new micropolymer technologies for increased drainage and retention for both wood and non wood...

New Micropolymer Technologies for Increased Drainage and New Micropolymer Technologies for Increased Drainage and Retention for both Wood and Non Wood Containing FurnishesRetention for both Wood and Non Wood Containing Furnishes

Ulf Stenbacka, Christopher Lewis & Marco PolverariUlf Stenbacka, Christopher Lewis & Marco PolverariKemira OyjKemira Oyj

Outline

Brief Review of Retention Mechanisms

Characterization of New Micropolymer Dispersion TechnologyA. Structure

B. Synergies

C. Retention Mechanisms

Pilot StudiesA. Alkaline Fine Paper

Case StudiesA. Alkaline Fine Paper – Strength

B. Alkaline Fine Paper – Dusting

C. Alkaline Fine Paper – Production

Conclusions

Retention Mechanisms

Narrow balance exists to achieve optimal retention and formation• Runnability vs. Quality

Dispersed colloids deposit onto fines and fibre to form flocs• Retained by filtration

Adsorption of small particles becomes more challenging as furnish exposed to greater hydrodynamic shear stress

• Increasing machine speed

Increased complexity with the presence of ash and elevated ash load

Traditional Retention Chemistries

Poly-acrylamides (PAM’s) are efficient for gross retention

• High molar mass long chain polymers• Generally linear some structured

versions

Development of large flocs via ‘bridging” mechanism to achieve sufficient retention of fillers and fines

• Sheet structure = “hard flocced” or macro flocculated

PAM’s can agglomerate filler particles• Effectively increase average particle size• Optical efficiency can be compromised

PAM created floc can contain a substantial level of bound water

Former drainage improved but pressing efficiency decreased

Traditional Retention Chemistries

High charged low molar mass polymers allow for fixation or patch retention

• Fillers, fines, detrimental substances

Can improve drainage via soluble charge control

Retention limited due to lack of floc structure

Necessary application rate for reactivity can overly decrease cationic demand

• Inhibit retention of other process additives

Next Generation Micropolymers

Creates floc and subsequent sheet structure that maximizes former drainage without compromising pressing efficiency

Very effective for retention of ash• Calcium carbonates (precipitated and ground)• Kaolin• Calcium Silicate

Unique structure and composition enables them to be reactive in low and high ash environments and in wood and non wood containing furnishes

• SC• News• LWC• Printing and Writing• Unbleached/Bleached Board

Unique synergies when applied in conjunction with traditional inorganic Unique synergies when applied in conjunction with traditional inorganic microparticle technologiesmicroparticle technologies

• Colloidal SilicaColloidal Silica• Swellable Minerals (Bentonite)Swellable Minerals (Bentonite)

A Dual System in a Single Application

A controlled molecular weight cationic or anionic polyacrylamide polymerized within a coagulant matrix. The coagulant matrix is either:

• Inorganic coagulant (Sulfate salt)

• Organic coagulant (e.g. polyamine)

In order to distinguish these new products from conventional water-in-oil emulsions the name “water-in-water dispersion” has been chosen

The coagulant matrices of these products is responsible for the fixation of anionic trash, and the high-molecular species for the retention of fibres and fillers

Inclusion of hydrophobic associative monomers• Cationic and anionic versions• Forms ‘hydrogel’ polymer

• Strongly hydrogen bonding

Advanced Micropolymer Technology

Fennosil® Micropolymers

ProductAverage

Charge Density (meq/g)

Mol. Wt. x E06 Solids Mole % Charge Chemistry

E-130 5,30 5 34% 40 AM/p-amineE-128 5,44 5 34% 30 AM/p-DADMACES-325 2,06 7 20% 10 AM/SaltE-126 5,02 8 36% 10 AM/p-amine

Cationic Micropolymers

Anionic Micropolymers

Product Solids Mol. Wt. x E06 Mole % Charge ChemistryES-210 25 5 -30 AM/AA + saltES-211 25 5 -13 AM/AA + salt

Product Characteristics

Schematic Illustration Micropolymer Series

Micropolymer Drop(~ 3 μm)

WaterCoagulant

Lower

MW

PAM

Higher MW

Water

Product: Technology

HydrophobeHydrophobe

Hydrophobic groups incorporated to HMW/LCD polyelectrolyte

Hydrophobic groups lead to inter and/or intra molecular interactions

• Formation of micelles• Higher solution viscosity• Higher elasticity• More structure

Properties

0

2

4

6

8

10

12

14

16

18

20

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Molecular Weight (MM)

Ch

arg

e D

ensi

ty (

meq

/g)

NEW Micropolymers (Cationic)

CATIONIC PAM'S

Pu

re P

EI

Modified PEI

p-DADMAC

DMA-Epichlorohydrin

Micropolymer Retention/Drainage Mechanism

Micropolymer unique charge and structural properties allows (cationic) polymer to control anionic trash while retaining fibres and fillers

Floc structure advantageous for both retention and drainage• Increased dewatering in former• Increased dewatering in press

Fines and filler flocculated along the long fibres as small discrete flocs• Minimize level of bound water• Reduction of blocking of inter-fibre pores

Floc

W ood Fiber

W ood Fiber

W ood Fiber

F loc

Floc

Floc

W LF204 W LF204

Conventional System Micropolymer System

Effect of Fennosil E on Ash Retention and Distribution

Electro-micrograph of filler distribution after Fennosil E-325 conversion.

Electro-micrograph of filler distribution prior to Fennosil E-325 conversion.

Pilot Study A: Strength and Structure Enhancement

Pilot machine study conducted using alkaline fine paper

Primary objective of the study was to increase sheet ash to 20% while reducing use of starch

Applied cationic potato starch pre-shear at 2 kg/T (1/3 regular dosage)

Applied cationic PAM pre-shear at ½ regular dosage

Applied silica and anionic dispersion micropolymer post shear simultaneously

Relate gains to the resulting sheet structure

Fibre and Process CharacteristicsFibre and Process Characteristics• ASA size• Precipitated calcium carbonate (PCC) used for filler• Cationic potato starch• OBA added at both size press and wet-end• Sheet ash 16-18% maximum

Pilot Study A: Scott Bond and TEA

Dosage of PCC = 6.0 kg/t

Ash in sheet = 28%

FS-515 dosage = 0.7 kg/t (active)

Increasing ASMP has a significant positive effect on internal bond strength

• 35% improvement

Increasing ASMP has a significant positive effect on tensile strength

• 30% improvement

150160170180190200210220230240250

0 0.2 0.5 0.7 1

Anionic Dispersion Micropolymer Dosage (kg/t)

Sco

tt B

on

d (

Jsm

)

400500600700800900100011001200

TE

Ain

dex

(m

J/g

)

Scott Bond TEAindex

Pilot Study A: Breaking Length and Specific Formation

Ash in sheet = 28%

Colloidal Silica dosage = 0.7 kg/t (active)

Increasing ASMP has a significant positive effect on tensile strength

• 25% improvement

Increasing dosage of anionic micropolymer improved formation. The lower the number the better the formation.

• 40% improvement

3.0

3.2

3.4

3.6

3.8

4.0

4.2

4.4

0 0.2 0.5 0.7 1

Anionic Dispersion MP Dosage (kg/t)

Bre

akin

g L

eng

th (

km)

0.0

0.2

0.4

0.6

0.8

1.0

Sp

ec. F

orm

atio

n

(Sq

. rt

g/m

)

Breaking Length Specific Formation

Case A: Uncoated Free Sheet

Machine Type: Top Former

Objective: Improve ash retention and strength to potentially increase sheet ash target

Grades: Offset, Xerographic

Sheet Ash: 15% - 18%

Incumbent Program: Silica (0.60 – 0.75 kg/t) and Cationic Potato Starch (4 – 5 kg/t)

Other Wet End Chemistry: Alkenyl Succinic Anhydride (ASA) Sizing, Precipitated Calcium Carbonate, Alum

Proposed Chemistry: Anionic Dispersion Micropolymer Chemistry + Colloidal Silica

Application: Anionic Dispersion Micropolymer (0.15 – 0.4 kg/t) applied post shear with existing silica (0.25 – 0.35 kg/t)

Case A: Retention

Anionic Dispersion MP applied post screen (shear) applied with colloidal silica

Applied with Cationic Starch

Significant increase in ash retention across all the grades

Improved additive efficiency: OBA & Size

This achieved with 40%+ reduction in application rate of colloidal silica

Ability to evaluate lower cost starch

• Some loss in efficiency

• Improved retention over incumbent program with potato

30

35

40

45

50

55

60

65

70

75

80

85

90

Xerographic(FPR)

Xerographic(FPAR)

Offset 50#(FPR)

Offset 50#(FPAR)

Offset 60#(FPR)

Offset 60#(FPAR)

Fir

st P

ass

Ret

enti

on

/Fir

st P

ass

Ash

Ret

enti

on

Silica Starch Anionic Dispersion MP/Silica

Case A: Strength (Tear)



Significant increase in both MD and CD tear

65

66

67

68

69

70

71

72

73

74

75

76X

ero

gra

ph

ic (

CD

Te

ar)

Xe

rog

rap

hic

(MD

Te

ar)

Off

se

t 5

0#

(C

DT

ea

r)

Off

se

t 5

0#

(M

DT

ea

r)

Off

se

t 6

0#

(C

DT

ea

r)

Off

se

t 6

0#

(M

DT

ea

r)

MD

/CD

Te

ar

(mN

)


Case A: Strength (Tensile/Burst)



Significant increase in tensile strength

• CD and MD

• Burst

With increased strength potential to increase sheet ash target by 3% (20% total)

Achieved in trials• Done with both corn and

potato starch & without significantly increasing retention chemistry

Potential for significant savings in fibre cost

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

Xe

rog

rap

hic

(Bu

rst)

Xe

rog

rap

hic

(C

DT

en

sil

e)

Xe

rog

rap

hic

(MD

Te

ns

ile

)

Off

se

t 5

0#

(Bu

rst)

Off

se

t 5

0#

(C

DT

en

sil

e)

Off

se

t 5

0#

(M

DT

en

sil

e)

Off

se

t 6

0#

(Bu

rst)

Off

se

t 6

0#

(C

DT

en

sil

e)

Off

se

t 6

0#

(M

DT

en

sil

e)

MD

/CD

Te

ns

ile

(k

N/m

)/B

urs

t (k

Pa

)


Case Study B: Uncoated Free Sheet

Machine Type: Top Wire Former

Objective: Increase sheet ash by 1% - 2% without negatively impacting sheet strength or increasing dusting propensity.

Grades: Xerographic

Basis Weights: 80 – 90g/m2

Sheet Ash: 22%

Machine Speed (Range): 950 - 1000 m/min

Furnish Components: Bleached Hardwood 50% , Softwood 50% Broke 20% - 30+%

Incumbent Program: Silicated PAC + Anionic PAM

Other Wet End Chemistry: Alkenyl Succinic Anhydride (ASA) Sizing, Precipitated Calcium Carbonate, Starch, Alum

Proposed Program: Anionic Dispersion Micropolymer applied with existing Anionic PAM (A-Pam) and silicated PAC system

Case Study B: Retention/Dosage (On-Line)

Anionic Dispersion Micropolymer introduced in addition to existing A-PAM and silicated PAC chemistry

• Co-Mixed with A-PAM

Immediate decrease in headbox ash

• 2.9 g/L to 2.2 g/L

Immediate decrease in white water solids

• 0.163 g/L to .137 g/L

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

10:5

0

11:3

0

12:3

5

13:3

5

18:0

0

0:00

8:30

9:30

11:0

0

12:1

0

14:0

0

16:0

0

20:4

0

22:4

0

1:00

8:25

9:20

10:0

0

WW

So

lids

(g/L

)

0

100

200

300

400

500

600

700

800

900

1000

Reten

tion

Ad

ditive A

pp

lication

Rate (g

/t)

white water solids (g/L)

Headbox Ash (g/L)

Anionic Dispersion MP Application RateTrial Start

Break

Case Study B: Retention (Lab)

Increase in First Pass Ash Retention better than 10+ points

Achieved both at equal and with sheet ash levels at 1% and 2% greater

46.3

57.2 55.857.6

43.4

30.0

35.0

40.0

45.0

50.0

55.0

60.0

65.0

70.0

75.0

80.0

Pre-Trial 22% SheetAsh

Trial 22% SheetAsh

Trial 23% SheetAsh

Trial 24% SheetAsh

Post Trial 22%Sheet Ash

Fir

st

Pa

ss

Re

ten

tio

n/F

irs

t P

as

s A

sh

Re

ten

tio

n (

%)

FPR FPAR

Case Study B: Dusting

Decreased dusting level at equal ash

Dusting propensity did not increase with higher sheet ash load

Sheet ash increment of 2% (24%) at equal dust level as 22% sheet

405.5

315.7

439.3

402.0

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

Av

era

ge

Du

st

Le

ve

l (m

g/1

00

00

)

average 22% ashbefore the trial

average 22% ash 450g/t Anionic Dispersion

MP


MP


MP

Case Study B: Defects

ULMA Defects 01 – 02 reduced by 45+%

Lowest defect level achieved at highest ash loading

• Function of transition• 22% data included start-

up• “Cleaning-Up” of wet end

5.5

4.3

3.0 3.0

6.0

0

1

2

3

4

5

6

UL

MA

De

fec

ts 0

1-0

2 (

co

un

t/m

2)

average 22% ashbefore the trial

average 22% ash450 g/t AnionicDispersion MP



average 22% ashafter the trial

Mill Case C: Uncoated Free Sheet

Machine Type: Fourdrinier

Objective: Replace existing retention program to improve formation and increase production

Grades: Lt. Wt. Opaque, Offset, Text

Sheet Ash: 12% - 16%

Incumbent Program: Bentonite, Linear C-Pam, Cationic Potato Starch

Other Wet End Chemistry: Alkenyl Succinic Anhydride (ASA) Sizing, Precipitated Calcium Carbonate

Proposed Chemistry: Anionic Dispersion Micropolymer Chemistry, A-Pam, and poly-aluminium chloride (PAC)

Application: Anionic Dispersion Micropolymer (0.6 – 1.0 kg/t) applied post shear with A-Pam (0.2 – 0.5 kg/t) applied pre shear, and PAC (1 – 2 kg/t) applied pre A-Pam

Mill Case C: Production

Anionic Dispersion MP applied post screen (shear)

A-Pam applied pre-screen (shear)

PAC applied at fan pump (pre A-Pam)

Significant increase in Significant increase in production across majority of production across majority of gradesgrades

• As much as 15+%As much as 15+%

This achieved despite that pre-size press moisture was reduced as much as 0.7%

• Bentonite program pre size press moisture average approximately 1.6%

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

35# Lt. Wt.Opaque

50# Book 55# Book 40# Offset 60# Offset 60# Copy

Pro

du

ctio

n R

ate

(t/h

r)

C-PAM/Bentonite

A-PAM/Anionic Dispersion MP

+3.8%

+2.1%

+2.8%+5.4%

+5.7%

+15.7%

Mill Case C: Formation

Higher formation values are better




Formation improved across Formation improved across majority of the gradesmajority of the grades

• At least equal

Grades with largest improvement in formation also saw an average of ½ point increase in opacity

• 50#, 55# book• 40# Offset

Grades where equal, generally greatest increase in production

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

35# Lt. Wt.Opaque


MK

Fo

rmat

ion

C-PAM/Bentonite


Hig

he

r is

Be

tte

r

Mill Case C: Additive Efficiency




Significant starch reduction Significant starch reduction across all the gradesacross all the grades

• 1.5 – 3.0 kg/t• No loss in retention• FPAR as high as 80% on some

grades

Quality not compromised

Sizing response equal or better at equivalent or lower ASA application rate

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

35# Lt. Wt.Opaque


Sta

rch

Usa

ge

(kg

/t)

C-PAM/Bentonite


Conclusions

A new generation of cationic and anionic micropolymer dispersions has been developed

Unique synergies exist with co-application of the micropolymer dispersions with traditional inorganic microparticle technologies

Chemistries are robust enough to be applied in a wide range of furnishes

Unique composition and structure allow them to increase sheet dewatering while significantly increasing retention in both low and high ash environments

Chemistry shows ash selectivity, particularly with presence of (precipitated) calcium carbonate

Significant increase in retention quality exhibiting lower propensities for dusting

Sheets formed with this technology impart greater strength (wood free) – significant increases of both tear and tensile have been observed

Appreciable increases in drainage have been observed

Thank you

new micropolymer technologies for increased drainage and retention for both wood and non wood...

Documents

ash retention

structure slide

retention of fibres

optimal retention

maximum slide

patch retention fillers

fines sheet structure

elevated ash load slide