Wetting characteristics of photographic base solid polymeric substrates

Abstract

Wetting is the fundamental physical process in many industrial applications that include; film coating such as in pulp and paper, painting, printing, spraying, adhesion, enhanced oil recovery, composite processing and many more. The surface property of the coating on a given surface plays a vital role in terms of performance and service life. Significant effort has been made in the last three decades in improving the coatings on different materials. Achieving a uniform layer of coating on a given surface requires careful control and understanding of mechanisms that influence the spreading dynamics of the liquid. In this study the wetting characteristics of a number of substrates (used as photographic base material by companies like Agfa) has been studied and discussed. A total of three substrates are used in this study. A drop shape analysis method was utilised and drop spreading (in terms of contact angle and wetted drop base area) on the solid substrates were recorded using the FTA 188 video tensiometer. The test liquid was glycerine/water solutions of viscosities 49 mPa.s and 643 mPa.s and the surface tension was 65 mN/m. The results show that of the three substrates, one substrate shows low wettable characteristics and the other two show high wettable characteristics.