Overview
ISO 6837:1982 specifies a laboratory method to quantify the water dispersing power of dry‑cleaning surface active agents (detergents) in organic dry‑cleaning solvents. The standard measures two complementary properties: the water solubilizing power (amount of water solubilized in the solvent by the detergent) and the water emulsifying power (amount of water that can be emulsified into a W/O emulsion stable for the intended purpose). Results are reported for a defined detergent concentration (typically 3–5 g/L).
Key topics and technical requirements
- Test principle: Prepare premixes with varying water content but relatively constant detergent and solvent, then make final test solutions at the target detergent concentration. Assess optical density and phase separation visually to determine solubilized and emulsified water contents.
- Apparatus & reagents: conical flasks (100/500 ml), beakers (150/400 ml), pipettes, 50 ml burette, graduated cylinders, magnetic stirrer, sieving disc (≈630 µm), illuminating box with matt black interior and 100 W lamp, Sudan III dye (for visual contrast), and distilled water complying with ISO 2456.
- Controlled conditions: tests carried out at 23 ± 2 °C; stirring regimes and standing times are specified (e.g., 3 min stirring; phase‑separation observed after 15 min).
- Observation method: use an illuminating box and a sieve‑mesh visual test - when the mesh is no longer visible the mixture is considered emulsified/solubilized; incremental additions of water determine thresholds.
- Expression of results: water solubilizing and emulsifying powers are expressed as grams of water per litre of solvent for the specified detergent concentration. Precision limits: repeatability and reproducibility differences should not exceed 0.5 (solubilizing) and 1 (emulsifying) in the method’s units.
Practical applications and users
- Manufacturers and formulators of dry‑cleaning detergents, spotting and prebrushing agents - to compare performance and optimize formulations for water handling in solvents.
- Quality control and R&D laboratories in the textile and professional cleaning industry - to verify that products meet functional requirements for solubilizing or emulsifying water in organic cleaning media.
- Standards bodies and testing laboratories - for method harmonization and comparative evaluations across solvents and surfactant chemistries.
- Chemical suppliers to professional laundries and dry‑cleaners seeking objective metrics to specify product performance.
Related standards
ISO 6837 references and aligns with laboratory and surfactant test standards such as:
- ISO 2456 (water for tests)
- ISO 607 (surface active agents - sample division)
- ISO 565 (test sieves)
- ISO 4797, 3819, 4788, 3851/38511 (laboratory glassware and measuring equipment)
Keywords: ISO 6837:1982, surface active agents, water dispersing power, dry‑cleaning solvents, water solubilizing power, water emulsifying power, detergents, dry‑cleaning tests.
