Plastics are the workhorse materials for Openair® plasma technology. All plastics, however they are processed, have contaminants on their surface that interfere with reliable bonding. Plasma treatment removes the contaminants and at the same time activates the surface, so it becomes more functional.

The applications for surface functionalization are many. They include printing, coating, bonding, two-shot injection molding and over-molding. Even difficult-to-bond materials like polypropylene (PP), polyethylene (PE), nylon (PA), polystyrene (PS), thermoplastic olefins (TPO) and thermoplastic elastomers (TPE) can be bonded reliably after functionalization.

With Openair® plasma dissimilar materials can be combined in a two-shot injection molding process, giving huge cost and time advantages. In this case the final piece will be a cellular phone housing that is thermoplastic and a grip that is thermoplastic polyurethane (TPU).

The power of Openair^® plasma to revolutionize manufacturing methods is illustrated by its use in the manufacture of car doors using a range of plastics and rubbers that replace the traditional material: stamped galvanized steel. The exterior panel is made of glass filled polypropylene (GFPP) along with plastics for the interior and artificial rubbers for the gasketing. A number of subassemblies can be integrated into one unit, saving costs and saving weight. Glass filled polypropylene is notoriously difficult to bond reliably. With Openair^® plasma, the material can be activated using robotics, at speeds of 2 feet per second, and cycle times of a few seconds. The total process is fast, very reliable and QS 9000 compliant, yielding consistent results year-round.

The painting of molded components is difficult, especially those that are prone to static charging and have been shipped and handled between molding and decorating. Openair^® plasma technology can reliably remove charges and electrostatically attracted dust. It can reduce scrap, in some cases by 80%, while at the same time reducing labor. "Plasma has allowed us to save 4 operators vacuuming, wiping and deionizing of shells, it paid for itself in months." Stated one process engineer of a large plastics fabricator.

There is a trend in automotive industry to simplify multiple stage surface finishing. The traditional sequence was: power wash, priming, base coat and then finish with clear coat. Openair^® plasma technology eliminates several of these steps.

For the labeling of polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) containers Openair^® plasma enables the adoption of inexpensive water-based inks and adhesives, resulting in substantial cost savings, reduced equipment maintenance and much better recyclability of container material.

In one case, prior to pad printing of a logo on polyethylene beverage caps the surface was treated with Openair^® plasma. As a result a 100% solids, UV curable ink could be used. The resulting logo was indelible and scratch-resistant. Not only was adhesion improved but also solvents were eliminated and scrap reduced.

Benzene is sometimes used in the manufacture of rubber tires to make the surface tacky. Openair^® plasma can perform the same function without the adverse effects that the solvent has on health and the environment.

Materials that respond well to Openair^® plasma include silicones, EVA, TPV, TPE (Santoprene) and synthetic rubbers (EPDM).

Most desirable material combinations do not adhere well together in a two-shot injection molding process. To get the process to work conventionally requires molding one component first, then priming, adding adhesive, mounting in an another station and then over-molding. With Openair^® plasma dissimilar materials like polycarbonate and silicone can be combined in a two-shot injection molding process. This gives huge cost and time advantages.

Openair^® plasma increases the number of possible material combinations that can be used in two-shot injection molding process. For instance, a well-known medical device manufacturer was able to mold together medical grade silicone and polycarbonate into a minute device that needed to be produced in the millions.

Openair® plasma can perform the same function as benzene in a more healthy and environmentally safe process.

Metals
After rolling or casting metals tend to be contaminated. Before printing, painting, bonding or over-molding they have to undergo a multistage solvent wash process in order for the surface to become adequately functional. Openair^® plasma removes layers of contaminants in one simple, reliable step.

Aluminum foil is coated with rolling oils when it comes out of the production process. In order to remove these toxic contaminants and prepare the foil so it is ready for packaging food it has to remain in an annealing oven for as much as 24 hours. An alternative process utilizes Openair^® plasma that removes the rolling oils in-line, at close to 1000 feet per minute, saving hours and considerable energy expenses.

Openair^® plasma treatment eliminates the chromating process used on aluminum extrusions prior to lamination or coating. This results in an environmentally safe process and high cost savings.

Automotive steel gaskets need to be cleaned before coating. Toxic solvent-based chemical processes can be replaced by Openair^® plasma, which is fast and environmentally friendly.

Openair¨ plasma in conjunction with PlasmaPlusTM coating can achieve stronger anti-corrosion layers on aluminum.

When aluminum and magnesium components are bonded their surface often needs to be prepared by anodizing. This is a considerable expense, especially when third party suppliers are used. Openair^® plasma, in conjunction with PlasmaPlus^TM coating, achieves local anodizing of automotive grade aluminum that withstands stringent testing used in the automobile industry, such as exposure to salt spray and humidity.

Most metals have surface contamination that slows down the welding process and negatively impact weld strength. Openair^® plasma technology can reliably remove the contaminants improving quality and reducing costs.

Openair^® plasma has been employed to micro-clean glass mirrors for bathroom doors before bonding to hinges giving reliable long-term adhesion under humid conditions.

Openair^® plasma has been used to enable printing on glass vials with UV inks, speeding up the overall process.

For high quality optical lenses absolute cleanliness of the glass surface is absolutely essential. Openair^® plasma cleans and functionalizes the surface so the lens can be coated perfectly.

Openair^® plasma removes primer over-spray used in the manufacturing of windshields, which facilitates reliable bonding and eliminates the need for toxic chemical treatments.

Glass vials can be sealed with Openair^® plasma replacing the traditional technique of using a flame, which carries the risk of contamination from combustion products.

Glass ampoules have traditionally been sealed by using a flame to sterilize and fuse the opening. However, combustion products from the flame can remain inside the ampoule and contaminate the contents. In 2004 we launched an extremely clean sealing technology. It was developed jointly with ROTA GmbH & Co. and Kg, a leading manufacturer of filling and sealing machines.

Traditionally metal/non-metal combinations are difficult to treat, because they have conductive and non-conductive surfaces, and they combine thermally insensitive with thermally sensitive surfaces. Openair^® plasma can handle these applications and remove organic and silicone contaminants as well as activating the surfaces before printing, coating and bonding.

The same applies for treatment of plastic components on conveyors with metal railings. Traditional blown corona systems can arc, whereas Openair^® plasma can be used safely.

Openair^® plasma can de-dust and activate printed circuit boards prior to clean-room processing.

Openair® plasma can treat metal/non-metal combinations, removing organic and silicone contaminants as well as activating the surfaces before printing, coating and bonding.

Composites
Carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics based on polyamide or polypropylene composites combine low weight with high strength. They are becoming more common especially in transportation. An example is the new 787 Dreamliner from Boeing that is built out of CFRP, with weight savings of around 30% and fuel savings of about 15%. These materials have a polymer surface that is difficult to bond and coat. Moreover, they are delicate because the differential thermal conductivity between fibers and matrix make them easily susceptible to thermal damage. Openair^® plasma with its high efficiency and low thermal impact solves the problem. A recent joint development with Boeing provided in situ verification to ensure that all traces of silicone and other additives had been removed. Bond strength, of course, is critical in these situations.

Treating fabrics with Openair^® plasma makes them more hydrophilic or absorptive. This improved wettability enables the use of adhesives that can replace mechanical methods of joining such as sewing or stapling.

Similarly, for non-woven and fleece materials, plasma treatment makes them more hydrophilic. The increased absorbency enables manufacturers to offer products with improved performance. Fleeces can be used as absorptive sponges in personal hygiene products such as feminine napkins or diapers.

Treating fabrics with Openair® plasma makes them more hydrophilic or absorptive, enabling manufacturers to offer products with improved performance.

One way of making low weight components with high strength is to sandwich a layer of foam between two plastic or metal sheets to add stiffness. If materials like polypropylene (PP) and polyethylene (PE) are used for foaming, bonding them to the outside skin materials can be difficult. Foams are extremely temperature sensitive as the cells have very thin walls. Therefore they cannot be treated effectively with heat. Openair^® plasma provides a solution. It activates the foam making it possible to bond it securely to the skin.

Openair® plasma activates temperature sensitive foam making it possible to bond it securely to outside skin materials.