Vacuum or low pressure plasma treatment, and Atmospheric plasma treatment are two relevant technologies for Industrial plasma systems
As opposed to vacuum plasma systems, atmospheric plasma systems do not require airtight vacuum chambers. Materials can be moved through a treatment zone via a conveyor belt. (Niemira, 2012)
Plasma technology’s advantages make it a versatile and efficient choice for various surface treatment applications.
The biggest general benefit of plasma technology for surface treatment solutions is the controlled atmosphere in which the process is executed. This independence from environmental conditions, offers several benefits :
- The technology enables high precision surface cleaning, activation and etching.
- It consistently delivers high-quality nano coatings.
- Plasma technology requires minimal chemistry consumption.
- It operates at a low process temperature (<50°C), making it suitable for sensitive substrates.
- The process has low environmental impact, contributing to sustainable production.
- Coatings with specific characteristics are created in a one-step coating process.
Schematic description of atmospheric plasma (grafting) treatment on Polyethylene (PE); no surface degradation by oxidation as oxygen is not present in the gas mixture.
Being able to select the chemistry of the treatment allows to specifically tune the treatment for an application.
When working with atmospheric plasma the gas composition is controlled and it is possible to prevent oxidation of the polymeric material by avoiding the presence of oxygen in the discharge. This allows for treatment at higher dosage without degrading the material and leads to stable surface after treatment with minimal ageing.
For atmospheric plasma treatment the nature of the grafted groups is more relevant than the surface energy.
Comparison of the evolution of the surface energy (SE)
over time of a BOPP film treated by plasma and Corona. SE measured with calibrated inks.
Evidence of surface damage on BOPP treated with Corona discharge. Both plasma and Corona samples were treated with the same dosage. Atomic Force Microscopy (AFM) image recorded in taping mode, scale 1×1 µm².
Peel force necessary to delaminate plasma treated PET glued with a thermoset adhesive and surface energy measured on the treated samples. Plasma A, B and C are plasma using different dopant gases.