Electrical Air Plasma
Electrical “air plasma” is a corona discharge spot treatment (also termed blown air plasma/forced air corona/blown arc). This treatment head consists of two hook electrodes in close proximity to each other connected to a high-voltage transformer generating an electric arc of approximately 7 to 12kV, and lower frequency 50 to 60 cycles/sec (relative to electrical corona discharge). Then using forced air, a continuous electric arc produces a corona discharge, “plasma.” No positive ground is needed. This pretreatment process has virtually no cleaning capabilities. Ozone is produced.
Myth: Corona discharge spot treatment yields longer shelf life than flaming.
Fact: Scholarly studies show flame plasma on polyolefins produces longer post-treatment shelf life due to its relatively shallower depth of treatment.
Frequently Asked Questions
What is electrical air plasma treatment?
Electrical air plasma is a corona discharge spot treatment, also called blown air plasma, forced air corona or blown arc. The head carries two hook electrodes close together on a high-voltage transformer, generating an electric arc of roughly 7 to 12 kV at a lower frequency of 50 to 60 cycles per second. Forced air carries the resulting corona discharge onto the part. No positive ground is needed.
How does electrical air plasma differ from electrical corona discharge?
Both are corona discharges, but air plasma runs at a much lower frequency -- 50 to 60 Hz against the 20 to 25 kHz of classical corona discharge -- and needs no earth ground or dielectric barrier. It is a spot treatment rather than an area treatment, which makes it suited to targeted locations rather than to treating a whole surface.
Does electrical air plasma clean the surface?
It has virtually no cleaning capability. Contamination present on the part before treatment will still be there afterwards, so parts carrying mold release, oils or handling residues need cleaning first.
Does corona spot treatment give a longer shelf life than flame treatment?
No -- the opposite, on polyolefins. Scholarly studies show flame plasma produces longer post-treatment shelf life on polyolefins, attributed to its relatively shallower depth of treatment. The belief that corona spot treatment lasts longer is one of the more persistent myths in this area.
Is ozone produced?
Yes. Ozone is generated by the discharge, which needs to be accounted for in the extraction and ventilation design around the treatment station.
