Overview
ISO 5633:1983 - "Paper and board - Determination of resistance to water penetration" is an international test method that specifies how to measure the time required for water to penetrate papers and boards rendered water‑resistant or waterproof. First published in 1983, the standard describes a hydrostatic, static‑head procedure that detects the first sign of water penetration under controlled conditioning and test conditions.
Key topics and requirements
- Scope: Applies to papers and boards made water‑resistant by internal sizing, surface sizing, coating, lamination with waterproof laminants, or other methods. Not suitable for corrugated fibreboard as a whole (components may be tested).
- Principle: Measure the time taken for water to penetrate from one face to the other under a static head of water.
- Reagent: Distilled water with 0.1% eosin dye to aid visual detection of penetration.
- Test pieces: Typical size 175 mm × 175 mm (other sizes allowed if compatible with apparatus); condition samples per ISO 187; sampling per ISO 186.
- Apparatus: Cylindrical metal cup and annular ring (internal diameter 112.8 ± 0.2 mm), rubber gaskets, clamping means to create a leakproof seal, manometer capable of up to 1 000 mm water head, timing device. Recommended hydrostatic head: 500 ± 5 mm water (other heads may be specified).
- Procedure: Clamp conditioned test piece between cup and ring, fill to remove trapped air, apply required head, and record the time when the first wet spot appears on the reverse face.
- Result expression: Report penetration time per defined rounding rules:
- < 2 h: to nearest minute
- 2–6 h: to nearest 15 minutes
- 6–24 h: as “between 6 and 24 h”
- 24 h–10 days: to nearest day
-
10 days: report as “greater than 10 days”
- Report contents: Include reference to ISO 5633:1983, number of test pieces, conditioning atmosphere, side tested, individual results, applied head, cup area if non‑standard, and any non‑standard procedures.
Applications and users
- Quality control and R&D for paper and board manufacturers evaluating water resistance of:
- Sized papers and boards
- Coated and laminated products
- Barrier‑treated substrates used in packaging and specialty papers
- Useful to: papermakers, coating formulators, laminators, converting and packaging engineers, testing laboratories, procurement/specification writers, and printers who require objective water‑penetration performance data.
Related standards
- ISO 186 - Paper and board: Sampling for testing
- ISO 187 - Paper and board: Conditioning of samples
ISO 5633:1983 provides a standardized, repeatable hydrostatic test for assessing resistance to water penetration - essential for specifying and verifying water‑resistant paper and board performance.
