When a bond fails, the first reflex is usually to change the adhesive. Yet most causes relate to process, surface or environment.
1. Look at the fracture surface
- Adhesive failure: The adhesive stays entirely on one surface; the other is clean. The issue is surface preparation or wetting.
- Cohesive failure: Adhesive on both surfaces, split within itself. Adhesive strength or curing may be insufficient.
- Substrate failure: Wood fibres or foil torn. The bond is stronger than the material; the ideal result.
2. Narrow down the causes
| Symptom | Check |
|---|---|
| Surface left clean | Surface energy, dirt/oil, primer |
| Adhesive stringy, not wetted | Open time exceeded, low temperature |
| Adhesive stays soft | Curing, mix ratio, moisture |
| Lifting only at edges | Coat weight, pressure distribution, stress |
| Opens over time | Heat resistance, water-resistance class |
3. Quick checklist
- Do application temperature and coat weight match the data sheet?
- Are substrate and ambient temperature/humidity recorded?
- Were batch number and expiry date checked?
- Did line speed or pressure change?
Send it to us
Send failed samples together with the adhesive batch number and process details, and our technical team will analyse them and suggest a solution.
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