• DK: +45 76 300 333
  • US: (312) 803-3691
  • [email protected]
Search
  • Careers
  • Contact Us
  • Products
    • Subitem
      • Products
      • Converting
      • Narrow Web
      • Extrusion
    • Subitem
      • Coating
      • iPlasma
      • Generators
      • Web Cleaner
    • Subitem
      • Accessories
        • Dyne Pens
        • Ozone Eliminator
        • Ozone Removal
  • Corona
    • Corona
    • HD Precision Corona
  • Plasma
  • KNOWLEDGE HUB
    • Knowledge Centre
    • Technical Whitepapers
    • FAQs
    • Knowledge Sharing
  • Test Lab
  • Showroom
  • Support & Spares
    • Support
    • Contact Support
    • Spare Parts & Returns
    • Request Spare Parts
    • Request Dyne Pens
  • About
    • About Us
    • Why Choose Us?
    • Meet the Team
    • Sustainability – ESG
    • History
  • News
  • Global Network
  • Careers
  • Contact Us

Corona Treatment

Home Our Offering Corona Treatment

Corona Treatment

Have you ever wondered why it is difficult to write or print on plastic – why the ink is smearing when you rub it? The reason is the relative energy between the two surfaces, and the only way to solve the problem is to modify the surface of the plastic and increase its adhesive capability. The process capable of this is called Corona treatment.

Whether a liquid wets a material well or poorly primarily depends on the chemical nature of both the liquid and the substrate. Wetting is the ratio between the surface energies of the liquid and the plastic material, and is measured in dyne/cm. Corona treatment ensures the surface energy of the plastic is higher than that of the liquid by increasing the adhesion of the plastic surface.

Surface Energy Graph

Surface energy with and without corona treatment
Left side: Low surface energy = high contact angle = poor adhesion
Right side: High surface energy = low contact angle = good adhesion

Being a man-made synthetic material, plastic consists of chains of molecules joined end to end to form even longer chains. These linked chains present few opportunities for bonding at the surface and need to be opened to increase wettability.

Directing a high frequency discharge at the plastic surface from close-range simply disrupts the molecules by oxidising it. The discharge splits the carbon molecules and breaks the oxygen into ions, some of which enter the surface layer of the plastic and improve the bonding, while others form into ozone that needs to be extracted.

The new carbonyl groups created have a higher surface energy, and this improves the chemical connectivity (dyne/cm) between the liquid and the plastic.

Corona treatment affects only the surface layer of the plastic, to a depth of 0.01 micron, and does not change its appearance or strength.

Corona Changes Graphic

The corona changes

Determination of treatment level

The effectiveness of Corona treatment depends on the specific material being used, as different materials have different characteristics and different amounts of slip and additives – and will therefore behave in different ways. Even two rolls of supposedly the same material can behave differently; it all depends on their precise chemical composition.

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.

Durability

In general, the more slippery the substrate the faster the dyne level will fall, and this applies also to thicker and older substrates where the slip agents may have migrated to the surface after treatment. Substrates that are difficult to treat will also decay faster, and those with a very high slip factor may lose their adhesion as soon as 24 hours after Corona treatment. The solution is to re-treat before using.

Material which has not been treated at extrusion can be difficult to treat afterwards. It is therefore recommended to treat the film just after the extrusion process and subsequently use a refresher treatment just before the liquid or media is applied to the surface.

The secret is to test and test again – and if you are unsure or require advice or assistance, please contact us – we will always be pleased to help.

Get a Quote

Get a quote today

Related Pages

  • Plasma Treatment
  • Corona Treatment
  • Knowledge Sharing

Global Network

Vetaphone has a worldwide network of local representatives.

Find your local agent

Get a Quote

Get a non-binding quote for a Vetaphone Corona system or send us an e-mail: [email protected]

Get a quote today

Case Studies

Tech Folien

Tech Folien is part of the Polyart Group and a leading UK niche manufacturer of...

Read more

LMI PACKAGING

LMI Packaging is a third-generation converter based in Pleasant Prairie, Wisconsin. Established in 1967 the...

Read more
Share

Members of

MEMBERS OF

  • FTA
  • TLMI
  • DANSK FLEXO FORUM
  • DFTA
  • DFTA

Newsletter Sign Up Modal

CSR

Quick Links

  • Products
  • Our Offering
  • Case Studies
  • Support
  • About Us
  • Global Network

Useful Information

  • Request a quote
  • Request Spare Parts

Follow us

Contact Us

Vetaphone A/S
Fabriksvej 11,
DK-6000 Kolding,
Denmark

Vetaphone North America
155 North Wacker Drive, Suite 4250
Chicago, IL 60606
USA

 

DK: +45 76 300 333
US: (312) 803-3691
[email protected]

© 2025 Vetaphone A/S

  • Privacy policy
  • Quality Policy
  • The Eisby Trust
  • Payment Details
  • Terms
  • Whistleblower
Manage Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage {vendor_count} vendors Read more about these purposes
View preferences
{title} {title} {title}

Support