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Cold atmospheric plasma technology for surface pretreatment and coating Dirk Vangeneugden & Robby Rego Surface Treatment - Paper 12.3
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Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Jun 02, 2019

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Page 1: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Cold atmospheric plasma technology for surface pretreatment and coating

Dirk Vangeneugden & Robby Rego

Surface Treatment - Paper 12.3

Page 2: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 2

Contents• Introduction to plasma technology

• Atmospheric plasma or advanced corona technology ?

• From tailored surface activation to in-line coating

• Envisioning future applications in flexible packaging

• Conclusions

Page 3: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 3

Introduction to plasma technology

Page 4: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 4

What is plasma ?• Next to solid, liquid and gas phase,

plasma is often referred to as the fourth state of matter

• A plasma is a (partially) ionised gas in which ions and electrons are present as well as radicals and molecules in an excited state

• In a “thermal” or “hot” plasma all species have approximately the same (high) temperature

• “Cold” or “non-equilibrium” plasmas have a high electron temperature but a low ion or gas temperature

Page 5: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 5

What is plasma ?

Page 6: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 6

How to generate a cold plasma ?• Cold plasma discharges can be

generated by stationary and pulsed (DC) or alternating (AC) electrical fields.

• Various electrical power supplies can be used to generate the plasma discharges: (pulsed) DC, DBD (corona), RF, microwave, ICP, …

• Although most applications are at low pressure, intermediate and atmospheric pressure applications are emerging.

Page 7: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 7

Plasma assisted surface modificationc c c

Cleaning, etching and sterilisation

Activation

Coating

O2 Plasma

N2 Plasma

cc

cc

cc

cc

CH4 /Ar

Plasmac

cc

cc

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cc

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cc

c

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cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

cc

c c c

Plasma

cc

cc

cc

cc

OH O COOH

cc

cc

cc

cc

NH2 NO2NH

Page 8: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 8

Plasma assisted surface modification

Advantages

• Environmental friendly

• Allows to deposit coatings with unique properties

• Flexible switching between process conditions

• Reliable operation

• Energy efficient

Page 9: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 9

Why Atmospheric plasma technology ?Surface activation + coating technology

Cost

Vacuum plasma

Atm. pressure plasma

New

Flame treatment

Corona treatment

Added Value

Page 10: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 10

Atmospheric Plasma or Advanced Corona Technology ?

Page 11: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 11

Plasma discharges at ambient pressure • Direct current (DC) and pulsed DC discharges

• Hollow cathode discharges

• Dielectric barrier discharges (DBD)

• Radio frequency (RF) discharges

• Microwave (µW) discharges High Voltage

Al2O3

Carrier gasPrecursors

Plasma

Advantages

• Lower investment costs

• In-line processing

Page 12: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 12

Corona treatment• Corona treatment is one of the oldest industrial

applications of plasma technology

• It is commonly used for surface activation of plastic foils or textiles before printing, gluing or lamination

• Conventional systems resulted in a non uniform spot-wise surface treatment

• Today, most systems make use of the principle of dielectric barrier discharges which results in more uniform treatment and less degradation

Filamentary discharge

Page 13: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 13

Beyond state of the art corona• By controlling the gas atmosphere and electrical

conditions, one can increase the efficiency of the plasma surface treatment significantly

• By adding reactive chemical precursors to the plasma discharge, the surface chemistry can be controlled

• For such surface treatments, the stability in time can be much higher, even up to a level than can be assigned as “permanent”

• The technology opens up possibilities to deposit functional coatings in a continuous system at ambient pressure

Page 14: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 14

Direct or indirect plasma treatment ?

PlasmaSpot®

Local treatment of 3D parts

Indirect

PlasmaLine®

Web activation without back treatment

Indirect

PlasmaZone®

Permanent functionalisation and coating

Direct

Page 15: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 15

Principle of DBD plasma treatmentInjection of chemicals

Carrier Gas

HVHV

Coated foil

Plasma

Ceramic

• Same principle as industrial corona

• Carrier gasHe – Ar – N2 (– Air)

• Frequency range 250 Hz – 250 kHz

• High voltage range 1 kV – 40 kV

• Dissipated power 0.5 – 10 W/cm2

Page 16: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 16

Lab scale atmospheric plasma system

Automation software

Tailor made AFS power supply

Moving HV electrode

Gas flow control

Frame + exhaust

Page 17: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 17

Aerosol Assisted DBD Plasma Deposition

Liquid precursor

Purge gas

Aerosol generator

Moving electrode + dielectricum

Fixed electrode + dielectricum

Page 18: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 18

Semi-industrial roll-to-roll system

System specifications• Max web width: 600 mm• Line speed: 1 – 200 m/min

Page 19: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 19

New development: plasma slit torchSystem properties:• Width: 40 cm• Gas consumption (N2): 300 l/min• Variable power: 1000 – 5000 W• Special electrode design • Unique precursor injection concept

CFD modeling of internal pressure and gas flow

Page 20: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 20

From tailored surface activation to in-line coating deposition

Page 21: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 21

Current process developments for permanent surface modification• Surface wettability (hydrophylic, hydrophobic,…)• Adhesive coatings (printability,…)• Controlled release coatings • Barrier coatings (O2, H2O, oils, …)• Anti-corrosion coatings• Scratch resistant coatings • Antibacterial coatings• Bio-functional coatings • …

Page 22: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 22

Tailored surface activation • Example: activation of plastic

substrates for production of innovative micro arrays

• DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid activation.

Page 23: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 23

Surface activation

0

10

20

30

40

50

60

70

80

0 50 100

150

200

250

300

350

400

450

500

550

600

650

700

750

time (h)

Surf

ace

ener

gy (d

ynes

)

Surface energy

Dispersive comp

Polar comp

Page 24: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 24

Surface activationSurface energy in function of scan speed

50

55

60

65

70

75

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20scan speed (m/min)

Surf

ace

ener

gy (d

ynes

)

Page 25: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 25

HMDSO release coatings on PET

0

50

100

150

200

250

300

350

PET

Targ

et

Peel

For

ce (c

N/2

0mm

) Initial

Aged 1wk 60°C

Aged 1 day 60°C as tape complex

Page 26: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 26

HMDSO coating deposition speed

0100200300400

500600700

800

0 20 40 60 80

treatment time (sec)

Thic

knes

s (n

m)

passes variationspeed variation

Page 27: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 27

Thickness evaluation by interferometry

140nm

Page 28: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 28

Thickness evaluation by interferometry

Page 29: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 29

Oxygen barrier coatings

S LPLAS LPLAEC projectDevelopment of Nanocomposite Hybrid Barrier Coatings on Plastic Films via an Aerosol Assisted Atmospheric Plasma Process • EC FP5 GROWTH project • Food and electronic packaging applications• Low cost, in-line deposition technology• Start: 01/04/2002 - End: 31/06/2005

Page 30: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 30

Oxygen barrier coatings

Precursors AlcoholCatalysts Stabilisors

Solution

Hydrolysis

OEtSiOx

OH

OH

OH

HO

HOOH

EtONano particle

Coating

Al(OC3H7)3Zr(OC3H7)4Ti(OC3H7)4

Si(OC2H5)4

H2N Si(OR)3

Si(OR)3

Si

O

OSi

R

R

OSi

O

O O

MO

OO

(RO)3Si O

O(RO)3Si

OO

Sin

R

Hybrid network formation

Sol-gel synthesis

GellingSol-gel system

Page 31: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 31

SEM pictures of plasma depositions

Silicon substrate

350

nm

Coating

Silicon substrate

TetraethoxysilaneTEOS

Methacryloxypropyl-trimethoxysilane

MEMO

Page 32: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 32

Sol-gel modification

O SiO

SiOSi

OSi

SiSi

SiSi

CH3

CH3

CH3

H3C

H3C

H3C

H3C

H3C

OO O

O

OO

O

O

O SiO

SiOSi

OSi

SiSi

SiSi

CH3

CH3

CH3

H3C

H3C

H3C

H3C

OO

O

OO

O

CH3 O

O SiO

SiOSi

O

Si

SiSi

SiSi

CH3

CH3

CH3

H3C

H3C

H3C

H3C

OO

O

O

OO

O

CH3

n

Bayresit

SiO

OO

OGLYMO

SiO

O CH3

PTMO

CH3

CH3

OO

OO

O NC

O HSi

O

O

GDMA silane

Si OO

O

O

MEMO

Inorganic cross-linker gives stable films in the plasma process

Page 33: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 33

O2-Barrier performance on BOPP

PP58pure

Plasma100 s UV

60 s UV

496

88 101

202

35 5947

1010

50

100

150

200

250

300

350

400

450

500

OTR

[cm

³/m²*

d*ba

r]

Bayresit/Memo50:50 20:80 Bayresit/GDMA

50:50 20:80 Bayresit/Glymo50:50 20:80

Bayresitpure

Film thicknessconventional: 10-30 µmplasma: 0,7-3 µm

Plasma cured

UV cured

Page 34: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 34

O2-Barrier performance on Arylite®

Arylitepure

Plasma100 s UV

60 s UV

1000

41 88

19 2110 35

1240

100

200

300

400

500

600

700

800

900

1000

OTR

[cm

³/m²*

d*ba

r]

Bayresit/Memo50:50 20:80 Bayresit/GDMA

50:50 20:80 Bayresit/Glymo50:50 20:80 Bayresit

pure

Plasma cured

UV cured

Film thicknessconventional: 10-30 µmplasma: 0,7-3 µm

Page 35: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 35

Chitosan based anti-bacterial coatings• Chitosan is obtained from

chitin, the second most abundant natural biopolymer after cellulose.

• Chitosan is an edible and biodegradable material, which also has antimicrobial activity against different groups of micro-organisms, both bacteria, yeasts and moulds.

012345678

No coating Chitosancoating

E.ColiB. Subtilis

Page 36: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 36

Plating experiments on CCA

Page 37: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 37

Biofunctional coatings

Bio-engineering by atmospheric plasma treatment

• EC FP6 NEST project • Immobilization of biomolecules in plasmapolymers• Development of low cost, one-step immobilization • Applications: bio-sensors, intelligent packaging, …• Start: 15/05/2004 - End: 14/05/2007

EC project BIOPLASMA

Page 38: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 38

Biofunctional plasma coatings• Selection of precursors that polymerize under mild

conditions in order not to destroy biomolecules• Determination of mild plasma conditions that allows

incorporation of biomolecules in plasmapolymers• Optimization of process conditions and type of precursor

for immobilization of biomolecules for specific applications

Page 39: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 39

Activity of immobilized enzymes

H2O2

DCFH-DA DCF

β-D-glucose β-D-gluconolactone

Glucose oxidase + O2

485 nm

530 nm

Page 40: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 40

Immobilization of BSA-FITCConfocal laser scanning microscopy

0 ng/cm² wet-chemical

~ 100ng/cm² in plasma coating

~ 1µg/cm² in plasma coating

Page 41: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 41

EC FP6 Project• Nanocomposite coatings based on inorganic

fullerene-like nanoparticles.• Enhanced reliability and durability of

mechanical components• Consortium: 30 partners (Renault, Rolls-

Royce, Fuchs, Goodrich …)• Start: 01/09/2005 - End: 01/03/2010

Incorporation of nano particles in plasma coatings

Page 42: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 42

Envisioning future applications in flexible packaging

Page 43: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 43

Improved adhesion In many multi-layered packaging materials delamination is still a topic of concern Tailored atmospheric plasma treatments could improve the adhesion significantly compared to the currently used flame, corona and/or (UV-) ozone treatments On the other hand, the use of chemical primer solutions could be reduced or even completely eliminated

Page 44: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 44

Controlled releaseReducing the adhesion properties is also possible by injection of adequate chemical precursors in the plasma discharge. This allows to control the release properties of materials (e.g. unwinding characteristics or peel-seal strength). Controlled release is also an important aspect for peal seals and reclosable packs.

Page 45: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 45

Alternative high barrier coatings

The actual barrier performance is still too low: log 2 reduction in oxygen transmission rate was obtained but log 3 to log 5 is often requiredCoating deposition rates (100 – 500 nm/min) are still too low which results in very low line speeds Current estimated costs are at least a factor 100 too high

Page 46: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 46

Biofunctional coatings

Chitosan based antimicrobial coatings as a food approved alternative for existing solutions involving migration of active substances (EC regulations)Towards smart and active packaging concepts for enhanced food quality monitoring (consumer driven)

Page 47: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 47

Conclusions

Page 48: Cold atmospheric plasma technology for surface ... · • DBD plasma jet treatment was superior to conventional techniques for surface activation like UV-ozone or wet-chemical acid

Paper 12.3 Dirk Vangeneugden & Robby Rego 48

Conclusions• Atmospheric DBD plasma processes, based upon

the same technology as current state of the art corona technology, offer new possibilities for sustainable dry surface engineering

• By controlling the gas atmosphere and the electrical conditions and by addition of reactive chemicals, one can increase the efficiency of the plasma surface treatment significantly and make the effects permanent

• The technology opens up new possibilities to deposit thin (bio)functional coatings in a continuous system at ambient pressure