Overview
ISO 5269-2:2004 - Pulps: Preparation of laboratory sheets for physical testing - Part 2: Rapid‑Köthen method specifies a standardized procedure to form, transfer, dry and condition circular laboratory sheets of pulp using a Rapid‑Köthen sheet former. The method produces sheets for subsequent physical tests that characterise pulp properties. It is applicable to most pulp types but is not suitable for very long‑fibred pulps (e.g., unshortened cotton, flax) or for preparing sheets for ISO brightness (diffuse blue reflectance, ISO 3688).
Key topics and technical requirements
- Scope and purpose: Preparation of laboratory sheets for physical testing to assess pulp properties; avoids use for ISO brightness determination.
- Primary equipment: Rapid‑Köthen apparatus comprising a stock container, sheet‑forming screen and supporting screen, suction chamber, transfer equipment (couch roll, carrier boards, paper cover sheets) and a dryer with heating chamber, rubber diaphragm and steam/evacuation system.
- Important parameters and limits (as specified in the standard):
- Stock dilution: 0.2% to 0.5% mass fraction (0.2%–0.3% for pulps that tend to floc).
- Suction limit in suction chamber: 27 kPa maximum.
- Heating water temperature for dryer: 93 °C ± 4 °C.
- Steam chamber evacuation: to 5 kPa absolute; cooling water ≤ 20 °C.
- Typical lab sheet oven‑dry grammage referenced: 65–85 g/m² for stock-concentration checks.
- Preparation and pretreatment: Disintegration of unbeaten pulps according to ISO 5263 (Parts 1–3) and laboratory beating per ISO 5264‑2 (PFI mill) when applicable.
- Transfer and drying: Specific couch roll mass/diameter, carrier board and cover sheet properties, and drying under controlled pressure to minimize shrinkage.
Applications and users
ISO 5269-2:2004 is used by:
- Pulp and paper laboratories for reproducible physical testing sample preparation.
- Quality control teams in pulp mills to assess fibre properties and production consistency.
- Research & development groups comparing pulps, refining methods, or validating processes.
- Manufacturers of laboratory sheet‑forming equipment (Rapid‑Köthen) to ensure compliance and interoperability.
- Accreditation and testing laboratories needing standardized, comparable sheet samples.
Practical benefits include faster sheet making than conventional formers, controlled drying to reduce shrinkage, and repeatable test specimens for tensile, porosity, and other physical tests.
Related standards
- ISO 5269‑1 - Conventional sheet‑former method (Part 1)
- ISO 5264‑2 - Laboratory beating - PFI mill method
- ISO 5263‑1/2/3 - Laboratory wet disintegration (chemical/mechanical pulps)
- ISO 4119 - Determination of stock concentration
- ISO 3688 - ISO brightness (diffuse blue reflectance) - method not applicable with Rapid‑Köthen sheets
- ISO 187 - Standard atmosphere for conditioning and testing
Keywords: ISO 5269-2:2004, Rapid‑Köthen method, laboratory sheets, pulp testing, sheet former, pulp quality control, ISO pulp standards.