Protocol Specification
Standardized testing of flexible barrier materials relies on a specific methodology to determine the maximum force required to separate a test strip of material containing a seal. Formulated to evaluate flexible barrier packaging, astm f88 establishes the baseline for measuring seal strength of materials like films, foils, and paper. The standard dictates the speed of the separation, the width of the specimen, and the angle at which the test is performed.
Measurement Variable
Grasping the specimens in pneumatic grips ensures that the tension is applied uniformly during the separation. This phase of the evaluation focuses on the peak load sustained by the specimen before failure. Technicians record both the maximum force and the mode of seal failure, distinguishing between adhesive peeling, cohesive tearing, and material de-lamination.
Mechanical Limit
Operational limits of the test appear when the material itself stretches or deforms before the seal yields. Such plastic deformation can inflate the recorded force, yielding an inaccurate measure of the actual adhesive bond. Restricting the analysis to rigid or non-elastic materials when high precision is required prevents these distortions from corrupting the test results.
In many converting operations, the moisture levels of the test environment must be controlled to prevent the paper or thermoplastic backing from softening, which would alter the angle of pull and the resulting force calculations.
