novel packaging materials using functional thin films and ... · novel packaging materials using...
TRANSCRIPT
Novel packaging materials using functional
thin films and coatings
European Coatings Conference
“Packaging and can coatings”
on 11 and 12 June, 2013 in Düsseldorf, Germany
Juha Nikkola*, Jari Vartiainen, Mika Vähä-Nissi and Kalle Nättinen
VTT Technical Research Centre of Finland
*Speaker information: Juha Nikkola, PO. Box 1300; 33101 Tampere,
Finland; +358 20 722 3672; [email protected]
2 14/06/2013
Outline
Introduction
Novel packaging materials
Coatings and surface modification
Sol-gel coatings
Atomic layer deposition
Conclusion
3 14/06/2013
Innovative materials and surfaces
Agile processes
Testing services
Protection and quality maintenance of packed products
Consumer convenience
Printing and communication
Value network development
Safe and sustainable value chain
VTT
PACKAGING
4 14/06/2013
Eco-efficient materials
Biofoam materials
Thin film barriers
Biobased latex
Biobased plastics
Biobarriers and hybrid materials
Biobased glues and adhesives
Bio-inks
Mouldable fiber web Renew
Light weight materials
High performance hybrid
materials and barriers
Bioreplacement oil-based
materials
Replacement of aluminum
Resource efficient fiber based
materials
Reduce
Recycle
5 14/06/2013
100% bio based packaging
Recyclable fiber based and biopolymer materials.
Efficiently processable biopolymer solutions
for packaging applications.
Flexible working models to interact and co-operate
with the industry and packaging value chain.
Mouldable
Light
6 14/06/2013
Limitations of bio based packaging
The current trend in packaging materials heads towards green
chemistry using sustainable and renewable materials
However, they have minor challenges, such as sensitivity to
moisture
The thin coatings (e.g. sol-gel or ALD) could solve the problem,
by improving the moisture, gas and grease barrier performance.
7 14/06/2013
Source: SustainPack and Pira International Ltd
Grafted
Hemicel.
PO
+C
ell
ble
nd
Nanocel. Sol-
gel
ALD
Pectin
hybride
TOFA
Cellulose
Barrier properties of typical coatings (normalized to 100μm thickness)
8 14/06/2013
Routes for Surface Functionalization
Functionalized
surfaces
Unmodified
surfaces
Atmospheric Plasma
ALD/MLD
Sol-gel Technology
Deposition
Activation
Further surface
processing
9 14/06/2013
Important Base Material Parameters
Roughness
and pore
structure
Thermal stability
Moisture content
Surface chemistry Surface morphology
Paper/board/
bulk polymer
Polymer surface
Diffusion &
solubility
Based on our hypothesis surface chemistry affects nucleation, initial
layer growth rate and bonding potential making biopolymer surfaces
very interesting substrates
Factors related to surface interactions and having effect on layer
performance include choice of precursors and surface pretreatments
10 14/06/2013
Key Tools and Facilities
ALD reactor in
semi-clean room Pilot coating environments at VTT in
addition to versatile laboratory tools
Plasma online
system by VITO/AFS
Sol-gel coatings
12 14/06/2013
Sol-gel synthesis and crosslinking
R
X
Si
OH
O
O
HO
Si
X
X
O
OH
Si
O Si
OH
Si
O
O
Si
Si
Si
O
O
O
Si Si
X
X
O
O
O
Si
O
Si
O
X
Si
O
Si O
HO
H O
O
O
Si
X
O
OH
R
O
Si O
OH
O
O Si
M
Si
O
X
X
X
X
R
R
R
R
O
O
O
M
O R
O
O
OH
RO M
OR
OROR + RO Si
R
OROR
RO Si
X
OROR+
T, h•
R
Si
OH
O
O
HO
Si
O
OH
Si
O Si
OH
Si
O
O
Si
Si
Si
O
O
O
Si Si
O
O
O
Si
O
Si
O
Si
O
Si O
HO
H O
O
O
Si
O
OH
R
O
Si O
O
O Si
M
Si
O
R
R
R
O
O
O
M
O R
O
O
OH
R
OH
+H2O
-ROH
-H2O
Source: Dr. Klaus Rose, Fraunhofer ISC
X = reactive groups for cross-linking;
~ = cross-linked polymer chain;
R = functional organic groups or components;
M = metals such as Zr, Ti, Al.
13 14/06/2013
Sol-gel coating application methods
Brabec, C., Dyakonov, V. & Scherf, U. . Organic Photovoltaics - Materials, Device Physics, and Manufacturing
Technologies. John Wiley & Sons. ISBN 978-3-527-31675-5.
14 14/06/2013
Roll-to-roll coated sol-gel coating on PLA-Cardboard
Sol-gel hybrid coating on PLA laminated paperboard.
15 14/06/2013
Grease barrier performances
Uncoated Paper, Paper + LDPE and Paper + PLA (T0 + 1h and 6h):
Sol-gel coated paper + PLA (T0 + 14d):
Fluorinated Non-fluorinated
Atomic layer deposition (ALD)
17 14/06/2013
Principle of Atomic Layer Deposition (ALD)
Above: single cycle with trimethylaluminium and water vapor as precursors
Thin film grows layer-by-layer based on self-limiting gas-solid reactions
Pressure from 10 Pa to atmospheric and temperature 50-500 C
Typical applications range from catalysts, microelectronics and beyond
Purging the slowest process step
www.beneq.com
18 14/06/2013
Effect of Oxidant & Pretreatment on PLA-coated Board
Pre-treatments prior to the ALD can improve barrier properties,
Most likely surface chemistry affects nucleation and initial growth rate
Choice of oxidant affects barrier properties – denser Al2O3 films with O3
Eveness of polymer-coating is of high importance for the ALD
19 14/06/2013
Coating of Fibres and Nanocoral Structures
ALD-Al2O3 on NFC fibres
ALD-Al2O3 on PVA fibres
Hollow ALD-Al2O3 fibres
20 14/06/2013
Flexibility Through Structural Tailoring
Metal oxide layers are brittle
Mechanical stresses and thick
layers lead to impaired barrier
There are indications that
chemical bonding with base
substrate is beneficial
Flexibility & elasticity improved
by dividing thick barrier layer
into thinner stacks and
separating these with flexible
”organic spacer” layer
”Organic spacer”
Inorgnic barrier
Inorgnic barrier
”Organic spacer”
Ino
rgn
ic b
arr
ier
Surface of streched
PLA film with Al2O3
21 14/06/2013
Effect of 5-layer Al2O3/Alucone Nanolaminates on BoPLA
OT
R,
cm
3/m
2/d
/10
5 P
a
Strain, %
10 nm of Al2O3 Al2O3/alucone (150/50/150/50/150)
Al2O3/alucone (50/100/50/100/50)
Al2O3/alucone (50/50/50/50/50)
Strain, % W
VT
R,
g/m
2/d
Oxygen transmission rate (OTR): Water vapor transmission rate (WVTR):
OTR sensitive to defects, WVTR more to overall thin film properties
25 nm of Al2O3
0
50
100
150
200
250
300
350
0 1 2 3
0
10
20
30
40
50
60
70
80
0 1 2 3
22 14/06/2013
ALD-Al2O3 layer (25 nm) does not impair disintegration
0
100
0 5 10 15
No
n-d
egr
ade
d s
amp
le (
%)
Weeks
positive control
negative control
board
board+ PLA
board+PLA+ALD
0
100
0 5 10 15 20 25
No
n-d
egr
ade
d s
amp
le (
%)
Weeks
BOPLA
BOPLA+ALD
BOPLA metallized
2 x BOPLA+ALD
2 x BOPLA metallized
Role and distribution of base substrate dominates!
PLA with &
without ALD
after 5 weeks:
PLA + board with
& without ALD:
23 14/06/2013
Towards R2R Processing
Lotus Applied Tech.
Beneq
General Electric
Kodak
Applied Materials
24 14/06/2013
Conclusions & Summary
Bio-based packaging materials have many advantages over their non-
biodegradable competitors.
However, they have minor challenges, such as sensitivity to moisture,
restricting their use in some application, which requires high barrier
properties.
Therefore, application of additional thin coating layer (e.g. sol-gel or
ALD) could be one way to overcome these problems and to improve
the barrier properties of such materials.
25 14/06/2013
Acknowledgements
Funding:
EU-FP7-NMP (PLASMANICE project)
Tekes – Finnish Funding Agency for Technology and Innovation
VTT Technical Research Centre of Finland
Collaboration:
Fraunhofer ISC, Germany (Dr. Klaus Rose)
Tampere University of Technology, Finland (Dr. Johanna Lahti)
Josef Stefan Institute, Slovenia (Dr. Janez Kovac)
26 14/06/2013
VTT creates business from technology
http://www.foresttech.fi/
http://www.vtt.fi