GB/T 31905-2015Paper and board—Determination of edge permeance (English PDF)

3.1 Edge permeance

It characterizes the degree of liquid permeating through the cross-section of paper or board.

3.2 Edge permeance mass

Under specified conditions, the mass of liquid that permeates into the paper or board per unit cross-sectional area.

3.3 Edge permeance distance

The maximum distance a liquid can permeate into a cross-section of paper or board under specified conditions.

4.1 Edge permeance mass

The front and back of the sample are stuck with tapes; it is cut into a test piece of specified size; the test piece is put into the soaking solution for a certain period of time, then taken out, and the excess liquid on the surface is removed with absorbent paper.

The masses of the test piece before and after immersion are weighed, and the difference between the mass of the test piece before and after immersion is divided by the cross-sectional area of the test piece to obtain the edge permeance mass.

4.2 Edge permeance distance

The front, back and cross-section of the sample are stuck with tapes; it is cut into a test piece of specified size; the test piece is put into the soaking solution for a certain period of time, then taken out, and the excess liquid on the surface is removed with absorbent paper. The maximum distance that the liquid permeates into the sample is measured, that is, the edge permeance distance.

5.1 Tape

The tape shall be waterproof and non-absorbent, with a width greater than 30 mm. The tape used for edge permeance distance determination shall be transparent.

5.2 Metal roller

The metal roller has a width of (200.0±0.5) mm, a diameter of (86.5±0.5) mm, a mass of (10.0±0.5) kg, and a smooth surface.

5.3 Balance

The graduation value is 0.001 g.

5.4 Soaking solution

The tertiary water for analytical laboratories, which meets the requirements of GB/T 6682.

5.5 Containers

Stainless steel or glass containers for the soaking solution.

5.6 Grid

A metal grid with brackets or hooks used to hold down the test piece to maintain the depth of the test piece immersed in the soaking solution.

5.7 Constant temperature water bath device

It is used to maintain the temperature of the soaking solution; the temperature can be controlled at (95.0±2.0) °C.

5.8 Stopwatch

The reading accuracy is up to 1 s.

5.9 Absorbent paper

The quantitative value is 200 g/m²~250 g/m², and its longitudinal and transverse capillary rises measured according to GB/T461.1 shall be no less than 75 mm/10 min.

When the quantitative value of a single layer of absorbent paper is less than 200 g/m², multiple layers can be stacked to meet the above requirements. As long as the absorbency of absorbent paper can be guaranteed, it can be reused.

5.10 Steel ruler

The graduation value is 1 mm.

7.1 Determination of edge permeance mass

7.1.1 Cut a specimen of 100 mm×100 mm in size and mark the longitudinal and transverse directions of the specimen.

7.1.2 Determine the thickness T of the specimen according to GB/T 451.3.

7.1.3 Stick the tape (5.1) on the front and back of the specimen and press it flat with a metal roller (5.2). […]