Overview
ISO 9398-2:2003 specifies definitions and standard test methods for batch drying tumblers used in industrial laundry. It defines how to measure machine capacity, energy consumption and productivity for tumblers with a net usable cage volume greater than 160 dm³ (litres). The standard is intended as a reference for procurement and performance comparison and does not cover safety requirements (see ISO 10472-4).
Key topics and requirements
- Scope and applicability
- Applies to batch drying tumblers (net cage volume > 160 dm³).
- Reference for drafting purchasing specifications.
- Reference standards
- Uses terminology and definitions from ISO 9398-1 and refers to safety standards in ISO 10472 series.
- Test loads and conditioning
- Test load = nominal capacity of the machine (given on rating plate).
- Test textile: decatized cotton towels, mass per unit area (420 ± 25) g/m², dimensions (90 ± 10) cm × (60 ± 10) cm.
- Conditioning moisture before drying: residual moisture (55 ± 1) % after rinsing/extraction.
- General test conditions
- Ambient: (24 ± 6) °C, relative humidity (50 ± 10) %.
- Rinse water temperature before extraction: (17 ± 3) °C (or (25 ± 5) °C for tropical countries).
- Energy supply as specified by manufacturer: steam, gas, electricity or heat-transfer fluid.
- Residual moisture and drying time determination
- Perform specified cycles and measure residual moisture after 0.85t and 1.15t (t = drying duration determined graphically for 8% residual moisture).
- Energy consumption
- Report energy required (kJ or kWh) to dry 1 kg of test load from ~55% to 8% residual moisture.
- Separate mechanical energy (motor(s) for drum and fan) and thermal energy; present total energy as their sum.
- Hourly productivity
- Defined as kilograms of the specified towels dried per hour (excluding loading/unloading time).
- Also expressed as mass of water evaporated per hour.
- Machine information required
- Identification and specs: cage diameter/length, net usable volume, speed, reversing, airflow at outlet, nominal steam pressure, machine mass, heating type and consumptions, and maximum electric power.
Applications and users
- Useful for: procurement managers, facility engineers, OEMs, test labs, and standards/quality teams in commercial and industrial laundry operations.
- Practical uses: supplier selection, performance benchmarking, energy-efficiency assessments, lifecycle cost comparison and contract specifications for industrial dryers and laundry plants.
Related standards
- ISO 9398 series (Part 1: flatwork ironing, Part 3: washing tunnels, Part 4: washer-extractors).
- ISO 10472 series for safety requirements (see Part 4 for air dryers).