Kemira's surface sizing range offers optimum solutions for all paper sizing applications.
Polymer-based surface sizing agents based on styrene acrylate emulsions (SAE) have been well-established on the paper market for many years. Paper mills use these products to improve paper surface properties, mainly to add hydrophobic properties to their paper to increase water or ink holdout and improve printability.
Surface sizing agents can also have a positive impact on dusting, toner adhesion, smoothness, and air permeability; and can reduce ketone migration in AKD-sized paper grades as well.
Small particles size are an advantage
“Kemira now offers a complete and competitive range of excellent polymer-based surface sizing agents, developed in Leverkusen and Krems. Customers can be sure of finding just the right solution for their needs,” says Dr. Klaus Möller, Application Specialist, EMEA, Kemira’s Paper Segment.
“We offer products with a very high dry matter content, for example, for customers keen to reduce freight costs and storage needs. These have a dry matter content of up to 37%, which compares very favorably with the typical 25–30% content of competing products.
We can also offer a variety of products with lower active content when logistics is not a crucial factor.” Another key strength of Kemira’s surface sizing technology is the very small particle size intrinsic to these products. Smaller particles spread more evenly on the paper surface, which increases the hydrophobic properties of the surface significantly.
“Polygraphix sizing agents can be used very flexibly with other products in size presses and are very tolerant of calcium and magnesium ions released from fillers in size presses – which is a big plus.” In addition to offering an excellent shelf life, Polygraphix products are very flexible when it comes to the pH of the environment in which they need to work.
“Sizing takes places quickly and is easy to control. Our new generation of Polygraphix sizes also offers significant improvements in terms of foaming behavior and solids content compared with conventional surface sizes.”
Products and expertise
Good products are only part of the equation. Application know-how is also very important, and Möller says this is another of Kemira’s strengths. A comprehensive range of sizing products and many years of close collaboration with pulp and paper producers translate into clear added value for Kemira’s customers.
“Our experts know their science inside out and have a lot of experience with different sizing applications. And our Polygraphix products have been successfully introduced with every type of paper that makes use of surface sizing.”
Prior to a mill trial with a new surface sizing agent, it pays to evaluate all the factors involved carefully. To avoid unexpected interactions between starch fl oat ingredients
and a new surface size, Möller recommends doing some pre-testing prior to a trial. “Our application expert will carry out compatibility tests directly at the mill. Alternatively, various composed size press solutions can be studied in one of our application labs.”
Text: Jussi-Pekka Aukia
Read the full article in Kemira Solutions magazine 1/2009. The theme of the issue is tissue paper.