ISO/TS 11371:2023

TECHNICAL ISO/TS
SPECIFICATION 11371
First edition
2023-07
Pulps — Guidelines for using
laboratory refiners to simulate
industrial low consistency refining
Pâtes — Lignes directrices relatives à l'utilisation de raffineurs de
laboratoire pour simuler le raffinage basse consistance industriel
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Machine parameters . 1
3.2 Refiner fillings parameters . 2
3.3 Process parameters . 4
4 Basics of pulp refining . 5
5 Refining intensity . 6
5.1 General . 6
5.2 Specific Edge Load (SEL) . 6
5.3 Specific Surface Load (SSL) . 7
5.4 Modified Edge Load (MEL) . 8
5.5 C-Factor Theory . . 8
6 Pulp types and properties .9
7 Laboratory refining procedures .10
7.1 Refining parameters . . 10
7.2 Pulp preparation . 11
7.3 Refining system . 11
7.3.1 General . 11
7.3.2 Determination 1 of no-load power using water.12
7.3.3 Determination 2 of no-load power using the pulp suspension .12
7.4 Measurements . .13
7.5 Maintenance . 13
7.6 Quality assurance . 13
Bibliography .15
iii
Foreword
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 6, Paper, board and pulps.
This first edition of ISO/TS 11371 cancels and replaces ISO/TR 11371:2013, which has been technically
revised.
The main changes are as follows:
— the focus lies exclusively on simulating industrial refining with laboratory refining;
— the basics of refining are further elaborated;
— Clause 3 has been updated;
— the refining procedures have been reviewed and detailed;
— the clause on pulp preparation and the two annexes have been removed.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
It is well known that the current standardized method (PFI mill method) for beating has only limited
value in the evaluation of pulps. It was originally developed for quality control purposes and has no
counterpart in real mill operations since the fibre property development is based on a different
principle.
The biggest shortcomings are the following:
— The refining principle is different from mill-scale refining processes (controlled by energy
consumption, refining intensity);
— No possibility to adjust refining parameters for specific pulps;
— No direct measure for specific energy consumption;
— Not consistent and correct usage of terms.
This well-known standardized method has good reproducibility and repeatability and the equipment
is easy to handle. Nevertheless, many laboratories have replaced this method by the use of refiners
enabling them to simulate industrial refining and to allow the evaluation of pulps for various mill-scale
refining applications.
The objective of this document is to address the related topics by providing a common basis with regard
to refining parameters, definitions, and procedures.
v
TECHNICAL SPECIFICATION ISO/TS 11371:2023(E)
Pulps — Guidelines for using laboratory refiners to
simulate industrial low consistency refining
1 Scope
This document provides guidelines for the laboratory refining of various pulps intended for paper
production including:
— Harmonization of terms and parameters for the simulation of industrial refining processes by
laboratory refiners;
— Treatment of pulp samples in a (semi) continuous operation in contrast to the batch operation of
laboratory beating equipment such as the PFI mill;
— Evaluation of fibres for papermaking, in particular chemical market pulps, under close-to-reality
conditions in terms of refining intensity and refining energy consumption.
This document only considers refiners operating at low stock concentration, i.e. 3 % to 5 %.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Machine parameters
3.1.1
total load power
P
tot
power provided to the refiner during refining of a fibre suspension to modify fibre properties and
overcome friction and the pumping effect
Note 1 to entry: It is expressed in kW.
3.1.2
no-load power
P
power required to overcome friction and the pumping effect measured in water or fibre suspension (at
refining stock concentration) in defined conditions for flow and open gap
Note 1 to entry: It is expressed in kW.
3.1.3
net refining power
P
net
difference between total load power and no-load power
Note 1 to entry: It is expressed in kW.
3.1.4
refiner rotational speed
n
revolutions of the refiner rotor per minute or per second
Note 1 to entry: It is expressed in 1/min or 1/s.
3.1.5
tangential speed
v
speed of the rotor at the outer diameter of the refining zones of the refining elements at a defined
refiner rotational speed
Note 1 to entry: It is expressed in m/s.
3.1.6
average tangential speed
ῡ
tangential speed of a point at half-length of the refining zones of the refining elements at a defined
refiner rotational speed
Note 1 to entry: It is expressed in m/s.
3.2 Refiner fillings parameters
3.2.1
filling
exchangeable plates used for fibre treatment (refining), including a stationary element (stator) and a
rotating element (rotor) in the form of a disk, cone or cylinder with bars and grooves
3.2.2
rotor
motor-driven (rotating) refiner filling
3.2.3
stator
stationary refiner filling
3.2.4
bar
one of a number of structures of rectangular cross-section on the active surface of the rotor and stator
filling
Note 1 to entry: It may be cast, fabricated or machined into the surface of an element. The bars cause the refining
of fibres (see Figure 1) and transport of the fibre suspension.
3.2.5
bar width
b
r,s
width of a single bar at the bar surface (rotor or stator)
Note 1 to entry: It is expressed in mm.
3.2.6
number of stator bars
z
s
total number of stator bars on the refiner filling
3.2.7
number of rotor bars
z
r
total number of rotor bars on the refiner filling
3.2.8
average rotor bar angle
α
r
angle formed between the rotor bars and the radius for disc fillings
Note 1 to entry: It is expressed in °.
3.2.9
average stator bar angle
α
s
angle formed between the stator bars and the radius for disc fillings
Note 1 to entry: It is expressed in °.
3.2.10
average cutting angle
ϕ
sum of the average rotor bar angle and the average stator bar angle
Note 1 to entry: It is expressed in °.
3.2.11
cutting edge length
C
EL
CEL
total length of all bar edges at a defined refiner rotational speed
Note 1 to entry: It is expressed in km/s.
3.2.12
cutting length factor
C
LF
CLF
total length of all bar edges for one
...