Overview
ISO 8067:2018 specifies laboratory methods for the determination of tear strength of flexible cellular polymeric materials (foam). It defines two test procedures:
- Method A - trouser test piece (trouser tear)
- Method B - angle test piece without a nick (angle tear)
The standard covers test-piece preparation, conditioning, test-machine requirements, test execution, calculation of tear strength and reporting requirements.
Key topics and requirements
- Test methods: Two accepted geometries - trouser and angle - with specified cutting, dimensions and orientation relative to the predominant foam-rise direction.
- Apparatus: A tensile-testing machine that records maximum force (automatic recording preferred). Machine accuracy: class 2 or better per ISO 7500-1.
- Test speeds: General range 50–500 mm/min. Referee speeds specified: Method A (50 ± 5) mm/min, Method B (500 ± 50) mm/min.
- Test pieces & sampling: Test pieces may be taken with or without skin. Thickness limits and die shapes are given (angle test piece usually cut from 10–15 mm thickness). Three test pieces are required; add two more if results deviate by >20% from the median.
- Conditioning: Minimum times after manufacture and conditioning atmospheres are specified (e.g., 23 ± 2 °C / 50 ± 5 % RH or 27 ± 2 °C / 65 ± 5 % RH). Minimum conditioning periods and quality-control exceptions are defined.
- Measurement & expression: Thickness measured per ISO 1923. Tear strength R (N/cm) calculated as R = (F / d) × 10, where F is maximum force in N and d is original thickness in mm. Report the median of test values.
- Acceptance & procedure notes: Reject pieces that rupture before 20 mm torn; light guiding of the tear with a blade is allowed but cutting should be avoided.
- Reporting: Test report must reference ISO 8067:2018 and include material description, test-piece type, conditioning, jaw speed, orientation vs foam-rise, median tear strength, deviations, and test date.
Applications and users
ISO 8067:2018 is used by:
- Materials testing and certification laboratories
- Foam and flexible polymeric-material manufacturers (R&D, QA/QC)
- Product engineers and specifiers creating performance requirements for cushions, seals, gaskets, insulation and other foam components
- Procurement and compliance teams requiring standardized tear-strength data for acceptance criteria
The standard provides reproducible methods to compare materials, set acceptance limits, and support product development and quality control.
Related standards
- ISO 1923 - measurement of linear dimensions for cellular plastics and rubbers (thickness measurement)
- ISO 7500-1 - calibration and verification of static uniaxial testing machines (force-measuring accuracy)
- ISO/TR 9272 referenced for precision calculation methodology (see Annex A for a comparative precision study between the two test-piece types).
