How to Increase Bonding Performance with In-line...

Increase Bonding Performance with Plasma & Flame Surface Treating

How to Increase Bonding

Performance with In-line Plasma &

Flame Surface Treating

Ryan Schuelke

Enercon Industries


Agenda

• Why surface preparation is needed

• Why plasma surface treaters are replacing other preparation techniques

• How plasma systems clean, etch & functionalize surfaces

• How effects of plasma treatment can be measured

• Industry examples from:

– Automotive, Aerospace, Construction, Electrical, Packaging and Assembly

• Application examples include:

– Printing, Bonding, Decorating and Potting


Cohesion & Adhesion

When you observe a liquid

beading up on a surface, you

are witnessing

the forces of cohesion

being stronger than the

forces of adhesion.

Interfacial Compatibility of Surface and Coating

Low Free Surface Energy


Interfacial Compatibility of

Surface & CoatingTo mechanically or chemically modify a coating or surface to improve adhesion:

• Modified Coating options

– More aggressive

– Solvent-based

• Considerations

– Cost

– Cleanup

– Hazardous



Surface & Coating

Mechanical and Chemical Surface Preparation Options

– Primers

Clean-up, consumable, human error

– Chemical Etching

Expensive, but permanent

– Mechanical Preparations

Cost, time, wear parts, clean-up

– Vacuum Plasmas

Capital & consumable cost, time, batch process

–Atmospheric Plasma & Flame

In-line, continuous process, line adaptation



Surface & Coating

Selecting a solution:

Permanent surface modification or temporary?

Supplier controlled or your control?

Batch process or in-line?

Pay back goal: initial investment or ongoing operating

costs?


What is Atmospheric Plasma?

plasma : n ; “Fourth state of matter”, (Solid, Liquid, Gas, Plasma.)

plasma treatment: Ionized gas that bombards the surface of a substrate & creates a more hydrophilic, micro-etched and functionalized surface.

Blown Ion Plasma Blown Arc Plasma Flame


How Plasma Treating Effects Surfaces

Surface Activation is a result of the following processes:

Removal of weak boundary layers – Surface treatment removes surface layers with the lowest molecular weight; at the same time, it oxidizes the uppermost atomic layer of the polymer.

Cross-linking of surface molecules - Oxygen radicals (and UV radiation) help break up bonds and promote the three dimensional cross-bonding of molecules.

Generation of polar groups - Oxidation of the polymer is responsible for the increase in polar groups which is directly related to adhesion properties of the polymer surface.


Plasma Treatment Cleans,

Micro-etches & Functionalizes

Clean: Removes organic and inorganic impurities & contaminants

Micro Etch: Increases surface area creating more bonding sites

Functionalize: Increases polar groups to improve adhesion properties.


Surface Analysis

Dyne Level

Contact Angle

Peel Strength

Tape Tests


Increased Surface Energy Examples

Material Initial Dyne LevelPost Treatment

Dyne Level

Polycarbonate 37 56-72

Polyethylene 32-34 42-60+

Polypropylene 30-34 45-60

Polystyrene 36 52-70

PTFE 30> 35-50

Rigid PVC 33-36 42-60+

TPU 34 40-48


Surface Polarity Comparison

Initial Surface Energy

Final Surface Energy Blown Ion

Final Surface Energy Flame

Polar Non Total Polar Non Total Polar Non TotalPP 1.5 28.1 29.7 14.3 35.4 49.6 9.5 35.1 44.6PE 0.3 28.4 28.7 21.4 38.5 59.9 16.9 39.4 56.3PA6 6.9 34.8 41.7 22.1 38.3 60.3 15.8 37.8 53.5PET 0.3 28.4 28.7 27.7 34.6 62.3 5.2 30.7 35.9CF 2.2 35.4 37.6 20.1 37.7 57.2 24.5 36.0 60.5


Peel Strength Adhesion Test

0.22

0.02

0.25

0.16

0.27

0.37

0.16

0.2

0.18

0.26

0.45

0.16

0.27

0.21

0.31

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

PP PE PA6 PET CF

Initial Flame Blown Ion


Material Type

Surface Treatment is effective on:

Glass, Plastics, Metals & More


Who Uses Surface Treating?

Medical

Electronics

Automotive & Aerospace

Wire & Cable

Packaging & Decorating

Folding Cartons

Construction & Assembly


Surface Treatment Benefits

& Industries that Use It


Folding Carton Applications

Green Bay PackagingApplication: Treat Folding Cartons

Goal: Improve bond strength and enable production speeds

"Previously, folder gluer press speeds were limited by glue application

speed and dwell time; with atmospheric plasma surface treatment,

press speeds can be significantly increased

while maintaining and even

improving quality.”

– Tom Vogel

Plant Engineer- Green Bay Packaging


Automotive Applications

Eissmann Automotive GroupApplication: Treat PP substrates prior to gluing

for automotive interiors.

Goal: Increase adhesion and production speeds.

“It took two minutes on average to treat each part

manually, and now it takes about 10 seconds with

the robot. The tolerance with the robot is

0.02mm, which results in incredibly consistent

coverage and far better adhesion.”

– Barrett White

Manufacturing Engineer- Eissmann Automotive


Headlamp Applications

Hella Austrailia PtyApplication: Secure a polycarbonate lens

to a PP headlamp assembly with silicone

adhesive.

Goal: Increase bond strength to withstand

high temperatures.

Solution: Plasma Treater integrated with

six-axis robot to follow precise path of

glue track.


Assembly Applications

Customer- ConfidentialApplication: Bond liquid potting compound with glass filled polyester

enclosure.

Goal: Ensure bonding compound adhesion to protect internal

components.

Solution: High velocity flame treater with combustion control system

for repeatable treatment.

Not actual product.


Assembly Applications

Customer- ConfidentialApplication: Foam filled constructions such as doors and windows.

Goal: Ensure foam bonding.

Solution: High velocity flame treater with combustion control system


Not actual product.


Potting Applications

Customer- ConfidentialApplication: Bond liquid potting compound with glass filled polyester

enclosure.

Goal: Ensure bonding compound adhesion to protect internal

components.

Solution: High Velocity Flame Treater with combustion control system


Not actual product.


Glow Plasma New Technology

• Treats the inside of plastics to improve surface adhesion

• Ionizes gas chemistries at lower power levels than

traditional plasmas

• Treats hard-to-reach places, including:

– Out of line-of-sight

– Recessed cavities

– Complex pathways


Review

• Plasma & flame surface treating are used in a wide variety

of industries to improve adhesive bonding.

• Surface treatment cleans, etches & functionalizes surfaces

to improve adhesion.

• Operational benefits may include improved bond strength,

line throughput, reduced waste & improved processes.

• Systems may be integrated with robotic and indexing

systems.

• Free lab testing can help you decide if surface treatment

can help solve your adhesion challenges.


Thank you!

www.enerconind.com/treating

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