Selection and well-arranged layout of the right electrodes can restrict activation to specific areas. Our customised stations enable precise surface treatment, ensuring good adhesion and reliably replicable results.
State-of-the-art corona systems are an established solution for the in-line surface treatment of films, sheets and moulded parts, achieving consistently reliable activation with a high throughput.
In electrical engineering a corona discharge is a discharge that occurs on high-voltage conductors. A similar discharge pattern results when a high-voltage electrode (several kVs) is brought into close proximity with the substrate’s surface to be treated. An earthed counter electrode is in contact with the back of the substrate.
As early as more than fifty years ago it was recognised that the targeted application of such a discharge can be used to improve adhesion on plastic surfaces and other substrates. A discharge zone is formed in the gap between the electrodes. This zone has a high concentration of different activated atoms and molecules striking the substrate surfaces to be treated.
The closed molecule chains of the surface are cracked open, allowing activated species, primarily oxygen radicals, to be deposited. Polar molecules are then generated on the previously non-polar surface, and colour molecules can chemically bind to them. Corona treatment is a method using physical surface activation.
We exclusively produce semiconductor generators with a significantly higher degree of efficiency and less stray radiation than tube-based models. The high-frequency clocking of the applied high voltage ensures the development of continuous plasma for reliably clean results at a consistently high level.
Thanks to customisable systems, pretreatment can be tailored to any user requirements, achieving maximum treatment efficiency even in challenging conditions. We are happy to provide you with tailored advice to find the solution that makes the most sense for you, technically and economically.
You can easily integrate our corona systems with existing or planned production lines, ensuring uninterrupted further processing of the treated products. The method eliminates drying times, which are necessary with chemical surface activation, ensuring effective surface treatment during ongoing production.
To easily check for treatment success we offer you a wide selection of arcotest® test inks. They help you to quickly and easily determine the surface tension.
Selection and well-arranged layout of the right electrodes can restrict activation to specific areas. Our customised stations enable precise surface treatment, ensuring good adhesion and reliably replicable results.
No. All our corona systems operate at atmospheric pressure. This means that the plasma needed for activation is created in regular ambient air, allowing you to integrate surface activation with your regular production process. Thanks to a higher treatment speed there is no negative impact from surface treatment on your manufacturing productivity.
To analyse pattern films and for similar tests, we offer you a compact laboratory system, helping you to determine the ideal parameters to pretreat various substrates. As an alternative you can ask our laboratory to perform this job for you.
From the automotive to the food or medical industry—plastic is an essential element in today’s production processes. However, plastic, metal, ceramics and other materials usually have a nonpolar surface, giving them good water resistance and storage stability but poor wettability.
To counter this problem, there are several options for surface treatment. Surfaces can be treated chemically using highly reactive primers, or using physical methods. The latter includes flame and plasma treatment as well as corona treatment. What is common with all these methods is that they aim to increase the surface tension.
Corona treatment is a very widely used method for the pretreatment of plastic films, but can also be applied to sheets and moulded parts.
The substrates to be processed move between an earthed roller and an isolated electrode while electrical high-voltage discharge is applied.
This electrical discharge generates a plasma on the substrate side facing the high-voltage electrode. This plasma creates a polar surface, resulting in increased wettability.
Corona systems are often used to treat thin substrates such as packaging films, labels, cups or tubes. You can, however, also use this method to activate moulded parts. Conductive as well as non-conductive substrates can be treated.
Generally speaking, a HF corona pretreatment system consists of the electrodes in the treatment station, the generator and the high-voltage transformer. To develop a continuous high-voltage plasma, high voltage is applied at a high frequency (25–50kHz), thus the name “high-frequency corona”.
Following the treatment, many customers want to verify its success. There are two options for that. One is the so-called contact angle measurement: It measures the angle between the surface of a drop of liquid and the plastic surface. The more acute (smaller) the angle, the larger the wettability of the treated materials.
For the practical execution of a wettability test, test inks have become an established tool for their easy application and immediately visible result. Test inks have a pre-defined surface tension. If this tension matches the surface tension of the substrate, a line drawn with the test ink remains unchanged, allowing you to easily and reliably determine the correct execution of the surface treatment using a corona system during ongoing production.