The use of plasma technology as a pretreatment on plastic and composite substrates enables these heat-sensitive materials to be successfully coated with ultraviolet (UV) curable powder coatings. This presentation discusses the many benefits of UV cured powder coating on plastics and composites using Plasma technology including no substrate deformation or degradation, improved coating adhesion, removal of contaminates and more.

1. Plasma – Plastics – UV-Cured Powder
Coating
UV-CURED POWDER COATING OF PLASMA TREATED
HEAT SENSITIVE SUBSTRATES

2. PRESENTATION AGENDA
• INTRODUCTION OF PLASMA
• PLASMA FOR INTERFACE ADHESION
• SUBSTRATE SURFACE ENERGY EVALUATION
• UV-CURED POWDER COATING APPLICATION
• ADHESION TESTING RESULTS
• PLASMA AND UV POWDER APPLICATION VIDEO
• CONCLUSION
• CITATIONS
• QUESTIONS
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3. WHAT IS PLASMA
Solid → Liquid → Gas → Plasma
Energy Energy Energy
Plasma:
• Partially ionized and neutralized gas mixture containing physically active
and chemically reactive species, like ions, electrons and free radicals.
• Sometimes referred to as the 4th state/phase of matter
• Similar to gas phase, but capable of conducting electricity
+ - + -
+ - + -
+ - + -
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4. COMPONENTS OF PLASMA
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• Electrons
• Ions
• Free Radicals
• Byproducts
• Photons
• Neutrals
Key Plasma Components
Ions = Physical
Radicals = Chemical

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HOW DOES PLASMA WORK?
• Surface activation, cleaning, and etching by chemical reaction and physical
bombardment
• Plasma Surface Activation Example:
The formation of oxy and amino functional groups on surface promotes the interface adhesion

6. VACUUM PLASMA TECHNOLOGY
• Samples placed in reactor
• Evacuate air, input desired process gas – argon – oxygen – air - other
• Apply electromagnetic (RF) energy across electrodes for surface treatment
• 3D surface treatment
• Low temperature
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CONTACT ANGLE & SURFACE MODIFICATION
HIGH CONTACT ANGLE LOW CONTACT ANGLE
UNTREATED TREATED
BEFORE AFTER

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PLASMA FOR ADHESION IMPROVEMENT
0
5
10
15
20
25
30
35
40
45
50
Shear T-peel
Loadforceatpeak(Ibf)
Test methods
Untreated
IFP, O2
Direct, O2
Direct, Ar
Shear Test: 216% Improvement
Failure Mode: PI-UF Adhesion ➔ PI
Cohesion
T-Peel: 435% Improvement
Failure Mode: PI-UF Adhesion Failure
FR-4 Substrate Clamped in Place
Force
Applied
(Speed = 0.5 in./min.)
FR-4 Substrate Clamped in Place
Force
Applied
(Speed = 0.5 in./min.)
Shear Test
Peel Test

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SURFACE ENERGY FOLLOWING PLASMA
TREATING
32
64 70
30
70
60
70
48
70 70 68
36
70 70 70
Measured Dynes
Notes:
1.) Surface tension (Dyne) tested using a Jemmco Dyne solutions 30-70 dyne. The higher the number the higher the surface
energy and better material wetting and adhesion.
2.) Test conditions for each material trial were the same
a.) Base pressure measured in (mTorr) b.) Gas pressure measured in (CCPM)
c.) Unit power measured in (Watts) d.) Time of treatment measured in (Secs)
3.) In some cases dyne test result exceeded 70 units
4.) Plasma unit Nordson/March AP-1500

10. PLASMA TREATING & UV POWDER ADHESION
ADHESION OF UV POWDER WITHOUT PLASMA TREATING
Material #1 Material #2 Material #3 Material #4
Material #1 Gas #2 Material #2 Gas #2 Material #3 Gas #2 Material #4 Gas #1
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ADHESION OF UV POWDER AFTER PLASMA TREATING

11. ADHESION TEST RESULTS FOLLOWING PLASMA
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0 4 5
0 4 5 4 0 4 5
2
5
3 4
ADHESION
ASTM - D3359
0B - 5B

12. UV-CURED POWDER COATING
Melt & Flow
1 – 4 min UV Cure
(secs)
Electrostatic
Powder
Deposition
Finished
Product
Substrate
Pretreatment
Melt, Flow & Cure
10-30 mins
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13. UV-CURED POWDER COATING THERMAL PROFILE
Melting powder not heating part
1 second 47 seconds 96 seconds
65°C/150°F 78°C/172°F 104°C/221°F
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Total time entry to exit 120 seconds
Total dwell time in front of IR panel 96 seconds
Surface temperature end of cure – 85°C/185oF

14. TIME & TEMPERATURE
Hold Temperature
EndEnter Melt/UV
Oven
Leave Melt/Cure
End
Start Enter Preheat
Leave Preheat
Enter Application
Exit Melt/UV Oven
0
20
40
60
80
100
120
140
160
0 5 10 15 20 25 30 35
Temperature(°C)
Minutes
UV
Thermal
Enter Melt/
Cure Oven
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15. UV-CURED POWDER COATING PERFORMANCE
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Reagent Result
Engine oil No effect
Gearbox oil No effect
Film Build No Effect
Hydraulic oil No effect
Brake Fluid Slight gloss loss
Antifreeze No effect
Cold cleaner No effect
Inert cleaner No effect
E95 No effect
Unleaded gas Slight/moderate gloss loss
Diesel fuel No effect
Battery fluid No effect

16. BENEFITS OF UV-CURED POWDER ON PLASTIC &
COMPOSITES
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17. CONCLUSION
• Plastics, plastic composites and carbon fiber materials are difficult to finish
• Low surface energy and presence of containments from mold release and
processing impedes the adhesion of coatings
• Low melt or distortion temperatures
• UV-cured powder coating used in combination with plasma treating is an
effective and efficient finishing system for these materials
• Different gases and variable power and time settings facilitate the use of plasma
treatment of a variety of materials prior to finishing
• High productivity
• 100% solid material - No solvents or water
• Low temperature and fast melting eliminates distortion of substrate
• Durable finish
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18. CITATIONS & NOTES
Keyland Polymer UV Powder, LLC
4621 Hinckley Industrial Parkway Unit 8
Cleveland, OH 44109 USA
216-741-7915
www.kpuvpowder.com
info@keylandpolymer.com
Slide data and images on slides 4 and 9-11 courtesy of David Foote at Nordson MARCH, Concord, CA
www.nordsonmarch.com
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