An attempt is made to demonstrate the relationship between paper as a substrate and the different properties of coating colours by photographs of microtome sections. The results are based on the coating technology of industrial and pilot plant experiences.
The first part deals with multi-roll application, mainly size press operation with starches and coating colours and makes obvious the penetration zone of the different aqueous coatings. The effect of different factors of the coatings (viscosity, starch modification, solids, paper smoothness, sizing degree ofthe base paper and machine speed) on the coating weight and the starch penetration have been investigated and demonstrated.
The effect of coating colour application and the use of airknife and blade applications is shown in paper sectioning pictures and the results are discussed.
Finally, the migration problem of the different binders is investigated, especially using intense hot-air drying.
These demonstrations by micrographs of paper sections show the possibility of making visible some parts of the mechanism of paper and liquid interaction during paper coating.