ISO 12625-11:2019

Overview

ISO 12625-11:2019 - "Tissue paper and tissue products - Part 11: Determination of wet ball burst strength" specifies a laboratory test method to measure resistance to mechanical penetration of tissue paper and tissue products after wetting. Commonly called the wet ball burst strength or wet burst test, this method determines the maximum perpendicular force (wet bursting force) a wetted test piece can withstand before penetration by a hardened ball.

Key topics and technical requirements

• Scope and principle
  • Applies to tissue papers and tissue products (application to other paper types is possible but not covered).
  • A clamped test piece is wetted and loaded perpendicularly by a polished steel ball until penetration.
• Reagents
  • Use deionized water (conductivity ≤ 0.25 mS/m at 25 °C) maintained at conditioning/test temperature.
• Apparatus
  • Rigid, vibration‑free setup with concentric annular clamping rings (rubber-coated, inner diameter (50.0 ± 0.2) mm; clause 12 allows 50 mm or 89 mm clamping ring diameters).
  • Penetration ball: highly polished stainless steel, diameter (16 ± 0.2) mm, sphericity < 1 µm.
  • Force measuring system: load cell calibrated per ISO 7500‑1, range 0.1 N to 15 N, display of peak burst force.
  • Drive mechanism: static uniaxial testing machine; penetration speed (125 ± 5) mm/min.
  • Water application: pipette or automated volumetric dispenser capable of delivering 5.0 ml within ~3–4 s.
• Sampling and conditioning
  • Sampling per ISO 186; condition specimens per ISO 187.
  • Rapid ageing (optional) to develop wet strength: e.g., 80 °C for 30 min (production) or 105 °C for 15 min for rapid inspection, then recondition.
• Test pieces
  • Prepare at least 10 defect‑free specimens larger than the clamping area; converted products tested as received.
• Measured outputs
  • Wet bursting force (mN), wet burst index (wet force divided by grammage, mN·m²/g) and wet burst retention (percentage of dry/dry-to-wet).

Practical applications and users

• Manufacturers of toilet tissue, facial tissue, handkerchiefs and multi‑ply tissue products use ISO 12625-11:2019 for quality control, product development and specification compliance.
• Laboratories and test houses apply the method to compare wet strength formulations (including wet strength agents) and to monitor production consistency.
• R&D teams use wet burst data to optimize fiber mixes, creping and converting processes for desired wet performance.
• Procurement and specification writers reference wet burst results when defining acceptance criteria for tissue suppliers.

Related standards

• ISO 12625-1 (terms and guidance)
• ISO 12625-9 (dry ball burst strength)
• ISO 186 (sampling)
• ISO 187 (conditioning)
• ISO 7500-1 (force measurement calibration)
• ISO 14487 (water quality)

Keywords: ISO 12625-11:2019, wet ball burst strength, wet burst test, tissue paper testing, ball burst strength, wet burst index, tissue product quality.