The impact dynamics and drying of paint films sprayed on steel were experimentally investigated. The rupture of sprayed liquid films was first photographed on different substrates. The critical film thickness, below which a film would break, was observed to increase with increasing advancing liquid-solid contact angle, and was unaffected by liquid viscosity for a given substrate. For viscous paint, it was observed that there is no rupture or splashing from a paint droplet impacting a solid substrate or another paint drop or film. For paint films drying at room temperature, mass fluxes were measured and correlated with a simple analytical model based on transient diffusion, and showed good agreement. The mass flux of sprayed paint films decreased slightly with time, and the volatile concentration decreased appreciably. For sprayed paint films cured with heat, there is a minimum stand-time in order to cure a film without any entrapped bubbles.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/30650 |
| Date | 08 December 2011 |
| Creators | Kadoura, Mahmoud |
| Contributors | Chandra, Sanjeev |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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