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Preface
Our task is to: disperse
the chemicals to approach molecular
dimensions, thereby reducing chemical usage by about 90%; and
neutralize the
repulsive negative particle charge to maximize process control,
productivity
and strength. The effort is initiated by
review of drawings and key metrics.
Proposal
We propose to provide advice
on installation and use of sensors and equipment, and to provide
continuing
process supervision support for computer control of nanotechnology
processes
that produce optimal digital printing paper. Integration
of nanochemistry optimizes
performance, as opposed to merely
applying a coating to the surface.
While we could have focused
on any grade of tissue, towel, fine paper or board, we selected digital
printing paper because the performance metrics are clearly defined and
widely
accepted; and because the short term market growth is expected to be
explosive.
Four Major
Benefits
1. Conventional
chemical supplier services are
replaced by closed loop
computer process control, resulting in a higher and far more consistent
level
of quality. Supply of all wet end
chemicals will preferably be provided by Paper Chemistry Laboratory,
Inc.,
(PCL) at competitive prices, to ensure maximum quality and
cost-effectiveness.
2. Chemical cost
efficiency will be increased in the range of 1 to 2 orders of
magnitude,
representing a cost reduction of 90-99%. This
occurs because nanochemicals in a
homogeneous matrix function as
molecules, rather than aggregates, with correspondingly greater mass
action
efficiency. The counter-intuitive result
is that the paper substrate will consume significantly less functional
chemical
than does a coating, while attaining a much higher level of
performance.
3. Product
smoothness and print quality will be greatly increased by employing a
nanoflocculation mechanism instead of conventional macroflocculation. Proprietary on-line zeta potential and
Specific
Filtration Resistance sensor and control technology, the Zeta Data
On-Line
System®, will be utilized, which has been under
continual
refinement
since 1985.
4. The coating
process with all of its requirements, performance issues and
accompanying
costs, is eliminated.
Papermaking is on the
verge of transformation from an art to a science. A
world of flawless digital printing is just
around the corner!
Nanotechnology
What magic is bringing
forth these miracles?
A nanometer, one
billionth of a meter, is the size measure of nanotechnology. It is the most precise (and perhaps the least
useful) characterization; not dissimilar from using billions and
trillions of
dollars to discuss economics with those whose purchases are principally
at the food
market and gas station.
The reason is that, as
particles get smaller, their properties change. Nanoparticles
are typically not described by
size, but by surface area. For example,
the colloidal silica used at the
wet end has a surface area of about 600m2 /gram. Additionally, the smaller they are, the more
negative, and (for quite different reasons) the more attracted to each
other.
Turning to the
specifics of wet end papermaking, the process is presently
uncontrolled, even
though the dry end has been under computer control for decades. Since closed loop computer control is one of
our objectives, let us review the semi-quantitative process parameters
and
physical properties in the context of computer control.
Please
refer to the
graph entitled “Computer Control of Papermaking
Nanotechnology”.
The stock is a
bleached hardwood Kraft (BHK) with precipitated calcium carbonate (PCC)
as filler. The cationic chemical component
is added
first, mixed to homogeneity, and followed by the negative nanoparticle
which is
also mixed to homogeneity.
The nanotechnology
papermaking example depicted is represented by the red line furthest to
the
right: cationic starch and colloidal
silica. The two chemicals inter-act
electrostatically to form a lattice work which functions to
simultaneously
increase both retention and water removal, or “drainage.”
PCL provides a sensor that measures Specific
Filtration Resistance (SFR), a parameter fundamental to drainage.
To illustrate the
significance of zero zeta potential, two additional lines are plotted. The orange line is polyethylenimine (PEI). It shows a sharp charge reversal at zero zeta
potential, towards macroflocculation, which results from its polymeric
nature,
and illustrates the importance of maintaining zero zeta potential in
order to
maximize smoothness, strength and sustainability.
The blue line is a
monomeric cationic starch which manifests a more gentle inclination
change at
charge reversal.
The red line
represents an optimum nanotechnology papermaking system, exhibiting the
best
retention and drainage.
Maximum
retention and drainage are simultaneously achieved by increasing both
feed
rates in balance, to maintain zero zeta potential, until the Specific
Filtration Resistance is maximized. This
action also maximizes productivity.
The
original data was
first published at the 1993 Papermakers’ in a microparticulate process
seminar
organized by the author, and presented by Christian Pierre of Centre
Technique
in Grenoble. The author worked with a
Lab Zeta Data® to produce
stock of fully characterized
physical
chemistry, followed by making hand sheets with the Mk V Dynamic Hand
Sheet Mold®.
After several years work, and
thousands of
experiments, we achieved the understandings explicit in the graphic
example.
This was a task of
considerable conceptual magnitude. Among
its many benefits is the generation of real-time actual cost of each
reel, to
the penny.
Installation
Outline and
Pay-Back
Our first action at a candidate
mill is a thorough review to determine its operating efficiency
metrics, and
the precise specifications for additional equipment and sensors to
enable
papermaking nanotechnology. Advisory
time spent at the mill by during this phase by PCL is compensable by
the
client.
The described efficiencies
and many others will result from additional equipment and sensors
specified by
PCL, which will be purchased by PCL on behalf of the paper mill at
out-of-pocket cost plus a 10% fee. The
single exception is the Zeta Data On-Line System®,
including
computer and software, which will be leased from PCL.
The annual lease is priced at $150K for the
first System and $25K for all additional Systems in a single order from
one
mill, including a warrantee for software maintenance, parts replacement. Continuing guidance will be provided in
process control refinement, with emphasis on the first System as the
prime
example.
The paper mill agrees to
make the wet end process and performance data available for viewing
remotely on
the Internet, and to appoint two young, fast-track chemical engineers
machine
to manage the day-to-day optimization effort.
The technology
primarily consists of a good half dozen nanotechnology concepts,
together with
the hardware and software for implementation. The
essential task is to flawlessly implement
and integrate all of them
harmoniously, under closed loop computer control, so they operate
together in
an optimal, self-reinforcing manner.
In summary,
we propose
to effectively apply the broad knowledge embodied in our patents,
patent
applications, related proprietary know-how, and the education, training
and
experience of our staff of engineers and chemists. Successful
realization will result in
maximizing quality, performance, productivity and sustainability at the
lowest
feasible cost, under closed loop computer control.
John Penniman
www.papermaking-chemistry.com
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