Large quantities of talc are also used in paper production. For this purpose, the products are often already provided by the manufacturer as water-based formulations. These are much easier to dose and the use of wetting and dispersing aids is lower.
Rheological problems in the production of the water-based formulations can thus be avoided, as can high air entrainment resulting from the poor wetting of the talc due to the hydrophobic character of its surface.
Talc is used as a functional additive with different objectives, both in the mass (in the fiber slurry) and in the coating color.
In the pulp, the main objective is to neutralize sticky impurities from waste paper, resinous pulps, or coated waste.
The impurities to be removed are adsorbed onto the surface of talc, coated by talc, and thus neutralized so that they can no longer stick to equipment parts in the mill, cake, and cause quality-impairing deposits. The quantities used here are a few kilograms per ton of paper.
In the coating colors, too, even small quantities of additives lead to improved printability and greater smoothness of the paper surface. In addition to improved smoothness and printability, a higher gloss can also be achieved through the platelet* form of the talc during calendering of the papers.
Due to its high whiteness, NOBELMIN talc can also be used as a partial substitute for high-priced white pigments such as titanium dioxide. In contrast to other chemical auxiliaries, talc is always a cost-neutral additive in paper production:
Each kilogram of talc remains in the paper as an additive, gives functionality and volume, and is resold as a kilogram of paper.
With chemical pitch control products, only a portion of the neutralized impurities is bound to the fibers. The portion remaining in the process water can, under certain circumstances, further cause problems, affect retention or sheet formation and thus the paper production process and product quality.
NOBELMIN talc products are currently not available as water-based formulations, but only in bagged or bulk form in big bags.* Platelets= all products are of high aspect ratio (high lamellarity)