The effects of AKD sizing on the frictional properties of paper

Measurements of the coefficients of static and kinetic friction of bond paper sized with various levels of AKD size and of ketone, a product of hydrolysis of AKD, show that both these agents reduce the friction of the paper. As expected, the ketone has negligible sizing effect. Values of friction coefficients were higher for papers filled with 10% PCC. While the degree of sizing reaches a steady level with the application of moderate levels of AKD size, application at higher levels causes further reductions in friction. The effect on friction appears to be attributable principally to sizing chemical that is unbound, i.e. readily extracted from the paper. The results emphasise the important of achieving sizing with minimal application of AKD, and of avoiding hydrolysis.