Coating Immobilization Using Soy Protein Polymers : Technical Concepts And Importance Toquality

Coating immobilization is the process by which the wet coating applied to paper or paperboard reaches the final form. A coating immobilization point is defined as the solids content reached during drying where no further redistribution of coating materials occurs. Good control of coating immobilization is important in producing coated paper and paperboard with consistent high quality. This paper discusses the technical concepts of how coatings immobilize, and describes the improtance of good immobilization control on coating holdout and coating structure, The use of soy protein polymers to modify the coating immobilization point is discussed . Soy proteins, because of their interaction with coating pigments , make a significant contribution to the immobilization characteristics of coatings. This technology gives the formulator options for changing the immobilization point to improve the performance of the coating . The importance of immobilization on coating uniformity, microporosity and sheet qualities is discussed, including binder migration mottle, gluing and print quality.