This standard provides a practice for evaluating the heat sealing properties of flexible barrier materials under laboratory conditions. By measuring heat seal strength, this method helps determine the heat sealing properties of materials and analyzes the effect of material performance changes on the sealing effect. Although the heat seal layer needs to have sufficient sealing strength, the overall structure and thickness of the material can also affect its performance. This standard applies to laboratory heat seals for hot rod or pulse sealing methods, but does not include verification procedures for production equipment. Laboratory data can provide a reference for heat seal condition setting for commercial equipment. This practice does not involve evaluating sealing continuity through Miscellaneous techniques such as air leakage or dyestuff infiltration.