Game-Changing Surface Pretreatment Technology Rory A. Wolf VP Business Development Enercon Industries Corporation SPE International Polyolefins® Conference.

Game-Changing Game-Changing Surface Pretreatment Surface Pretreatment

TechnologyTechnologyRory A. Wolf Rory A. Wolf

VP Business DevelopmentVP Business Development

Enercon Industries CorporationEnercon Industries Corporation

SPE International Polyolefins® Conference and FlexPackCon®

Flexible Packaging Industry Graphic Challenges Higher Productivity & Efficiencies

Higher press speeds Minimal press set-up Fully automatic change-over of

plate cylinder mandrels/sleeves, anilox rollers/sleeves

Next job make-ready organization Self-adhesive plate sleeves


Surface Adhesion Challenges

Substrate

Water-based interfaces are formulated with non-soluble binders composed of styrene acrylic alkali-soluble binder and resin emulsion.


Substrate

As interfaces dry, ammonia and volatile amines leave and emulsion particles can “touch”, combining to form a surface film.


Substrate

Trapping these interfaces can trap volatile amines which can exist as salts, interfering with interface-to substrate and interface-to-interface bonding.


Tribocharging caused by contact and separation of a web from rolls can cause “spidering” of flexible packaging inks and coatings following impression to the web.

Tribocharging effect influences surface tension requirements


2x2 micron images of PP film

A.No Corona Treatment

B.WD = 1.16W/ft2/min (12.5W/m2/min)

C.WD = 1.93W/ft2/min (20.8W/m2/min)

D.WD = 2.71W/ft2/min (29.2W/m2/min)

Topographical Image Phase Image (Height – 10nm) (Range – 60º)


Slow Speed High Speed

Treater Ground Roll

Treater Ground Roll

Contact Area

Contact Area

…………………………………….. ……………………………………..

Boundary Air

Boundary Air

Contamination

Contamination

Boundary layer air and surface contaminations reduce ground roll contact area at high speed with current art surface activation systems

Reduction in complete surface activation by entrained air behind the web, causing backside treatment.


Current Surface Activation Technologies Limitations of Current State Corona

& Atmospheric Plasma Systems

Boundary layer air not sufficiently removed at high speeds.

Backside treatment creates ink picking. Tribocharging effect on ink spidering

not neutralized at treater. Ionized air (ozone) or plasma gases

entrained with web.


Limitations of Current State Corona & Atmospheric Plasma Systems

Limited removal of low molecular weight organic surface contaminations.

Splices and varying material thicknesses require manual gap adjustments, reducing productivity

No recent system designs which offer flexographic printers new solutions with integrated sustainability.


Current Surface Activation Technologies

Plasma Technology Change

Step-Changes for Next-Gen Atmospheric Plasma Technology Completely remove boundary layer air effect to

minimize flexible packaging ink/coating adhesion issues.

Neutralize tribocharging/ink-spidering effects at surface treatment.

Higher discharge concentration to remove surface contamination and improve ink/coating adhesion

Significantly reduce gas entrainment with webs, gas consumption.

Reduce treater maintenance/damage due to material thickness variations, splice impact.


Current State APT Next Gen APT


Plasma Technology Change

Experimental DesignParameter Description

MaterialUntreated & pre-corona treated BOPP film

Process

Current state semi-chambered atmospheric plasma

Next-Gen Atmospheric Plasma design

Power DensityHigh Low

Gas Composition100% Air (ozone-generating)100% N2 (non-ozone)


Trial Results/Data Analysis


Treatment Longevity (Days)

Sur

face

Ten

sion

(m

N/m

)

34

36

38

40

42

44

46

48

50

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46

Next Gen/High PD/AirNext Gen/High PD/AirCurrent/High PD/AirCurrent/High PD/AirNext Gen/High PD/N2Next Gen/High PD/N2Current/High PD/N2Current/High PD/N2

Next Gen/Low PD/AirNext Gen/Low PD/AirNext Gen/Low PD/N2Next Gen/Low PD/N2Current/Low PD/ AirCurrent/Low PD/ AirCurrent/ Low PD/ N2Current/ Low PD/ N2

Summary of Results Next Gen Atmospheric Plasma Technology

improves surface energy level relative to Current State technology, at both high and low power density, relative to gas chemistry.

Gas-Phase treatment longevity patterns similar between Next Gen and Current State.

No significant difference between air plasma and inert plasma treatment level or longevity relative to either system.


Boundary Layer Air Completely removed. No Interference with Plasma Chemical Reaction at Surface

Additional Trial Parameters Measured



Gas Containment > 40% Reduction in Gas Consumption vs. Current State technology





Tribocharging Both system designs neutralized web charge at the discharge






Footprint / Sustainability Next Gen electrode discharge capacity > 3:1 vs. Current State Technology







Gap Maintenance/Adjustment

Assembly (Gap) maintained throughout trial; auto-adjusted to web thickness









Backside Treatment Air plasma discharge generated < OSHA allowable ozone ppm









Backside Treatment No backside treatment for either system design

Exhausted Emissions Air plasma discharge generated < OSHA allowable ozone ppm



THANK YOU!Rory A. Wolf

Enercon Industries Corporation

[email protected]
