Paper Sizing

The use of Aluminium Sulphate to impart paper with resistance (“sizing”) to penetration by water or aqueous liquids is well established and has been used for many years. Rosin is the most commonly used sizing agent to to impart a moisture-resisting property to the paper. Aluminium Sulphate precipitates the rosin size on to the pulp fibres prior to paper formation, provides the acid conditions required for reaction and a positive charge which attracts the negatively charged fibre surface.

Low cationicity PAC in the form of PLUSpac500 is also used extensively in this application which provides a slightly higher positive charge than Aluminium Sulphate.