TAPPI T 555 om-22 PDF

This method measures the roughness of paper and paperboard under conditions intended to simulate the nip pressures and backing substrates found in printing processes. It is applicable to coated and uncoated papers and paperboards which are intended to be printed by contacting printing processes. The measuring principle, that of determining the resistance to flow or air between the test surface and a metal band in contact with it, is similar to that employed in TAPPI Test Method T 538 om-96 “Roughness of Paper and Paperboard (Sheffield Method).” The major difference between this and other air leak methods is that the metal band dimensions, clamp pressures and composition of the measuring nip are all intended to simulate printing process conditions.