Production of NC film via Spray Coating

1. Spray Coating
A Rapid Method of Preparation of Free-
standing Nanocellulose Film
PRESENTED BY
Kirubanandan Shanmugam
Swambabu Varanasi
Gil Garnier
Warren Batchelor
Australian Paper and Pulp Institute, Monash University,
Australia.

2. Introduction and Background of the research
Research Objective
Methods
Results
Conclusion

3. Bio-degradable
Bio-renewable
Bio-compatible
Characteristics
High Specific Strength
Thermal Stability
Hydrophilicity
Chemical
Modification
Hierarchical structure of wood fibers, Network of micro fibrils (Zhu et al., 2014)
INTRODUCTION

4. APPLICATIONS OF NANOCELLULOSE
Solar Cell (Georgia Tech News, 2013) Water and Air Filtration
Touch Screens (Zhu et al., 2014) High performance barrier materials

5. BARRIER MATERIALS
Wax
Aluminium
Plastics
Limitation:
Poor barrier
properties

6. NANOCELLULOSE FILMS PREPARATION TECHNIQUES
2. Vacuum filtration
Filtration Separation Drying
1. Casting and Solvent evaporation
Processing Time –10-27 mins Is it possible to scale-up about methods?

7. RESEARCH OBJECTIVE
Problem statement:
Is it possible to develop a scalable method to prepare nanocellulose
films/sheets????....
Research Objectives:
Tailoring barrier properties of spray coated nanocellulose sheet by adjusting
the basis weight of nanocellulose films
Outcome
• Spraying could be a suitable alternative method for vacuum filtration

8. SPRAY COATING PROCESS
Concept Atomization
Spray Coating Provided uniform surface on the
substrate.(Sanna Tiekstra, 2012, Functional Bio
Based Coating for Moulded Pulp Trays,
www.cepi.org)
A Professional spray gun for performing
spray coating process

9. EXPERIMENTAL SETUP
A Professional spray gun for performing spray
coating process
Experimental Conditions :
• Spray distance - 30 cm
• Suspension concentration - 1.0 to 2.0 wt %
• Velocity of conveyor – 0.25 to 0.62 cm/sec

10. SUSPENSION CONSISTENCY Vs BASIS WEIGHT & THICKNESS
0
50
100
150
200
250
300
0
50
100
150
200
250
0.8 1 1.2 1.4 1.6 1.8 2 2.2
BasisWeighting/m2
Concentration of nanocellulose in wt%
Basis Weight Vs Suspension Concentration
Thickness Vs Suspension Concentration
Thicknessinµm

11. THICKNESS MAPPING
SprayDirection
Surface exposed to atmosphere - rough
Surface adjacent to plate - Smooth

12. THICKNESS DISTRIBUTION
Spray Coated MFC Sheets MFC Sheet made by Vacuum Filtration
1 2 3 4
1
2
3
4
Region
Region
111.0
116.0
121.0
126.0
131.0
136.0
141.0
146.0
151.0
1 2 3 4
1
2
3
4
Region
Region
109.0
111.4
113.8
116.1
118.5
120.9
123.3
125.6
128.0

13. SEM IMAGES OF NANOCELLULOSE SHEET
1µm 10 µm 100 µm
1 µm 10 µm 100 µm
Free
surface
Spray
coated
surface

14. AFM STUDIES ON THE SHEET
Rough Smooth
AFM Image of the nano-fibrillated sheet – Rough and Smooth surface at 500 nm

15. AFM STUDIES ON THE SHEET
Rough Smooth
AFM Image of the nano-fibrillated sheet – Rough and Smooth surface at 2 µm

16. OPTICAL PROFILOMETRY
Rough Smooth

17. PROPERTIES OF SPRAY COATED NC FILM
Properties Spray Coated Sheet Sheet Prepared by
Vacuum filtration
Tensile Index 60.2±1.5 Nm/g 62.3±3.4 Nm/g
Tensile stiffness 946±86 KN/m 941±78 KN/m
Air permeability <0.003 µm/Pa.s <0.003 µm/Pa.s
Water Transmission Rate 35.6 g/ m2 day 33.9±3.5 g/ m2 day
Water Vapour
Permeability
34.1 g.µm/ m2 day KPa 38.2±3.5 g.µm/ m2 day
KPa

18. CONCLUSION
• A rapid technique to prepare the nano-cellulose sheet was
developed.
• The sheet has better uniformity and two different surface.

19. ACKNOWLEDGEMENT
• Dr. Warren Batchelor and Prof. Gil Garnier
• Dr. Swambabu Varanasi
• Student friends and staff members at BioPRIA

20. Thank you
PRESENTED BY
Swambabu Varanasi
Research Fellow
Monash University
Australia