SIST EN ISO 14446:2012 PDF

Overview

EN ISO 14446:2010 specifies a standardized laboratory method for determining the viscosity of industrial cellulose nitrate (nitrocellulose) solutions and for classifying those solutions. The procedure covers cellulose nitrate grades with nitrogen content typically between 10.7 % and 12.6 % by mass. Using a single solvent system and measurement method ensures consistent "standard" types and avoids classification discrepancies caused by different solvents or test procedures.

Key topics and requirements

• Test solvent and concentration: Solutions are prepared in an acetone/water mixture (95/5 by mass); concentration depends on the cellulose nitrate grade.
• Viscosity measurement: Dynamic viscosity is measured with a Höppler falling‑ball viscometer (ISO 12058‑1) using ball No. 4, at (20 ± 0.1) °C. Four repeat falls are required; fall times must agree within 0.5 s.
• Density measurement: Solution density is determined using a pyknometer, plummet or oscillator (ISO 2811 series).
• Calculation: Dynamic viscosity h is computed from the viscometer constant, densities and fall time per the method.
• Classification system (Annex A): Types are designated by the concentration (%) that gives a viscosity of (400 ± 25) mPa·s, plus a letter indicating solvent solubility/N content:
  • E - ester‑soluble (N ≈ 11.8–12.3 %)
  • M - medium‑soluble (N ≈ 11.3–11.8 %)
  • A - alcohol‑soluble (N ≈ 10.7–11.3 %)
  • Example: 24E = 24 % solution of an ester‑soluble grade giving ~400 mPa·s.
• Precision: Repeatability ~0.5 %; reproducibility ~2 %.
• Safety & sample handling: Nitrocellulose must remain moistened for safety; drying is done at (65 ± 2) °C to constant mass with precautions.

Applications and users

This standard is essential for:

• Nitrocellulose manufacturers - quality control and product specification.
• Paints & varnishes formulators - selecting binders with predictable viscosity behavior.
• Raw material suppliers and purchasers - unambiguous grading (e.g., 24E, 27A) for procurement and inventory.
• Testing laboratories and certification bodies - reproducible viscosity data for compliance and interchangeability.
• Practical uses include formulation of coatings, inks, lacquers and other applications where binder rheology and solvent compatibility are critical.

Related standards

• ISO 12058‑1 - falling‑ball viscometer method
• ISO 2811‑1/2/3 - density determination (pyknometer/plummet/oscillation)
• ISO 760 - Karl Fischer water determination
• ISO 15528 - sampling of paints and varnishes

Keywords: EN ISO 14446:2010, cellulose nitrate, nitrocellulose, viscosity measurement, Höppler falling‑ball viscometer, binder classification, acetone/water solvent, paint binders.