Paper and board - Determination of air permeability

Air permeability of paper and cardboard refers to the ability of paper and cardboard materials to gas permeability, that is, the amount of gas permeating the material per unit time. Air permeability testing evaluates the air permeability of paper and paperboard materials to ensure proper air permeability in specific application environments. For example, some packaging materials need to have good air permeability, so as to prevent the air pressure inside the package from being too high, causing the packaging material to break or deform. In addition, in some printing and coating applications, air permeability is also an important factor, which can affect the drying speed and quality of printing and coating liquids.

The air permeability of paper and cardboard refers to the ability of air to pass through paper or cardboard, and its measurement method is as follows:

• Standard Apparatus: Use a Gurley porosity meter or a Bendtsen porosity meter with standard specifications. The Gurley porosity meter is generally used to measure the porosity of cardboard, and the Bendtsen porosity meter is used to measure the porosity of paper.

• Sample preparation: Cut the sample into the specified size and shape according to the standard. The sample size is typically 100 square centimeters for the Bendtsen Densometer and 1 inch by 1 inch for the Gurley Densometer.

• Measurement operation: put the sample on the air permeability meter, and apply pressure to make air pass through the sample. By measuring the time or resistance value of air passing through the sample, the air permeability of the sample is calculated.

NBCHAO reminds you: the sample preparation and operation process should meet the standard requirements, and the influence of environmental factors such as temperature and humidity should be controlled during the measurement process to ensure the accuracy of the measurement results.