June 17-18, 2013 – Columbus, OH

Question: “Is there a way to improve adhesion of two-component polyurethane adhesives to polyester- and epoxy-based powder–coated surfaces?” PC Summit, 2013 Source: Products Finishing Magazine, Powder Coating Clinic, April 2013

Answer: “It is possible to apply an adhesive over a powder. The challenge is to find an adhesive/powder combination that works. You need to select a powder that meets the performance and appearance properties you need, and then work with an adhesive supplier to find the correct adhesive…” PC Summit, 2013 Source: Products Finishing Magazine, Powder Coating Clinic, April 2013

Answer: “…Polyester powder is more likely to provide adhesion than epoxy powder. You can roughen the surface where you need the adhesion, but that may not be feasible. Talk to an adhesive supplier and you should be able to make it work.” PC Summit, 2013 Source: Products Finishing Magazine, Powder Coating Clinic, April 2013

Problem Statement Powder coated materials present downstream bonding issues. Potential Applications adhesive bonding label application decoration (pad printing, silk screening) foam gaskets PC Summit, 2013

Fundamentals of Paint Adhesion  The molecules in the paint film wet or flow freely over the substrate  Chemical bonds are formed at the interface  The paint film penetrates the roughness on the substrate surface, resulting in mechanical interlocking once the paint dries. PC Summit, 2013 Source: Fundamentals of Paint Adhesion, Ed Petrie

Surface Wetting PC Summit, 2013

Surface Energy Measurement Low Surface EnergyHigh Surface Energy PC Summit, 2013

Contamination Anti- oxidants Cross- linkers Fillers UV Modifiers Pigments Slip Agents, Waxes

PC Summit, 2013 Wet Chemical Cleaner Solvent Primer Mechanical Scuff Sand Blast Physical Flame Corona Plasma Surface Modification Options

Is There a Perfect Solution? PC Summit, 2013 Reliable Repeatable Easy to use Robust Process In-Line Easy to automate Easy to integrate Labor Reduction No chemicals No ozone No waste Safe Material savings Labor savings Reduced liability Cost Effective

Plasma: The 4 th State of Matter SolidLiquidGas + + * * e-e- e-e- e-e- * * gas molecule * (excited) * ions free electron + e-e- – + – – + + Plasm a molecule fragment (high- energy) Plasma PC Summit, 2013

Flame Treatment  Low ion density  Activation only- little or no cleaning  Thermal distortion  Inconsistent-ambient conditions  Contamination  Liability – open flame  High consumable cost  Metals/mixed materials not possible PC Summit, 2013

Corona Discharge  Better ion density  Activation only- little or no cleaning  Tight application tolerances  Liability - ozone  High voltage at interface  Metals/mixed materials not possible PC Summit, 2013

Vacuum Plasma  High ion density  Cleaning & activation  Complex chemistries possible  Offline process  Not selective PC Summit, 2013

Openair™ Plasma  High ion density  Cleaning & activation  Simple inputs – power/air  In-line process  Selective treatment  Low/no voltage  No ozone  $0.10 to $0.25/hour PC Summit, 2013

Source: Guideline to Bonding Plastics, ANTEC-2013 Michael Oliveira, Henkel

Openair™ Plasma Jet Substrate Inner Electrode Ionization Gas High voltage Current Plasma Ring Electrode (SS casing) Discharge Chamber PC Summit, 2013

Attack Surface Contamination C O O N * * * * N N O N N N O N O O N O * * * CCCCCCC HHHHHHH HHHHHHH PC Summit, 2013

Remove Surface Contamination C CCCCCCC HHHHHHH HHHHHHH O O N * * * * N N O N N N O N O O N O * * * PC Summit, 2013

C O N CCCCCCC HHHHH H H H H HHHHH O O O O O O N N N N N N N * * * * * * * Form Functional Sites PC Summit, 2013

Straight Jet  Focused plasma cleaning & activation  Long term stability  Low consumable parts  Flexible with different nozzles  Speed: up to 70m/min  Gap: 5 to 20 mm  15 mm max treatment width PC Summit, 2013

Rotational Jet  Wide area plasma cleaning & activation  Long term stability  Low consumable parts  Flexible with different nozzles  Speed: up to 35m/min  Gap: 5 to 20 mm  50 mm max treatment width PC Summit, 2013

Openair™-Plasma Jet Heads – Rotating Jet PC Summit, 2013

Continuous Monitoring If you can’t see the treatment, how do you know it’s there? PC Summit, 2013 Voltage Amperage Air Flow Air Pressure Pulse Frequency Duty Cycle Jet Rotation (if required) Control the Inputs

Reliable, repeatable, fast No dilution effect, steady state No expensive consumables Surface cleaning of the complete structure of the material In-line integration = small footprint Economical and environmentally friendly No change in bulk properties of substrate Advantages of Openair™ Plasma Cleaning & Activation PC Summit, 2013

Powder Coating on Plastic! PC Summit, 2013 What’s Next? Plasma Cleaning & ActivationConductive AgentPowder ApplicationHeat (IR or Convection)UV Cure

Q & A/Discussion PC Summit, Ext. 2121