Mineral/microfibrillated cellulose composite materials:

Recycled fibres, engineered minerals and new product forms

David Skuse, Tom Larson, Michel Schenker, Mark Windebank and Paymaan Tahamtan

PRESENTED BY:
David Skuse
VP Technology,
FiberLean Technologies Ltd.

Contents

• Introduction
  • Mineral/microfibrillated cellulose composite materials
  • Fibrils and fibres
  • Minerals
  • Mineral/ fibril composites
• Recycled fibre sources
• Applications
• Product forms
• Conclusions

Introduction:

Mineral/microfibrillated cellulose composite materials

• MFC: Utility for increased bonding in fibre-based structures, viscosification, re-inforcement……
• A cost effective grinding-based method for the production of mineral/ MFC composites from minerals and cellulose pulp
  • Cellulose fibres are co-processed with mineral particles. The mineral particles act as micro-grinding media, thus, reducing the energy requirement
  • The process can be accomplished using robust, industrially proven grinding equipment
• 10 000 dry metric tonnes pa of fibril capacity (40 000 dry metric tonnes of mineral/ MFC composite) installed and operational across three continents. Further capacity under construction
• FDA FCN for food contact paperboard
• Processsing and handling of mineral/ MFC composites are dominated by the high viscosity of MFC arising from presence of high surface area hydrophillic fibrils. Typical fibre solids is ~2%

Photograph (a) and micrograph (b) of mineral/ MFC composite showing the high viscosity and fibrillar structure

Fibrils and fibres

Structure performance relationships

PropertiesEngineered fibrils Fibril length Fibril width Microgel-like or discrete Surface charge Surface hydrophobicity Colour ……

Performance Enhancement of web properties (mechanical, porosity, surface, optical) Viscosification/ rheological property modification Reinforcement Stand-alone objects Barrier Cost-effectiveness Re-use ……

Applications Paper/ Packaging Building materials Coatings Oil field Food and beverage Non-wovens Composites Electrical/ electronic ……

Minerals

Structure performance relationships

Properties Particle size Particle shape Particle packing Crystal microstructure Colour Reflectance Absorbance Scattering efficiency Refractive index Specific gravity Hardness Chemical composition Surface character ……

Performance Opacity Clarity Gloss Density modification Wear / abrasion resistance Barrier Blocking Flame retardant Mechanical reinforcing Chemical delivery/ reaction ……

Applications Paper/ Packaging Building materials Coatings/ inks Oil field Food and beverage Non-wovens Composites Electrical/ electronic Abrasives Filtration Ceramics ……

Calcium carbonate: Ground and precipitated forms: High level of control over crystal morphs and dimensions

Kaolin: Can be engineered for very high shape factor

Mineral fibril composites

• There are a multitude of options available to the formulator

Recycle fibres

• Mineral/microfibrillated cellulose composite materials prepared from mixed office waste and OCC
• Tensile properties at ~ equivalent to/ better than virgin NBSK controls

Mixed office waste feed

50% OCC/ 50% kaolin mineral/ MFC composite (right) and control with NBSK

Applications

Viscosity modification

• 50% NBSK/ 50% mineral/microfibrillated cellulose composite materials
• Can control viscosity with choice of mineral shape factor.
• Low shape factor for high solids application
• High shape factor for high viscosity

Barrier

Base	Base + MFC layer	Base + Coating	Base + MFC layer + Coating

Electronics

50% NBSK/ 50% graphite mineral/ MFC composite slurry and sheet		20% NBSK/ 80% mineral/ MFC composite printed electronic substrate

Product forms

• Slurry (~2% MFC fibre solids)
• Bottles and barrels, Transitanks, Trucks and ISO tanks, satellite plant
• Filter cake (~10-15% MFC fibre solids)
• Buckets, barrels, big bags
• High solids powder (~37% MFC solids/ 75% total solids), developmental
• Sacks, bags and bulk

Slurry

• Slurry (~2% MFC fibre solids)

	Bottles 10 liter (2.65 US Gallon) = 200 g (~8 oz) dry MFC Barrels 220 liter (60 US Gallon) = 4.4 kg (~10 lb) dry MFC Transitanks 1000 liter (265 US Gallon) = 20 kg (~44 lb) dry MFC Trucks/ ISO tanks 25 meter3 (6600 US Gallon) = 500 kg (~1100 lb) dry MFCLargest shipments to date 80 Transitanks = 1600 kg (~3500 lb) dry MFC 7 Trucks = 3500 kg (~7700 lb) dry MFC

Filter cake

• Filter cake (~10-15% MFC fibre solids)

• 50% OCC/ 50% Kaolin
• Filter cake
• Bag weight ~ 1000 kg (~2200 lb) = 150 kg (~330 lb) dry MFC
• Largest shipments to date
• 292 bags = ~44 tonnes (~48 short tons) of dry MFC

• 50% NBSK/ 50% GCC

High solids powder

50% NBSK/ 50% GCC, 75% solids

Conclusions

• Mineral/ MFC composites are produced using a cost-effective, robust process and have proven full-scale availability
• Mineral/ MFC composites can be produced using a wide range of minerals and pulps. Variations in the selction of pulp and mineral allow the formulator to select in favour of a wide range of properties
• Recycled pulp streams can be used
• We believe that mineral/ MFC composites are an important additive for a wide range of applications
• These mineral/ MFC composite materials have been commercialised as FiberLean^® MFC