TENSILE STRENGTH AFTER IMMERSION IN WATER
Purpose of the test
This test is performed to determine the tensile strength of a paper after inmmersion in water.
Procedure
Cut the test pieces according to ISO 1924-2. The test span must be 180±1 mm.
Soak in distilled water at 23°C, the recommended soaking time for both Level 1 and Level 2 is overnight (approx. 16 hours) to allow a complete water saturation of the sample.
After complete saturation, remove the strip, lay it flat on a pad of blotting paper, cover it with a sheet of blotting paper and press lightly to remove excess water.
Remove one specimen each time and immediately after blotting apply the tensile stress as specified in ISO 1924-2.
Clamping pressure just sufficient to prevent the specimen from slipping should be applied. Excessively high clamping pressure must be avoided.
Report the width of the test piece, 10 measures, their mean and standard deviation calculated to 3 significant figures, express the results in N/m.
ISO 3781
Nr. of samples
12 test pieces per level
Sample size 50 x 250 mm²
No special size
Levels
Level 1: 500÷700 N/m
Level 2: 1500÷2000 N/m
Reporting
Report 10 valid results of measurements in N/m, their mean and their standard deviation. All to three significant digits.