Effect of inorganic particles on slot die coating of poly(vinyl alcohol) solutions

Abstract

The slot die coating of poly (vinyl alcohol, PVA) solutions with particles such as TiO₂ and SiO₂ added was examined. The physical properties such as viscosities and surface tensions of PVA solutions with particles were measured and analyzed. The coating experiment was carried out in a lab coater and a flow visualization technique was applied to observe the flow behavior in the coating bead region. The effect of different particles, particle sizes, concentrations and surface characteristics were analyzed on the operating window of PVA solutions. The results show that adding a certain amount of particles to PVA solutions can effectively expand the operating window of PVA solutions. The attraction of function groups of PVA to the particle surfaces is considered as the major factor to expand the operating window.

Keywords

inorganic particles / slot die coating / PVA solutions

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