1986 Volume 40 Issue 3 Pages 275-283
To characterize microtopography of paper surface, roughness testing was investigated by means of three different smoothness testers of air-leak, optical contact and stylus types.
Applying these testers, surface roughness of papers could be studied from different points of view. For instance, the surface of handsheets on the plate side had many pores at fiber crossings and it was macroscopically smoother. Handsheets from hardwood pulp showed finely rugged surfaces compared to those from softwood pulp. No large pore was found on the surface of an India paper due to filler loading and it was more finely even compared to the anti-plate side of handsheets. The surface of a coated paper was affected by roughness of the base stock and it still exhibited high smoothness.
It was understood that the air-leak type smoothness tester gave ruggedness of paper surface as a total volume and the optical contact type showed it as a distribution of depth in ruggedness. The three dimensional roughness was measured by scanning the stylus in x and y directions by the stylus type smoothness tester.
