Abstract:

The surfaces of physical bodies are the subject of fascinating research, which combines different scientific disciplines, such as physics, chemistry and material science. A physical body’s surface properties determine its wettability, among other things. The wetting of solid planes has been quite well understood in scientific terms for centuries. Nonetheless, the wetting properties of cylindrical bodies (e.g. fibres), which are the objects of research in the present work, may differ significantly from those of plane surfaces, because the wetting of cylindrical bodies exhibits some unique features due to their inherent curvature. Whilst the study of liquid film instability on fibres was first studied by Lord Rayleigh in the second half of the 19th century, and has been analysed further by numerous researchers over recent decades, there is still a lack of literature on the complete understanding of the factors that drive liquid instability, due to the immense complexity of break-down mechanisms. It is evident that a more detailed study of liquid film instability process is needed. No evaluation of the behaviour of liquid on fibre, which is inclined at different angles, has been found in the literature either. This research aims to add greater understanding to the processes that take place when a fibre is coated by a fluid. In particular, we investigate the instability of a glycerol film on a motionless polyamide 6 fibre after withdrawing it at varying inclination angles from a liquid (glycerol) reservoir. The results showed that liquid behaviour is to a certain degree influenced by the inclination angle of a fibre.