Note: Descriptions are shown in the official language in which they were submitted.
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
FRACTIONATING AND REFINING SYSTEM FOR ENGINEERING FIBERS TO
IMPROVE PAPER PRODUCTION
FIELD
[0001] The present invention generally relates to a system for making paper
from cellulosic
fibers. More specifically, it relates to a system that engineers the
cellulosic fibers to
improve paper quality and reduce paper production costs.
BACKGROUND
[0002] Paper, board and tissue are made from pulp that includes cellulosic
fibers originally
processed from wood chips. These chips are processed mechanically or
chemically to
liberate the fibers from the fiber/lignin structure. Liberated fibers are
usually bleached and
refined as a single slurry before being formed and dried on a paper machine to
make reels of
paper. Softwood and hardwood fibers are usually processed separately until
final blending
just before paper machine processing.
[0003] Cellulosic fibers are a natural biological material derived from trees.
As a biological
material there is great diversity in fiber quality within one tree, let alone
regionally and
among different species. Current state of the art paper fabrication systems
generally assume
this diversity is a constant when transforming fibers into paper with the
exception of
distinguishing between softwood and hardwood fibers. In order to accommodate
this
assumption, large operating safety margins are built into the paper making
process. The
assumption that all incoming fiber quality is constant limits the potential
benefit of specific
fibers in the overall distribution and also limits the flexibility of
optimization within the
overall process. For example, if one tries to improve sheet strength through
refining then
water removal will be adversely affected and vice versa. The ability to change
paper
properties independent of paper machine operation variables is restricted by
the assumption
that pulp is made up of fibers with constant quality.
[0004] The present invention aims to provide a new system for treating
cellulosic fibers that
improves upon the currently unresolved issues described above by allowing one
to select
out defined fiber distributions that can be independently processed and
recombined to make
a superior paper product at lower costs.
1
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
SUMMARY
[0005] In one implementation, the present disclosure is directed to a system
for measuring
properties of fluid suspended cellulosic fibers. The system is comprised of a
fractionator, a
fractionator monitoring device and a vibration analyzer. The fractionator
monitoring device
includes a vibration sensor. The vibration sensor measures the vibration
spectrum of the
fractionator. The vibration analyzer determines vibration characteristics of
the fractionator
spectrum and compares the vibration characteristics to an acceptable
characteristic; if the
fractionator vibration characteristic is outside of a characteristic limit an
alert signal is
generated.
[0006] In another implementation, the present disclosure is directed to a
system for
engineering fiber properties suspended in a fluid. The system comprises a
fiber
fractionation system inlet that splits fibers from feed pulp into an original
portion containing
original fibers and a fractionable portion containing original fibers. The
original portion
and the fractionable portion have substantially the same composition. The
system also
comprises a fractionator to fractionate the original fibers of the
fractionable portion into a
heavies fraction having heavies fibers and a lights fraction having lights
fibers. The system
further comprises a refiner to refine the heavies fraction into refined
heavies. An amount of
refined heavies is blended back with the original portion to create a
recombined slurry for
making a paper product.
[0007] In another implementation, the present disclosure is directed to a
system for
engineering fiber properties of fluid suspended fibers, the fibers pass
through primary,
secondary, and/or tertiary fractionators to generate fractionated fiber
slurries. Each
fractionator has an incoming fractionable portion and produces a heavies
fraction and a
lights fraction. The system is comprised of an incoming fiber measurement
device and a
heavies fiber measurement device. The incoming fiber measurement device is
interfaced to
measure incoming fiber properties of the fractionable portion. The heavies
fiber
measurement device is interfaced to measure outgoing heavies fiber properties
of a
combination of the heavies fractions from the plurality of fractionators.
Incoming
fractionable fiber properties are compared to the combination of outgoing
heavies fiber
properties and a process parameter is adjusted to generate a targeted fiber
property.
2
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0008] In another implementation, the present disclosure is directed to a
system for
engineering fiber properties of fluid suspended cellulosic fibers. The system
is comprised
of a plurality of fractionators that generate fractionated fiber slurries,
each fractionator
receiving an incoming fractionable portion with incoming fiber properties and
incoming
pressure and each fractionator producing a heavies fraction and a lights
fraction. The
heavies fraction having outgoing heavies fiber properties and an outgoing
heavies pressure,
flow and consistency. The lights fraction having outgoing lights fiber
properties and an
outgoing lights pressure, flow and consistency. The system also includes an
incoming fiber
measurement device interfaced to measure the incoming fiber properties of a
combination
of the incoming fractionable fiber portions. The system further includes a
heavies fiber
measurement device interfaced to measure outgoing heavies fiber properties of
a
combination of the heavies fractions from the plurality of fractionators. The
incoming fiber
properties are compared to the outgoing heavies fiber properties and the
heavies pressure,
flow or consistency is adjusted relative to the incoming pressure, flow or
consistency to
optimize the outgoing heavies fiber properties.
[0009] In another implementation, the present disclosure is directed to a
system for
engineering cellulosic fibers suspended in a fluid. The system comprises a
fiber
fractionation system inlet that splits incoming cellulosic fibers into an
original portion and a
fractionable portion. The original portion and the fractionable portion have
substantially the
same composition. The system also comprises a fractionator to fractionate the
original
fibers of the fractionable portion into a heavies fraction having heavies
fibers and a lights
fraction having lights fibers. The system further comprises a refiner feed
chest that is fed by
a heavies fiber storage, and a refiner receiving heavies fibers from the
refiner feed chest.
The heavies fibers are processed through the refiner to create refined fibers
and recirculated
back into the refiner feed chest until optical refined properties and crill
bonding area targets
are achieved to create glue pulp. The system also comprises a fiber
measurement system
interfaced to measure cellulosic fiber properties of the original fibers,
refined fibers and
additionally at least one fiber property from the group consisting of the
lights fraction and
heavies fraction. The system still further comprises glue pulp storage tank to
store glue
pulp from the refiner feed chest. The system measures cellulosic fiber
properties that are
3
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
used to determine an amount of glue pulp to be re-combined with original
portion to
construct a recombined slurry for making a paper product.
[0010] In another implementation, the present disclosure is directed to a
system for
engineering cellulosic fibers suspended in a fluid. The system comprises a
fiber
fractionation system inlet that splits incoming cellulosic fibers into an
original portion and a
fractionable portion. The original portion and the fractionable portion have
substantially the
same composition. The system further comprises a fractionator to fractionate
the original
fibers of the fractionable portion into a heavies fraction having heavies
fibers and lights
fraction having lights fibers. The system has a plurality of refiners in
series receiving
heavies fibers from a heavies refiner feed chest. The heavies fibers are
processed through
the refiners to create refined fibers that have a specific refined fiber
property to create glue
pulp. A fiber measurement system is interfaced to measure cellulosic fiber
properties of the
original fibers, refined fibers and additionally at least one fiber property
from the group
consisting of the lights fraction and the heavies fraction. A glue pulp
storage tank stores
glue pulp from the plurality of refiners. The system measures cellulosic fiber
properties to
determine an amount of glue pulp to be re-combined with the original portion
to construct a
recombined slurry for making a paper product.
[0011] In still another implementation, the present disclosure is directed to
a system for
engineering cellulosic fibers suspended in a fluid that has been split into an
original portion
and a refinable portion. The system is comprised of a refiner to refine the
refinable portion
into a refined portion. The system further comprises a fiber property
measurement system
interfaced to measure cellulosic fiber properties of the cellulosic fibers.
Measured cellulosic
fiber properties are then used to determine an amount of said refined portion
to be re-
combined with the original portion to construct a recombined slurry that will
produce an
optimized paper product.
[0012] In still another implementation, the present disclosure is directed to
a method for
optimizing paper machine operation. The method comprises first providing
original pulp,
glue pulp comprised of refined heavies fractionate from the original pulp and
a blender.
The method then involves blending the original pulp and the glue pulp to
create a pulp
mixture in the blender. The method further involves adjusting the percentage
of glue pulp
4
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
mixture to optimize the paper properties and paper machine operation while
maintaining a
targeted amount of blended pulp mixture.
[0013] In still yet another implementation, the present disclosure is directed
to a method for
optimizing paper machine operation and paper properties. The method comprises
first
providing original pulp. The method then involves splitting the original pulp
into a
fractionable portion and an original portion that are substantially the same
composition.
The method then involves fractionating the fractionable portion into a heavies
fraction
having heavies fibers and a light fraction having light fibers. The method
then involves
refining the heavies fibers to produce glue pulp. The method finally involves
blending the
original portion and an amount of glue pulp to create a recombined slurry.
[0014] In still yet another implementation, the present disclosure is directed
to a method for
preparing cellulosic fibers within a paper mill. The method comprises first
providing feed
pulp and a plurality of individual paper machines. The method then involves
splitting the
original pulp into a structural portion and a portion to be turned into glue
pulp. The method
further involves processing the portion to be turned into glue pulp into glue
pulp through a
single refining step to create a single source of glue pulp. The method
further involves
supplying a portion of the glue pulp from the single source of glue pulp to
the individual
paper machines. Finally the method involves combining the glue pulp with the
original
structural portion prior to processing through each individual paper machine
to make a
paper product. All bonding material for all paper machines in the mill comes
from the
single source of glue pulp.
BRIEF DESCRIPTION OF DRAWINGS
[0015] For the purposes of illustrating the invention, the drawings show
aspects of one or
more embodiments of the invention. However, it should be understood that the
present
invention is not limited to the precise arrangements and instrumentalities
shown in the
drawings, wherein:
[0016] FIG. 1 is a schematic diagram of one exemplary deployment of the system
for
engineering fibers to improve paper production;
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0017] FIG. 2a is a schematic diagram of one embodiment of the fiber
fractionation system
shown in FIG. 1;
[0018] Fig. 2b is a schematic diagram of an alternative embodiment of the
fiber
fractionation system shown in FIG. 2a, now having primary, secondary and
tertiary
fractionators;
[0019] FIG. 3 is a schematic view diagraming the internal working of a
hydrocyclone
fractionator used in the system of FIGS. 2a and 2b;
[0020] FIG. 4a is a schematic, sectional view of a thin walled cellulosic
fiber before
treatment by the system of FIG. 1;
[0021] FIG. 4b is a schematic, sectional view of a thick walled cellulosic
fiber before
treatment by the system of FIG. 1;
[0022] FIG. 5a is a diagram illustrating one technique for measuring fiber
wall thickness of
fibers processed by the system of FIG. 1;
[0023] FIG. 5b is a graph of exemplary fiber wall thickness distribution for
pulp after
processing through the fiber fractionation system of the system of FIG.1;
[0024] FIG. 6a is a schematic, perspective view of an unrefined fiber before
treatment by
the system of FIG. 1;
[0025] FIG. 6b is a schematic, perspective view of the cellulosic fiber of
FIG. 6a, after one
possible treatment step to the fiber is completed as part of the system of
FIG. 1;
[0026] FIG. 7a is a diagram illustrating one technique for measuring fiber
crill for fibers
processed by the system of FIG. 1;
[0027] FIG. 7b is a graph of exemplary crill properties for pulp before and
after processing
through the refiner of the system of FIG. 1;
6
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0028] FIG. 8 is a schematic diagram of the fiber measurement system of the
system shown
in FIG. 1;
[0029] FIG. 9 is a schematic diagram of the fractionation maintenance system
of the system
shown in FIG. 1;
[0030] FIG. 10 is a plot of vibration spectra and a specific vibration
characteristic that may
be measured from the vibration sensor shown in FIG. 9;
[0031] FIG. 11 is a flowchart of how the vibration spectra and vibration
characteristic
shown in FIG. 10 may be used to produce an alert in conjunction with the
fractionation
maintenance system of FIG. 9;
[0032] FIG. 12 is an exemplary process flow diagram for one embodiment of
processing
cellulosic fibers in conjunction with the system of FIG. 1;
[0033] FIG. 13 is an exemplary process flow diagram for another embodiment of
processing cellulosic fibers in conjunction with the system of FIG. 1;
[0034] FIG. 14 is a schematic diagram of another exemplary deployment of the
system for
engineering fibers to improve paper production;
[0035] FIG. 15 is an exemplary process flow diagram for one embodiment of
processing
cellulosic fibers in conjunction with the system of FIG. 14;
[0036] FIG. 16 is an exemplary process flow diagram for another embodiment of
processing cellulosic fibers in conjunction with the system of FIG. 14;
[0037] FIG. 17 is a table indicating processing for several samples using the
system shown
in FIGS. 1 and 14 as compared to standard conventional processing;
7
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0038] FIG. 18 is a plot of sample data from FIG. 17 comparing strength of
paper prepared
with the present invention against paper prepared with standard whole pulp
refinement;
[0039] FIG. 19 is a schematic diagram of a conventional system used in paper
production;
[0040] FIG. 20 is a block diagram for the process flow associated with the
conventional
system of FIG. 19;
[0041] FIG. 21 is a schematic diagram of an exemplary deployment of the system
for
engineering fibers to improve paper production as shown in FIG. 1 now
illustrating the
integration of a glue pulp processor;
[0042] FIG. 22 is a schematic diagram showing the chemistry of bonding between
fiber
wall surfaces when making paper using the system of FIG. 21;
[0043] FIG. 23 is a formula definition of curl relating to one aspect of the
invention
embodied by the system in FIG. 21;
[0044] FIG. 24 is data obtained using the system in FIG. 21 defining critical
percentages of
curl for one embodiment of the invention;
[0045] FIG. 25 is a schematic diagram of the fiber processing system of the
system shown
in FIG. 21;
[0046] FIG. 26 is a block diagram for the process flow associated with the
system for
engineering fibers of FIG. 25;
[0047] FIG. 27 is a schematic diagram showing conventional processing within a
paper
mill;
[0048] FIG. 28 is a schematic diagram showing new processing within a paper
mill using
the system in FIG. 1, FIG. 14 or FIG. 21;
8
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0049] FIG. 29 is a schematic diagram of an embodiment for a batch glue pulp
processor
for the glue pulp processor in FIG. 21;
[0050] FIG. 30 is a schematic diagram of an embodiment for a series glue pulp
processor
for the glue pulp processor in FIG. 21;
[0051] FIG. 31 is a schematic diagram of an embodiment for a parallel glue
pulp processor
for the glue pulp processor in FIG. 21;
[0052] FIG.32 is an exemplary process flow diagram for one embodiment of
processing
cellulosic fibers through the system of FIG. 21;
[0053] FIG. 33 is an exemplary process flow diagram for one embodiment of
processing
cellulosic fibers through the system of FIG. 21;
[0054] FIG. 34 is an example of hydrocyclone processing operation conditions
when
making paper using the system of FIG. 21;
[0055] FIG. 35 is an example of fiber property profiles when making paper
using the
system of FIG. 21;
[0056] FIG. 36 is an example of fiber properties of glue pulp production when
making
paper using the system of FIG. 21;
[0057] FIG. 37 is an example of paper property improvements when making paper
using
the system of FIG. 21;
[0058] FIG. 38 are examples of length distribution of fractionated and
unfractionated feed
pulp showing improvements that may be obtained using the system of FIG. 21;
and
[0059] FIG. 39 is an example of strength comparison between fractionated and
unfractionated pulp using the system of FIG. 21.
9
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
DETAILED DESCRIPTION
[0060] The present invention embraces the biological variability of cellulosic
fibers 118
(a.k.a. fiber) found in wood and provides a system 120 that uses this fiber
variability to
improve paper production and allow for new paper products to be produced with
improved
quality and reduced production costs. The way in which system 120 accomplishes
this is
by separating cellulosic fibers 118, then preferentially refining these
separated fibers to a
higher level of development than can now be achieved with the common practice
where the
full pulp flow is refined, and then blending back preferentially refined pulp
to accommodate
for fiber quality variations in the original pulp. Instead of adjusting
refining, which is the
current state of the art; paper makers will adjust blending to balance
production output with
respect to the type of paper and quality of paper. The resulting pulp mixture
can be used to
produce paper with various desired improved characteristics and reduced
process costs.
[0061] System 120 for engineering fibers to improve paper quality is
illustrated in FIGS. 1-
39. Cellulosic fibers 118 created from wood are generally suspended in a fluid
such as
water during processing. Suspended fibers along with the suspension fluid are
generally
known as a slurry. The slurry may also include additives such as defoamers,
bonding
agents, sizing agents, retention agents, drainage agents, fillers, enzymes,
etc. System 120
(120a and 120b), FIGS. 1 and 114 comprises incoming fibers (a.k.a. original
fibers 118a) as
original slurry 122 obtained from a pulp source 124. In one embodiment, FIG.
20a, original
slurry 122 (a.k.a. feed or feed pulp) is then split between a fractionable
portion 126 and the
remaining original portion 128. Remaining original portion 128 is directed to
blender 130.
Fractionable portion 126 is then processed by fiber fractionation system 134.
Here fibers
118 are separated by a given fiber property/characteristic, such as fiber wall
thickness, fiber
density, fiber size, etc. One fraction, unrefined portion 138, is sent to
blender 130 while the
other portion to be refined is sent to refiner 136 where fibers 118 are
refined to create a
refined portion 140. Refined fibers 118d are held in storage tank 142. Varying
amounts of
refined portion 140, non-refined portion 138 and original portion 128 are then
blended
together in blender 130 to produce optimized slurry 139 with optimal
characteristics to be
processed by paper machine 144 and create an optimized paper product 146. For
example,
the cellulosic fibers may have the same or increased bonding area with better
drainage or
the optimized cellulosic product may have increased strength while maintaining
bulk,
caliper and stiffness. Although the word "paper" is used as a modifier
throughout this
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
disclosure as in "paper machine" and also as an example of an end product that
can be
fabricated with system 120, it should be understood that the use of the word
"paper" is
meant to also include board, tissue and all other sheeted products made from
cellulosic
wood fibers
[0062] Fiber fractionation system 134 (a.k.a fractionator) may be any type of
system that
can separate cellulosic fibers 118 based on a fiber property. Fiber properties
may include
fiber wall thickness, fiber density, fiber size (length, width), fiber shape,
amount of
crill/nanofibrils (total, attached, unattached), fines content, etc. In one
embodiment fiber
fractionation system 134a is a bank of hydrocyclones 150 connected in
parallel, FIG 2a. In
another embodiment fiber fractionation system 134b may include hydrocyclones
150 in
series to create primary, secondary, and/or tertiary banks in series, FIG. 2b.
In FIG. 2b
arrows indicate direction of flow. Fractionators may also be screens,
differential belt
washers, flotation devices, etc. Hydrocyclones 150 each separate cellulosic
fibers 118
based on at least one from the group including fiber wall thickness and fiber
size.
Connecting multiple hydrocyclones 150 in parallel allows for greater
throughputs as each
hydrocyclone can only process a limited flow rate.
[0063] Fiber fractionation system 134 (134a and 134b), FIGS. 2a and 2b, may
have
additional components that aid in the process of fractionation. For example,
an incoming
diluter 148 may be used to adjust the fluid content of the fractionable
portion 126 of the
slurry before it enters hydrocyclone bank 147. A lights thickener 149 may be
used to adjust
the fluid content of the lights fraction 153 exiting fiber fractionation
system 134. A heavies
thickener 151 may be used to adjust the fluid content of the heavies fraction
155 exiting
fiber fractionation system 134. Additionally pressure meters, mass flow
meters, and
consistency meters may be integrated to measure pressure, flow and consistency
of the
slurry as it enters the fiber fractionation system at fiber fractionation
system inlet 157 and
exits as one or more of the fractionated portions 153 and/or 155 at either
lights outlet 159 or
heavies outlet 161. Consistency is defined as the percent solids content in a
slurry.
Incoming pressure meter 154 measures incoming pressure of fractionable portion
126 to all
fractionators. Incoming flow meter 156 measures a combination of incoming flow
rates of
fractionable portion 126 flowing into all fractionators. Heavies pressure
meter 158, if
present, measures outgoing heavies pressure of the heavies fraction 155.
Heavies flow
11
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
meter 162, if present, measures a combination of outgoing flowing rates of the
heavies
fraction 155 flowing from all fractionators. Incoming consistency is measured
by fiber
measurement system 180 as a combination of incoming consistency of
fractionable portion
126 flowing into all fractions. Lights pressure meter 164 measures outgoing
lights pressure
of the lights fraction 153. Lights flow meter 168 measures a combination of
outgoing flow
rates of the lights fraction 153 flowing from all fractionators. Lights
consistency is
measured as outgoing lights consistency of lights fraction 153. Incoming
pressure and
consistency, outgoing heavies pressure and outgoing lights pressure can be
adjusted relative
to each other to regulate flow rates and the degree of fractionation desired.
[0064] Each hydrocyclone 150 works as shown in FIG. 3. Incoming slurry is fed
under
pressure through fractionator inlet 170. Fractionator inlet 170 is offset to
one side of
hydrocyclone 150. The slurry spins in a downward spiral towards the outer
walls of
hydrocyclone 150 as depicted by heavies flow arrow 172. Thicker, heavy fibers
118c drift
outwards towards the walls of hydrocyclone 150 and exit through the bottom
heavies
fractionator outlet 174. Lighter fibers 118b and fines drift towards the
center of
hydrocyclone 150 and spin centrally upwards as depicted by lights flow arrow
175. Fines
are defined as fiber components that can pass through a 200-mesh Bauer McNett
screen.
These lighter fibers 118b and fines spiral upward exiting through the top
lights fractionator
outlet 176.
[0065] In one embodiment fiber fractionation system 134 operates as follows.
Each
fractionator receives incoming fractionable portion with incoming fibers
properties,
incoming pressure, and incoming consistency. The fractionators then generates
fractionated
fibers slurries. Each fractionator produces a heavies fraction and a lights
fraction. The
heavies fraction has outgoing fiber properties, outgoing pressure and outgoing
consistency.
The lights fraction has outgoing lights fiber properties, outgoing lights
pressure and
outgoing lights consistency. An incoming fiber measurement device is
interfaced to
measure the incoming fiber properties of a combination of said incoming
fractionable fiber
portions. A heavies fiber measurement device may be interfaced to measure
outgoing
heavies fiber properties of a combination of the heavies fractions from the
plurality of
fractionators. The incoming fiber properties are compared to the outgoing
heavies fiber
12
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
properties and for example the heavies pressure is adjusted relative to the
incoming pressure
to optimize the outgoing heavies fiber properties and to control fractionation
efficiency.
[0066] FIGS 4a and 4b depict cross-sections of a thin walled, light fiber 118b
(a.k.a. lights)
and a thick walled, heavy fiber 118c (a.k.a. heavies). The thicker the wall of
fiber 118, the
more weight the fiber has and the more likely to exit the bottom heavies
fractionator outlet
174. The thinner the wall of fiber 118, the less weight the fiber has and the
more likely to
exit top lights fractionator outlet 176. Fiber wall thickness may be measured
by red green
blue (RGB) circular polarized light as shown in FIG. 5a and taught in U.S.
Patent
7,289,210, which is herein incorporated by reference. FIG. 5b shows exemplary
data where
fiber wall thickness has shifted after fractionation.
[0067] Refinement of fibers 118 can be used to modify fiber elements contained
within the
slurry. Refining is the development of a fiber to generate more surface area
through
mechanical, chemical or biological processing. FIGS. 6a and 6b schematically
show the
fiber elements of crill/nanofibrils 178, macrofibrils 179, fiber width 181 and
fiber length
183 before and after refinement. Generally these cellulosic elements are sized
as follows:
crill/nanofibrils 178 (having lengths of 0.1-1 micron), macrofibrils 179
(having lengths of 1-
20 microns), fiber widths 181 (20-microns to 1-millimeter) and fiber lengths
183 (1-5
millimeters). Other engineering or refinement of fibers 118 may include
deflaking,
deshiving or fiberizing. A fiber property such as the amount of crill 178
(total, attached and
unattached) determines the bonding surface area of fiber 118 and directly
relates to the
strength of the paper. A larger percentage of crill 178, both attached and
unattached also
affects the speed of drying of paper, board and tissue and can affect the
amount of energy
and time required to make the paper, board and tissue and adversely affecting
paper
production costs. A thick walled or heavy unrefined original fiber 118a in
cross-section is
depicted in FIG. 6a. After refinement through refiner 136, the refined fiber
118d in cross-
section will be deformed and have more crill 178 (total, attached and
unattached) as shown
in FIG. 6b. Crill (total, attached and unattached) is cellulosic material in
the nanofibril size
range and is measured by the ratio of UV light absorption to IR light
absorption as shown in
FIG.7a and taught in U.S. Patent 4,514,257, which is herein incorporated by
reference.
Light is projected through the cellulose fiber components and scatter is
recorded. Crill is
calculated by the relationship between the scatter generated by UV versus IR
light, where
13
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
UV light scatters the nanofibrils (crill). FIG. 7b shows representative crill
bonding area
data before and after refining.
[0068] Fiber measurement system 180, FIG. 8, includes one or more fiber
measurement
devices. Although many fiber measurement devices are shown with fiber quality
tester 104
testing many properties of the fiber, it should be understood that only a
select few of the
fiber measurement devices and properties may actually be implemented in any
system 120
depending on what the final paper product to be manufactured requires. Fiber
measurement
system 180 may include incoming fiber measurement device 182. Incoming fiber
measurement device 182 is interfaced to measure incoming fiber properties of
the
fractionable portion 126 and includes an incoming sampler 184. Fiber sampled
from
incoming fiber sampler 184 is directed to sample prep 186. Fiber measurement
system 180
may include heavy fiber measurement device 188. Heavy fiber measurement device
188 is
interfaced to measure outgoing heavies fiber properties of a combination of
the heavies
fractions from a plurality of fractionators and includes a heavy fiber sampler
190. Fiber
sampled from heavy fiber sampler 190 is directed to sample prep 186. Fiber
measurement
system 180 may include light fiber measurement device 192. Light fiber
measurement
device 192 includes a light fiber sampler 194. Fiber sampled from light fiber
sampler 194 is
directed to sample prep 186. Fiber measurement system 180 may include refined
fiber
measurement device 196. Refined fiber measurement device 196 includes a
refined fiber
sampler 198. Fiber sampled from refined fiber sampler 198 is directed to
sample prep 186.
Fiber measurement system 180 may include blended fiber measurement device 196.
Blended fiber measurement device 100 includes a blended fiber sampler 102.
Fiber
sampled from blended fiber sampler 102 is directed to sample prep 186.
Individual fiber
samples prepared by sample prep 186 are then each tested for one or more fiber
properties
or slurry attributes such as fiber dimensions (length and width), fines
content, fiber wall
thickness, percent crill (total, attached, detached), freeness, consistency,
pH, etc. Sample
prep 186 and the tests that follow for each fiber property make up the fiber
quality tester
104. A fiber data controller 106 is integrated with fiber quality tester 106
to send
appropriate fiber data to master control system 108.
[0069] In one embodiment fiber measurement system 180 is used to compare
incoming
fractionable fiber properties to a combination of outgoing heavies properties
and then use
14
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
this result to adjust process parameters to achieve a targeted fiber property.
In another
embodiment fiber measurement system 180 is used to compare incoming
fractionable fiber
properties to a combination of outgoing lights properties and then use this
result to adjust
process parameters to achieve a targeted fiber property.
[0070] System 120 may include a fraction maintenance system 110, FIG. 9.
Fraction
maintenance system 110 includes a fractionator monitoring device 112
interfaced with one
or more fractionators to monitor operation of the fractionator. When
fractionating by
weight of fibers the fractionator is preferably a hydrocyclone 150.
Fractionator monitoring
device 112 includes a vibration sensor. The vibration sensor measures the
vibration
spectrum of the fractionator. One example of a vibration spectra showing a
vibration
characteristic indicating a blockage within a hydrocyclone is shown in FIG.
10. A vibration
analyzer, FIG. 11, determines vibration characteristics of the fractionator
vibration spectrum
and compares the vibration characteristics to an acceptable characteristic in
vibration
measurement module 113. If the fractionator vibration characteristics are
outside of a
characteristic limit (a.k.a. threshold) an alert is signaled. Alert data 116
is transmitted to
master control system 108.
[0071] Fiber data controller 104 receives fiber data and uses that data for
overall control of
system 120 through master control system 108. Master control system 108
adjusts
incoming pressure, incoming consistency, outgoing heavies pressure and
outgoing lights
pressure to regulate flow rates and the degree of fractionation desired.
Master control
system 108 also regulates refiner 136 to refine heavies fraction 155 to the
appropriate level
of refining. Master control system 108 further regulates the amount of refined
fiber stored
in storage tank 142. Master control system 108 also regulates how original
unrefined fiber
118a, refined fiber 118d and possibly additionally fractionated unrefined
fiber is blended in
blender 130 to produce an optimized slurry with optimal characteristics to be
processed by
paper machine 144 to create an optimized paper, board or tissue products 146.
Master
control system 108 also receives fractionator alert data 115 and sends out
alerts to keep fiber
fractionator system 134 in optimal working condition.
[0072] In one embodiment (Example 1), system 120, 120a, is used in a static
mode where
the amount of fiber flowing through each portion of the system is a constant
pre-determined
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
amount. FIG. 12 illustrates step-by-step processing for such an embodiment
showing the
amount of fiber flow in each portion of system 120. When operating in this
mode, previous
experimental data is used to predetermine what the fiber flow will be through
each portion
of system 120. In step 1 - 100-percent of original fibers 118a suspended in a
fluid enters the
system as original slurry. Step 2 ¨ the slurry is split. 150-percent goes to
fiber fractionation
system 134 as fractionable portion 126 and the other 50-percent (original
portion 128) is
redirected to blender 130. Step 3 ¨ fractionation occurs. The fractionable
portion 126 is
introduced into the fractionators and is separated/fractionated by the
fractionators into 15-
percent heavy fibers 118c (heavies fraction 155) and 35-percent light fibers
118b (lights
fraction 153). The 35-percent lights fraction is directed to blender 130. Step
4 ¨ refining
fibers to maximize bonding area, the 15-percent of heavies fibers is directed
to and
processed by refiner 136. Step 5 ¨ blending the three fiber types: original
fibers 118a, light
fibers 118b and refined heavy fibers 118d are recombined and blended together.
Step 6- the
optimized slurry is achieved and sent to paper machine 144 to be turned into
an optimized
paper, board or tissue product 146. Percentages stated above are only for this
one
illustrative example; however these percentages should not be considered
limiting and other
percentages may be used.
[0073] In one embodiment (Example 2) system 120 is used in a dynamic mode
where the
amount of fiber flowing through each portion of the system is adjusted as
measurements
come in and are analyzed by master control system 108. FIG. 13 illustrates
step-by-step
processing for such an embodiment showing ranges for the amount of fiber flow
in each
portion of system 120 at any given time. In step 1 - 100-percent of original
fibers 118a
suspended in a fluid enters the system as original slurry. Step 2 ¨ the slurry
is split within
the given ranges depending on what type of paper is to be manufactured and
feedback
information gathered in the rest of the process flow. For example, fiber in
the range of 45-
55 percent goes to fiber fractionation system 134 as fractionable portion 126
and the other
45-55 percent (original portion 128) is redirected to blender 130. Step 3 ¨
fractionation
occurs. The fractionable portion 126 is introduced into the fractionators and
is
separated/fractionated into 13.5-16.5 percent heavy fibers 118c (heavies
fraction 155) and
33.5-36.5 percent light fibers 118b (lights fraction 153). The 33.5-36.5
percent lights
fraction is directed to blender 130. Step 4 ¨ refining, the 13.5-16.5 percent
of heavies is
directed to and processed by refiner 136. Step 5 ¨ capacitance involves
storing the fiber and
16
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
then drawing upon the stored fibers as needed to mix the ideal fiber
composition. Step 6 ¨
blending the three fiber types: original fibers 118a, light fibers 118b and
refined heavy
fibers 118d are recombined and blended together in any percentage that is
required to
produce the optimized slurry. Step 7- the optimized slurry is achieved and
sent to paper
machine 144 to be turned into an optimized paper, board or tissue product 146.
Percentages
stated above are only for this one illustrative example; however these
percentages should
not be considered limiting and other percentages may be used.
[0074] In an alternative embodiment, FIG. 14, system 120, 120a has been
modified to
remove fiber fractionation system 134 and fractionator maintenance control
system 110
giving a modified system as shown in system 120, 120b. In system 120b,
cellulosic fibers
118 are split into a refinable portion 160 and the remaining original portion
128 at feed
splitter 117. Remaining original portion 128 is directed to blender 130.
Fibers 118 from
refinable portion 160 are then refined into refine portion 140. Refined fibers
118d are held
in storage tank 142. Varying amounts of refined portion 140 and original
portion 128 are
then blended together in blender 130 to produce optimized slurry 139 with
optimal
characteristics to be processed by paper machine 144 and create an optimized
paper product
146.
[0075] In one embodiment (Example 3), system 120, 120b is used in a static
mode where
the amount of fiber flowing through each portion of the system is a constant
pre-determined
amount. FIG. 15 illustrates step-by-step processing for such an embodiment
showing the
amount of fiber flow in each portion of system 120. When operating in this
mode, previous
experimental data is used to predetermine what the fiber flow will be through
each portion
of system 120. In step 1 - 100-percent of original fibers 118a suspended in a
fluid enters the
system as original slurry. Step 2 ¨ the slurry is split. 15-percent goes to
refiner 136 as
refinable portion 160 and the other 85-percent (original portion 128) is
redirected to blender
130. Step 3 ¨ refining fibers to maximize bonding area, the 15-percent of
refinable fibers is
directed to and processed by refiner 136. Step 4 ¨ blending the two fiber
types: original
fibers 118a and refined fibers 118d are recombined and blended together. Step
5-the
optimized slurry is achieved and sent to paper machine 144 to be turned into
an optimized
paper, board or tissue product 146. Percentages stated above are only for this
one
17
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
illustrative example; however these percentages should not be considered
limiting and other
percentages may be used.
[0076] In one embodiment (Example 4), system 120, 120b is used in a dynamic
mode
where the amount of fiber flowing through each portion of the system is
adjusted as
measurements come in and are analyzed by master control system 108. FIG. 16
illustrates
step-by-step processing for such an embodiment showing ranges for the amount
of fiber
flow in each portion of system 120 at any given time. In step 1 - 100-percent
of original
fibers 118a suspended in a fluid enters the system as original slurry. Step 2
¨ the slurry is
split within the given ranges depending on what type of paper is to be
manufactured and
feedback information gathered in the rest of the process flow. For example,
fiber in the
range of 10-20 percent goes to refiner 136 as a refinable portion 160 and the
other 80-90
percent (original portion) is redirected to blender 130. Step 3 ¨ refining,
the 10-20 percent
of refinable portion is directed to and processed by refiner 136. Step 4 ¨
capacitance
involves storing the fiber and then drawing upon the stored fibers as needed
to mix the ideal
fiber composition. Step 5 ¨ blending the two fiber types: original fibers 118a
and refined
fibers 118d are recombined and blended together in any percentage that is
required to
produce the optimized slurry. Step 6- the optimized slurry containing
optimized fibers is
achieved and sent to paper machine 144 to be turned into an optimized paper,
board or
tissue product 146. Percentages stated above are only for this one
illustrative example;
however these percentages should not be considered limiting and other
percentages may be
used.
[0077] FIG. 17 (Table 1) lists data for samples prepared in accordance with
system 120
(120a, 120b) discussed in this disclosure and also for comparison samples that
were
prepared using standard conventional processing. Variables included whether
fractionation
occurred, the amount of feed and refined fibers combined, and the amount of
refining the
fibers were exposed to. For samples that were fractionated, a portion of feed
slurry was
fractionated at 0.5% TAPPI Standard T240 consistency. TAPPI is a registered
trademark
of Technical Association of the Pulp and Paper Industry, Inc. Fractionated
heavies were
refined in a TAPPI standard T248 PFI mill at varying revolutions. Fractionated
and refined
heavies were blended back with feed slurry at varying percentages. TAPPI
Standard T227
CSF drainage testing was performed on each blended slurry. TAPPI Standard T205
18
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
handsheets at 80 g/m2 were generated. TAPPI Standard T822 Ring Crush Strength
Testing
was performed. For samples that were not fractionated (unfractionated), a
portion of feed
slurry was refined in a TAPPI standard T248 PFI mill at varying revolutions.
Refined feed
slurry was then blended back with unrefined feed slurry at 25%. TAPPI Standard
T227
CSF drainage testing was performed on each blended slurry. TAPPI Standard T205
handsheets at 80 g/m2 were generated
TAPPI Standard T822 Ring Crush Strength Testing was performed. For standard
conventional processing, all feed slurry was refined in a TAPPI standard T248
PFI mill at
varying revolutions. TAPPI Standard T227 CSF drainage testing was performed on
each
level of refining. TAPPI Standard T205 handsheets at 80 g/m2 were generated
from sample
from each level of refining. TAPPI Standard T822 Ring Crush Strength Testing
was
performed on all handsheets.
[0078] FIG. 18 shows a plot of the exemplary data for paper strength of the
samples of FIG.
17 using standard refining practices and those practices outlined in this
disclosure by the
current invention associated with system (120, 120a, 120b). Triangular data
points on the
line are strength numbers of handsheets made from pulp using standard
conventional
refining practices. Circular data points are handsheet strength numbers made
from pulp
where highly refined fibers were blended with feed pulp at different blend
percentages and
refining levels. Paper strength was significantly increased using the system
and method
proposed by the current invention. TAPPI Standard T220 "beater curves",
plotting strength
of increasingly beaten pulp with freeness, were used to quantify the paper and
board making
strength potential for a given pulp sample. The comparison to be observed in
FIG. 18 is the
strength of new engineered paper according to the present invention with the
TAPPI
standard process. Obtaining higher strength at higher drainage levels is
desirable as the
easier it is for water removal at target strength, the greater the
productivity (by increased
production levels and with lower fiber usage). FIG. 18 shows refining heavies
such that
once blended back with original portion there is a step change of 5-15 percent
higher ring
crush strength at a target freeness (proxy for paper machine drainage) than
when all fibers
are refined. Refining has diminishing returns where increasing bonding levels
are
compromised by the break down in fiber structure. For the currently engineered
fibers is it
critical that only a portion of the fiber is refined. In this way it is
possible to maximize
bonding levels on that portion without compromising water removal or fiber
structure. This
19
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
is achieved in two ways, either by refining a portion of fractionated heavies
or by refining a
portion of the feed pulp. To get results A to H, which represents an average
of 10%
increase in strength at the same drainage as standard results, it is critical
to blend either
refined feed or refined fractionated heavies with feed pulp. These results
cannot be
achieved by conventionally refining of all feed pulp.
[0079] The slurry required to make paper includes bonding material and
structural material.
Bonding material is the additional surface area created during the generation
of new
cellulosic elements when preparing pulp fibers for making paper products on a
paper
machine. Surface area is related to the amount of crill and optical fines.
Structural material
is the cellulosic elements most closely resembling the original unrefined feed
pulp fibers.
The structural material maintains the drainage characteristics and paper
structure
characteristics. Drainage is commonly measured by Canadian Standard Freeness.
Paper
structural characteristics include bulk, stiffness, caliper and opacity
properties.
[0080] A typical conventional system 119 for making paper, FIG. 19, processes
structural
material and bonding material together at the same time. Feed pulp 122 is
directed into a
refiner 136. Refiner 136 refines feed pulp 122 to create conventionally
refined cellulosic
fibers 118e with a targeted level of refining. Conventionally refined fibers
118e are then
directed to a blender 130 where they are blended with broke. Tickler refiner
136a is where
final bonding material can be generated, and the only location where added
broke is also
refined. Structural material and bonding material exit the tickler refiner
136a and are
directed to paper machine 144 where they are used to create a conventional
paper product.
[0081] The process flow for the conventional system 119, FIG. 20, shows slurry
for
bonding material and structural material entering the system together as feed
pulp. The
process involves refining the bonding and structural material together. The
process then
involves blending the refined bonding and structural material with broke. The
process may
include tickler refining after blending. The purpose of tickler refining is
the final adjustment
of bonding material. Paper making then occurs by using the bonding and
structural material
to make paper.
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0082] There are several limitations associated with conventional processing.
In
conventional processes there is always a compromise between making the most
effective
bonding material and maintaining sufficient structural material. This
compromise is a result
of refining all pulp fibers together, which is exacerbated by multiple
refining processes.
Further limitations come from operator judgment being applied to refining. The
operator
judgment is required to continually reassess the refining compromises.
[0083] The limitations of the conventional system discussed above are
eliminated by new
paper making system 120, FIG. 21, that uses fiber processor system 200. The
purpose of
fiber processing system 200 is unique in that the system can create optimized
bonding
material in the form of glue pulp. This glue pulp is made for the sole purpose
of generating
bonding material. Glue pulp does not need to provide structure to the paper so
there is no
operational compromises between generating bonding and structural material.
Glue pulp is
generated using much higher refining energy levels than conventional refining.
The higher
refining energy levels produce optimum surface area with a high percentage of
curl in the
0.2-0.5mm fiber length fraction. In preferred embodiment, glue pulp supplies
all of the
bonding material needed within a paper mill. Producing a single source of
bonding material
promotes control and automation throughout the paper mill.
[0084] Glue pulp is defined as follows. Glue Pulp is a pulp that supplies all
the refiner
induced bonding material to make a targeted grade of paper or board. Bonding
material are
cellulose elements that support many more available hydrogen bonding sites
than is present
in conventionally refined pulp, FIG. 22. More surface area is directly
correlated with more
available hydrogen bonding sites. Glue pulp is a pulp with maximized surface
area and a
balance between fibrillated structural elements to connect across fiber groups
and fibrillated
fines material to connect fibers to fibers. Glue pulp is not "enhanced fibers"
as disclosed in
U.S. Patent 9,879,361 to Pande, which is incorporated herein by reference.
Pande teaches
peeling fiber surfaces to create more attached surface area. This creates more
fibrils
attached to the surface of a fiber, but the created fibrils will not be
available to relocate
among unrefined fibers to generate hydrogen bonds. Glue pulp is also not
cellulosic nano
fibrils (CNF) from as disclosed in U.S. Patent Publication 2017/0073893 to
Bilodeau et al.,
which is incorporated herein by reference. Bilodeau teaches using high
specific edge load
for fiber cutting for the first refiner and low specific edge load for a
second refining step for
21
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
brushing the cut fibers to makes CNF with an average fiber length between .2-
.5mm.
Bilodeau further teaches that a fiber processed to an average fiber length of
0.2 to 0.5mm
will have an optical fines content of between 70-90%. Optical fines are
cellulosic particles
less than 0.2 mm. Bilodeau's process does not create glue pulp because the
nature of the
fibrils released by mechanical action will not provide the necessary length to
connect
unrefined fibers efficiently. In contrast to the above noted prior art
processes, the present
invention increases the curl of structural cellulosic elements. Curl is the
ratio of actual fiber
length to projected fiber length, FIG. 23. Increased curl implies longer and
thinner fibrils
are being generated. In an experiment to define the properties of glue pulp,
three different
refiners were used to produce the glue pulp - a valley beater, a high shear
dispersion mill,
and a series disc refiner. The feed and resulting glue pulps were measured
optically. Each
glue pulp was blended 10% with 90% feed pulp. Handsheets were generated and
tested.
FIG. 24 shows that increasing the curl of fibers between 0.2 and 0.5 mm
increases the
tensile strength of paper fabricated from those fibers. It is critical that
the glue pulp fiber
length fraction in the range of 0.2-0.5mm have a curl index that is at least
30%, preferably
to 50%, ideally above 50% from the feed
[0085] Fiber processing system 200 for making glue pulp, FIG. 25, comprises a
fiber
fractionation system inlet 157 that splits incoming cellulosic fibers 118a
into an original
portion 128 and a fractionable portion 126, the original portion and the
fractionable portion
having substantially the same composition. Original portion 128 is then
processed through
fractionator 134 (shown as a hydrocyclone 150) to fractionate original fibers
118a of
fractionable portion 126 into a heavies fraction 155 having heavies fibers
118c and a lights
fraction 153 having lights fibers 118b. Fiber processor system 200 further
comprises a
refiner feed chest 222, refiner 136 glue pulp storage tank 224. Heavies fibers
118c are
stored in refiner feed chest 222, refined in refiner 136 and refined heavies
fibers 118d stored
in glue pulp storage tank 224. Fiber processing system 200 further comprises a
blender 130
for combining original fibers 118a, fibers 118d and optionally lights fibers
118b. The
processing of heavies fibers 118c, to make glue pulp 205, takes place within
glue pulp
processor 210. The details of system (120, 120a), and how the glue pulp
processor 210 is
integrated within that system, is shown in FIG. 21. Heavies fibers 118c may be
processed
through several types of glue pulp processors (210a, 210b and 210c).
22
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0086] The process flow for fiber processing 200, FIG. 26, shows feed pulp
entering the
system together. The process involves splitting the feed pulp containing both
structural
material and bonding material into two portions. Only a small portion of the
original feed
pulp is processed through the separating step. In one embodiment separation
involves the
use of hydrocyclones, where optimized slurry (heavies) for bonding material is
separated
from structural material (lights). The process further involves refining the
optimized slurry
to create bonding material as refined heavies. The process then involves
blending varying
amounts of original structural material, lights structural material and
optimized bonding
material to create an optimized slurry. Paper making then occurs by blending
the glue pulp
bonding and structural material to make paper products.
[0087] Using new fiber processing system 200, the generation of bonding
material is
separated from those fibers that will provide the structural integrity of the
paper. Fiber
processing system 200 generates bonding material from only a small portion of
the feed
pulp allowing most of the feed pulp to maintain its structural integrity. The
remaining
structural material can independently supply the necessary water removal
characteristics
and contribute to sheet structure. So instead of refining all fiber flows to
generate bonding
material while maintaining structural integrity, the bonding material is
produced separately
and then reintroduced. This new fiber processing system 200 and resulting
process allows
for generating ideal bonding material instead of compromising to maintain
drainage and
bulk physical properties in the same action of refining. In this fiber
processing system 200,
blending of glue pulp is used to accommodate for changes in grades, paper
machine
operations and reel quality. This bonding material, or glue pulp, is a one
step process which
eliminates the need to refine any other fiber flow for the generating of
bonding material.
[0088] Instead of two or three refining processes needing to be adjusted to
accommodate
feed pulp variability, paper machine variability and reel quality variability
there is now only
one refining process and this process is adjusted to target fiber properties.
The new single
process flow for generating bonding material can change the way that paper
mills are
configured. A comparison of a conventional paper mill with a paper mill
configured to run
with the new system 120 is represented in FIGS. 27 and 28, respectively. The
new fiber
processing configuration is a much simpler system that provides for the
removal of many of
the extra refining steps for generating bonding material required in
conventional
23
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
papermaking. Conventional paper mills currently have a refining strategy that
needs to
accommodate for the pulp quality variation, that strategy becomes more
complicated with
each additional refining step. The new single process flow for generating
bonding material
simplifies the accommodation for pulp quality variability by decreasing the
refining steps
and significantly reducing the fibers that need to actually be refined for
bonding material.
The new single process for generating bonding material using bonding material
processing
system 228 can use a system such as 120a or 120b to make the bonding material.
[0089] Glue pulp processor 210 is central to the fabrication of high quality
bonding
material. Glue pulp processor 210 may take several forms (210a, 210b, 210c).
In one
embodiment, FIG. 29, glue pulp processor A 210a is a batch system having a
single refiner
feed chest 222 feeding and receiving fibers to and from a single refiner 136.
Heavies fibers
118c from fractionation system 134 are first kept within a heavies fiber
storage tank 226
where the heavies fibers are then fed as a batch to refiner feed chest 222.
From the refiner
feed chest 222 all of the fibers are sent through refiner 136. Refined fibers
are recirculated
back to the refiner feed chest 222. The fibers are sampled and then tested by
a fiber
property measurement system 180 to determine if target fiber properties have
been met. If
the target fiber properties have been met, refined fibers 118d are sent to
glue pulp storage
tank 224 to be held prior to blending. If the specific fiber properties have
not been met, a
portion or all of the fibers are sent through refiner 136 for more refining
and then returned
to refiner feed chest 222 where the fibers are again sampled and tested by
fiber property
measurement system 180 to determine if specific fiber properties have been
met. This
process continues until the specific fiber properties have been met. The
contents of refiner
feed chest 222 are passed on to glue pulp storage tank 222 and a new set of
heavies fibers
118c feed to the refiner feed chest 222.
[0090] In one embodiment, FIG. 30, glue pulp processor B 210b is a series
system having a
plurality of refiners 136. Heavies fibers 118c from fractionation system 134
are stored
within refiner feed chest 222. From the refiner feed chest 222 all of the
fibers are sent
through refiner 1, then refiner 2, then refiner X. The fibers are sampled
after refiner X and
then tested by a fiber property measurement system 180 to determine if target
fiber
properties have been met. If the specific fiber properties have been met,
refined fibers 118d
24
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
are sent to glue pulp storage tank 224 to be held prior to blending. If the
specific fiber
properties have not been met, then adjustments to refining are made.
[0091] In one embodiment, FIG. 31, glue pulp processor C 210c is a parallel
system having
a plurality of refiners 136 feeding a single refiner feed chest 222. Heavies
fibers 18c from
fractionation system 134 are first kept within a heavies fiber storage tank
226 where the
heavies fibers are then fed as a batch to refiner feed chest 222. From the
refiner feed chest
222 a portion of the fibers is sent through each refiner 136. Refined fibers
are returned to
the refiner feed chest 222. The fibers are sampled and then tested by a fiber
measurement
system 180 to determine if target fiber properties have been met. If the
specific fiber
properties have been met, refined fibers 118d are sent to glue pulp storage
tank 224 to be
held prior to blending. If the specific fiber properties have not been met, a
portion or all of
the fibers are sent through one or more of the plurality of refiners 136 for
more refining and
then returned to refiner feed chest 222 where the fibers are again sampled and
tested by
fiber property measurement system 180 to determine if specific fiber
properties have been
met. This process continues until the specific fiber properties have been met.
The contents
of refiner feed chest 222 are then passed on to glue pulp storage tank 222 and
a new set of
heavies fibers 118c feed to the refiner feed chest 222.
[0092] In the present invention there are various methods for optimizing paper
machine
operation and paper properties using glue pulp. In one embodiment the method
comprises
providing original pulp, glue pulp held in glue pulp storage and comprised of
refined
heavies fractionated from the original pulp, and a blender. The method
involves blending
the original pulp and the glue pulp mixture in the blender, and then adjusting
the percentage
of glue pulp in the pulp mixture to optimize the paper properties and paper
machine
operation while maintaining a targeted amount of blended pulp mixture. The
method may
further comprise providing lights fractionated from the original pulp;
blending the original
pulp, the glue pulp and the lights to create the pulp mixture; and then
adjusting the
percentage of glue pulp in the pulp mixture to optimize the paper properties
and paper
machine operation while maintaining a targeted amount of blended pulp mixture.
[0093] In another embodiment the method comprises providing a fractionable
portion and
an original portion that are substantially the same composition. The
fractionable portion is
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
fractionated into a heavies fraction having heavies fibers and a lights
fraction having lights
fibers. The heavies are refined to produces glue pulp which may be held in
glue pulp
storage and then blended with the original portion and an amount of glue pulp
to create a
recombined slurry. It is critical to have the fractionable portion be 5-30
percent of the
original portion. After fractionation and refining this provides a critical
amount of glue
pulp in the range of 2.5-28.5 percent of the original portion. If under 2.5
percent glue pulp,
there is insufficient bonding material to obtain strength. If over 28.5% glue
pulp then the
negative economic consequence of loss of drainage due to lack of structural
material will
overcome the benefit of increases in paper properties.
[0094] During processing (Example 5) system 120, 120a can be run in a static
mode where
the amount of fiber flowing through each portion of the system is a constant
pre-determined
amount. FIG. 32 illustrates step-by-step processing for such an embodiment
showing the
amount of fiber flow in each portion of system 120. When operating in this
mode, previous
experimental data is used to predetermine what the fiber flow will be through
each portion
of system 120. In step 1 - 100-percent of original fibers 118a suspended in a
fluid enters the
system as original slurry. Step 2 ¨ the slurry is split; 20-percent goes to
fiber fractionation
system 134 as fractionable portion 126 and the other 80-percent (original
portion 128) is
redirected to blender 30. Step 3 ¨ fractionation occurs. The fractionable
portion 126 is
introduced into the fractionators and is separated/fractionated by the
fractionators into 10-
percent heavy fibers 118c (heavies fraction 155) and 10-percent light fibers
118b (lights
fraction 153). The 10-percent lights fraction is directed to blender 30. Step
4 ¨ Glue pulp
processing occurs to maximize bonding material. Here the 10-percent of heavies
fibers is
directed to and processed by refiner 136. Step 5 ¨ blending the three fiber
types: original
fibers 118a, light fibers 118b and refined heavy fibers 118d are recombined
and blended
together. Step 6- the optimized slurry is achieved and sent to paper machine
144 to be
turned into an optimized paper, board or tissue product 146. Percentages
stated above are
only for this one illustrative example; however these percentages should not
be considered
limiting and other percentages may be used.
[0095] During processing (Example 6) system 120, 120a can be run in a dynamic
mode
where the amount of fiber flowing through each portion of the system is
adjusted as
measurements come in and are analyzed by master control system 108. FIG. 32
illustrates
26
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
step-by-step processing for such an embodiment showing ranges for the amount
of fiber
flow in each portion of system 120 at any given time. In step 1 - 100-percent
of original
fibers 118a suspended in a fluid enters the system as original slurry. Step 2
¨ the slurry is
split within the given ranges depending on what type of paper is to be
manufactured and
feedback information gathered in the rest of the process flow. For example,
fiber in the
range of 5-30 percent goes to fiber fractionation system 134 as fractionable
portion 126 and
the other 70-95 percent (original portion 128) is redirected to blender 130.
Step 3 ¨
fractionation occurs. The fractionable portion 126 is introduced into the
fractionators and is
separated/fractionated into 2.5-28.5 percent heavy fibers 118c (heavies
fraction 155) and
0.25-15.0 percent light fibers 118b (lights fraction 153). The 0.25-15.0
percent lights
fraction is directed to blender 130. Step 4 ¨ glue pulp processing occurs to
maximize
bonding material, the 2.5-28.5 percent of heavies is directed to and processed
by refiner
136. Step 5 ¨ glue pulp storage involves storing the fiber and then drawing
upon the stored
fibers as needed to mix the ideal fiber composition. Step 6 ¨ blending the
three fiber types:
original fibers 118a, light fibers 118b and refined heavy fibers 118d are
recombined and
blended together in any percentage that is required to produce the optimized
slurry. Step 7-
the optimized slurry is achieved and sent to paper machine 144 to be turned
into an
optimized paper, board or tissue product 146. Percentages stated above are
only for this one
illustrative example; however these percentages should not be considered
limiting and other
percentages may be used.
[0096] The critical fiber engineering steps of splitting, fractionation, glue
pulp production
(refining) and blending have been experimentally verified for fiber processing
system 200.
The first verification show hydrocyclone operating conditions and output fiber
properties.
The fractionation of the "light" fraction from the "heavy" fraction was
accomplished using
reverse cleaner principles. A high yield kraft pulp was fractionated using a
hydrocyclone
with a feed consistency of 0.5% an input pressure of 32 psig, a pressure drop
of 25 psig and
a flow rate of 73 gallons a minute. These conditions are outlined in FIG. 34.
These
conditions, processed through this particular hydrocyclone, produced a top
flow consistency
of 0.18%, a bottom flow consistency of 3.03%, a mass balance split of 31% to
top flow and
69% to bottom flow and a volumetric balance split of 89% to top and 11% to
bottom flow.
This treatment produced fractioned pulp. Three samples, feed ¨ bottom flow ¨
top flow,
were measured optically to generate fiber quality data. The bottom flow had
199% less
27
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
optical fines than the top flow, 185% less fibers between 0.2 ¨ 0.5mm, 75%
less fibers
between 0.5mm and 1.0mm, and an increase in fibers between 1.5 ¨ 2.5mm and 2.5
-
5.0mm. Also the average fiber wall thickness was increased by 9% and fibers,
with a fiber
wall thickness greater than 3.2 p.m increased by 23%. The pulp exiting the
bottom flow of
the hydocyclone presented the best fibers for glue pulp production because the
fiber length
distribution was reduced and these fibers are best suited to generate long
thin unattached
fibrils when refined. The bottom flow fiber quality characteristics include a
decrease in
fines, small fiber (0.2-1.0mm) and thinner fiber walled pulp according to the
table in FIG.
35.
[0097] The second verification shows the glue pulp fiber properties made from
fractionated
feed pulp. Glue pulp production was accomplished by using the bottom flow of
the
fractioned pulp to become the feed to refining. Refining treatment liberates
surface area by
mechanical action. This treatment produced cellulose elements with increased
fines,
increased smaller fibers, increased curl for the fiber length fraction between
0.2 and 0.5mm,
increased crill bonding area and decreased long fibers according to the table
in FIG. 36.
[0098] The third verification is to show the superior paper properties of
handsheets when
produced from blending unrefined feed pulp with glue pulp. Blending was
accomplished in
a blender. The glue pulp that was produced by fractionation is then blended
back with the
original feed pulp at a ratio of 90% feed and 10% glue pulp. This blended pulp
was then
measured for Canadian Standard Freeness (CSF), made into 120g/m2 handsheets
and tested
for several physical properties. These resulting physical properties and CSF
were compared
with the reference condition of pulp fibers taken from the stuff box in the
paper machine
system.
Experimental results were obtained for the static process above, FIG. 32.
These results,
FIG. 37, show the improvements obtained with the invention over conventional
processing
for static processing. Strength properties (tensile, stretch, STFI, burst) are
increased with
increasing Bulk and minimal impact on drainage (CSF).
[0099] A comparison was made between glue pulp produced from fractionated and
unfractionated feed pulp. Both feed and bottom flow fractionated pulp were
refined in a
laboratory refiner at increasing levels of energy (0 ¨ 50 horse power day/ton,
in 10 hpd/t
increments). The resulting pulps, starting with unrefined feed, were measured
optically to
28
CA 03087854 2020-07-07
WO 2020/005289 PCT/US2018/040392
determine fiber length distribution as shown in FIG. 38. The fractionated pulp
is much
more responsive to mechanical treatment as evidenced by the changes in fiber
length
distribution as energy was applied to both the unfractionated feed and
fractionated pulp.
Fractionation maximizes the efficiency of energy transfer from refiner to
fiber. Maximizing
energy transfer supplies refiner feed fiber that is superior as a bonding
material. Glue pulp
can be produced without fractionation. However fractionation provides a
superior feed pulp
for glue pulp production as indicated in the experiment below.
[0100] This difference in how fractionated and unfractionated pulp responds to
refining
energy also is seen in difference to paper properties. Here both fractionated
and
unfractionated pulp were refined at 10, 20, 30, 40, 50 horse power day / ton
energy levels in
a lab disc refiner, to become glue pulp. This glue pulp was blended with
unfractionated,
unrefined feed pulp to make 120g/m2 handsheets comprising of 80% feed and 20%
glue
pulp. These handsheets were then tested for tensile strength and a tensile
index result
derived. Tensile is known to be a good proxy for bonding strength. The
difference between
producing glue pulp from fractionated versus unfractionated feed pulp is shown
in FIG. 39.
In this example unfractionated glue pulp requires twice the energy to generate
comparable
tensile strength index results as fractionated pulp.
[101] The blending range of 2.5%/97.5% to 28.5%/71.5% was determined to be
important.
This range was derived by balancing three considerations: (1) costs of
generating glue pulp,
(2) likely impact of glue pulp on blended pulps water removal characteristics
and (3) the
benefits of glue pulp addition to sheet structure. For any given grade the
blending range
closer to +/-2% from target blend percent. For any given paper machine, the
grade structure
will also incorporate a blending range less than +/-10% from average blending
percentage.
Conventional paper making uses blending as a way to introduce longer versus
shorter fiber,
recycled versus virgin and dry waste (broke) versus feed pulp. In conventional
papermaking, all components are refined to generate bonding sites while
maintaining
structural integrity for drainage and some of the reel properties. While
conventional
blending also incorporates the net effect of differential bonding
contribution, balancing that
contribution is only assessed by its effects on drainage (freeness) and paper
machine reel
properties rather than target fiber quality.
29
CA 03087854 2020-07-07
WO 2020/005289
PCT/US2018/040392
[0102] While several embodiments of the invention, together with modifications
thereof,
have been described in detail herein and illustrated in the accompanying
drawings, it will be
evident that various further modifications are possible without departing from
the scope of
the invention. The scope of the claims should not be limited by the preferred
embodiments
set forth in the examples, but should be given the broadest interpretation
consistent with the
description as a whole.
