BENDING RESISTANCE (7.5°; 15°; 50mm) Taber
Purpose of the test
This test is performed to determine the bending resistance of paper, solid board or folding board at 7,5° or 15° according to the Taber method.
Procedure
Operate the instrument in accordance with ISO 2493-2 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 38 mm wide and approximately 80 mm long with the longer side in the direction of the arrow.
Measure the bending resistance on 5 test pieces against the upper side and 5 test pieces against the bottom side, with a bending length of 50 mm and a bending angle of 15° for Level 1 and 2 and of 7,5° for Level 3.
After 5 measurements, the direction in which the first bend is made should be changed.
Record the scale reading (Taber bending moment in Taber units) and calculate the average of both directions for each test piece. Convert the results to bending moment in mNm.
Report 10 measures in mNm, their mean and standard deviation calculated to 3 significant figures.
ISO 2493-2
Nr. of samples
12 test pieces per level
Special size A4
Levels
Level 1: 2.5÷3.5 mNm
Level 2: 13.0÷14.5 mNm
Level 3: 65.0÷75.0 mNm
Reporting
Report 10 valid results of measurements in mNm, their mean and their standard deviation. All to three significant digits.