T E S T I N G N E W S
PREVENTIVE
MAINTENANCE & CALIBRATION
ISO Conformance
Production Cost Savings
Increased Profitability
Traceable
Reliable
Cost effective
Economical on-site service for your Q.C. testing instruments.
Call to discuss your requirements 01795
553234
BURST
TESTER DIAPHRAGMS
are available
'PFI-MILL' LABORATORY BEATING OF PULP
For
beating of pulp under standardized conditions for laboratory purposes.
Product Testing Apparatus are aware of four laboratory beaters used around
the world for the evaluation of pulps, the "Valley" Beater and
the PFI Mill are the most commonly used. The Lampen Mill is popular in
Scandinavian countries, also sometimes in U.K. and Australia. The Jokro
Mill is favoured in Germany. The following is a description of the
'Valley' beater principle.
The HM1PTB508A PFI mill is one of the key instruments in the evaluation of
the potential development of a cellulose pulp. The beating action develops
the fibrillation and bonding potential of paper and board making fibres.
It is fully standardized and able to show up
differences existing between pulps.
The principle of operation comprises a roll containing beating bars being
pressurised against a bedplate which in the case of the PFI Mill is a
solid bowl in which the roll rotates. The beater roll and bowl are made of
stainless steel.
Pulp consistency is constant throughout the operation and roll and
bedplate revolve at constant speed (both in the same direction but at
differing speeds). The rate
of development is governed by the pressure between roll and bedplate which
can be adjusted according to the pulp type under evaluation. The degree of
beating is proportional to the beating time. Separate pulp samples are
required for each point on the beating development curve.
The PFI Mill is suitable for use in evaluating all types of pulps in
common use. It is not
recommended for very long fibred materials such as hemp or for the
defibration of semi-digested raw materials.
Topping
up Fluids for Hydraulic (Mullen) Type Burst Testers.
Paper and Board version
Beater Roll
PRECISION SAMPLE
CUTTERS FM2000
A range of robust punch and die action cutters, designed to produce
precision test samples from paper, light carton board,
tissue paper, film and foil.
O1795
553234.
Beating in the PFI Mill is carried out automatically once the pulp charge
has been placed in the bowl.
The
beating elements consist of a stainless steel roll with 33 bars and a
smooth sided circular bedplate. The bedplate bowl is charged with a
weighed and disintegrated pulp sample forming an endless band round the
circumference. The beater
roll is inserted into the bowl and after closing the lid, the beating is
started. The beating cycle is fully automatic in operation. After reaching
the preset number of revolutions, the beating process stops
automatically.
Physical testing of hand-sheets formed from this pulp helps predict the
pulp’s performance. As the roll rotates with a higher peripheral speed
than the bedplate, the roll bars cut out sections of the pulp band,
transporting them into the beating zone. The beating pressure is obtained
from a load applied by means of a weight lever action via a cantilever
mounted on the base of the supporting pillar which is rigidly attached to
the frame.
Brass weights are attached to the lever arm to vary the load. The
normal beating pressure with the fixed weight is 1.8 kgf/cm of bar height
and with the additional weight 3.4 kgf/cm.
In the standard operating procedure the load is applied directly to the
pulp and the beating gap between roll and bedplate forms naturally.
The PFI Mill also allows pulp to be beaten with a fixed gap set by
means of a micrometer placed against the pillar adjusting the amount of
swing made by the cantilevered arm.
The rotating speed of the roll is set to 1440 +/- 30 r.p.m. and that of
the bedplate 720 +/- 20 r.p.m., under no load conditions. The roll and bedplate both rotate clockwise.
BENDTSEN
ROUGHNESS HEAD Refurbishment
Service
New
measuring land supplied and fitted, land lapped and polished.
Certificated to ISO
8791-2
For Bendtsen Tester Models 5, 6, M512
Call for full details
01795
553234
or
contact us
---------
The automation of the PFI Mill
both reduces the risk of operator error and allows more free time for
other tasks in the laboratory.
The
mill is very much a precision instrument and has found favour in many
laboratories because of its good calibration characteristics and ease of
operation, both of which enhance the reproducibility of pulp evaluation.
Sample reproducibility is well controlled due to the fact that samples may
be weighed out.
The
design of the beating elements gives rise to good reproducibility and
correlation of fibre characteristics with mill beaten stock. The
HM1PTB508A PFI –Mill accords with ISO 5264-2, BS 6094, DIN EN 25264-2,
TAPPI T 248, PAPTAC C.7 and SCAN C24.
Follow
this link to learn more about PFI MILL BEATER