Overview
ISO 5264-2:2011 - Pulps - Laboratory beating - Part 2: PFI mill method specifies a standardized laboratory procedure for beating pulp using a PFI mill. The document covers sampling, sample preparation, the PFI beating equipment and the step‑by‑step beating procedure used before preparing laboratory sheets or measuring drainability. It is applicable in principle to most chemical and semi‑chemical pulps, although the method can be unsatisfactory for pulps with extremely long fibres.
Key topics and technical requirements
- Scope and principle: Beating is performed by pressing a roll with bars against a smooth housing while both rotate at different peripheral speeds to modify fibre properties prior to sheetmaking and testing.
- Sampling & preparation: Test portion = (30.0 ± 0.5) g oven‑dry pulp. Wet or machine‑dried samples require soaking and/or disintegration to ensure fibres are separated.
- Disintegration: Use a laboratory disintegrator (ISO 5263‑1); typical propeller revolutions are 30 000 for high dry‑matter pulps (≥20 %) or 10 000 for lower concentration pulps.
- Stock concentration: Thickened to 10 % stock by mass (300 ± 5 g diluted to 2 000 ± 25 ml for beating).
- PFI mill specification: Detailed in Annex A - roll with 33 bars, housing dimensions, rotational frequencies (roll ≈ 24.3 s‑1, housing ≈ 11.8 s‑1) and beating force per unit bar length (nominally 3.33 ± 0.10 N/mm; alternate lower setting 1.77 ± 0.10 N/mm where required).
- Beating procedure: Even distribution of pulp in the housing, controlled application of load over 2 s, counting roll revolutions, rinsing and re‑disintegration (10 000 revolutions) prior to downstream testing.
- Quality control: Annex C recommends use of a reference pulp for control and checking PFI mill stability; Annex B covers mill maintenance.
- Reporting: Test report must include reference to ISO 5264‑2:2011, sample ID, temperatures, disintegration and roll revolutions, applied beating force, material of beating elements, drainability results and any deviations.
Applications
- Laboratory conditioning of pulp for physical testing (tensile, tear, drainability)
- Quality control and acceptance testing in pulp mills and paper mills
- Research & development on fiber modification, refining effects and sheet properties
- Calibration, validation and stability checks for PFI mills in test laboratories
Who uses this standard
- Pulp and paper laboratory technicians
- QA/QC managers in pulp and paper production
- R&D scientists studying fibre properties
- Instrument manufacturers and service engineers for PFI mills
- Standards bodies and testing laboratories
Related standards
Keywords: ISO 5264-2:2011, PFI mill, laboratory beating, pulps, pulp testing, disintegration, drainability, reference pulp, pulp quality control.
