Describes an accelerated speed method for determining the surface strength in terms of the pick velocity and pick resistance of coated and uncoated paper and board, and in terms of the delamination resistance of the liner on paperboard, by simulating the behaviour in the printing process.

This International Standard specifies an accelerated speed method for determining the surface strength in terms of the pick velocity and pick resistance of coated and uncoated paper and board, and in terms of the delamination resistance of the liner on paperboard, by simulating the behaviour in the printing process. Because of the limited area tested and the general character of the test, it will not usually detect local imperfections such as surface debris.

This test is especially important for papers and boards which are to be printed in lithographic offset or letterpress, because the inks used in these techniques traditionally have a high viscosity and high tack values. Due to the increasing tendency for the tack and viscosity of modern flexographic inks to be high, this method is also useful in that field.

In the interpretation of the test results, attention must be given to the fact that the results can be seriously influenced by differences in testing conditions, differences in instruments and differences in the calibration state of the test equipment.

The pick velocity, etc., determined here should not be interpreted as being the running speed of a printing press in practice.

NOTE1 Although IGT-type testers of the pendulum type are outside the scope of this International Standard, the described method can also be used for these instruments. The results will be slightly different, due to the difference in velocity profile.

NOTE2 The use of the Westvaco type device and the use of tack-graded inks are not covered by this International Standard.