Sizing principle of AKD emulsion
The biggest advantage of AKD sizing: calcium carbonate can be used as filler, improve the whiteness, opacity, folding resistance, surface strength, durability and printing performance of paper
Disadvantages: the brittleness of paper is reduced
The sizing mechanism of AKD: when the AKD emulsion is added to the slurry, the sizing particles are dispersed in the slurry, and a lot of sizing particles form larger flocs. These flocs are adsorbed on the surface of fibers and fillers, then these paper materials are kept in the wet end.
In the drying part, AKD particles melt and expand on the surface of the fiber, and the reactive functional groups on the molecule face the fiber, forming irreversible keto group with the fiber; the hydrophobic group part outward, making the paper water-resistant.