Overview
ISO 814:2017 - Rubber, vulcanized or thermoplastic - Determination of adhesion to metal - Two-plate method defines a standardized laboratory procedure to measure the adhesion strength of rubber-to-metal bonds when a rubber disc is sandwiched between two parallel metal plates. The method is intended for producing reliable adhesion data for rubber compound development and for manufacturing quality control of bonded rubber-to-metal assemblies.
Key topics and requirements
- Test principle: Measure the maximum force required to rupture a rubber-to-metal bonded unit by pulling the metal plates apart at 90° to the bond.
- Standard test piece:
- Rubber cylinder thickness: 3 mm ± 0.1 mm; diameter between 35 mm and 40 mm (measured to 0.1 mm).
- Metal plates: diameter ≈ 0.1 mm less than the rubber; plate thickness ≥ 9 mm; typically rolled carbon steel unless otherwise specified.
- Apparatus and settings:
- Tensile-testing machine meeting ISO 5893 requirements; force accuracy class 2.
- Rate of traverse (separation): 25 mm/min ± 5 mm/min.
- Inertialess (electronic/optical) dynamometers preferred to avoid inertial/friction errors.
- Fixtures that allow accurate centring of the test piece.
- Preparation and conditioning:
- Test pieces moulded and cured under the adhesive system being evaluated; surfaces must be kept free of contamination.
- Condition in accordance with ISO 23529 for at least 16 h at a standard laboratory temperature (23 °C ± 2 °C or 27 °C ± 2 °C) immediately before testing.
- Minimum of three test pieces per test series.
- Results and reporting:
- Adhesion value = maximum force / cross-sectional area; reported in pascals (Pa).
- Failure modes are recorded with standard symbols: R, RC, CP, PS, CS, D, S (definitions provided in ISO 814).
- Test report must reference ISO 814 and include cure and conditioning details, specimen dimensions, materials, test temperature, individual results and failure-type percentages.
- Calibration: Test apparatus must be calibrated per Annex A and guided by ISO 18899.
Applications and who uses it
ISO 814:2017 is used by:
- R&D laboratories developing rubber compounds and adhesive systems.
- Quality control and production engineers in manufacturers of rubber-to-metal bonded parts (e.g., mounts, seals, vibration isolators).
- Accredited testing laboratories performing adhesion testing and material comparison.
The method provides repeatable adhesion metrics useful for formulation optimization, process control, supplier verification and failure analysis.
Related standards
- ISO 5893 - Tensile, flexural and compression test equipment specification
- ISO 18899 - Guide to calibration of test equipment
- ISO 23529 - General procedures for preparing and conditioning test pieces
Keywords: ISO 814:2017, rubber-to-metal adhesion, two-plate method, adhesion testing, tensile-testing machine, rubber compounds, test piece conditioning.
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