1. Ulf Stenbacka, Christopher Lewis & Marco Polverari Kemira Oyj
New Micropolymer Technologies for Increased Drainage and Retention for both Wood and Non Wood Containing Furnishes
Ulf Stenbacka, Christopher Lewis & Marco Polverari
Kemira Oyj

2. Outline Brief Review of Retention Mechanisms
Characterization of New Micropolymer Dispersion Technology
Structure
Synergies
Retention Mechanisms
Pilot Studies
Alkaline Fine Paper
Case Studies
Alkaline Fine Paper – Strength
Alkaline Fine Paper – Dusting
Alkaline Fine Paper – Production
Conclusions

3. 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

4. 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

5. 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

6. 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 microparticle technologies
Colloidal Silica
Swellable Minerals (Bentonite)

7. Advanced Micropolymer Technology
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

8. Fennosil® Micropolymers
Cationic Micropolymers
Anionic Micropolymers

9. Product Characteristics
Schematic Illustration Micropolymer Series
Micropolymer Drop
(~ 3 μm)
Water
Coagulant
Lower MW
PAM
Higher MW

10. Product: Technology
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
This slide explains why the polymer is not linear, and form some agregates.

11. Properties

12. 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
Conventional System
Micropolymer System

13. Effect of Fennosil E on Ash Retention and Distribution
Electro-micrograph of filler distribution prior to Fennosil E-325 conversion.
Electro-micrograph of filler distribution after Fennosil E-325 conversion.

14. 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 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

15. Pilot Study A: Scott Bond and TEA
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
Dosage of PCC = 6.0 kg/t
Ash in sheet = 28%
FS-515 dosage = 0.7 kg/t (active)

16. Pilot Study A: Breaking Length and Specific Formation
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
Ash in sheet = 28%
Colloidal Silica dosage = 0.7 kg/t (active)

17. 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)

18. Case A: Retention
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
Anionic Dispersion MP applied post screen (shear) applied with colloidal silica
Applied with Cationic Starch

19. Case A: Strength (Tear)
Significant increase in both MD and CD tear
Anionic Dispersion MP applied post screen (shear) applied with colloidal silica
Applied with Cationic Starch

20. 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
Anionic Dispersion MP applied post screen (shear) applied with colloidal silica
Applied with Cationic Starch

21. 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):
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

22. 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

23. 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

24. 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

25. 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

26. 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

27. Mill Case C: Production
Significant increase in production across majority of grades
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%
Anionic Dispersion MP applied post screen (shear)
A-Pam applied pre-screen (shear)
PAC applied at fan pump (pre A-Pam)

28. Mill Case C: Formation
Formation improved across majority 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
Higher formation values are better
Anionic Dispersion MP applied post screen (shear)
A-Pam applied pre-screen (shear)
PAC applied at fan pump (pre A-Pam)

29. Mill Case C: Additive Efficiency
Significant starch reduction across 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
Anionic Dispersion MP applied post screen (shear)
A-Pam applied pre-screen (shear)
PAC applied at fan pump (pre A-Pam)

30. 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

31. Thank you