What are theair permeability standards for battery separators?

1. ISO 5636-5:2013 Paper and board — Determination of air permeance (medium range) — Part 5: Gurley method

ISO 5636-5:2013 specifies the Gurley method for determining the air permeance of paper and board using an air resistance tester, the Gurley apparatus.

It is applicable to papers and boards which have air permeances between 0,1 µm/(Pa⋅s) and 100 µm/(Pa⋅s) when tested with the Gurley apparatus.

It is unsuitable for rough-surfaced materials, which cannot be securely clamped to avoid leakage.

ISO 5636-5:2013 may also be used to determine the air resistance of paper and board.

2.TAPPI T 460-Air resistance of paper (Gurley method)

TAPPI T 460 is used to measure the air resistance of approximately 6.45 sq. cm. (l sq. in.) circular area of paper using a pressure differential of 1.22 kPa. The recommended range of the liquid column instrument is from 5 to 1800 seconds per 100 mL cylinder displacement. For more impermeable papers the time requirements become so excessive that other techniques are preferable.

This method measures the volume of air that passes through the test specimen, along with any possible leakage of air across the surface; therefore it is unsuitable for paper or paperboards which cannot be securely clamped so as to avoid significant surface and/or edge leakage.

This method measures the amount of time required for a certain volume of air to pass through a test specimen. The air pressure is generated by a gravity-loaded cylinder that captures an air volume within a chamber using a liquid seal. This pressurized volume of air is directed to the clamping gasket ring, which holds the test specimen. Air that passes through the paper specimen escapes to atmosphere through holes in the downstream clamping plate.

What are the air permeability standards of paper or board materials

Air permeability is an important property for some paper grades, such as paper bags that are filled industrially.  air permeance testing with the Bendtsen and Gurley methods.

The Bendtsen method (ISO 5636-3) is suitable for papers with permeance from 0.35 µm/(Pa*s) to 15 µm/(Pa*s). It is not suited for rough-surfaced papers that cannot be securely clamped to the device. The results are reported in ml/min, expressing the average volume of air that passes through the material in a minute at elevated pressure.

The Gurley Method (ISO 5636-5) is suitable for papers with permeance between 0.1 µm/(Pa*s) and 100 µm/(Pa*s). The test may also be used to determine the air resistance of paper and board. In the Gurley test, the time it takes for a certain volume of air to pass through the paper at a certain pressure is measured in seconds.

TAPPI T460：TAPPI T 460-Air resistance of paper (Gurley method）

JIS P8117：JIS P 8117, 9th Edition, October 22, 2018 - Paper and board - Determination of air permeance and air resistance (medium range) - Gurley method

ISO 5636-5: Paper and board - Methods for determination of gas permeability - Part 5: French method of determination (porous materials).

What are the air permeability standards of foam materials

ISO 4638:1984 ：Polymeric materials, cellular flexible — Determination of air flow permeability

Applicable to test pieces cut from products of cellular materials. Useful for two purposes: a) studying the structure of cellular products in connection with their physical properties and their method of manufacture and b) ensuring product quality (quality assurance). Describes principle, apparatus, test piece and conditions, procedure and calculation and expression of the results. Three figures deliver the details for testing.