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  • Writer's pictureDavide

Corona Treatment: Unveiling its Impact on Materials

Corona treatment utilizes low-temperature corona discharge plasma to modify surface properties, especially of plastics, enhancing their compatibility, adhesion, and readiness for further processing. This process, fundamental for printing, coating, and laminating, not only revolutionizes how materials bond but also introduces a new level of efficiency and reliability in material treatment.

As technology evolved, plasma treatment emerged as a sophisticated counterpart to corona treatment, offering enhanced versatility, precision, and control over surface modification. Plasma treatment's ability to cater to a wider array of materials and more complex geometries, along with its environmental benefits, positions it as a preferable option for high-quality, reliable surface treatments in cutting-edge applications.

This article delves into the intricacies of corona and plasma treatments—exploring their mechanisms, applications, and benefits. Here we uncover the critical role these technologies play in material science's ongoing evolution.

What is Corona Treatment?

At its core, corona treatment involves the application of low-temperature corona discharge plasma, a process ingeniously devised to alter the very surface properties of various materials, most notably plastics. This technique has opened up new dimensions in material compatibility, adhesion, and preparation for subsequent processing or finishing.

The invention of corona treatment can be traced back to the innovative work of Verner Eisby in the mid-20th century. Eisby's pioneering research and development led to the realization of a method that could effectively increase the surface energy of polymer-based materials, thereby enhancing their ability to bond with inks, adhesives, and coatings.

Process and Mechanism of Corona Treatment

Corona treatment is achieved by applying a high voltage to an electrode system, typically consisting of a sharp electrode and a grounded roller covered with a dielectric material. The material to be treated, such as plastic film, cloth, or paper, is passed near the electrode. The high voltage induces a strong electric field, so intense that it ionizes the air (or another gas) gap between the electrode and the material surface, leading to the formation of corona discharge.

For materials like plastics, which are inherently hydrophobic and have low surface energy, the introduction of polar groups is transformative. These groups increase the surface energy of the material, significantly improving its wettability. This enhancement in wettability is crucial for applications requiring the application of inks, adhesives, and coatings, as it ensures a stronger and more uniform adherence to the material surface.

Applications and Benefits of Corona Treatment

Corona treatment is a versatile technology used to improve the adhesion properties of various materials. It's employed across multiple industries for printing, coating, and laminating applications. 

One of the primary applications of corona treatment is in the printing industry. It is used to treat surfaces like plastic films, paper, and textiles to ensure that inks adhere better. In the production of coated materials, such as coated papers, films, and specialty fabrics, corona treatment is used to enhance the surface characteristics of the base material. For laminated products, such as safety glass, packaging materials, and multi-layer films, corona treatment improves the bond strength between layers. 

Corona treatment is a safe process for both the materials being treated and the operators. It operates at low temperatures, avoiding any thermal degradation of materials, which is especially important for sensitive substrates. Additionally, the equipment used for corona treatment is designed with safety features to protect operators from high-voltage exposure.

Plasma Treatment?

While corona treatment is effective for certain applications, plasma treatment offers greater versatility, precision, and control over the surface modification process. Its ability to treat a wide variety of materials and complex geometries, combined with its environmental benefits and depth of modification, makes plasma treatment a preferred choice for industries requiring high-quality and reliable surface treatments.

Plasma treatment is applicable to a wider range of industries beyond printing and packaging, including electronics, automotive, medical devices, and aerospace. Its ability to improve the surface characteristics of materials is crucial for high-tech applications where durability, precision, and reliability are paramount.

Plasma treatment allows for a more controlled modification of the surface, potentially altering the surface chemistry to a greater depth than corona treatment. This can lead to stronger and more durable adhesion properties, which are crucial in applications requiring long-term reliability.

Final Thoughts

At SCI Automation, our team is made up of seasoned experts, each contributing a wealth of experience. Known as leaders in our industry, we aim to set benchmarks through innovation, developing solutions that not only satisfy but also define standards for the industry.

Our mission is to offer bespoke solutions designed to address your specific needs and challenges seamlessly. At SCI Automation, we view our role as more than mere service providers; we consider ourselves your allies in achieving excellence. Should you have inquiries or require assistance with plasma technologies, we invite you to connect with our team for professional guidance and support.



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