Overview
EN ISO 14678:2005 - Adhesives: Determination of resistance to flow (sagging) specifies seven standardised test methods to assess the flow characteristics of adhesives after application at room temperature and during cure by measuring sagging (downward movement under gravity). The standard is intended for both product specification and routine quality control and applies to a wide range of adhesive types and consistencies.
Key topics and technical requirements
- Scope: Measurement of adhesive resistance to flow (sagging) after application and during curing; selection of method depends on adhesive type and intended application.
- Seven test methods:
- Method 1 - Applicator to apply a defined wet film (resistance after application).
- Method 2 - Plug former (extruded adhesive plug; resistance to sagging).
- Method 3 - Scraper-applied film (resistance during cure; QC recommended).
- Method 4 - Test blocks (static flow at different inclinations).
- Method 5 - Flow from a lap joint (simulates post‑assembly flow).
- Method 6 - Flow through a hole (resistance to dripping).
- Method 7 - Flow of structural adhesive films (during cure cycle).
- Test conditions and preparation: Sampling per EN ISO 15605, surface prep per EN 13887 (where applicable), and adherence to conditioning atmospheres (common default: 23 ± 2 °C, 50 ± 5 % RH).
- Measurement and reporting: Sagging quantified in millimetres (usually mean of repeated tests). Test reports require identification of the adhesive, detailed test conditions (substrate, conditioning/test atmosphere, application procedure, temperature, mixing times), individual results, means, deviations from the method and any test incidents.
Applications and users
- Practical uses:
- Establishing adhesive specifications (how much sagging is acceptable for an intended assembly).
- Incoming and production quality control to detect consistency, batch variation or formulation changes.
- Comparative testing during adhesive development to optimise viscosity and cure profiles for vertical or inclined bonding surfaces.
- Typical users:
- Adhesive manufacturers and R&D laboratories
- Automotive, aerospace and construction bonding engineers
- Third‑party test laboratories and quality assurance teams
- Standards writers and certification bodies
Related standards
- EN 923 - Adhesives: Terms and definitions
- EN 1067 - Examination and preparation of samples for testing
- EN 13887 - Structural adhesives: Surface preparation guidelines
- EN ISO 15605 - Adhesives: Sampling
EN ISO 14678:2005 is a practical, method‑based standard widely used to ensure that adhesives meet required resistance to flow (sagging) performance in real-world bonding and curing scenarios.
