If roughness is caused by overwetting, which adjustment helps?

• A. Improve Drying Conditions in the Process
• B. Increase Solids Content to Decrease Viscosity
• C. Reduce Spray Rate
• D. Increase Pan Speed

Answer: (A)

Roughness from overwetting happens when the coating has too much liquid and doesn’t dry quickly enough, so the surface doesn’t have time to level out before the next stage. Improving drying conditions speeds up evaporation, allowing the film to level and smooth out, which directly reduces the rough texture. In practice, you’d increase airflow, raise the drying temperature within safe limits, or otherwise enhance drying efficiency so the solvent leaves faster and a uniform, smooth surface forms. The other adjustments don’t directly address the moisture problem: adding more solids thickens the film and can hamper leveling, reducing spray rate lowers input but may not fix the drying rate, and increasing pan speed can cause other defects without solving the overwetting issue.