EN ISO 2758:2014 (ISO 2758:2014) specifies a standardized laboratory method for measuring the bursting strength of paper by applying increasing hydraulic pressure to a test piece mounted over an elastic diaphragm. The method applies to papers with bursting strengths from 70 kPa to 1 400 kPa. This European-adopted international standard is intended for paper testing and quality control; it is not the recommended method for components of combined board (e.g., fluting medium or linerboard) where ISO 2759 is more suitable.
Key topics and technical requirements
- Test principle: A paper sample is clamped over a circular elastic diaphragm and bulged by hydraulic fluid until rupture; the maximum pressure equals the bursting strength.
- Applicable range: 70 kPa to 1 400 kPa (materials below 600 kPa should be tested per this standard where no other commercial agreement exists).
- Apparatus essentials:
- Clamping system with parallel annular faces; capable of repeatable clamping pressures up to 1 200 kPa (grooved face details in Annex A).
- Diaphragm: natural or synthetic rubber, 0.86 mm ± 0.06 mm thick; bulge-pressure requirement ~30 kPa ± 5 kPa for a specified bulge height.
- Hydraulic system: motor-driven piston using compatible fluid (glycerol, silicone oil, etc.); pumping rate 95 ml/min ± 5 ml/min.
- Pressure measurement: accuracy ±10 kPa or ±3%, whichever is greater; response must capture true peak within ±3%.
- Calibration & maintenance: Equipment must be calibrated before initial use and regularly thereafter; Annexes cover calibration of pressure sensors, clamps and clamping pressure.
- Sampling & conditioning: Sampling per ISO 186 if representing a lot; conditioning and atmosphere per ISO 187; grammage for burst index per ISO 536.
- Derived metric: Burst index = bursting strength (kPa) ÷ grammage (g/m2).
Applications and users
- Quality control laboratories in paper mills and converting/printing plants
- Packaging and corrugated-board manufacturers (for paper components within the specified range)
- Third‑party test laboratories, R&D teams developing paper products, and procurement/specification teams assessing material performance
- Useful for product specifications, supplier acceptance testing, and comparative product development
Related standards
- ISO 2759 - Bursting strength test for boards and board components
- ISO 186 - Sampling to determine average quality
- ISO 187 - Standard atmosphere for conditioning and testing
- ISO 536 - Determination of grammage
EN ISO 2758:2014 provides a repeatable, internationally recognized hydraulic burst test procedure critical for reliable assessment of paper strength and performance in end-use applications.