functional web coating: from food packaging to technical applications · 2018-10-08 · blown films...

© Fraunhofer IVV

Functional Web Coating: from Food

Packaging to Technical Applications

Stanislav Dribinskiy

Materials Development

Fraunhofer Institute for Process

Engineering and Packaging IVV

Giggenhauser Str. 35

D-85354 Freising

[email protected]

http://www.ivv.fraunhofer.de __________________________________

© Fraunhofer IVV

Business Fields of the Fraunhofer IVV

© Fraunhofer IVV

Small pilot plant

• Compounding of plastics

• Production of single or

multi-layer flat films or

blown films

• Extrusion coating and

extrusion lamination

Polymer processing

• Vacuum web coating via

conventional or e-beam

evaporation

• Lacquering and lamina-

tion of films and film

composites

• Manufacturing of barrier

film composites by combi-

ning vacuum coating and

lacquering

Polymer modification

Materials testing

• Determination of the per-

meability of packaging

materielas to water vapor

and oxygen

• Test on surface properties

• Determination of

mechanical properties of

packaging and packaging

materials

Measurment of functional

properties

Dep.


BF 2 Functional Materials BF 4 Food Quality

Small pilot plant

• Compounding of plastics

• Production of single or

multi-layer flat films or

blown films

• Extrusion coating and

extrusion lamination

Polymer processing

• Vacuum web coating via

conventional or e-beam

evaporation

• Lacquering and lamina-

tion of films and film

composites

• Manufacturing of barrier

film composites by combi-

ning vacuum coating and

lacquering

Polymer modification

Materials testing

• Determination of the per-

meability of packaging

materielas to water vapor

and oxygen

• Test on surface properties

• Determination of

mechanical properties of

packaging and packaging

materials

Measurment of functional

properties

Dep.


BF 2 Functional Materials BF 4 Food Quality

Polymer films with barrier and ultra-barrier properties or having selective permeability to

permanent gases and vapors.

Incorporation of functional components (scavengers and indicators) into composite films for

technical applications.

Functional Materials - Overview

© Fraunhofer IVV

Requirements for outstanding performance of polymer films

Gas barrier and low out gassing

Balance of mechanical, thermal, electrical and surface properties

Chemical and optical performance customized to application

Combination of long term thermal stability with dimensional stability

Flame redundancy

Weight reduction compare to standard materials: metal, ceramic and etc.

Compromise needs to be obtained for a given application

© Fraunhofer IVV

Effects of oxygen plasma surface treatment on BOPP film Main objectives

characterisation of barrier properties (oxygen, moisture) of the aluminium

coated BOPP film and the effect of plasma pre-treatment on barrier

to gain a better insight into the adhesion

mechanisms acting between the pre-treated

BOPP film surface and the deposited

aluminium layer

establishment of a correlation between

aluminium adhesion (via peel-test) and

measured surface energy and plasma energy

density

Source: Schlussbericht Verbundvorhaben: „Umweltentlastung in

der Produktion und Nutzung von Verpackungen aus Verbundfolien durch

Halbierung des Materialeinsatzes“ gefördert vom Bundesministerium für

Bildung und Forschung (BMBF) Laufzeit des Vorhabens: 01.03.2003 bis

31.05.2006

© Fraunhofer IVV

Vacuum coater and plasma treater

Vacuum web coater at GVE (K4000)

Plasma treatment levels:

0 7200 J/m²,

Plasma treater with power: 2 9

kW at 40 kHz

web speed: 200 600 m/min

100% oxygen plasma

Aluminium coating:

Thermal evaporation, optical density

of coated film: 2.0

1 – Unwind

2 – Plasma pre-treater

3 – Evaporation unit

4 – Coating drum

5 – Non-contact eddy current resistance

monitor

6 – Rewind

1

6

4

3

© Fraunhofer IVV

Surface energy vs. XPS

Correlation between surface energy and relative oxygen concentration

obtained by XPS analysis

oxygen plasma

species react with

the film surface and

create polar O-

functional groups

Corelation between XPS results and surface energy analysis

y = 1,4805x + 27

y = 0,7168x

0

5

10

15

20

25

30

35

40

45

50

0,0 2,0 4,0 6,0 8,0 10,0 12,0

Relative oxygen concentration [atomic-%]

Surf

ace e

nerg

y [

mJ/m

²]

Total Polar DispersiveLinear (Total) Linear (Polar)

© Fraunhofer IVV

Aluminium adhesion

the optimum for plasma treatment level

overtreatment

etching of the BOPP film surface

formation of a low-molecular-weight

polymer fragments layer

high plasma treatment levels reduces

the adhesion

© Fraunhofer IVV

Aluminium adhesion

the optimum total surface energy of 35 to 37 mJ/m²

polar component between 3 and 5 mJ/m²

a high total/polar surface energy is an essential but not always

a sufficient requirement to achieve good adhesion of the Aluminium coating

© Fraunhofer IVV

Roughness of BOPP

Correlation between surface roughness of BOPP film and

plasma treatment level

No tendency observed with AFM-surface roughness measurements

© Fraunhofer IVV

What does this mean this „g/m2d“ of water vapour?

~ 100m

~50m

Food packaging

100 10 1 10-2 10-4 10-6

Polymer Foil OPV OLED

How much

water would pass through

this area over a MONTH at

various barrier

properties? Source: according to Alf Smith,

The Centre for Process

Innovation, GB

© Fraunhofer IVV

Oxygen Transmission Rate (OTR) and Water Vapour Transmission Rate (WVTR)

Decreasing Oxygen Transmission Rate with increaising plasma energy

density

Slight decreases of WVTR:

average of 0.55 g/(m²·d)

WVTR (23 °C, 85 % RH) 1.6 g/(m2·d)

OTR (23 °C, 50 % RH) 1915 cm3/(m2·d·bar)

© Fraunhofer IVV

Summary of main results

Measured characteristic Change with plasma energy density (07120 J/m²)

Surface energy Increase, constant level from 4500 J/m² on

Roughness No clear tendency (possibly a slight increase

compared to untreated film)

Aluminium adhesion Maximum between 1500 and 3500 J/m²

OTR Strong decrease, gradually levelling off

WVTR Slight decreases

optimal barrier properties optimal aluminium adhesion

Compromise needs to be obtained for a given application

© Fraunhofer IVV

Project “Elektroplas” -Functional Coatings on PET Films

Development and manufacture of ultra-thin barrier layer systems (thickness

less as 2 microns) consisting of an inorganic barrier layer and a hybrid polymer

coating layer for the PET protection against thermo-oxidative and hydrolytic

aging

Investigation of the fundamental influences of the coating on the electrical

properties of the films

Determination of the electrical and thermal aging performance to determine

the temperature limit of the new film materials

To show the roll-to-roll production possibility and transfer to pilot-application

© Fraunhofer IVV

PET Melinex ® 401 film after 4 hours at 180º C

500x

The crystal structure on the surface are cyclic

oligomers, these are created at

polycondensation of PET

Melinex®401 film has about 1.1 wt% cyclic

oligomers

PEN Teonex® film has about 0.3 wt%

AFM

Source: Fraunhofer IVV

© Fraunhofer IVV

Functional Coatings on PET Films

Polymer film

Water vapour

Oxygen Temperature

Functional coating

Functional coating

© Fraunhofer IVV

LDPE Low Density Polyethylene

HDPE High Density Polyethylene

EVA/PE Ethylene-Vinyl-Acetate copolymer

PS Polystyrole

PC Polycarbonate

PP Polypropylene

BOPP Biaxiale Orientierted Polypropylene

PVC Polyvinylchloride

PET Polyethylenterephthalate

PA 6 Polyamid 6

PAN Polyacrylonitrile

PEN Polyethylene naphthalate

PVDC Polyvinylidene Chloride

EVOH Ethylene-Vinyl-Alkohole Copolymer

PUR Polyurethane

ORMOCER Sol-Gel Lacquer

LCP Liquid Crystal Polymer

Gas permeability of polymers with the thickness of 100 µm

OTR: 23 °C, 50 % re. Humidity; WVTR: 23 °C, 85 --> 0 % re. humidity


Polymer + the single inorganic barrier layer

0,1 1 10 100

0,1

1

10

100

1000

LDPE

HDPE PP

BOPP

PS

PVC weich

EVA/PE

PVC hart

PET

PEN

LCP

PA 6

PVDCEVOH

PC

PAN

PUR

ORMOCER

PLA,

PCL

PHB / V

Celluloseacetat

PLA/SiOx

Celluloseacetat/SiOxBOPP/SiOx

PET/SiOxOT

R [

cm

3/m

2 d

bar]

WVTR [g/m2 d]

© Fraunhofer IVV

IVV- Vacuum coating machine with microwave plasma source and EB

1: coating drum

2: film (max. 28 cm wide)

3: EB evaporator

4: coating volume

5: microwave plasma source

Plasma pre-treatment (e.g. using O2, N2 as

reactive gases)

High rate electron beam vacuum deposition

Coating of paper and different substrate films

with metals (e.g. Al, Cr, Ti), semiconductors (e.g.

Si) or oxides (e.g. Al2O3, MgO, SiOx and their

mixtures)

Analysis and monitoring of treatment and

deposition processes

Pilot-scale development of products and

processes including scale-up in collaboration with

external partners

1

2

3

4 5

© Fraunhofer IVV

PET Melinex®401/SiOx surface after 4 hours at 180º C

Transmitted light microscopy,

SiOx-side Crystals just on

the uncoated side

AFM


© Fraunhofer IVV

Combination of an inorganic barrier layer and a hybrid

polymer

Polymer

Defects filling in inorganic layer

SiOx

Cryo-transverse fracture preparation,

recorded in high resolution SEM

Ormocer®


ORMOCER® from Fraunhofer ISC is an inorganic-organic

hybrid polymer with heat-enhanced inorganic

polycondensation and cross linking of the organic network.

© Fraunhofer IVV

1

4

2

3

5

„Reverse Gravure“ roll-to-roll coating


1: gravure roll, 2: tub with application medium, 3:

coating knife, 4: “Presseur” – rubber covered roll, 5:

film

© Fraunhofer IVV

Consecutively

heating

at 120°C

5

5

IVV roll-to-roll lacquer pilot machine

Foil

PET

1

1

pre-tratment

Corona

2

2

Cleaning

optional

3

3

„Reverse

Gravure“

4

4

Rewind

6

6


© Fraunhofer IVV

Gas permeation, film thickness range 50-52 µm

Layer structure OTR, cm³/m² d bar

BIF WVTR, g/m² d BIF

PET(Melinex®) 25 3

PET(Melinex®)/SiOx/ORM 0,05/0,08 500/400 0,5/0,1

6/30

PET(Melinex®)/ORM/SiOx 0,05 600 0,05

60

PET(Melinex®)/SiOx 0,8 - 4 40 - 8 0,2 15

SiOx/PET(Melinex®)/SiOx 4,21 7 0,6 5

ORM/SiOx/PET(Melinex®)/SiOx 2,2 10 0,4

7

ORM/SiOx/PET/SiOx/ORM 0,27 100 0,25 12

SiOx/PET/ORM/SiOx/ORM 0,1 200 0,7 5

ORM/SiOx/PET/ORM/SiOx/ORM 0,05 500 0,5 6

© Fraunhofer IVV

Accelerate life time, aging and thermo-effect on PET

full scale aging PET 160°C -

0,00

25,00

50,00

75,00

100,00

125,00

150,00

175,00

200,00

225,00

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

Time[h]

elo

ng

ati

on

at

bre

ak [

%] PET (MD)

PET (TD)

Polynomisch (PET (MD))

Linear (PET (TD))

full scale aging PET 180°C

0,00

25,00

50,00

75,00

100,00

125,00

150,00

175,00

200,00

225,00

0 50 100 150 200 250

Time [h]

elo

ng

ati

on

at

bre

ak [

%]

PET (MD)

PET (TD)

Polynomisch (PET (MD))

Polynomisch (PET (TD))

20 40 60 80 100 120 140 160 180 200

10

100

1000

10000

100000

1000000

1E7

1E8

1E9

Tim

e, h

ou

rs

Temperature


Source: Rudolf Brütsch et all, Insulation Failure Mechanisms

of Power Generators, IEEE Electrical Insulation Magazine, July/August 2008 Vol. 24, No.4, 17-25p.

© Fraunhofer IVV

Accelerate life time, aging and thermo-effect on PET at 190°C

the mechanical

properties of coated

PET-films are dependent

on the stretching of

substrate film

the SiOx-coating has a

strongly negative effect

on mechanical

properties of PET-films

Conclusion:

different aging and degradation mechanisms

at 160°C, 180°C and 190°C

Zugversuch: Vergleich verschiedener Materialien (MD), Alterung 190 °C

0

50

100

150

200

250

300

0 20 40 60 80 100

Zeit [h]

Bru

ch

deh

nu

ng

[%

]

PET (MD)

PET/SiOx (MD)

PET/SiOx/ORM (MD)

PET/ORM/SiOx (MD)

50% Grenze

mechanische

Stabilität

vorhanden

weicher

spröder

elo

ng

ati

on

at

bre

ak

, %

Aging time, hours

hard

flexible

50%fall

mechanical

stability

© Fraunhofer IVV

Changes in gas permeability and breakdown voltage after 30

hours at 190°C

Source: Projekt „ElektroPlas“

Permeationsmessung: Vergleich verschiedener Materialien

PET

PET/SiOx

PET/SiOx/ORM

PET/ORM/SiOx

PET 30 h 190 °C

PET/SiOx 30 h 190 °CPET/SiOx/ORM 30 h

190 °C

PET/ORM/SiOx 30 h

190 °C

0,01

0,1

1

10

0,01 0,1 1 10 100

OTR [cm3/m2 d bar]

WV

TR

[g

/m2 d

]

PET

PET/SiOx

PET/SiOx/ORM

PET/ORM/SiOx

PET 30 h 190 °C

PET/SiOx 30 h 190 °C

PET/SiOx/ORM 30 h 190 °C

PET/ORM/SiOx 30 h 190 °C

PET

PET/SiOx

PET/ORM/SiOx

PET/SiOx/ORMPEN

70 %

80 %

90 %

100 %

Relative breakdown voltage changes

after 30 hours loading at 190ºC

Changes in gas permeability

© Fraunhofer IVV

„ElektroPlas“ main results

thickness of the barrier system was 1 2 microns,

barrier properties against oxygen ~ 10-2 cm³/(m² d bar) and water vapor ~ 10-2

g/(m2d) based on 50 micron thick substrate

the breakdown voltage has not changed compared to the uncoated reference PET

foil

a new insights into the basic correlations between film topography, temperature

stability and the resulting mechanical and barrier film properties

a good aging stability of the coated films for short-term thermal storage (two weeks

at 160°C, some layers combinations for one week at 180°C)

reduction of growth of crystalline structures on PET surface (100 hours at 190°C) by

application of barrier layers

© Fraunhofer IVV

Possible applications

Thin Film Batteries

Inorganic Thin Film Transistor back

sheets

Vacuum Insulation Panels

Photovoltaic modules

Organic electronics

Hydrolysis resistant, heat stabilized,

“electrically friendly” foils with

temperature peaks of 170°C for

Electric Motors

High-temperature film for Capacitors

Source:Siemens AG

© Fraunhofer IVV

Thank you for your attention!

Thanks to

Prof. Horst-Christian Langowski, Dr. Klaus Noller, Dr. Kajetan Müller, Carolin Struller,

Simone Moravec, Matthias Kohlmayer and Wolfgang Busch from Fraunhofer IVV

Dr. Sabine Amberg-Schwab and Ulrike Weber from Fraunhofer ISC

Dr. Christian Seidel from Siemens AG

Nick Copeland, Graham Simpson and Robert Astbury from General Vacuum

Equipment Ltd.

Dr. Giovanni Schnelle from Kopafilm Elektrofolien GmbH

Dr. Andreas Holländer fromFraunhofer IAP

functional web coating: from food packaging to technical applications · 2018-10-08 · blown films...

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