Improved Paint Adhesion

Enhanced Paint Adhesion Enhanced Paint Adhesion, Optimised Processing of Painted Components: Increasing Adhesion with Plasma Technology Industrial companies face unique challenges created by surfaces coated with paint and subsequently processed. The automotive industry is a prime example. Metal or plastic components are bonded as part of the production process, and plasma technology can help here. Plasmatreat GmbH, based in Steinhagen, demonstrates how plasma can create long-lasting adhesive bonds and addresses the additional benefits and opportunities that plasma can offer. The company specializes in the development, production and application of atmospheric plasma technology in industrial manufacturing. Surfaces can be painted for decorative purposes, but painting also serves a protective function. Paint makes the product look attractive and also reliably protects the substrate from moisture, dirt, UV light and other environmental factors. However, when it comes to painted surfaces, industry often faces various challenges. Difficulties arise when paint, despite being decorative and protective, does not adhere properly to the surface, or when a painted surface needs to undergo further processing (for example, when a painted component needs to be bonded). It is precisely in these problematic areas that plasma technology can be particularly helpful in the production process.

Plasma Technology and What It Can Do Precisely

Plasma pretreatment is the key technology for micro-fine cleaning, surface activation and plasma coating of almost any material. It is based on a simple physical principle: adding energy causes a change in the state of matter. When energy is added to a gas, the gas becomes ionized and transforms into energized plasma, the fourth state of matter. When plasma with high energy levels subsequently comes into contact with materials, the surface properties of these materials change, for example a hydrophobic surface becoming hydrophilic. This means that plasma can be used to deliberately alter the surfaces of substrates. Plasmatreat specializes in surface treatment with atmospheric pressure plasma and offers numerous processes for a wide range of different applications. Openair-Plasma performs micro-fine cleaning, safely and gently removing dust, oil, release agents and additives from surfaces. Additionally, for example the incorporation of oxygen and nitrogen-containing groups into mostly nonpolar materials increases surface energy, a process known as activation. This optimizes the surface's wettability, providing a significant increase in the surface's adhesive properties. This allows paint to adhere to surfaces such as plastic or metal in a long-lasting and stable manner. The PlasmaPlus process enables the creation of functional surfaces with defined properties by building nano layers. Specific additives are added to the plasma for various applications through jet heads specially developed for PlasmaPlus applications. Plasma excites the additives, significantly increasing their reactivity. This ensures that substances bind best and adhere tightly to the material surface during the plasma coating process. The result is a nano layer with functional surface properties that can be specifically adapted to the process, such as a corrosion-preventive coating or a binder layer applied inline during production and capable of being further processed immediately after application.   Application Areas: Adhesion Enhancement and Bonding We primarily use plasma technology to improve adhesion between paint and substrate. Processing the surface with Openair-Plasma enables paints to achieve an adhesion level to the substrate that would otherwise not be possible. Products used in industrial applications exhibit different adhesion levels on different surfaces such as plastic or metal. Special additives are added to paints to give them additional properties such as resistance to dirt, moisture or sunlight. However, these additives often affect adhesion: paints no longer form an optimum bond with the substrate. To avoid compromising functionality, industrial companies employ a number of different pretreatment methods such as sanding, blasting, abrasion or flame treatment to alter the surface's properties to achieve better adhesion. Solvent-based binders (primers) are also frequently used to improve adhesion. However, these processes tend to be labour-intensive and/or environmentally harmful. This represents a significant difference between these processes and plasma treatment, which is an efficient and more environmentally friendly alternative. The second application area in this field is the processing of painted surfaces for bonding. This process is becoming increasingly important across a range of different industrial sectors for bonding various components to one another. In many industries, and particularly in the automotive and aerospace industries, these processes must be 100 per cent reliable, because the failure of adhesive bonds can have catastrophic consequences. Surface coatings typically contain a number of additives to impart specific properties to the surface such as high gloss, scratch resistance, dirt resistance and more. But a common characteristic of these paints is their low surface energy, which prevents the formation of strong adhesive bonds. Plasma technology allows you to overcome this barrier by using Openair-Plasma for surface activation and adding a PlasmaPlus coating to enhance adhesion – or in most cases, to make adhesion possible in the first place.  

What Are the Benefits of Using Plasma Technology Compared to Other Processes?

When comparing processes used to improve paint adhesion on various surfaces such as metal, plastic, wood, glass, ceramic or fibre-reinforced polymer (FRP), plasma treatment is the most versatile pretreatment method: unlike other processes, it can be used for all materials and surfaces. Another major advantage is its targeted use: plasma jets allow selective alteration of the substrate's surface properties, so that only the relevant areas are targeted and there is no need to pretreat the entire surface. The speed of the jet heads, their distance from the substrate and the intensity of the plasma beam are precisely adjusted according to the surface to be treated. This ensures that the processes can be continuously repeated with high quality and precision. Determining optimal parameters and providing specially adapted jet heads are core competencies of Plasmatreat. And unlike other processes, surfaces pretreated with plasma can continue to be processed immediately after plasma treatment. Another advantage of plasma technology is that the process is environmentally friendly: whereas a process such as flame treatment uses propane or methane gas, plasma jets operate with electricity and compressed air. And if you use electricity from renewable sources, plasma treatment is actually carbon neutral. PT-Bond is a special PlasmaPlus coating process used to achieve better adhesive bonds and also replaces the use of primers that are harmful to the environment and human health, preventing VOC emissions. Additionally, it is important to our industrial customers that our systems can be seamlessly integrated into existing production lines. Our innovative control systems provide process control and repeatability. In conclusion, the decisive advantage for our users is that they can select the paint they want according to its primary purpose; ensuring adhesion to the substrate or during the bonding process is our responsibility.

Real-World Examples of the Versatility of Plasma Technology Applications

The range of applications for plasma is essentially unlimited. One of the main areas of use is the automotive segment. Recognized vehicle manufacturers use Openair-Plasma technology and PlasmaPlus coatings for painted surfaces as an alternative to conventional treatment options. One example is the activation of automotive paint before the application of EPDM door seals. Openair-Plasma here serves as a cost-effective and environmentally friendly alternative to solvent-based primer as part of a fully automatic process. We have other examples in our portfolio: we helped a leading watch manufacturer use Openair-Plasma to create long-lasting prints on their products' dials without damaging the precision dials during pretreatment. In the metal box industry, we help create long-lasting, stable adhesive bonds between tinplate used in box production and a newly developed UV paint. Thanks to the transition to UV-cured paints made possible by plasma technology, our customer benefits from faster production processes, higher productivity and significant cost and energy savings. At the same time, this modern process is safe for the environment and the natural world. In the electronics industry, Openair-Plasma pretreatment is used to clean and activate printed circuit boards. Special grounding-free jets are used to avoid damaging sensitive electronics. The examples are endless: Plasmatreat operates in virtually every conceivable sector, from battery production to the toy industry. Hakan Sağkal General Manager Plasmatreat Turkey