ASTM F392/F392M - Standard Practice for Conditioning Flexible Barrier Materials for Flex Durability:
Flexible barrier materials are widely used in industries such as packaging, healthcare, electronics, and more. The ASTM F392/F392M standard provides a comprehensive guide for conditioning and testing these materials in various flexing situations. This practice is designed to evaluate a material's resistance to pinhole failures that may occur due to flexing.
ASTM F392/F392M specifies how to determine the resistance of flexible packaging materials to flex-formed pinhole failures. Conditioning levels A, B, or C are typically used. The ASTM E171 reference practice and the F2097 guide are essential for a detailed understanding of this process.
Conditioning levels D and E are typically applied to determine the impact of flexing on barrier properties related to gas and/or moisture transmission rates. This helps in understanding the barrier properties of these materials under flexing conditions.
However, this standard does not measure or condition materials for flex failure related to abrasion. It specifically focuses on the aspect of flex durability.
Failures in the integrity of multi-ply structures are addressed in this standard. In such situations, alternative testing methods may be necessary. Supplementary permeation testing using gas or water vapor can be performed alongside the flex test to measure the loss of ply integrity. Other test methods may be used after flexing to evaluate the presence of pinholes. For a comprehensive list of these methods, the F2097 guide is referenced.
ASTM F392/F392M emphasizes the importance of the various conditions described. The objective is to avoid evaluating a material structure with either too many holes to effectively count (usually greater than 50) or too few to be significant (usually less than five per sample). The material structure, testing basis, and specified objectives should be considered in selecting the conditioning level for testing.