In the development of high-quality offset printing paper, the force/deformation performance during printing testing is pivotal for clean print. Missing raster points and blurry print are undesired. The compressibility test, in which the paper is loaded up to the nominal load, provides insight into the performance of paper during offset printing. Compressive force and deformation are measured during the test. A high-resolution path measurement is necessary as the deformation is on the scale of 10 microns.
The Zwick/Roell solution comes from hardness testing, where deformations on the same scale are measured: A compression platen with floating bearing and loaded by a ball swivel presses on the paper. The deformation between the paper and in front of the load cell is measured with a resolution of 20 nm.
The innovative path measurement system is integrated into the hardness measurement head. A quick-change penetrator, the automatic and fast reconfiguration to different specimen heights, and the automatic test sequence and the evaluation guarantee convenient testing within a short period of time. The tests are evaluated automatically using the testXpert® test software with the results, including the statistical data, also presented automatically in a clearly laid out log. The test log can be adapted to customer requirements. In addition, it is possible to transfer the data to external databases.
The Zwick hardness testing solution with hardness measurement head can be used in testing machines as well as in automatic testing systems. A productive application, e.g., “pass/fail tests” is also possible. The indentation/depth measurement system corresponds to accuracy class 0.2 in accordance with DIN EN 1002-4.