BENDING STIFFNESS – Resonance Method
Purpose of the test
This test is performed to determine the bending stiffness of paper.
Procedure
Operate the instrument in accordance with ISO 5629 and the manufacturer’s instructions.
Leave the samples exposed for 24 h to 23°C and 50% R.H., according to ISO 187.
Cut 10 test pieces 15,0±0,1 mm wide from the middle of each sheet, edge strips are not to be used.
Report 10 measures in mNm, their mean and standard deviation calculated to 3 significant figures.
ISO 5629
Nr. of samples
12 test pieces per level
Special size A4
Levels
Level 1: 0.30÷0.75 mNm
Level 2: 6.00÷8.50 mNm
Level 3: 22.0÷30.0 mNm
Level 4: 50÷100 mNm
Reporting
Report 10 valid results of measurements in mNm, their mean and their standard deviation. All to three significant digits.