Overview
EN ISO 8067:2018 (ISO 8067:2018) specifies laboratory methods for determining the tear strength of flexible cellular polymeric materials (soft foam plastics and rubbers). Adopted by CEN as a European Standard in 2018, it replaces the 2008 edition and defines two test geometries and full test conditions to ensure repeatable, comparable tear-strength results.
Key Topics and Requirements
- Two prescribed methods
- Method A - Trouser test piece: rectangular test piece with a 45–55 mm cut and a marked 25 mm tear length; tear direction and foam-rise orientation are specified.
- Method B - Angle test piece (no nick): cut from sheet thickness 10–15 mm using a die as specified in the standard.
- Apparatus
- Use a tensile-testing machine capable of indicating rupture force; automatic recording preferred.
- Machine accuracy: class 2 or better per ISO 7500-1.
- Test speeds
- General: 50 mm/min to 500 mm/min.
- Referee tests: (50 ± 5) mm/min.
- Number of test pieces
- Minimum three specimens; additional specimens where result spread or tear progression requires.
- Conditioning
- Test not less than 72 h after manufacture unless 16 h or 48 h results match within ±10 %.
- Standard atmospheres: (23 ± 2) °C, (50 ± 5) % RH or (27 ± 2) °C, (65 ± 5) % RH. Shorter conditioning allowed for quality control (min. 12 h after manufacture; min. 6 h conditioning).
- Specimen preparation and orientation
- Test pieces may be with or without skin; orientation relative to the predominant foam‑rise direction must be recorded.
- Measurement
- Thickness measurement per ISO 1923; expression of tear strength as maximum force per unit thickness; test reporting requirements included.
Applications and Who Uses It
- Quality control in foam and flexible polymer manufacturing - verify tear performance batch-to-batch.
- R&D and product development - compare formulations, cell structure, or skin vs. core behavior.
- Third‑party testing laboratories and certification bodies - provide standardized, comparable data for specs and compliance.
- Material selection for footwear, automotive interiors, cushioning, seals and gaskets, acoustic/thermal insulation where tear resistance of foams is critical.
Related Standards
- ISO 1923 - determination of linear dimensions of cellular plastics and rubbers (thickness measurement).
- ISO 7500-1 - calibration and verification of force-measuring systems for tensile testing machines.
EN ISO 8067:2018 is essential for consistent evaluation of tear strength in flexible cellular materials and enables reliable comparisons across suppliers and applications.