Cationic Starches for Surface Sizing: The Better Solution, 1998 Coating Conference Proceedings

In contrast to cationic wet-end starches, cationic starches used for surface applications contain a lower number of cationic moieties in the molecules. The number of these charges is adjusted to give enough affinity to the cellulose fibres and filler and guarantee a good self-retention of that starch.

Originally this starch-type was developed for the Scandinavian market where the problem of starch load in the effluents of fine paper manufacturers had to be solved.

The move from native to cationic starches for surface sizing in these modern factories, which had good control of the production parameters, allowed further advantages for the system as a whole to be observed. That is why these mills see the use of the more expensive cationic starch, not as a necessary evil but as a step that makes good sense from an overall economic point of view.

In the following paper these improvements will be explained step by step. We will discuss in the first part the cleaning or the reduction of the effluent load then we will briefly consider the improved runnability of the machine. We will then discuss the replacement of fibres by filler and the economies achieved by this. After that we briefly consider the possible savings of other wet-end additives. Finally, we will look into the question of ink-jet printability.