The effect of rewetting on the adhesion tendency of styrene–butadiene latices on steel surfaces

Abstract

Styrene–butadiene latices are widely used as binders in pigmented coatings for the paper and board industry, primarily because of their good ability to bind pigments and fibres. White pitch deposition is a well-known problem at the drying section of paper machines using coated broke as a raw material. The main component of white pitch is latex, such as styrene–butadiene. The viscoelastic properties of styrene–butadiene latex affect white pitch formation.In this paper, we studied the sticking potential of different styrene–butadiene latices by using a cylindrical probe tack method under dry and wet conditions and varying the cross-linking density of the latex. In addition, the tackiness of the latices was measured as a function of decreasing moisture content to simulate the process in the drying section of a paper machine. The results show that the sticking potential can be derived from the storage modulus in dry conditions. The presence of water in the styrene–butadiene structure changes the sticking behaviour, and the results support the hypothesis of water acting as a plasticiser for latex.