Overview
EN ISO 10066:1997 (ISO 10066:1991) specifies a laboratory procedure for determining creep in compression of flexible cellular polymeric materials. Its primary purpose is quality assurance in packaging applications, and it describes the test principle, required apparatus, specimen preparation, conditioning, test procedure and reporting. The standard is intended for materials such as flexible foams used for cushions and packaging where compressive creep and recovery affect performance.
Key topics and technical requirements
- Scope and purpose
- Test measures time-dependent change in compression (creep) under a static compressive stress and the residual compression after a recovery period.
- Specimen geometry
- Test pieces are right parallelepipeds: 50 mm × 50 mm in plan, with mean thickness 20–30 mm (±1 mm tolerance). Plying of sheets (2–3 plies) is permitted where required, provided orientation and minimum cell diameters are respected.
- Apparatus
- Two flat, smooth (not polished) plates, at least one self-aligning, mounted to apply uniform vertical compression. Plate separation must be measurable to 0.1 mm and applied static stress must remain constant within ±1% during the test.
- Conditioning and test environment
- Standard conditions: 23 °C ± 2 °C and 50% ± 5% RH (temperate) or 27 °C ± 2 °C and 65% ± 5% RH (tropical). Specimens conditioned at least 16 h at test conditions before testing.
- Test procedure and timing
- Apply the agreed static compression stress (commonly 0.5–10 kPa) smoothly without impact. Measure thickness under load after 15 minutes and again after 72 hours. Remove load and allow 30 minutes recovery, then measure thickness after recovery.
- The standard gives a typical acceptance stress to produce a creep strain near (2.5 ± 0.125) %, but the stress used is agreed between purchaser and supplier.
- Results and reporting
- Calculate percentage creep from the change in thickness between 15 minutes and 72 hours, and percentage compression after recovery from original thickness and thickness after the 30-minute recovery. Two specimens per sample are tested and averaged.
- Test report must include material description, conditioning, stress applied (kPa), creep values, recovery values, ply information and skin presence.
Applications and users
- Useful for packaging manufacturers, material suppliers, QA laboratories and product designers specifying cushioning performance over time.
- Helps select foams for long-term support, prevent slippage or excessive deformation during storage, and set supplier acceptance criteria.
Related standards
- Normative reference: ISO 1923 (measurement of linear dimensions for cellular plastics and rubbers).
- CEN adoption: EN ISO 10066:1997.
