Overview
ISO 15509:2019 - "Adhesives - Determination of the bond strength of engineering-plastic joints" specifies a laboratory test method for measuring the tensile and/or shear strength of adhesively bonded plastic/plastic joints using a purpose-designed, hollow cylindrical specimen. The standard produces design-relevant bond strength values and supports combined shear–tensile characterization for engineering plastics.
Key topics and requirements
- Test geometry: rotationally symmetrical hollow cylindrical specimen (injection-moulded adherends) designed to reduce bending and stress peaks typical of metal-derived test methods.
- Specimen preparation: injection moulding with cone-gate filling, ejector-pin moulds to avoid weld lines, removal of the sprue, and strict geometry controls. Typical example dimensions are given (outer/inner diameters resulting in a bonded area of about 138 mm²).
- Surface preparation: follow ISO 17212; corona discharge at ambient pressure is the preferred method for plastics.
- Assembly and bond gap: use a mounting jig with metal sleeves and spacers (spacers made from the same material as adherends); bond gap commonly adjusted to ~0.1 mm.
- Adhesive application and curing: controlled dispensing (automated rotating dispensers recommended) and curing per manufacturer instructions.
- Conditioning and atmosphere: condition and test in standard atmospheres per ISO 291.
- Test procedure: apply tensile loading at 1 mm/min and/or torsional loading at 5°/min until failure; record ultimate force and examine failure pattern per ISO 10365.
- Results and reporting: formulas provided to calculate bonded area, tensile strength and average shear strength; full test report requirements are specified (adhesive and adherend IDs, test conditions, failure patterns, etc.).
Practical applications and users
ISO 15509:2019 is used where accurate, design-useable bond strength data for plastics are required:
- Adhesive and plastics manufacturers - to qualify formulations and joint processes for engineering plastics.
- Design and structural engineers - to obtain shear/tensile inputs for load-bearing bonded plastic assemblies.
- Quality control and test laboratories - for batch testing, certification and comparability of adhesive performance.
- Industries - automotive, aerospace, electronics, medical devices and general industrial manufacturing where bonded plastic components must meet performance and safety requirements.
Related standards
- ISO 17212 - surface preparation guidelines for metals and plastics prior to bonding
- ISO 291 - standard atmospheres for conditioning and testing
- ISO 10365 - designation and recording of failure patterns
Keywords: ISO 15509:2019, adhesives, bond strength, engineering-plastic joints, shear strength, tensile strength, test method, specimen geometry, injection moulding, surface preparation.