Overview
ISO 4044:2017 - Leather - Chemical tests - Preparation of chemical test samples specifies standardized procedures for preparing leather samples for chemical analysis. It defines two accepted sample-preparation routes: grinding leather into a homogenized “ground leather” or cutting leather into small pieces. The standard ensures representative, reproducible test material for laboratory chemical tests and sets practical requirements for apparatus, sample handling and storage.
Key topics and requirements
- Two preparation methods
- Grinding: Use a grinding/cutting mill (blade speed recommended 300–1 000 rpm) with a perforated sieving plate of (4.0 ± 0.5) mm holes. Prefer slower rotation to avoid heating.
- Cutting: For small or consumer-item samples, cut into pieces with 2–3 mm edge length using a sharp blade.
- Sample size guideline
- Grinding is intended when a sufficiently large piece (typically ≥ 200 mm × 200 mm) is available; cutting is for smaller pieces.
- Pre-treatment
- Wet test pieces (> ~30 % moisture) should be pre-dried at temperatures not exceeding 40 °C. Consider analyte sensitivity when selecting drying temperature.
- If dried at elevated temperature, recondition samples per ISO 2419.
- Apparatus and contamination control
- Grinding mills should minimize heating, be easy to clean (no water for cleaning), and use chromium‑free steel parts and hardened tungsten‑carbide blades to avoid contamination (e.g., chromium).
- Mixing and storage
- After preparation, mix thoroughly and store in a clean, dry, airtight container away from localized heat.
- Reporting
- The chosen sample-preparation method must be recorded in the test report. If a test method specifies a preparation route, that route is mandatory.
Applications and users
ISO 4044 is used by:
