Plasma Surface Treatment vs Corona Treatment: What’s the Difference?

Today surface treatment technologies are needed for improving product quality. Two popular methods often come to mind. They are plasma surface treatment and corona treatment. Now, these are both capable of enhancing adhesion and wettability on various surfaces.

Yet, it begs the question “What sets these processes apart?”

We prepared this article to explain the basics of these surface treatment applications. Here we will cover how each method works. We will also provide you with their pros and cons. The goal is to help you choose one over the other. But in since cases, they can be combined.

Whether you work in packaging, printing, or high-tech manufacturing, understanding these treatments is crucial.

What is Corona Plasma?

“Corona plasma” is a term that describes a specific corona discharge process. A device for corona plasma treatment is typically utilized on plastics and other surfaces. 

The corona plasma method uses a high-voltage electrical field. This produces a localized plasma, often called “corona.” The latter may also be called a “corona discharge plasma.”

Once the corona plasma hits a material, it generates a plasma effect. The interaction makes the surface more receptive to inks, coatings, or adhesives. 

The corona process improves a material’s surface energy. These may include plastic films, rubber, and paper. With this effect, corona treatment enables the materials to bond better with other substances.¹

The corona surface treatment is highly common in the packaging and printing industries. It is even more prevalent for corona discharge treatment plastics. By increasing the surface energy, corona treatment allows for better adhesion. This effect is crucial for several industrial applications. 

Many consider corona plasma to be a straightforward solution. It is suitable for companies looking to improve adhesion yet are avoiding intensive set ups or high costs

Brief Introduction of Plasma Surface Treatment

Plasma surface treatment is a more advanced technique than the corona application. Its primary function is to alter the physical and chemical properties of a material’s surface.

Unlike the corona process, plasma treatment occurs under controlled conditions. For a plasma treatment to work, it can occur in a low-pressure or atmospheric-pressure environment. The unique feature makes plasma treatment suitable for more precise applications.²

You must ionize a gas in order to produce plasma. To do this, a plasma treatment device uses energy sources such as radio frequencies or microwaves. This plasma interacts with the surface, changing it at a microscopic level.

Unlike corona treatment, plasma surface treatment machines can perform the following:

• Etch surfaces
• Clean contaminants
• Create functional groups on the surface²

As a result, it’s widely used in sectors requiring precision. Examples are industries related to medical devices, automotive, and electronics.

The difference between gas and plasma in this context is significant. Corona treatment uses ionized gas, or plasma, produced in the air. Plasma surface treatment devices, however, often involve specialized gases and controlled environments. The latter helps achieve specific surface characteristics.

Comparison of the Corona Process & Plasma Surface Treatment

Aspect	Corona Process	Plasma Surface Treatment
Mechanism	Uses a corona discharge plasma in air	Controlled gas ionization under various pressures
Precision	Primarily increases surface energy	High precision; can etch, clean, or functionalize
Depth of Treatment	Limited to the surface; no deep changes	Can achieve micro-level modification
Materials Treated	Commonly used for non-porous plastics	Compatible with metals, ceramics, polymers, and more
Cost	Cost-effective, simple setup	Higher setup cost, especially with specialized gases
Industries	Packaging, printing, film manufacturing	Packaging, printing, film manufacturing, electronics, automotive, medical devices

Both methods utilize plasma in different forms. Corona treatment is generally easier and quicker for increasing surface energy. A plasma surface treatment device, on the other hand, offers deeper and more controlled modifications.

Pros and Cons of Plasma Surface Treatment vs Corona Treatment

Corona Treatment

Pros:

• Cost-effective and straightforward to implement.
• Works in open-air settings, reducing complexity.
• Ideal for treating non-porous materials, like plastics.

Cons:

• Limited to surface energy increase; lacks depth
• Less control over modification, restricting precision
• Primarily suitable for plastics and select polymers

Plasma Surface Treatment

Pros:

• Allows for highly controlled and precise treatment
• Can modify different materials, from metals to polymers
• Effective for intricate applications (cleaning, etching, functionalizing)

Cons:

• Higher initial setup and operational costs
• Often requires a controlled environment, especially for low-pressure plasma
• May require trained operators due to complex machinery

Combination of Corona Plasma and Plasma Surface Treatment

It is possible to combine corona plasma and plasma surface treatment. This combination can be beneficial in scenarios requiring both speed and surface versatility.

For example, corona surface treatment can improve surface energy on large packaging surfaces. Afterward, plasma surface treatment machines can enhance adhesion on specific parts for high-performance applications.

This dual approach leverages the strengths of each technique:

• Corona discharge treatment can provide needed efficient, high-speed surface energy improvement.
• Plasma surface treatment allows for customized, precise modification of critical sections.

When Should You Choose One Treatment Over the Other?

In the debate of Plasma Surface Treatment vs Corona Treatment, both applications have key roles in surface modification. However, they have unique qualities, too. This makes them suited to different industrial environments.

Corona surface treatment is ideal for quick, cost-effective improvements. The technology is widely employed for corona discharge treatment plastics. On the flip side, plasma surface treatment comes with precision and flexibility. These properties make plasma surface treatment perfect for applications where you need deeper modifications.

Understanding the difference between gas and plasma treatments is essential. Each treatment has its own benefits. This knowledge is essential to choosing which is the right surface treatment for your needs. Whether used independently or in combination, corona and plasma treatments are effective tools.

Partner with Keylink Today for Your Plasma Treatment Needs

Keylink Technology is recognized as one of the Asian leaders in manufacturing advanced plasma systems for surface treatment. The company offers a wider range of technological products. Keylink products have been a popular choice for businesses seeking Atmospheric Plasma and Low-Pressure Plasma solutions.

Keylink’s plasma systems go beyond giving industries high-performing products. Sustainability is also a core value of the company.  Keylink’s plasma processes are ideal alternatives over traditional, chemical-intensive surface treatments. Thus, Keylink can help your business contribute to a significant reduction in CO₂ emissions.