What is “Surface Roughness” in Composite Materials?

Quite often in the process of manufacturing & fabricating industrial laminates a specific surface roughness is indicated. Be it the purpose of reducing electrical arc tracking across the surface of the composite material, or to make sure the surface is rough enough to hold an adhesive; surface roughness can be a vital component of a machined composite part’s integrity.

A surface, as defined by Merriam-Webster is “n:the exterior or upper boundary of an object or body (1).” Essentially; for the composite world, this is the topography of the sheet or part and the area that typically comes into contact with another apparatus. The surface roughness of the material is a direct result of the manufacturing & fabrication process.