THE INFLUENCE OF THE CHEMICAL COMPOSITION OF SYNTHETIC REACTIVE SIZES ON THE SIZING EFFICIENCY OF PAPER

• Published in: Materials and Technology Vol. 39; no. 1-2; pp. 55 - 58
• Main Authors: Zule, Janja, Dolenc, Jozica
• Format: Journal Article
• Language: English
• Published: 01.01.2005
• ISSN: 1580-2949

Sizing is a process of producing paper of hydrophobic character which becomes suitable for printing purposes due to its enhanced liquid penetration resistance. Alkylketene dimers (AKD) are the most common sizing agents in neutral or slightly alkaline papermaking systems. They may be applied together with CaCO3 as filler. Consequently, the paper produced is typically more chemically stable and durable. Some practical results of AKD analyses of different label paper grades are also presented and discussed. It is well known that sizing efficiency depends on the properties of fibre, filler and sizing agent as well as on pH, system temperature, contact time and method of drying . The results of our extensive research show that the chemical properties of sizing agents, such as the percentage of active substance, the proportion of C16/C15 chains on the AKD structure or the content of impurities and addition of promoters, all significantly influence the sizing quality which is represented by the total amount of retained AKD in paper as well as by the proportion between adsorbed and chemically bound portions of the sizing agent.