Light scattering from glossy coatings on paper.

Area of Science:

• Materials Science
• Optics
• Surface Science

Background:

• Surface roughness is a critical property of paper coatings, influencing printability and aesthetics.
• Traditional methods like stylus profilometry can be slow or limited in resolution for certain applications.

Purpose of the Study:

• To investigate the efficacy of angle-resolved light scattering (ARLS) for measuring the surface roughness of glossy paper coatings.
• To compare ARLS measurements with established techniques like stylus profilometry and optical surface probes.

Main Methods:

• ARLS patterns were generated using laser light scattered from glossy paper samples.
• Experimental ARLS patterns were compared to theoretical models based on plane-wave scattering.
• Mechanical stylus profilometry provided input data (rms roughness, autocorrelation functions) for theoretical calculations.
• A commercial optical surface probe was used for cross-validation.

Main Results:

• Good agreement was observed between experimental and calculated ARLS patterns when profilometry roughness values were reduced by 30%.
• ARLS measurements correlated well with stylus profilometry and optical surface probe data across various samples and incidence angles.
• The results suggest ARLS is a viable method for determining coating roughness parameters.

Conclusions:

• Angle-resolved light scattering (ARLS) offers a promising non-contact method for assessing the surface roughness of glossy paper coatings.
• The study validates ARLS by demonstrating its consistency with mechanical and optical metrology techniques.
• ARLS has the potential to become a valuable tool in the quality control and characterization of paper products.