Overview
ISO/TS 11371:2023 - "Pulps - Guidelines for using laboratory refiners to simulate industrial low consistency refining" provides harmonized guidance for using laboratory refiners to reproduce mill-scale, low-consistency refining conditions. The technical specification focuses on simulating industrial refining in (semi)continuous operation for pulps intended for paper production, particularly chemical market pulps, and limits refining to low stock concentrations (3%–5%). It updates terminology, refining parameters, and laboratory procedures to give more realistic evaluation of fibres than traditional batch beating (e.g., PFI mill).
Key Topics
- Terminology and machine parameters: Definitions of total load power, no‑load power, net refining power, rotational and tangential speeds (units in kW, 1/min, m/s).
- Refiner fillings and geometry: Rotor and stator, bars and grooves, bar widths, cutting edge length (CEL) and cutting length factor (CLF).
- Process parameters: Refining gap, stock concentration, flow and mass flow rates, refining time, and measures of refining energy.
- Refining intensity and energy metrics: Discussion of Specific Edge Load (SEL), Specific Surface Load (SSL), Modified Edge Load (MEL) and C‑Factor Theory as ways to describe intensity in addition to net specific refining energy (kWh/t or kJ/kg).
- Laboratory refining procedures: Guidance on (semi)continuous treatment vs batch beating, pulp preparation, determination of no‑load power (in water and in pulp suspension), measurements, maintenance and quality assurance.
- Basics of refining effects: How refining alters fibre properties (external/internal fibrillation, shortening, fines generation) and consequent sheet properties (drainage, strength, bulk, optics).
Applications / Who Should Use It
- Mill process engineers and R&D teams seeking to simulate industrial low‑consistency refining in a laboratory setting.
- Pulp and paper laboratories performing fibre evaluation, product R&D, or process optimization.
- Pulp suppliers and quality control laboratories comparing pulps under close‑to‑real refining conditions.
- Equipment manufacturers and test labs that need standardized definitions and procedures for laboratory refiners and energy/intensity reporting.
Practical uses include comparing pulp refining responses, estimating refining energy consumption, optimizing refining intensity for desired sheet properties, and harmonizing lab-to-mill correlations.
Related Standards
- ISO/TS 11371:2023 replaces and revises ISO/TR 11371:2013 and was prepared by ISO/TC 6 (Paper, board and pulps).
- The specification is intended to complement existing test methods for beating and refining; users should consider laboratory accreditation and national adoption documents when implementing procedures.
Keywords: ISO/TS 11371:2023, laboratory refiners, low consistency refining, pulps, refining intensity, specific refining energy, SEL, SSL, MEL, C‑Factor.