First
Firstsymposium
symposiumwithin
withinthe
theCOST
COSTE32
E32Action:
Action:
Paper/Ink
Paper/Ink Properties
Properties and
and their
their Relation
Relation to
to
Offset
Printability
Offset Printability
October
October6-7,
6-7,2005,
2005,Madrid
Madrid
The effect of formation on paper properties with
respect to different aggregation mechanisms
Elena Bobu and Florin Ciolacu
Technical University of Iasi, Romania
Vera Rutar
Pulp and Paper Institute of Ljubliana, Slovenia
SUMMARY OF PRESENTATION
Research
Research background
background
Research
Research approach,
approach, experimental
experimental
Effectiveness
Effectiveness of
of different
different aggregation
aggregation
mechanisms
in
controlling
mechanisms in controlling the
the retention
retention
and
and drainage
drainage rate
rate
Effect
Effect of
of the
the aggregation
aggregation mechanism
mechanism on
on
the
formation
quality
and
related
proprieties
the formation quality and related proprieties
of
of printing
printing paper
paper
Conclusions
Conclusions
1
PRINTING PAPERS - EMERGING PRESSURES
Good
Good quality
qualityat
at competitive
competitivecost
costis
isparamount
paramountin
in
performance
of
papermaking
system.
performance of papermaking system.
Higher
Higherbrightness
brightnessand
andopacity
opacity→
highfiller
fillerlevels
levels
→high
Market
Marketchange
changefrom
fromtight
tightsupply
supplyto
tooversupply
oversupply-more
morefocus
focuson
onquality
qualityand
andvalue
valueand
andless
lesson
ontonnage
tonnage
Advances
Advances in
in printing
printing techniques
techniques--new
new requirements
requirements
for
runnability
and
printability
for runnability and printabilitycharacteristics.
characteristics.
characteristics.
Increased
Increasedspeed
speedof
ofpaper
papermachine
machine-- more
moredemand
demand for
for
wet
wet
endprocess
processcontrol
control
wetend
THE IMPORTANCE OF FORMATION
Formation
Formationis
isthe
thespatial
spatialdistribution
distributionof
ofmass
masswithin
within
the
sheet
and
manifests
itself
as
variations
of
the sheet and manifests itself as variations ofthe
the
local
localbasis
basisweight:
weight:
The
Thebasis
basisweight
weightvariations
variationsarise
ariseout
outof
ofthe
theformation
formationof
of
fiber
fiberflocs
flocscreated
createdbefore
before and
andduring
duringsheet
sheetformation.
formation.
The
Theformation
formationquality
qualityof
ofpaper
papersignificantly
significantlyinfluence
influence
the
theend
enduse
useproperties
propertiesbecause
becauseitit affects
affectsalmost
almostall
all
physical
physicalproperties
propertiesof
ofpaper
paper
(Source:
(Source:Dodson,
Dodson,C.T.J.,
C.T.J.,and
andSchaffinit,
Schaffinit,C.,
C.,1992.
1992.Flocculation
Flocculationand
and
Orientation
Effects
on
Paper-Formation,
Tappi
Journal,
Orientation Effects on Paper-Formation, Tappi Journal,75,
75,1:
1:167-171.)
167-171.)
2
FORMATION AFFECTS PAPER PROPERTIES
One
Oneway
wayto
to optimize
optimizethe
theproperties
properties of
ofpaper
paperis
isto
to
improve
improvethe
theformation
formationbecause:
because:
The
Thepaper
paper strength
strengthdecreases
decreaseswith
withformation
formation
decreasing
decreasing
The
Theprintability
printabilityof
ofpaper
papersupports
supportssignificant
significantchanges
changesas
as
aafunction
of
formation
due
to
its
effect
on:
function of formation due to its effect on:
•• surface
surfacetopography
topography
•• porosity
porosityand
andpore
porestructure
structure
•• compressibility
/conformability
compressibility /conformability
•• stiffness
stiffnessand
andbulk
bulk
Optical
Opticalproperties
propertiesare
arenegatively
negativelyaffected
affected by
bydecreasing
decreasing
formation
quality
formation quality
(Source: Kajanto, I.”Effect of Formation on Print Unevenness.” Proceedings of the
TAPPI International Paper Physics Conference , Kona, HI, September 1991, 281-290.)
KEY PARAMETERS OF SHEET FORMATION
Highretention
retentionwith
withaauniform
uniform distribution
distributionof
ofthe
thestock
stock
High
components
during
sheet
formation,
and
a
high
drainage
components during sheet formation, and a high drainage
rate
are
key
elements
in
process
performance
rate are key elements in process performance
Drainage
Drainage
Formationquality
quality
Formation
is
caused
by
local
is caused by local
variations
of
the
variations of the
basisweight
weight
basis
Formation
Formation
Retention
Retention
Aggregation
Aggregation
(Flocculation)
(Flocculation)
Local
Localvariations
variationsof
of
the
basis
the basisweight
weight
occur
occurbecause
becauseof
of
fiber
flocs
fiber flocsformation
formation
Source:
Source:N.Jopson
N.JopsonAchieving
Achievingproduct
productquality,
quality,PPI
PPIAugust
August2004,
2004,p.22-24
p.22p.22-24
3
ROLE OF RETENTION CHEMICALS
Retention
Retentionchemicals
chemicalsare
areaakey
keycomponent
componentto
tomost
most
papermaking
systems:
papermaking systems:
Throughthe
thephenomena
phenomenaof
ofadsorption
adsorptionand
andelectrostatic
electrostatic
Through
interactions,
retention
chemicals
are
able
to
develop
interactions, retention chemicals are able to develop
differentaggregation
aggregationmechanisms
mechanismsby
bywhich
whichfillers,
fillers,fines,
fines,
different
andother
otherfunctional
functionaladditives
additivesare
areretained
retainedin
inthe
thesheet.
sheet.
and
Conventionalwisdom
wisdomis
isthat
thatthe
therelationship
relationshipbetween
between
Conventional
retention
/
drainage
and
sheet
formation
is
a
tradeoff:
retention / drainage and sheet formation is a tradeoff:
Increasingretention
retentionproduces
produces aadecrease
decreasein
information
formation
••Increasing
qualityand
andlow
lowretention
retentionresults
resultsin
inbetter
betterformation;
formation;
quality
Frequentlywhen
whenthe
thedrainage
drainageis
isimproved
improvedthe
the
•• Frequently
retention
falls
and
poor
formation
is
obtained.
retention falls and poor formation is obtained.
AGGREGATION
AGGREGATION IN
IN PAPERMAKING
PAPERMAKING
Aggregation
Aggregationdefinition:
definition:destabilization
destabilizationof
ofthe
thestock
stock
components
by
forming
“aggregates”
(flocs),
components by forming “aggregates” (flocs),which
which
cannot
cannotpass
passthrough
throughthe
theforming
formingwire.
wire.
..
The
The “flocs”
“flocs” could
could be
be different
different in
in terms
terms of
of ::
■■ Characteristics:
Characteristics: size,
size,density,
density,shear
shearstrength
strengthand
and
reversibility
reversibilityafter
afteraadispersion
dispersionstage.
stage.
■■ Type
Typeof
ofparticles
particlesinvolved:
involved:
•• fiber
fiberflocculation
flocculation
•• fines
finesand/or
and/orfiller
fillerflocculation
flocculation
•• adhesion
adhesionof
offines
finesand
andfiller
fillerto
tofibers
fibers(heteroflocculation)
(heteroflocculation)
4
AGGREGATION STATE
Variousfactors
factorsinfluence
influencethe
theinteraction
interactionmechanisms
mechanisms
Various
betweenstock
stockcomponents,
components,and
andfinely
finelydetermine
determinethe
the
between
aggregation
or
stabilization
of
the
colloidal
system.
aggregation or stabilization of the colloidal system.
Factors
Factors that
that affect
affect the
the aggregation
aggregation mechanism:
mechanism:
■■
■■
Surface
Surfacecharacteristics
characteristicsof
ofparticles
particles →
→electrical
electricalcharge
charge
Size
Sizedistribution
distributionof
ofparticles
particles →
→fines
finesand
andCDM
CDM
■■ Polymers
Polymers characteristics
characteristics →
→ MW,
MW,charge,
charge,structure
structure
■■ Electrolyte
Electrolyteconcentration
concentrationand
andpH,
pH,conductivity
conductivity
■■ Hydrodynamic
Hydrodynamic conditions
conditions→
→intensity
intensityand
and duration
duration
AGGREGATION
AGGREGATION -- RELEVANCE
RELEVANCE TO
TO PAPERMAKING
PAPERMAKING
The
Thewet
wetend
endprocesses
processesand
andpaper
paperproperties
propertiesare
areintimately
intimately
related
to
the
aggregation
state
of
the
furnish
components.
related to the aggregation state of the furnish components.
Paper sructure
Retention
Specific Filtration
Resistance
Aggregation mechanism
Fiber
CDM
Additives
Fines
Hydrodynamics
Dewatering
Formation
Papermakers
Papermakershave
haveto
tocontrol
control
the
aggregation
state
the aggregation state during
during
furnish
furnishpreparation
preparationand
andsheet
sheet
formation.
formation.
5
AGGREGATION MECHANISMS
The
Thewet
wetend
end aggregation
aggregationmechanisms
mechanismsare
aregenerally
generally
referred
as
retention
mechanisms,
and
could
referred as retention mechanisms, and couldbe
bedivided:
divided:
■■ Coagulation:
Coagulation:
Less relevant for
printing paper stock
““The
Thedestabilization
destabilizationof
ofaacolloidal
colloidalsystem
systemwith
withsalts
saltsor
orlow
lowmolecular
molecular
weight,
weight,high
highcharge
chargedensity
densitypolyelectrolytes”
polyelectrolytes”
••Coagulation
Coagulation by
bycharge
chargeneutralization
neutralization
••Coagulation
Coagulationby
bypatch
patchmodel
model
■■ Flocculation:
Flocculation:
Very important for
printing paper stock
“The
“Thedestabilization
destabilizationof
ofaacolloidal
colloidalsuspension
suspensionby
bybonding
bondingthe
the
particles
together
with
a
long
chain
polymer”
particles together with a long chain polymer”
•• Flocculation
Flocculationby
bybridging
bridgingpolymers
polymers
•• Complex
Complexflocculation
flocculationwith
with multi-component
multi-componentsystems
systems
RELATIONSHIPS BETWEEN FLOCCULATION
MECHANISM AND PAPER PROPERTIES
Study
Study objectives:
objectives:
To
To develop
develop different
different aggregation
aggregation mechanisms
mechanisms
and
and evaluate
evaluate their
their effectiveness
effectiveness in
in controlling
controlling
the
retention
and
drainage
processes.
the retention and drainage processes.
To
To evaluate
evaluate the
the effect
effect of
of the
the different
different aggregation
aggregation
mechanisms
mechanisms on
on the
the printing
printing paper
paper properties.
properties.
6
EXPERIMENTAL
EXPERIMENTAL APPROACH
APPROACH
Selecting
Selecting chemicals
chemicals for
for different
differentaggregation
aggregation mechanisms:
mechanisms:
••Bridge
Bridgeflocculation
flocculation by
bypolyacrylamides
polyacrylamides(PAM)
(PAM)
••Microparticle
flocculation
with
two
components:
Microparticle flocculation with two components:
PAM
PAM++Bentonite
Bentonite(B);
(B); PAM
PAM++Micropolymer
Micropolymer(MP)
(MP)
••Microparticle
flocculation
with
three
components:
Microparticle flocculation with three components: PAM
PAM++BB++MP
MP
Evaluation
Evaluationof
ofthe
thefirst
firstpass
passretention
retention(FPR)
(FPR)and
andfree
free
drainage
at
constant
dosages
of
chemicals,
drainage at constant dosages of chemicals,established
established
for
for maximum
maximum effectiveness
effectiveness
Preparing
Preparinghandsheets
handsheetswith
withoptimum
optimumdosages
dosagesof
of
chemicals
for
retention
and
drainage
chemicals for retention and drainage
Evaluating
Evaluatingformation
formationquality
qualityand
andrelated
relatedpaper
paperproperties.
properties.
MATERIALS
MATERIALS
Paper
Paper stock
stock basic
basic components:
components:
■■ Fibrous
Fibrousfurnish
furnish was
wasone
onetypical
typicalfor
forfine
fineprinting
printingpaper:
paper:
hardwood
hardwood(BHWP)
(BHWP)and
andsoftwood
softwood(BSWP)
(BSWP)bleached
bleachedkraft
kraft
pulps
at
a
ratio
BHWP/BSWP
of
80/20
by
dry
weight,
pulps at a ratio BHWP/BSWP of 80/20 by dry weight,
0
separately
separatelybeaten
beaten in
in aa Valley
Valleybeater
beater to
to 30
300SR.
SR.
■■ Filler
Fillermaterial:
material:natural
naturalcalcium
calciumcarbonate
carbonate(Hydrocarb
(HydrocarbHO,
HO,Omya)
Omya
■■ Sizing
Sizingagent:
agent:AKD
AKDemulsion
emulsion(Aquapel-210D,
(Aquapel-210D, Hercules)
Hercules)
■■ C
Cationic
ationicstarch
starch((CS
CS))––substitution
substitutionindex
indexof
of0.003
0.003
7
MATERIALS
MATERIALS
Retention
Retention additives
additives -- CIBA
CIBA Specialty
Specialty Chemicals
Chemicals
■■ Bridge
Bridge flocculation
flocculation polymers:
polymers:
Polyacrylamides
Polyacrylamides with
withdifferent
different molecular
molecularweight
weight and
and
cationic
charge
density:
Percol
292;
Percol
3040
cationic charge density: Percol 292; Percol 3040
■■ Microflocculation
Microflocculation -- nanoparticles:
nanoparticles:
Bentonite
Bentonite --anionic
anionicinorganic
inorganiccomponent
component--Hydrocol
HydrocolOT
OT
Micropolymer
Micropolymer -- anionic
anionic organic
organic component
component --Polyflex
PolyflexCP3
CP3
MATERIALS
Bridge flocculation
The
Theaggregates
aggregates are
areforming
formingby
by
bonding
the
particles
together
bonding the particles together
with
withaa long
longchain
chainpolymer.
polymer.
Chemicalsof
ofPercol
Percolseries
series--copolymer
copolymerof
of acrylamide
acrylamide
Chemicals
andacryloxyethyltrimethyl
acryloxyethyltrimethyl-ammonium
-ammoniumchloride
chloride::
and
Percol 292::medium
mediummolecular
molecularweight
weight(MMW)
(MMW)
Percol
292
cationic
density1.455
meq/g
cationic density- 1.455 meq/g
highmolecular
molecularweight
weight(HMW)
(HMW)
Percol 3040 :high
Percol
3040 :
cationic
density1.0
meq/g)
cationic density- 1.0 meq/g)
8
MATERIALS
Microparticle flocculation
Bridgeflocculation
flocculationby
bycationic
cationicPAM
PAM
••Bridge
Flocsdispersion
dispersionby
byintense
intenseshear
shear
•• Flocs
•
Microflocculation
by
anionic
microparticle
• Microflocculation by anionic microparticle
Microparticle:
Microparticle:
Hydrocol
HydrocolOT
OT--Bentonite
Bentonite(B)
(B)
Sodium
Sodiumform
formof
ofmontmorillonite
montmorilloniteclay
clay
-- anionic
in
slurry
anionic in slurryform
form
Nanoparticle:
Nanoparticle:
Polyflex
PolyflexCP.4
CP.4--micropolymer
micropolymer(MP)
(MP)
Polyacrylamide,
Polyacrylamide,water
watersoluble,
soluble,
anionically
charged
anionically chargedmicronetwork
micronetwork
structure
structure. .
LABORATORY
Wet
Wet end
end processes:
processes:
TESTS
Firstpass
passretention
retention(FPR)
(FPR)--on
onDDJ
DDJapparatus
apparatus
●●First
Thecalculation
calculationof
ofthe
theFPR
FPR (total/
(total/CaCO
CaCO33))was
wasbased
based
The
onthe
theconcentration
concentrationof
ofwhite
whitewater
water
on
Drainagetime
time(DT)
(DT) --on
onShöpper
Shöpper
●● Drainage
Rieglerapparatus
apparatus
Riegler
Thedrainage
drainagetime
timemeans
means time
timeto
tocollect
collect700
700 mL
mLww
ww
The
Chargedensity
density(CD)
(CD)of
ofthe
the
●● Charge
additivesand
andcationic
cationic
additives
charge
demand
(CCD)
of
the
furnish
were
determined
charge demand (CCD) of the furnish were determined
by colloidal
colloidal titration
titrationwith
withstandard
standardpolymers
polymers
by
9
LABORATORY
TESTS
Paper
Paper properties:
properties:
Formation ––Optical
OpticalScanner
ScannerMeasurement
Measurement
●●Formation
Calciumcarbonate
carbonatecontent
content(TAPPI
(TAPPI––T413)
T413)
●●Calcium
Opticalproperties
properties -- Elrepho
Elrepho 2000
2000 (Opacity
(Opacity --ISO
ISO2471)
2471)
●●Optical
Airresistance
resistance––Gurley
Gurley(ISO5636-5)
(ISO5636-5)
●●Air
Micro-macroporosity
porosity(Microcontour
(Microcontourtest-IGT
test-IGTW
W26)
26)
●●Micro-macro
Inkstability
stabilitytest
test ((lab
labprinting
printingpress
press––Prufbau,
Prufbau,optical
opticaldensity
density––
●●Ink
spectrophotometerEyeOne)
EyeOne)
spectrophotometer
Tensilestrength
strength((ISO1924-1,
ISO1924-1,1992)
1992)
●●Tensile
PROCEEDING WORK
Byproceeding
proceeding experiments,
experiments,the
theeffectiveness
effectivenessof
of
By
polyacrylamides with
withdifferent
different molecular
molecularweight
weight and
and
polyacrylamides
cationic
density
was
evaluated
for
their
performance
in
cationic density was evaluated for their performance in
improvingretention
retentionand
anddrainage.
drainage.
improving
Theexperimental
experimentalprogram
programwas
wasperformed
performedwith
withvariable
variable
The
dosagesof
ofadditives
additivesconsidering:
considering:
dosages
►Fourpolyacrylamides
polyacrylamideswith
withdifferent
differentmolecular
molecularweight
weight
►Four
Percol63;;Percol
Percol 3335;;Percol
Percol3040
andcationic
cationicdensity:
density:Percol
Percol292;;Percol
and
292
63
3335
3040
►Four
Fouradditive
additivesystems:
systems:
►
Flocculationwith
withsingle
singlecomponent
component(PAM)
(PAM)
Flocculation
Micro-flocculation
with
two
components
(PAM/B)
Micro-flocculation with two components (PAM/B)
Micro-flocculation
with
two
components
(PAM
MP)
Micro-flocculation with two components (PAM //MP)
Micro-flocculation
with
three
components
(PAM
MP)
Micro-flocculation with three components (PAM //BB//MP)
10
CONCLUSIONS ON PAMs PERFORMANCE
The best
best performance
performance for
for retention
retentionand
anddrainage
drainagewas
was
The
recorded
for
two
polyacrylamides
with
different
properties:
recorded for two polyacrylamides with different properties:
Percol-292and
andPercol-3040
Percol-3040..
Percol-292
Retention system
Filler
Retention, %
PAM dosages,
%
PAM
PAM/MP
PAM/B
66.5
PAM/B/MP
66
P3040
52
P292
0.08
0.08
0.08
0.07
P3040
0.10
0.10
0.08
0.10
59
72
64
77
76
The highest levels
of filler retention
P292
Retention system
The best
drainage
capacity
PAM
Drainage
time (s)
P292
16
P3040
22
PAM dosages,
%
P292
0.08
P3040
0.08
PAM/MP
PAM/B
16
7
10
16
15
0.08
0.08
24
0.08
PAM/B/MP
0.08
0.08
0.08
EXPERIMENTAL PROGRAM
Tasks:
► Evaluation
Evaluationretention/drainage
retention/drainageperformance
performanceof
ofthe
theP-292
P-292
►
andP-3040
P-3040at
atoptimum
optimumdosages
dosagesin
indifferent
differentcombinations
combinations
and
► Preparing
Preparinghandsheets
handsheetsand
andmeasuring
measuringpaper
paperproperties
properties
►
Paper stock:
basic
composition
BHWKP /
BSWKP
80 / 20
CaCO3 - 30%
A0
Without retention additives
A1-3
PAM - 0.07: P292; P3040; MP
A4-5
PAM / MP- 0.07 / 0.07 : P292; P3040
A6-7
PAM / B - 0.07 / 0.7: P292; P3040
AKD - 8 kg/t
A8-9
CS - 10 kg/t
PAM / B / MP- 0.07/0.35/0.035: P292; P3040
11
RESULTS AND DISCUSSIONS
Developing different
different flocculation
flocculation mechanisms
mechanisms with
with
Developing
optimum dosages
dosages of
of chemicals
chemicals and
and evaluation:
evaluation:
optimum
►Total
►Total and
and Filler
FillerFirst
First Pass
Pass Retention
Retention (FPR)
(FPR)
►
► Drainage
Drainage rate
rate of
of paper
paper stock
stock
►
► Formation
Formation quality
quality and
and printing
printing properties
properties of
of
paper
paper sheets
sheets
RETENTION and DRAINAGE TIME
35
100
35
90
30
90
30
80
25
80
25
70
20
70
20
60
15
60
15
50
10
50
10
40
5
30
0
w/o add.
P292
P3040
MP
FPR-total
62
82
72
80
FPR-CaCO3
33
66
53
62
28.7
15.4
21.3
27.8
Drainage time
FPR (%)
100
40
30
5
P3040
w/o add. P292 + B
+B
P292 + P3040 +
MP
MP
FPR-total
62
84
89
82
FPR-CaCO3
33
69
77
66
61
28.7
6.4
13.6
17.1
23.3
Drainage time
Drainage time (s)
Micro-flocculation
Two components
Drainage time (s)
FPR (%)
Flocculation
Single component
0
77
As
Assingle
singlecomponent
componentthe
thePercol-292
Percol-292(medium
(mediummolecular
molecularweight
weightand
and
high
cationic
density)
give
the
highest
retention
and
drainage
high cationic density) give the highest retention and drainagerate.
rate.
Two
Twocomponent
componentsystem
systemusing
usingbentonite
bentoniteas
asmicroparticle
microparticledevelops
developsthe
the
highest
retention
with
P-3040
and
the
best
drainage
with
P-292.
highest retention with P-3040 and the best drainage with P-292.
12
RETENTION and DRAINAGE TIME
Micro-flocculation
Three components
35
100
35
90
30
90
30
80
25
80
25
70
20
70
20
60
15
60
15
50
10
50
10
40
5
40
5
30
0
w/o add. P292 + B
P3040
+B
P292 + P3040 +
MP
MP
FPR (%)
30
0
w/o add.
P292 + MP/B P3040 +MP/B
FPR-total
62
84
89
82
77
FPR-total
62
83
FPR-CaCO3
33
69
77
66
61
FPR-CaCO3
33
68
72
28.7
6.4
13.6
17.1
23.3
28.7
9.3
15.3
Drainage time
Drainage time
Drainage time (s)
100
Drainage time (s)
FPR (%)
Micro-flocculation
Two components
83
In
Inthree
threecomponent
componentsystem,
system,the
thelevels
levelsof
ofretention
retentionand
and
drainage
drainage are
areaalittle
littlelower
lowerthan
thanin
intwo
twocomponent
componentsystem,
system,
but
butthere
thereis
isaaless
lesssensibility
sensibilityto
tothe
thetype
typeof
ofpolyacrylamide.
polyacrylamide.
FILLER
FILLER RETENTION
RETENTION VS.
VS. DRAINAGE
DRAINAGE TIME
TIME
•• Excepting
Exceptingthe
themicropolymer
micropolymer(MP)
(MP)as
assingle
singlecomponent,
component,all
alladditive
additive
systems
systemsimprove
improvethe
therelationship
relationshipbetween
betweenretention
retentionand
anddrainage
drainage
The
effectiveness
of
the
P-292
is
less
dependent
of
the
additive
The effectiveness of the P-292 is less dependent of the additivesystem
system..
In
Inaathree
threecomponent
componentsystem,
system,the
themicropolymer
micropolymerallows
allowsaabetter
bettercontrol
control
of
drainage
rate
of drainage rate
100
w/o add.
90
P292
80
FPR-CaO3 (%)
••
••
P292
P3040
MP
70
P292 + B
60
P3040 + B
50
P292 + MP
40
P3040 + MP
30
P292 + B/MP
w/o add.
20
0
5
10
15
20
25
30
P3040 + B/MP
35
40
Drainage time (s)
13
FORMATION EVALUATION
Since, the retention additives cause flocculation of fibers, fines
and filler particles, they further tend to impair paper formation.
Consequently, evaluating the impact of retention additive
systems on the formation quality is an important step in
optimizing printing paper manufacture.
Method for formation evaluation:
Scanner - MicroTek ScanMaker 5900
Transmission light
Resolution - 300 dpi
Measured surface - 400 x 400 pixel
Processing – Image J.
Result – CV
FORMATION
FORMATION vs.
vs. ADDITIVE
ADDITIVE SYSTEM
SYSTEM
19
Percol
: MMW
Percol292
292: MMW
CD
CD=1.45
=1.45meq/g
meq/g
18
Formation
17
Produces
Producesbetter
betterinteraction
interaction
with
withanionic
anionicfines
finesthat
thatare
are
flocculated
flocculatedon
onthe
thefiber,
fiber,dedecreasing
creasingprobability
probabilityof
offiber
fiber
flocculation.
flocculation.
16
15
14
13
12
11
10
o
w/
d.
92 040
ad P2
P3
M
P
92
P2
+
M
P
P
P
P
B
M
M
M
+
B/ 0 +
0
B/
04 0 +
4
2
3
0
9
P
04
P3
P2
P3
92
P2
+
B
+
Percol
HMW
Percol3040
3040: : HMW
CD
CD==1.0
1.0meq/g
meq/g
By
Byits
itslong
longchains
chainsand
andlow
low
cationic
cationicdensity
densityfavors
favorsfiber
fiber
flocculation.
flocculation.
•• Excepting
Exceptingthe
thesample
samplewithout
withoutretention
retentionadditives,
additives,the
thebest
bestformation
formationwas
was
obtained
,,but
its
obtainedusing
usingaapolyacrylamide
polyacrylamidewith
withMMW
MMWand
andhigher
higherCD
CD--PP292
but
its
292
combinations
combinationswith
withmicroparticle
microparticlegive
givepoorer
poorerformation.
formation.
••Polyacrylamide
as single flocculation chemical impairs
Polyacrylamideof
ofHMW
HMW--PP3040
3040 as single flocculation chemical impairs
formation
quality,
and
significant
formation quality, and significantimprovements
improvementsof
offormation
formationare
areobtained
obtained
when
it
is
applied
in
combinations
with
microparticle
components.
when it is applied in combinations with microparticle components.
14
OPACITY
OPACITY vs.
vs. FILLER
FILLER CONTENT
CONTENT
86
w/o add.
P292
85
Opacity, %
P3040
84
MP
P292 + MP
83
P292 + B
Percol
: MMW
Percol292
292: MMW
CD
CD=1.45
=1.45meq/g
meq/g
Percol
HMW
Percol3040
3040: : HMW
CD
CD==1.0
1.0meq/g
meq/g
P292 + B/MP
82
P3040 + MP
81
P3040 + B
P3040 + B/MP
80
8
10
12
14
16
18
20
Filler content, %
Micropolymer
Micropolymer(MP):
(MP):
anionic
anioniccharge,
charge,
micromicro-network
network
structure
structure
■ When they are applied as single component, all polyacrylamides provide a
consistent increase in filler content (about 5 units, % ), but only a slight
improvement in opacity (~ 1 unit, %)
■ The microflocculation systems give an increase in filler content of 5 -8 units,
and higher levels of opacity ( 2-5 units, %) as a function of the polyacrylamide
and/or microparticle type.
OPACITY
OPACITY vs.
vs. FORMATION
FORMATION
■ There are no direct correlations between paper opacity and formation
quality because of differences in filler content and aggregation mechanism.
■ At about the same formation, the opacity is higher for microflocculation
systems, especially combinations with Percol 292 → P292 + B/MP
86
w/o add.
P292
85
Opacity, %
P3040
84
MP
P292 + MP
83
P292 + B
P292 + B/MP
82
P3040 + MP
81
P3040 + B
P3040 + B/MP
80
10
12
14
16
Formation
18
20
CaCO3, %
10.8
15.8
15.5
15.1
15.2
16.5
16.9
15.2
17.2
17.8
PP292 single
292 single
produces
produces
filler
fillerparticle
particle
aggregation
aggregation
and
and reduces
reduces
scattering
scattering
surface,
surface,but
but
no
nofiber
fiber
flocculation.
flocculation.
P3040 favors fiber
flocculation and less
filler aggregation
15
OPACITY
OPACITY // FILLER
FILLER CONTENT
CONTENT vs.
vs. FORMATION
FORMATION
20
86
w/o add.
P292
18
P292
P3040
P3040
16
MP
MP
P292 + MP
P292 + MP
P292 + B
P292 + B
P292
12 + B/MP
P292 + B/MP
P3040 + MP
P3040 + MP
10 + B
P3040
P3040 + B
Filler content (%)
Opacity, %
85
w/o add.
84
83
82
81
14
P3040 + B/MP
P3040 + B/MP
80
8
10
12
14
16
18
20
10
Formation
12
14
16
18
20
Formation
■ The two polyacrylamides applied as single component give about the same
filler content, very different formation quality and close values of opacity
■ The microflocculation systems, especially as a three components, give
lower variation in the filler content and formation quality but large difference
in opacity → at the same formation and lower filler content, the P292 produces
higher opacity comparatively with P3040
TENSILE STRENGTH vs. ADDITIVE SYSTEM
■ Tensile strength decreases when formation becomes more no uniform,
as it is the case of the P3040 (HMW –PAM) as single component.
5000
20
4500
18
4000
16
3500
14
3000
12
2500
10
2000
w /o
Formation / Filler (%)
Breaking length, m
■ By using a proper additive system, the negative effect of higher filler
content on tensile strength is balanced by a better formation.
8
ad
d.
P2
92
P3
0
40
Form ation
P
P
M P 0 + B B/ M
+B
/M
MP +
4
92 2 + B
2
0+
+
0
2
4
9
0
3
0
P
9
P
P2
04
P3
P2
P3
MP
Filler content,%
Breaking length, m
16
STRENGTH
STRENGTH vs.
vs. FILLER
FILLER CONTENT
CONTENT // FORMATION
FORMATION
5000
5000
Breaking length (m)
Breaking length (m)
4500
4000
3500
3000
2500
w/o add.
w/o add.
P292
4500
P292
P3040
P3040
4000
MP
MP
P292 + MP
P292 + MP
3500
P292 + B
P292 + B
P292 + B/MP
P292
3000 + B/MP
P3040 + MP
P3040 + MP
P3040 + B
2500 + B
P3040
P3040 + B/MP
P3040 + B/MP
2000
2000
8
10
12
14
16
18
20
8
Formation
10
12
14
16
18
20
Filler content (%)
■ The single component flocculation systems show a normal correlation of the
tensile strength with formation, but not with filler content.
■ In the case of micro-flocculation systems there are different relationships as
a function of the polyacrylamide and microparticle types : generally, P292
and micropolymer give higher strength at the same filler content.
AIR RESISTANCE vs.
ADDITIVE SYSTEM
The air resistance can be an indirect indicator of internal / surface
structure of paper, being influenced by additive system and filler
content. At a relative low variation in filler content, the flocculation
mechanisms give structures with different air resistance:
16
14
12
3
10
8
2
6
4
1
Filler content (%)
18
4
2
M
P2
92 P
+
M
P
P2
92
P2
+
92
B
+
B/
P3
M
P
04
0
+
P3 MP
04
P3
0
+
04
B
0
+
B/
M
P
0
P2
92
P3
04
0
0
ad
d.
In all combinations, the
micropolymer- MP
determines an increase
and bentonite-B a
decrease of the air
resistance.
Air resistance (s,Gurley)
P3040 produces fiber
flocculation and a more
permeable structure.
20
5
w/
o
P292 induces fines
flocculation leading to a
structure with high air
resistance:
Air resistance
Filler content
17
AIR RESISTANCE VS. FORMATION
• There is a trend of air resistance increase with formation
improvement (from sample P3040 to P292 and w/o add.)
• However, the microparticle systems gives very different
values of the air resistance for a relative narrow range of
formation quality
5
Air resistance (s, Gurley)
w/o add.
P292
4
P3040
MP
3
The two types of
micro particles can
be applied in different
manners in order to
control air resistance:
P292 + MP
P292 + B
2
P292 + B/MP
• Bentonite for
lowering
P3040 + MP
1
P3040 + B
P3040 + B/MP
0
10
12
14
16
18
20
• Micropolymer for
increasing
Formation
MICRO – MACRO PORES
IGT W 26: Test ink – blue micro contour 3811
Micro pores – interior pores
Macro pores – exterior (surface pores)
Example of calculation:
Micro pores - y = ΔR1450
ΔR 450 = Rpaper1 - Rprint1
ΔR450 = 82.09 – 46.20
y = 35.9
100
90
80
R (%)
70
60
50
Macro pores - x
40
30
20
10
0
400 420 440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740
nm
paper
MCprint
x = ΔR450 – ΔR600
ΔR600 = Rpaper1 - Rprint1
ΔR600 = 84.96 – 4.51= 80.45
x = 35.9
18
MACRO / MICRO PORES
50.0
20
46.0
18
46.0
18
42.0
16
42.0
16
38.0
14
34.0
12
38.0
14
34.0
12
Relative value (%)
20
Formation
Relative value (%)
50.0
30.0
30.0
10
o
w/
d.
ad
92
P2
Macro pores
0
04
P3
M
Micro pores
o
w/
P
Formation
Microflocculation
Two- and three-components
Flocculation
PAM –single component
10
d.
ad
92
P2
Formation
+
M
P
92
P2
+
B
92
P2
Macro pores
+
M
B/
P
0
04
P3
+
M
P
B
+
0
B
+
04
0
P3
04
3
P
Micro pores
P
/M
Formation
■ There are not direct correlations between formation and values of pore
components, these depending mainly of the PAM type and additive system
■ The relative value of the macro-pores is higher for all additive systems
comparatively with sample without additives. P3040 leads to more uniform
ratio between micro and macro pores comparatively with P292.
MACRO / MICRO PORES RATIO
Macro pores (relative value)
50
w/o add.
P292
46
All additive systems produce a
change of the ratio between
relative values of the macroand micro-pores by
increasing the surface
component
P3040
MP
42
P292+MP
P292+B
38
P292+B/MP
P3040+MP
34
P3040+B
P3040+B/MP
30
30
34
38
42
46
50
Micro pores (relative value)
1.5
w/o add.
P292
At very different formation
qualities (from 12 to 18), the
ratio between micro- and
macro-pores varies in a
relative narrow range
(from 0.7 to 1.0)
Micro / Macro Pores
1.3
P3040
MP
1.1
P292+MP
P292+B
0.9
P292+B/MP
P3040+MP
0.7
P3040+B
P3040+B/MP
0.5
10
12
14
16
18
20
Formation
19
INK STABILIZATION MEASUREMENT
The measurement gives information on the ink drying speed.
The principle of the measurements is the optical density
determination of the printed areas after different time intervals
• The optical density as a function of
drying time for a sample is compared
with that for a optimal curve.
INK S T AB IL IZAT IO N
2
1.8
1.6
• The shape of the optimal curve is
determined in practise.
1.2
1
0.8
• Sample preparation → Dürner-Prüfbau device
0.6
0.4
• Drying speed evaluation →
0.2
Spectrophotometer
EyeOne (Macbeth)
0
0
100
200
300
400
500
600
tim e (s )
INK
INK STABILIZATION
STABILIZATION vs.
vs. ADDITIVE
ADDITIVE SYSTEM
SYSTEM
1.4
Standard
w/o add.
P 292
P 3040
MP
1.2
Optical density
Optical density (Drs)
1.4
1
0.8
Single component
additive system
0.6
0.4
0.2
0
0
60
120
180
240
300
Time (s)
Comparing the optimal curve (standard) of ink stabilization with
those of paper obtained with different types of PAM, one can observe:
• A higher initial penetration rate, but a lower drying rate
• However, ink stabilization of samples with PAM is better than
sample without additives, and MP gives the best drying rate
20
INK
INK STABILIZATION
STABILIZATION vs.
vs. PORE
PORE STRUCTURE
STRUCTURE
1.4
Standard
w/o add.
P 292
P 3040
MP
Optical density
1.2
1
0.8
• The drying rate
improvement by flocculation
additives seems to be
correlated with increase of
macro-pores level.
0.6
0.4
0.2
0
60
120
180
240
300
• There are no correlations
between ink stabilization
and formation quality
Relative value (%)
Time (s)
50.0
20
46.0
18
42.0
16
38.0
14
34.0
12
30.0
Formation
0
10
w
/o
ad
d.
9
P2
2
Mac ro pores
P
4
30
0
M
Mic ro pores
P
Form ation
INK
INK STABILIZATION
STABILIZATION vs.
vs. ADDITIVE
ADDITIVE SYSTEM
SYSTEM
P292
1.4
P3040
1.4
Standard
1.2
P 292 + MP
1
P 292 + B/MP
0.8
P 3040
P 3040 + MP
1
P 292 + B
Optical density
Optical density
Standard
1.2
P 292
0.6
P 3040 + B
0.8
P 3040 + B/MP
0.6
0.4
0.4
0.2
0.2
0
0
0
60
120
180
Time (s)
240
300
0
60
120
180
240
300
Time (s)
■ Ink stabilization is consistently improved for microparticle
additive systems, excepting combination P3040 + B
■ The P292 appears to have a better balancing effect in interaction
with both microparticle types (Bentonite and Micropolymer) →
drying curves are well fitting on the optimal curve
21
CONCLUSIONS
Different
Different aggregation
aggregation mechanisms
mechanisms were
were
developed
developed considering:
considering:
►Polyacrylamides
►Polyacrylamideswith
withdifferent
differentmolecular
molecularweight
weight
and
Percol-3040
andcationic
cationicdensity:
density:Percol-292;
Percol-292; Percol-3040
►
►Four
Fouradditive
additivesystems:
systems:
Flocculation
Flocculationwith
withsingle
singlecomponent
component (PAM)
(PAM)
Micro-flocculation
Micro-flocculationwith
withtwo
twocomponents
components(PAM/B)
(PAM/B)
Micro-flocculation
Micro-flocculationwith
withtwo
twocomponents
components (PAM
(PAM // MP)
MP)
Micro-flocculation
Micro-flocculationwith
withthree
three components
components (PAM
(PAM // BB//MP)
MP)
CONCLUSIONS
Influence
Influence of
of polyacrylamide
polyacrylamide type:
type:
Flocculation
Flocculationwith
withaasingle
singlecomponent:
component:
►The
►The polyacrylamide
polyacrylamidewith
withmedium
mediummolecular
molecularweight
weight and
and
) is the most effectively
high
highcationic
cationicdensity
density(Percol
(Percol292
292) is the most effectively
for
for retention/drainage,
retention/drainage,and
andalso
alsogives
givesaagood
goodformation.
formation.
►The
►The polyacrylamide
polyacrylamidewith
withhigh
highmolecular
molecularweight
weight and
and low
low
cationic
)
produces
slight
increase
of
cationicdensity
density(Percol
(Percol3040
)
produces
slight
increase
of
3040
retention/drainage,
retention/drainage,but
butimpairs
impairsstrongly
strongly formation
formation quality.
quality.
►
► The
Themicropolymer
micropolymer (Polyflex
(PolyflexCP4)
CP4) alone
aloneis
isnot
noteffective
effectivein
in
controlling
wet
end
processes
and
sheet
formation
controlling wet end processes and sheet formation
22
CONCLUSIONS
Influence
Influence of
of additive
additive system
system
Microflocculation
Microflocculationwith
withbentonite
bentoniteand
and//or
ormicropolymer:
micropolymer:
►
► Effectiveness
Effectivenessof
ofall
all PAMs
PAMsis
isimproved
improvedin
incombination
combination
with
withmicroparticle
microparticleby
bybalancing
balancingwet
wetend
endprocesses
processesand
and
paper
properties
paper properties
►The
►Thecombinations
combinationswith
withbentonite
bentoniteare
arevery
veryeffectively
effectivelyfor
for
drainage
in
both
systems
and
the
retention
drainage in both systems and the retentionsupports
supportsalso
also
aaconsistent
consistentincrease,
increase,but
butformation
formationquality
qualityis
islower
lower
comparatively
comparativelywith
withmicropolymer
micropolymersystems.
systems.
►The
►Thecombinations
combinationswith
withmicropolymer
micropolymer show
show an
anincrease
increase
of
air
permeability
without
damage
the
formation
of air permeability without damage the formation quality,
quality,
and
andtensile
tensilestrength
strengthis
isalso
alsoimproved.
improved.
CONCLUSIONS
The
The flocculation
flocculation mechanism
mechanism influences
influences most
most
part
of
the
printing
paper
properties:
part of the printing paper properties:
►Generally,
►Generally, the
theretention
retentionadditives
additivesproduce
produceaadecrease
decreaseof
of
formation
quality,
but
choosing
an
adequate
flocculation
formation quality, but choosing an adequate flocculation
mechanism
mechanismallow
allowus
usto
toget
getthe
theoptimum
optimumcompromise
compromise
between
formation,
retention
and
drainage.
between formation, retention and drainage.
►Some
►Someproperties
properties--air
airpermeability
permeabilityand
andtensile
tensilestrength
strength––
are
arewell
wellcorrelated
correlatedwith
withflocculation
flocculationformation
formationquality
quality
►Other
►Otherproperties
propertieslike
likeopacity
opacityand
andink
inkstabilization
stabilizationare
are
influenced
influencedby
byflocculation
flocculationmechanism
mechanismas
asresult
resultof
of
differences
differencesin
information
formationquality
qualityand
andlevel
levelof
offiller
fillerretention.
retention.
23
OVERALL CONCLUSION
The
The results
resultspresented
presentedhere
hereshow
show that
thatititis
is
possible
possible to
toobtain
obtainmore
more benefits
benefits from
from
microparticle
microparticleretention
retention systems
systemsby
byoptimum
optimum
combination
combinationof
ofbentonite
bentoniteand
andmicropolymer
micropolymer
with
withan
anadequate
adequate cationic
cationicpolyacrylamide
polyacrylamide::
Balancing
Balancing the
the wet
wet end
end processes
processes
Better
Better control
control of
of paper
paper properties
properties
Product
Product innovation
innovation and
and development
development
AKNOLEDGEMENT
The
The authors
authors wish
wish to
to thank
thank Oskar
Oskar Vogel
Vogel and
and
Konstantin
Konstantin Ivanov
Ivanov from
from Ciba
Ciba Specialty
Specialty Chemicals
Chemicals
for
for their
their support
support in
in developing
developing these
these studies.
studies.
24