Overview
ISO 15166-1:1998 specifies standardized procedures for preparing bulk specimens of two‑part adhesives (epoxies, polyurethanes, acrylics, etc.) for mechanical testing. The standard describes mould design, mixing and dispensing, moulding, curing and test-report requirements so that bulk specimens have reproducible geometry and properties comparable to adhesive material in bonded joints.
This part does not apply to adhesives that cure by solvent evaporation or gas evolution, pseudo‑one‑part systems that need an applied initiator, or adhesives with a working life too short to mix, dispense and close a mould.
Key topics and technical requirements
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Mould construction
- Two metal plates (≥ 5 mm thick) with spacers, a U‑shaped frame or a continuous frame to define specimen thickness.
- Plate materials: thermally conductive metals (copper/brass suggested) or alternatives when chemically incompatible; plates may be water‑cooled for highly exothermic cures.
- Spacer/frame thickness must be uniform to within ±0.5%; typical specimen thickness 2–3 mm recommended.
- Minimum mould length when producing ISO 3167 multipurpose specimens: >150 mm.
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Mixing and degassing
- Mix components in correct ratio per manufacturer instructions using static or dynamic mixers.
- Minimize entrapped air (vacuum degassing or allow bubbles to rise for low‑viscosity components); when using static mixers, ensure sufficient mixing elements.
- Ensure mixed volume suits mould volume (mixing machine discharge constraints).
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Dispensing and moulding
- For non‑free‑flowing adhesives: dispense from cartridges/nozzles with continuous steady flow; keep nozzle submerged and withdraw along a path (nozzle angle ≈ 30° suggested).
- For free‑flowing adhesives: pour into continuous‑frame moulds; degassed mixes should be poured from a container with a lip.
- Close mould by pressing upper plate down, apply clamping for continuous frames, and incline mould 45°–90° during curing if required.
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Curing and monitoring
- Follow manufacturer cure schedules; for exothermic systems monitor temperature with a thermocouple to avoid property changes; consider lower cure temperatures or extended times if exotherm is excessive.
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Test report contents
- Reference ISO 15166‑1, adhesive identification (manufacturer, batch), casting date/time, moulding and curing parameters, post‑cure and storage conditions.
Applications and users
- Producing reproducible bulk specimens for mechanical tests (shear, uniaxial tension) used in:
- Adhesive R&D and formulation development
- Quality control and acceptance testing
- Materials data generation for bonded joint design and finite element analysis
- Independent testing laboratories and certification bodies
Typical users: materials scientists, QA/R&D engineers, test laboratories and adhesive manufacturers.
Related standards
- Normative references in ISO 15166‑1:
- ISO 472 (Plastics - Vocabulary)
- ISO 2818 (Preparation of test specimens by machining)
- ISO 3167 (Multipurpose test specimens)
- See also ISO 15166‑2 for elevated‑temperature‑curing one‑part systems.
