Everything From One Pot

2023 Author: Hannah Pearcy | [email protected]. Last modified: 2023-11-26 11:39

The coating of plastic components has become easier than ever with the help of water-based polyurethane paints. Usually, a single product is enough for renovation, with which extremely high-quality surfaces are achieved. And by the way, the products comply with all applicable environmental and health guidelines, which is particularly important for public objects. Susanne Sachsenmaier-Wahl It can be so simple: only one material is sufficient for all coating processes on plastic substrates and a very high quality surface is also achieved. No wonder that polyurethane coatings (PUR coatings) are the new stars in plastic coating. "The enormous advantage lies in the direct coating of old plastic surfaces without prior priming," says Benjamin Wolf, Product Manager at Meffert,the positive properties of the varnishes and explains: "With a single product, the processor can give an old, weathered and unsightly plastic window a new shine." This not only saves time, but also simplifies the work enormously. But these are far from the only advantages that PUR paints have. PUR lacquers are mechanically and chemically highly resilient, even hand perspiration, cleaning agents or solvents cannot harm them. What is also an advantage with plastic windows and doors is their resistance to plasticisers, since a migration of plasticisers from the rubber seals (which of course must not be painted over!) Cannot be ruled out. Optically, PUR coatings also meet the highest demands. They have a good flow and result in very smooth surfaces. Due to their high UV and weather resistance, they have a long color stability, and they do not tend to yellow, unlike alkyd resin paints. Their high blocking resistance and quick drying make them the first choice for window and door renovations. All of these properties, which are known from solvent-based PUR coatings, also apply to the water-based variants. Dagmar Riefer from CD-Color summarizes the importance of the water-based systems as follows: "The water-dilutable 2K system was specially developed for the coating of mechanically and chemically stressed surfaces indoors and outdoors and is therefore the environmentally friendly alternative to odor-intensive solvent-based 2K systems. Systems,which are increasingly banned from public tenders.”The areas of application therefore include, for example, hospitals, schools, kindergartens, but also the private sector, since builders tend to reject odor-intensive products. One product is enough But how can it be explained that priming is unnecessary? We learn from Rebecca Carl from the paint manufacturer Mipa that the in-house PUR product "Mipa PU 250" is set so that despite the hard and scratch-resistant surface, there is still a high flexibility of the coating, which enables direct adhesion. CD-Color refers to the high binder content of "CWS 2K DurTop Satin", through which a very good adhesion to plastic can be achieved. And Meffert makes the addition of hardener and the resulting chemical crosslinking of “ProfiTec 2K Seidenmattlack P 326” responsible for the good adhesion to plastic. Finally, Jansen relies on the interaction of a special cleaner ("SR-Plus") and an adhesion promoter for "Jansen PUR-Plast" that creates such good adhesion to the substrate that an adhesive primer is not necessary. The application of the cleaner is extremely simple, as Norbert Frenken, application engineer at Jansen, confirms: "Simply spray the cleaner into a cloth - do not apply directly to the plastic - and thus rub the surface." The processing of the water-based PUR differs fundamentally - Lacquers not from conventional lacquers. When used on plastic substrates, the usual substrate tests and preparations apply, as listed in BFS Leaflet No. 22, unless the paint manufacturer explicitly deviates from them in its recommendations. Jansen, for example, "does not allow" wetting agent foam washing if instead the medium-grain plastic (240 to 280) is pre-sanded and then washed off with the special cleaner "SR Plus". Water-based PUR lacquers can be applied by brushing, rolling and spraying. With the two-component systems, which include all of the products mentioned above, with the exception of the one-component "Jansen PUR-Plast", the pot life, i.e. the time in which the product can be processed after the hardener has been added, must be taken into account. After the pot life specified by the manufacturer, the chemical reaction has progressed too far to ensure perfect processing. The processor can make an old plastic window shine in new splendor with a single product.

practice plus

For more information on the products mentioned in the text, contact the manufacturers: