Surface finishing with transparent functional layers

For many years, lacquering and decor foil lamination have been established finishing methods in the manufacture of wood-based materials for the furniture and floorings industries. Now, high-gloss finishing with transparent functional layers has increasing widespread appeal. A perfect interaction between engineering technology and special adhesives is crucial for superior results.

Especially premium furniture, like for instance kitchen furniture with surfaces which are exposed to a lot of stress, but also design floors have to meet highest requirements regarding quality, durability and appearance. Finished surfaces, glossy looks in particular, are in high demand. The lamination of wood-based materials with decor foils and visually expressive designs produced in multistep lacquering processes have long been established finishing methods. Transparent foil lamination has only recently started to gain widespread appeal in the furniture industry. Today, this low-cost process is increasingly becoming an alternative to long established finishing methods. Foil lamination provides several advantages in manufacturing and design possibilities which open up new fields of application. For instance, it facilitates the production of highly demanded superior design floorings which are protected by a transparent functional layer and give rooms a personal touch.

In the manufacture high-gloss surfaces, the carrier substrate is laminated with transparent foils from reels. Due to the wide variety of wood-based materials used in the production of furniture fronts and design floors, the creative possibilities are virtually unlimited. The challenge for the adhesive is to ensure an impeccable surface and not impair the transparency of the foil: The decorative layer is directly visible through the transparent foil. Ideally, the adhesive promotes the visual features of the product. Jowat has developed a powerful PUR hot melt for thin, transparent foils, which was presented at the LIGNA 2017. Due to the broad spectrum of adhesion, hot melt adhesives based on PUR are ideal for bonding a wide range of foils, for instance foils based on PET, PVC or PU, with different gloss effects and tactile properties. The new reactive hot melt adhesive from the Jowatherm-Reaktant® series is also characterised by highest UV resistance, transparency and purity, and reaches a high surface hardness after already a few minutes ensuring a permanent true brilliance of colour. With excellent long-term heat resistance and optimum moisture protection, it meets the very high requirements for interior products which are exposed to a lot of stress. The low-viscosity formulation and excellent, homogeneous melting behaviour facilitate a smooth and even application with width-adjustable slot nozzles onto the reverse of the foil – a prerequisite for superior appearance in the lamination of transparent foils. Compared to other finishing methods such as lacquering, foil lamination provides a more efficient manufacturing of high-gloss and other functional surfaces in a single process step.

Apart from facilitating out-of-the-way and very individual designs, and a superior look of e.g. high-gloss surfaces, the additional functional layers provided by the foil and the adhesive ensure an optimum protection of the decor underneath like increased scratch resistance and high surface hardness – for durable products of superior quality and appearance.

The professional article is published in the magazine 'HK 4/17' in German language. You can download the original article down below.