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TAPPI T 555 Parker Print-Surf

Standard:

TAPPI

Method:

TAPPI T 555

Title:

Roughness of paper and paperboard
(Print-surf method)

Scope

The TAPPI T 555 Parker Print-surf 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 “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.

Summary

The measuring head, which carries a circular metal measuring land surrounded by concentric guard lands is pressed against the specimen, which is supported by a resilient backing surface consisting of lithographic blanket or other material designed to simulate backing materials used in printing processes. Air under pressure is led into the gap between one of the guard lands and the measuring land and the rate of flow between the edge of the measuring land and the specimen is measured.

Significance

Surface roughness is a significant factor in determining the printability of papers and paperboards. By measuring roughness under conditions approximating letterpress, litho and gravure printing processes this method yields information relevant to the performance of the product during printing. The results of the test are expressed directly as an average value of roughness in micrometers, which in many cases correlates better with printability than other comparable methods. In some cases, it is possible to relate average roughness to ink film thickness, thus providing guidance on setting printing conditions.

Samples

IPS will test using a soft backing and 10 kgf/cmclamping pressure (offset) unless other test parameters are requested by the customer.

 

Please note:
IPS cannot sell or otherwise provide standards, specifications, or test procedures to third parties.