Pouch Cell Heat Seal Micro-Void Detection and Transport Leak Resistance
Pouch cell heat seals require precise thermal pressing and non-destructive inline acoustic or helium screening to prevent micro-void leaks during transit.
ASTM F88
Meaning
Tensile testing method measures the seal strength of flexible barrier materials. Within battery development, astm f88 evaluates the force required to separate a test strip of the pouch seal. This test ensures the thermo-compressed seams of the pouch cell can withstand internal pressure build-up without rupturing.
Specimen Preparation
Cutting precise strips across the sealed area is required before clamping the material in the tensile tester. These strips must have uniform width to ensure comparable force measurements. The test strip can be supported or left unsupported during the pulling action.
Force Measurement
Pulling the two tails of the seal in opposite directions yields a force profile. Sourcing specialists utilize the peak force value to qualify different aluminum laminate suppliers. This value must exceed a specific threshold to ensure the battery pack remains safe under harsh operational conditions.
Sealing Calibration
Low peel strength indicates that the heating temperature or the pressure of the sealing jaws was insufficient during cell packaging. The resulting data helps engineers adjust the dwell time in the manufacturing line. By optimizing these mechanical settings, the facility reduces scrap rates and protects the dry internal chemistry.
This optimization prevents premature failures under mechanical shock and high-temperature cycling.