Plasma Activiation

plasma_activation

The process of cleaning and activating a surface prior to applying an adhesive or coating to increase adhesion is a great way to improve the strength of the bond between the base material and adhesive or coating applied to that material. The application of the plasma activation process can significantly increase the reliability and performance of a product. This increase in reliability leads to a decrease in scrap and cost of manufacturing in a production value stream. This is why plasma activation is an important part of manufacturing where a bonding process is incorporated in building a product.

Plasma Activation Functional Principles

What is Plasma Activation?

Activation is the process of changing the wettability or surface energy of a material.  When we discuss wettability we are observing the effect or force of a substance and  a surface to stay in contact with each other.  This force is often governed on a molecular level by a weak electrostatic charge (Van Der Waals forces) or as a chemical bond by the sharing of electron pairs between atoms (covalent bond).  

When this surface energy is low, a fluid moves across the material leaving little to no observed residue on the surface.  When this fluid dries or cures on the surface in this condition the resulting coating easily loses contact with the surface.   When a surface has high surface energy and a fluid is moved across the surface, a film of the fluid is observed coating the surface.  When this fluid dries or cures on the surface in this condition the resulting coating has better adhesion to the surface.

Plasma Activation of Polymers

The activation of plastics like polypropylene or polytetrafluoroethylene PTFE have relatively low surface energy in its natural state.  This means the material must be pre-treated before gluing, painting or printing.  Conventional activation by increasing surface area by mechanical roughing, priming or using a volatile organic compound (VOC) liquid adhesion promoter can give a slight shift in surface energy.

Plasma activation of plastics using low pressure plasma or atmospheric plasma provides an increase in surface energy.  Oxygen or air plasma replaces the non-polar hydrogen bonds of the polymer with oxygen bonds providing free valence electrons for covalent bonding to the adhesive or coating ensuring much better adhesion.

Plasma Activation of Metals, Ceramics and Glass

The activation of metals, ceramics, and glass can be improved with plasma activation as well. These materials when activated are able to covalently bond to adhesives and coatings ensuring a better adhesion in comparison to conventional surface preparation.

Plasma activation on these materials must be immediately followed by the application of the gluing, painting or secondary process steps because these materials typically react with the oxygen or water vapor in the air which lowers the surface energy and diminishes the impact of activation.  

Plasma Activation of Powders

The application of activation can be applied to powders as well.  Powder activation increases the surface energy of the powder increasing the ability of powdered material to blend into a fluid.  This process of powder activation has a significant effect on the mechanical properties of blended materials when applied to the manufacturing of a composite solid. 

eBook

Plasma Etching and Cleaning Strategy for Better Product Quality

Plasma Activation Uses

Improving adhesive bonds

Plasma activation for the process of increasing the adhesion between an adhesive and a base material increases the peel and shear in the joint between the adhesive and the base material.  This optimization in adhesion increases the reliability and quality of a product produced with adhesive bonding methods.

Improving paint adhesion

Plasma activation of base materials for optimization of paint adhesion is a great use of plasma activation.  Having the ability to increase the adhesion between a material with low surface energy and a water based paint without the use of a primer or adhesion promoters is a significant improvement in manufacturing strategy.  This shift of using plasma activation in these kinds of manufacturing methods is a reliable way to remove the cost of adhesion promoters which are often volatile organic compounds (VOCs) from a manufacturing value stream. 

Improving durability of industrial coatings

Plasma activation can also be used anytime a coating, ink or dye is being used in material that exhibits poor ware performance.  Using plasma activation on these types of processes increases the material properties of these coatings which improves the durability in the coating performance. Often, this application of plasma activation can deliver performance advantages not typically realized by other methods.

Popular Plasma Activation Systems

{id=1, name='Femto', order=0}

Femto Version 1

Control Cabinet:
W 310 mm H 330 mm D 420 mm

Chamber:
Ø 3.9 in, L 10.9 in

Chamber Volume:
2

Gas Supply:
1 gas channel via needle valve

Generator:
1 pc. with 40 kHz
(optional: 13.56 MHz or 2.45 GHz)

Control:
Semi-Automatic

{id=2, name='Pico', order=1}

Pico Version 4

Control Cabinet:
W 310 mm H 330 mm D 420 mm

Chamber:
Ø 5.9 in, L 12.6 in

Chamber Volume:
5

Gas Supply:
Mass flow controllers

Generator:
1 pc. with 40 kHz
(optional: 13.56 MHz or 2.45 GHz)

Control:
Touch Screen

{id=3, name='Nano', order=2}

Nano Version 5

Control Cabinet:
W 600 mm H 1700 mm D 800 mm

Chamber:
Ø 10.5 in, L 16.5 in

Chamber Volume:
24

Gas Supply:
2 gas channel via needle valve

Generator:
1 pc. with 40 kHz
(optional: 13.56 MHz or 2.45 GHz)

Control:
Semi-Automatic

{id=5, name='Special Tetra', order=4}

Special Tetra 30-LF-PC

Control Cabinet:
W 600 mm H 1700 mm D 800 mm

Chamber:
W 12" x H 11.8" x D 14.6"

Chamber Volume:
30

Gas Supply:
Mass flow controllers

Generator:
1 pc. with 40 kHz
(optional: 13.56 MHz or 2.45 GHz)

Control:
PC

{id=8, name='Atto', order=7}

Atto Version 3

Control Cabinet:
W 425 mm H 275 mm D 450 mm

Chamber:
Ø 8.3 in, L 11.8 in

Chamber Volume:
10.5

Gas Supply:
Mass flow controllers

Generator:
1 pc. with 40 kHz
(optional: 13.56 MHz)

Control:
Touch Screen

{id=12, name='Plasma Beam Duo', order=11}

Plasma Beam Duo

Control Cabinet:
W 562 mm H 211 mm D 450 mm

Generator:
1 pc. with 40 kHz

Control:
Semi-Automatic

Workshop

Learn about a Plasma Processing Workshop