MFC and its applications in papermaking

MFC and its applications in papermaking



Per Svending, FiberLean Technologies Ltd
Johannes Kritzinger, FiberLean Technologies Ltd

MFC-mineral composite in paper

Pilot machine produced paperThis picture of a pilot machine produced paper was shown when we first presented FiberLean some years ago.

From this picture it is clear that the composite approach is interesting from the point of view of the association between the MFC and the mineral being able to survive the turbulent papermaking conditions so that the mineral ends up being well bound into the paper structure.

Global Patent filings have exploded since 2008

Patent Applications in Micro- and Nanocellulosics

Patent Applications in Micro- and NanocellulosicsWe are certainly not alone in this field! Since the FiberLean project started in 2008 the general development has evolved extremely rapidly.

What is Micro- and Nanocellulose?

What is Micro- and Nanocellulose?The activities are however spread over quite a wide range of product types. Most are wood based, but some are also based on agricultural waste. The broader product groups can be split up as MFC, NFC and NCC, but within these there are significant differences between the various product concepts being presented.

Numerous companies active in this field

companies active in this field+ a very large number of universities and research institutes.

A mix of pulp & paper suppliers, Kruger, Sappi, NPI, Weidmann, Domtar (Celluforce) Fibria, UPM, StoraEnso, and start-up´s.

Their aim is to exploit the unique properties of Micro- and Nanocellulose

Potential advantages:

  • Abundant, natural raw material
  • Renewable, biodegradable and biocompatible
  • High strength and modulus
  • High thermal stability
  • Lightweight
  • Optical transparency
  • High water binding capability
  • High aspect ratio and high surface area
  • Chemical functionality and modification opportunities
  • Dimensional stability
  • Barrier properties

There are a number of potentially valuable properties that Nanocellulosics can offer for a wide range of industrial applications. The area of use is certainly not limited to the paper industry. In fact, most producers aim at markets outside of paper.

Global market potential estimates differ, but all say a major market is emerging

global market potential estimatesAll estimates are optimistically forecasting this to become a huge market!

FiberLean® Technologies is strong in MFC

  • FiberLean ProcessA “Technology Joint Venture” between Imerys and Omya
    • Imerys and Omya both offer unique networks and know-how to commercialize FiberLean products
  • Industrial process
    • Co-grinding pulp and mineral
    • Robust, reliable and scalable
  • Multiple customer implementations on-going
    • Satellite plants for paper and packaging customers
    • Installed capacity 40k tons of FiberLean® MFC
  • Growing portfolio of Applications and Intellectual Property

FLTL is a strong player in this market. One of our core strengths is that we have two strong owners with established presence in most of the industries where the use of MFC/NFC is expected to grow. We also have a proven industrial scale process capable of delivering serious quantities of MFC.

Approximate Nanocellulose dimensions and position of FiberLean® MFC

Nanocellulose dimensions and position of FiberLean MFCFiberLean MFC is around 100 nm in width but, importantly, also very long, around 100 microns. We believe that fibril length and a network structure is critical to make MFC work well as a paper-making wet-end additive.

A conceptual view of the filler increase concept

conceptual view of the filler increase concept




  • MFC and filler replacing pulp
  • Maintained PM efficiency
  • Maintained quality
  • Cost reduction!





Our core application today is “filler increase for cost savings”. This is based on the optimised MFC-mineral composite having a lower cost than the market pulp it replaces. Given established levels of pricing for pulp and fillers this effectively restricts the level of cost for MFC to a level where industrial efficiency and cost control is crucial in order to create cost savings for the paper mill.

MFC strength effect at the press section

MFC strength effect at the press sectionNote: Results from a pilot machine trial using 450 ml CSF, 30% Pine / 70% Euca furnish and GCC filler.
Actual filler content of trial points indicated above.

The most important impact of adding MFC to paper is the effect on initial wet web strength. This is basically what allows running at higher filler loading with maintained paper machine operations efficiency. This is also the key differentiator versus other dry strength additives, such as starch.

Increasing filler though applying FiberLean® MFC has a positive impact on a wide range of properties

FiberLean MFC has a positive impactThe other differentiators are OPACITY and POROSITY where MFC works different than pre-flocculation and addition of water soluble polymers. BULK is the challenge and this is where most of the trial time is spent to work out adjustments and paper making compromised to end up with high filled paper with acceptable bulk and stiffness.

On-site plants are relatively significant in size

One of the two commercial FiberLean on-site plants.

One of the two commercial FiberLean on-site plants.

The filler increase application typically requires a few thousand tonnes of MFC per year. Our on-site approach means we need to build a fairly substantial local plant. It is not a piece of euipment! It is a plant.

On-site plants are relatively significant in size

One of the two commercial FiberLean on-site plants.

One of the two commercial FiberLean on-site plants.

An internal view from one of our plants

Global Packaging is a huge business

Growing faster than GDP


Global packaging marketContainerboard

  • Kraftliner (virgin fiber based)
  • Testliner (recycled fiber based)
  • White Top Liner
  • Fluting or Medium, mainly recycled


Boxboard or Cartonboard

  • Chipboard (recyled fiber based)
  • Solid Bleached Board, Ivoryboard (virgin fiber based)
  • Folding Boxboard (virgin fiber based)
  • Coated Unbleached Kraft (virgin fiber based)


Other packaging

  • Sackpaper
  • Wrapping
  • Specialities
  • etc.

Today we are working hard to widen the application areas to include packaging grades where ”filler increase” is typically not what they want.
This is an attractive growth market fighting to win market share against plastics and other materials.

FiberLean® MFC and FDA food contact notification

FiberLean® MFC has received clearance from the Food and Drug Administration (FDA) for use as a food contact substance in paper and paperboard for food packaging applications.

A Food Contact Notification (FCN) became effective on November 6, 2015. This FCN allows up to 5 weight percent of FiberLean® MFC fibrils in the packaging.

A prerequisite for going after this market is that the product is safe to use in food contact applications. FL MFC has been cleared by the FDA and is in the process of getting clearance by the European regulatory authorities.

Folding Boxboard application, full scale results

Filler increase and basis weight reduction in Top/Back

Filler increase and basis weight reduction

  • 2.25% MFC in each
  • +10% filler in each, 4 g/m2 of top layer and 3 g/m2 of bottom replaced by middle layer
  • Conditions chosen to maintain stiffness
  • Machine speed, filler retention and runnability maintained

Specification maintained at reduced cost

Specification maintained at reduced cost


  • Bending stiffness and brightness unchanged
  • Significantly improved smoothness




FL in the outer layers of FBB was the first packaging application we went after. It is similar to the P&W paper filler increase application but here the opacity advantage is used to allow reduction in basis weight of the outer plies. By moving weight to the bulkier middle ply it is possible to end up with maintained stiffness, lower cost and improved surface properties.

Folding Boxboard mid-ply application

Strength is the limiting factor when striving for the highest possible bulk and stiffness. Addition of MFC changes the game.

Folding Boxboard mid-ply applicationIn full scale operation we have proven that it is possible to achieve light-weighting of high quality FBB while still increasing speed and production output.

The other FBB application is to put a MFC-mineral composite with minimum level of mineral into the middle ply as a strength reinforcement. This allows the mill to move to a higher Freeness middle ply furnish and gain bulk/stiffness. The change also results in overall easier drainage and a positive impact on productivity.

Global containerboard consumption growth


  • Overall growth broadly in line with GDP
  • Increasing recycling rate (becoming a problem)
  • Rapid sub-segment growth in white printed boxes.





containerboard consumption growthContainerboard is another attractive segment for MFC. The growth rate is sound with rapidly increasing use of recycled grades. Within this segment there is particularly good growth in demand for white boxes suitable for printing.

White Top Liner application, full scale results

Filler increase and basis weight reduction

Filler increase and basis weight reduction

  • 2.5% MFC in white layer
  • +9% filler in the white layer
  • 10 g/m2 of top layer replaced by brown layer
  • Conditions chosen to maintain brightness
  • Machine speed, filler retention and runnability maintained

Specification maintained at reduced cost

Specification maintained at reduced cost

  • Minor changes in strength properties
  • Large reduction in air permeability
  • 40% increase in Scott Bond
  • Potential for higher filler increase and brightness



Our proven concept for White Top Liner is very similar to our work in FBB outer layers. The difference is that here you can go further in filler loading and grammage reduction as the key contribution to strength comes from the base liner. In full scale trials we have proven this 9% filler increase with good results and reduced overall cost.

FiberLean on Top, coating at the wet-end

FiberLean on top

  • Pure FiberLean applied as a low solids slurry on the consolidating base layer.
  • The composite of MFC and mineral is typically of lower cost than market pulp and has the ability to stay on the surface without penetrating into the base.
  • The top layer can be drained using existing foils and vacuum boxes.
  • Pressing and drying works well with increased press solids.
  • The top layer is strong and has good adhesion while offering excellent coverage, low porosity and good smoothness.


In this new application, still under development, we have taken a quantum leap forward. After having struggled with the poor rheology of MFC for regular coating we have taken the extreme approach of coating at the wet-end.

Properties as a function of coat weight

Pilot scale trial results.
Base substrate: 86 g/m2 unbleached kraft linerboard.

Regular WTL brightness levels can be reached by as little as 25-30 g/m2 of coat weight. The surface becomes much more closed and smooth. Scott Bond remains constant as the surface layer is stronger than the base.

White Top Linerboards

Compromise between strong base and printable surface

white top linerboards

Brightness: 70-75 75-80 75-80
Base ply: 61% 50% 78%

The most important strength property for linerboard is tensile stiffness or modulus (although these are never specified directly) It´s about building the I-beam effect with the medium. The FLoT surface is lower in tensile than conventional White Top but instead we can offer a much greater proportion of strong base liner.

Suitable for roll-to-roll aqueous Inkjet printing

Suitable for roll-to-roll aqueous Inkjet printingThe coating can be tailored to suitable printing properties by varying the mineral.
High print density in combination with rapid drying is possible.

The cost of making WTL can be greatly reduced using this technology. There are clearly lower variable costs and the capital cost for rebuilding a machine from brown or grey liner to White Top can be reduced by an order of magnitude. The most promising part is however the good printability that can be achieved. The 80% mineral and 20% MFC containing surface offers a great combination of ink hold out and ink drying in both Flexo and Inkjet. The properties can be fine tuned by optimising the mineral that goes into the formulation. We expect this to become a major future market for MFC.