Wetting behaviour of alkyl ketene dimer on cellulose and model surfaces

The dynamic wetting of a commercial alkyl ketene dimer (AKD) wax was measured on model cellulosic surfaces. The variables investigated were temperature and the surface composition. The model surfaces consisted of cellulose, cellulose acetate films as well as glass. These surfaces are smooth by industrial standards but not on a molecular level. The objective of the study was to understand the wetting of AKD in sufficient detail in order to predict the extent of AKD wetting during the time frame of papermaking. Our studies show that it is very unlikely that spreading, i.e. a complete wetting (θ_E = 0) of pulp fibres by AKD, occurs during papermaking.