PAPER CHEMISTRY LABORATORY, INC.
.....the acknowledged leader in papermaking chemistry Instrumentation
Principle of Operation:
The papermaking system comprises a highly complex and
dynamic series of interdependent
processes. Unfortunately, even the
slightest change in chemistry can
adversely affect the entire system.
The paper machine is an expensive
place to experiment with new
chemicals or even to change
dosage rates or addition points of
existing chemicals. Balancing the
chemistry must first be done in the
laboratory. Three different Dynamic
Paper Chemistry Jars are available
to meet the specific needs
described below.
MARK III
The DYNAMIC PAPER
CHEMISTRY JAR® MARK III is
used to measure key parameters
such as Dynamic Drainage, First
Pass Retention, Water Removal Efficiency and 'Fines Fraction of
Paper Stock by Wet Screening'
under TAPPI Provisional Test
Method T 261 pm-80.
The MARK III includes a
Plexiglass® vaned jar top and a jar
base. The base is separated from screen. An easily manipulated
valve controls the rate of flow of fluid
from the jar. A 21/2 inch variable
speed impeller provides agitation.
The vanes, combined with a variable impeller speed, provide
reproducible shear and turbulence.
This is particularly important in systems which employ high molecular
weight flocculants which can be
broken down by shear. Importantly,
the turbulence and shear provide
realistic First Pass Retention data.
MARK IV
The DYNAMIC PAPER
CHEMISTRY JAR® MARK IV incorporates all the features of the
MARK III. Additionally, it provides
the capability of making dynamic
handsheets of 4" diameter. This is
accomplished by providing a
second, inter-changeable, jar base
with a large valve which allows
rapid evacuation of water and
therefore enables good handsheet
formation.
The conventional methods of
laboratory handsheet preparation
give handsheets which are:
-
Not representative of the
papermaking system because they
are not under dynamic conditions,
which include shear and turbulence.
-
Not representative of the
process chemistry because the furnish is greatly diluted immediately
prior to web formation.
- Limited in scope because one
is not able to collect drainage,
retention, or electrokinetic data.
For these reasons the DYNAMIC
PAPER CHEMISTRY JAR®
MARK IV was developed as a tool
to provide the paper chemist with
the most information possible, while
incorporating the dynamic conditions of the real world. In addition,
the MARK IV was designed to be
easy to use, require a minimum of
space, and be portable for use in
mill trials.
The MARK IV produces handsheets of equal uniformity to those
made with a conventional handsheet mold. The amount of furnish
and its consistency may be varied
in order to correspond to machine
headbox consistency or to provide
a handsheet of a predetermined
basis weight.The MARK IV is the
most versatile laboratory instrument currently available which
enables the chemist to measure the
effect of a wide range of chemistry
process changes on the papermaking system.
MARK V
The DYNAMIC PAPER
CHEMISTRY JAR®
MARK V was
developed to further streamline
laboratory preparation of handsheets. By producing handsheets
of four times the area, while retaining the same degree of uniformity,
it yields four times as much data in
measuring parameters such as tensile strength, z-strength, opacity,
sizing and ash.
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