dry web strengthening effect of xyloglucan-borax. In addition to laboratory studies, pilot machine trials were also conducted to examine the influences of spray application of chemicals on runnability and the quality potential of fine paper. The results suggest that non-charged polysaccharides, when sprayed on a wet web, can improve both the efficiency of paper production and the material efficiency of fibre