How does a corona treatment work?
A corona treatment is used to increase a material's surface tension in an effective way. By treating the material with a high frequency corona discharge, its surface becomes much more receptive to adhesives, inks and coatings.
How long does corona surface treatment last?
six monthsWhen treating paper with Corona you will get the benefits of cleaning the surface and removing any unwanted paper fibres that could create pin holes during the coating process. The treatment level lasts for a minimum of six months.
How is corona treatment measured?
There are no limits to the substrates that can be Corona treated, but the intensity of the treatment required will vary significantly according to their chemical make-up. The best way to determine the exact value is by testing a sample of the actual film that is being used for a specific application.
What is plasma treatment of plastics?
Plasma Treatment of Plastic Plasma treatment of plastics to improve adhesion is a two-fold surface activation and cleaning process. In the first instance, the plasma treating the plastic cleans away volatile organic compounds that otherwise impede bonding, painting and gluing.
What is the difference between Corona and plasma treatment?
Plasma systems are used when corona treatment, which again ionizes only air, are unable to produce the desired treatment results. In some cases, plasma treatment produces higher and longer lasting surface effects than corona, but the benefits must offset the additional equipment investment and operational costs.
What is corona treatment plastic?
Corona treatment is used to increase the surface energy of plastic and other materials for improved adhesion of inks, adhesives, and coatings. Corona treated materials feature higher printing and coating quality than materials that do not undergo this treatment.Jul 26, 2021
What is meant by surface treatment?
Surface treatment is an additional process applied to the surface of a material for the purpose of adding functions such as rust and wear resistance or improving the decorative properties to enhance its appearance.Aug 23, 2021
How does corona discharge occur?
Corona discharge can cause an audible hissing or cracking noise as it ionizes the air around the conductors. This is common in high voltage electric power transmission lines. The corona effect can also produce a violet glow, production of ozone gas around the conductor, radio interference, and electrical power loss.Oct 26, 2020
How long does plasma treatment last?
It will also take several days for the tiny scabs to disappear from the pinpoint wounds on the skin's surface. During this time you will begin to see the results of your treatment, and your skin will continue to improve over the next six months. After that, results generally last about three years.Aug 25, 2020
How long does plasma coating last?
Most plasma treatments last approximately 48 hours if the treated surface remains clean and dry.
What is plasma used to treat?
WHAT ARE PLASMA PROTEIN THERAPIES? FROM DONATED PLASMA. These therapies are used to treat a number of rare, chronic, conditions including primary immunodeficiencies, chronic inflammatory demyelinating polyneuropathy, hereditary angioedema, alpha-1 antitrypsin deficiency, and bleeding disorders such as hemophilia.
Overview
Corona treatment (sometimes referred to as air plasma) is a surface modification technique that uses a low temperature corona discharge plasma to impart changes in the properties of a surface. The corona plasmais generated by the application of high voltage to an electrode that has a sharp tip. The plasma forms at the tip. A linear array of electrodes is often used to create a curtain o…
History
The corona treatment was invented by the Danish engineer Verner Eisby in 1951. Verner had been asked by one of his customers if he could find a solution which would make it possible to print on plastic. Verner found that there were already a couple of ways to accomplish this. One was a gas flame method and the other was a spark generating method, both of which were crude and uncontrollable and did not produce a homogeneous product. Verner came up with the theory tha…
Materials
Many plastics, such as polyethylene and polypropylene, have chemically inert and nonporous surfaces with low surface tensions causing them to be non-receptive to bonding with printing inks, coatings, and adhesives. Although results are invisible to the naked eye, surface treating modifies surfaces to improve adhesion.
Polyethylene, polypropylene, nylon, vinyl, PVC, PET, metalized surfaces, foils, paper, and paperboardstocks …
Equipment
Corona discharge equipment consists of a high-frequency power generator, a high-voltage transformer, a stationary electrode, and a treater ground roll. Standard utility electrical power is converted into higher frequency power which is then supplied to the treater station. The treater station applies this power through ceramic or metal electrodes over an air gap onto the material's surface.
Pre-treatment
Many substrates provide a better bonding surface when they are treated at the time they are produced. This is called “pre-treatment.” The effects of corona treatment diminish over time. Therefore, many surfaces will require a second “bump” treatment at the time they are converted to ensure bonding with printing inks, coatings, and adhesives.
Other technologies
Other technologies used for surface treatment include in-line atmospheric (air) plasma, flame plasma, and chemical plasma systems.
Atmospheric-pressure plasmatreatment is very similar to corona treatment but there are a few differences between them. Both treatments may use one or more high voltage electrodes which charge the surrounding blown gas molecules and ionizes them. However, in atmospheric plasm…
See also
• Flame treatment
• List of plasma (physics) articles
• Plasma activation
• Polymeric surface
• Surface finishing
External links
• Technical article describing how surface treatment with Corona and plasma works