Commercial Manufacture and Application of Micro-Fibrillated Cellulose in Paper and Paperboard

Per Svending, Imerys Mineral AB, Sweden September 17th 2015

Specialty Papers Conference Milwaukee WI, USA Publicised images of ”cellulose nanofibrils” show great diversity

A wide range of shapes and sizes made through different processes by companies, universities, and institutes across the world. FiberLean™ microfibrillated cellulose (MFC), a recent addition to the papermakers toolbox Surface micrograph of finepaper containing FiberLean MFC and filler The FiberLean™ MFC process

 Co-grinding pulp to MFC in the presence of minerals. – The mineral acts as a very fine grinding media

 Robust and reliable equipment of relevant industrial scale.

 On-site manufacturing, using a minor side stream of mill pulp.

 No pre-treatment of fiber required.

 The FiberLean product is a MFC/mineral composite. Co-grinding pulp to MFC in the presence of mineral

• Relatively coarse fibrils. • Fibril length is important for wet end addition • A wide range of pulps can be used • Also flexible with regard to the mineral  GCC  PCC  Kaolin  Talc

 TiO2

1 μm Commercial scale experience with FiberLean™ MFC

Packaging

Coated Woodfree

Specialty + mechanical

Uncoated Woodfree

0 50 100 150 200 250 300 350 Basis weight, g/m2

 Close to 50 full scale trials on 21 paper machines to date • In Europé, North America, South America and Asia.  Trials ranging from a few hours to several days.  Extensive experience across segments • 6 mills in UWF • 6 mills in speciality and mechanical paper • 8 mills in CWF • 2 mills in Packaging  3 commercial contracts for on-site MFC plants. Impact of MFC on paper strength

Tensile Burst 35 3

30 2 25 No MFC No MFC 20 3% MFC 1 3% MFC 15 5% MFC 5% MFC Tensile Index (Nm/g) Index Tensile Burst Index (kN/g) Index Burst

10 0 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Bond Tear 200 12 10 150 8 100 No MFC 6 No MFC 3% MFC 4 3% MFC 50

Scott Bond (J/m2) Bond Scott 5% MFC 5% MFC

Tear Index (mN.m2/g) Index Tear 2 0 0 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%) It is possible to increase

Lab study filler by 10% or more and Mesmer recirculating hand sheets (12 sheets) 70% Eucalyptus, 30% NBSK, 550 CSF suffer no strength loss. Intracarb 60 filler Impact of MFC on paper tensile

Tensile Elongation 35 6

30 5 4 25 No MFC 3 No MFC 20 3% MFC 2 3% MFC 15 5% MFC 5% MFC Tensile Index (Nm/g) Index Tensile 1 Breaking elongation (%) elongation Breaking 10 0 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

TEA Modulus 1400 2.5 1200 2 1000 800 1.5 No MFC No MFC 600 1 3% MFC 3% MFC 400 5% MFC 0.5 5% MFC 200 Youngs modulus (GPa) modulus Youngs 0 0

Tensile Energy Absorption (J/kg) Absorption Energy Tensile 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Lab study Mesmer recirculating hand sheets (12 sheets) 70% Eucalyptus, 30% NBSK, 550 CSF Intracarb 60 filler Behaviour of MFC in the tensile stress-strain curve

8 28% filler no MFC Force (N) 6 28% filler with 1,7% MFC

0 0 0.5 1 1.5 2 2.5 3 3.5 4 Displacement (mm)

Pilot study 80% Eucalyptus, 20% NBSK, 500 CSF Intracarb 60 filler Behaviour of MFC in the tensile stress-strain curve

14 + 24% Tensile 12

8 28% filler no MFC Force (N) 6 28% filler with 1,7% MFC

4 + 0,6 %-units of stretch 2 + 21% 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Displacement (mm)

Pilot study 80% Eucalyptus, 20% NBSK, 500 CSF Intracarb 60 filler Impact of MFC on paper tensile

Tensile Elongation 35 6

TEA Modulus 1400 2.5 1200 2 1000 800 1.5 No MFC No MFC 600 1 3% MFC 3% MFC 400 5% MFC 0.5 5% MFC 200 Youngs modulus (GPa) modulus Youngs 0 0

Tensile Energy Absorption (J/kg) Absorption Energy Tensile 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Lab study Mesmer recirculating hand sheets (12 sheets) 70% Eucalyptus, 30% NBSK, 550 CSF Intracarb 60 filler Impact of MFC on optical properties

Brightness Opacity 91 93 92 90 91 90 89 No MFC 89 No MFC 3% MFC 88 3% MFC Opacity (%) Opacity 88 87 5% MFC 5% MFC 86 87 85 Brightness (% at D65 – 400 nm) 400 – D65 at (% Brightness 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Scattering Absorption 900 5

800 4.5 g)) /g) 2 2/ 700 No MFC 4 No MFC K (cm K S (cm S 3% MFC 3% MFC 600 3.5 5% MFC 5% MFC

500 3 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Lab study Mesmer recirculating hand sheets (12 sheets) 70% Eucalyptus, 30% NBSK, 550 CSF Intracarb 60 filler Impact of MFC on other properties

Porosity Density 3500 0.7 3000 2500 0.65 2000 No MFC 0.6 No MFC 1500 3% MFC 3% MFC 1000 Density (g/cm3) Density 0.55 5% MFC 5% MFC 500 Porosity, Bentsen (ml/min) Bentsen Porosity, 0 0.5 5 15 25 35 45 5 15 25 35 45 Paper filler content (%) Paper filler content (%)

Initial drainage 10 • The porosity impact can be important for 8 hold-out of ink or coating colour. 6 No MFC • Density can be regained by trading the 4 3% MFC positive impact on smoothness and bond

Drainage time (sek) time Drainage 2 5% MFC strength with less intense calendering

0 and/or use of coarser fiber, such as CTMP. 5 15 25 35 45 • While initial drainage slows down there is a Paper filler content (%) positive impact on couch and press solids.

Lab study Mesmer recirculating hand sheets (12 sheets) 70% Eucalyptus, 30% NBSK, 550 CSF Intracarb 60 filler FiberLeanTM performance summary

Tensile Index 30% 20% 10% Density 0% Tear Index -10% -20% -30% -40% -50% -60%

Porosity Scott Bond

Opacity TEA

20% filler, No MFC 30% filler, 3% MFC

14 Date Title of the presentation Full scale results from adding FiberLean to increase filler level in a woodfree paper

5 2% MFC 4% MFC +8% filler +16% filler 4.5

4 MD Tensile 3.5 The strength of the paper

3 is maintained at increasing levels of filler and MFC. 2.5 CD Tensile

Tensile strength Tensile 2

1.5

0.5

0 0 5 10 15 20 25 Addition of FiberLean with 20% MFC content (%) Beyond the primary target application of filler increase in P&W papers there are new product development opportunities to pursue

 Based on porosity reduction • Improved hold-out of coatings

 Based on strength and opacity • De-materialisation Reduction in coat weight to reach a given gloss level Adding FiberLean™ MFC to specialty paper at constant filler loading all chemical pulp at 250 CSF and 20% filler

Tensile Bendtsen Energy Tear Index Scott Bond Opacity Porosity Absorption J/kg mN m 2 /g J/m 2 ml/min % Reference 792 5,7 209 258 87,8 1% MFC 924 5,7 288 180 88,2 2% MFC 859 5,8 291 114 88,3 4% MFC 1224 6,5 377 104 88,8

To facilitate applications like this FiberLean can be supplied at up to 50% MFC content with the balance being almost any type of mineral filler. Selecting correct filler loading to reach a given opacity and strength at minimum basis weight

No filler - minimum sheet weight for required opacity ) 2

Target strength and opacity Basis (g/m weight

No filler - minimum sheet No filler - minimum sheet weight weight for required opacity for required strength

Filler content (%) Selecting correct filler loading and sheet weight with FiberLean™ Pilot paper machine data

84% Opacity no mfc 84% Opacity 2% mfc 84% Opacity 3% mfc 84% Opacity 4% mfc

for for target 60 2

g/m 50

30 0% 5% 10% 15% 20% 25% 30% Total Filler Loading Selecting correct filler loading and sheet weight with FiberLean™ Pilot paper machine data

84% Opacity no mfc 84% Opacity 2% mfc 84% Opacity 3% mfc 84% Opacity 4% mfc

for for target 60 2

g/m 50

30 0% 5% 10% 15% 20% 25% 30% Total Filler Loading Selecting correct filler loading and sheet weight with FiberLean™ Pilot paper machine data

84% Opacity no mfc 84% Opacity 2% mfc 84% Opacity 3% mfc 84% Opacity 4% mfc

1,5 kN/m tensile strength no mfc 1,5 kN/m tensile strength 2% mfc 1,5 kN/m tensile strength 3% mfc 1,5 kN/m tensile strength 4% mfc 90

for for target 60 2

g/m 50

30 0% 5% 10% 15% 20% 25% 30% Total Filler Loading Selecting correct filler loading and sheet weight with FiberLean™ Pilot paper machine data

84% Opacity no mfc 84% Opacity 2% mfc 84% Opacity 3% mfc 84% Opacity 4% mfc

1,5 kN/m tensile strength no mfc 1,5 kN/m tensile strength 2% mfc 1,5 kN/m tensile strength 3% mfc 1,5 kN/m tensile strength 4% mfc 90 Paper with no MFC 63 g/m2 58 g/m2 80 8% filler Fiber 84% opacity Paper with 2% MFC 1,5 kN/m tensile 53 g/m2 44 g/m2 Paper with 4% MFC 70 17% filler Fiber 48 g/m2 38 g/m2 84% opacity 21% filler Fiber 1,5 kN/m tensile 84% opacity for for target 60

2 1,5 kN/m tensile

g/m 50

30 0% 5% 10% 15% 20% 25% 30% Total Filler Loading Summary and conclusions

 MFC is now available for commercial use in papermaking

 Filler increase in P&W paper is a key application

 Several product development projects for packaging and specialty papers are ongoing

 Using MFC and filler to tailor a paper grade to required opacity and strength targets with minimum material use offers one of the most exciting opportunities. Acknowledgements

To my colleagues at Imerys FiberLean R&D in Par Moor Centre in the UK who have done most of the test work, and especially to Dr Jon Phipps, who designed and ran the constant opacity/strength experiments. Thank you!

Source: Peter Callesen, www.petercallesen.com