What does a plasma surface treatment system look like?
The equipment needed to generate a low-pressure plasma for surface modification is basically as follows:
Vacuum chamber
Vacuum pump
Gas supply
Middle or high frequency generator
Electrode
Plasma FAQ
- What does a plasma surface treatment system look like?
- How does a plasma system work?
- Which materials can be plasma treated?
- Vacuum chamber capacity size and quantity?
- Which gases are used?
- Power supply requirements?
- What is Plasma etching / plasma activation?
- Is plasma treatment of selected areas possible?
- Are there environmental and health impacts?
How does plasma work?
A vacuum chamber is evacuated with the vacuum pump to produce a
low-pressure environment in the chamber.
The process gas 0²
for example is introduced in a controlled manner.
Generally, the pressure in the chamber is now at 0.1 to 1.0 mbar.
The gas is then ionized by introducing energy via the electrode
creating a plasma.
Fresh gas is continuously
bled into the chamber and the used gas is pumped out via the
vacuum pump.
Depending on the desired process the plasma surface treatment can
take anywhere from less than 1 min to 30 minutes.
On completion of the process air is allowed into the chamber and
once atmospheric pressure is achieved the parts or material can be
removed.
Which materials can be plasma treated?
Metal
Plastics /Polymers
Elastomers
Polymers combined with other materials, metals for example
Textiles
Parts with complex geometries can be treated or cleaned as the
plasma penetrates even the smallest gaps. Textiles and roll goods
can be treated in special roll to roll plasma chambers. We offer
this as a service at our factory in Herrenberg.
Vacuum chamber capacity size and quantity?
The size of the parts and the quantity determine the vacuum
chamber size.
The maximal throughput for parts is dependent on the plasma
process.
For example, surface activation usually only takes about 5 min
whereas cleaning and etching may take up to 30 minutes.
Dependent on the components to be treated it may be possible to
bulk treat large quantities in a rotating drum system.
Flat parts can be treated on multiple racks at various levels in
the vacuum chamber.
Textiles and foils can be treated on a roll to roll system.
It is also no problem to design a chamber for large complex
parts.
Which gases are used?
Oxygen
Hydrogen
Argon
Nitrogen
Fluor gas
Dependent on the desired treatment either a mixture or even other
gases may be used. We will advise you on the best option.
Power supply requirements?
For the larger production systems, you will need a 400V supply.
For the small table top Laboratory / small production systems you
will need a 230-volt socket.
What is Plasma etching / plasma activation?
Plasma etching is the process by which the surface is accurately
roughened hence greatly increasing the surface area available for
adhesive or paint to bond to.
Time taken to complete this process is dependent on power and the
gas used. Generally, between 10 and 100 µm is removed.
Plasma activation process creates functional groups on to the
surface of the work piece. This is carried out relatively quickly
(up to 5 min).
The treated areas ensure an optimal bonding
of paints and adhesives even on difficult materials.
Is plasma treatment of selected areas possible?
The areas on the surface that should not be treated can be masked,
so that only selected areas of the work piece are treated.
Our Plasma-spot ® offers an alternative.
This employs a specially designed delivery system that focuses the
plasma on to the specific areas to be treated. An advantage of the
Plasma-spot ® process method is the extremely short cycle time due
to the short time needed to evacuate the chamber.
Are there environmental and health impacts?
The low-pressure process is extremely environmentally friendly.
Due to the very small amounts of process gas used there is
no danger of creating a poisonous or explosive environment.
Where fluorinated gasses are used a special filter, technique is
used to eliminated any last risk due to the exhaust gases.
No heath damaging radiated energy is given off from the process.
Remember plasma is a naturally occurring state of matter, the
“Northern lights” being a popular visible example.