Hot melt adhesives for Foil lamination of PVC windowsills
Internal and external windowsills
High water and vapour resistance
Foil lamination of windowsills
Just as the PVC window continues to develop into a design object, the windowsill element is also following this trend. The same decorative films that are applied to the inside and outside of the PVC window are also used on the PVC windowsill to meet the high aesthetic demands of customers.
If the windowsill is installed on the inside of the window, its appearance must match the chosen interior design, just like the inside of the window. Therefore, the choice for the interior often falls on wood-look decorative foils so that they match the furniture, doors and skirting boards in the room. Designers and interior designers have recently started to include interior windowsills in their room projects.
Exterior windowsills, on the other hand, must be visually integrated into the building project or the façade design of the building. In most cases, the same decors are chosen as for the window profiles. With regard to the weather resistance of the lamination, windowsills must not be inferior in any way to the quality of the windows, so as not to impair the overall impression of the outside of the building.
The lamination of windowsills
The lamination process of windowsills is very similar to that of window profiles, often inline lamination is used, which significantly optimises the production process. In this process, windowsills are often extruded as a double board in one strand and then separated lengthwise to achieve a double production output. Accordingly, the adhesive used in the inline lamination of windowsills must have a sufficiently high initial adhesion or initial adhesion in order not to risk surface defects when separating the workpieces.
Due to their profile geometry, the lamination of windowsills is made up of two sub-processes, each of which places different demands on the laminating company. On the one hand, the foiling of the flat upper side corresponds to the flat lamination of panels and should ideally produce a surface finish free of streaks and wrinkles.
On the respective outer edge there is the drip edge of the windowsill, also called the nose, around which the film must be folded to fit exactly. It is particularly important that the end of the film is perfectly glued to the lower edge of the drip nose. This is because the penetration of rainwater and moisture over the years could drastically shorten the possible lifetime of the product.
It is advisable to choose the PUR adhesive that matches the respective laminating process to achieve the best possible foiling results. Especially for wide extrusion lines that are run at very low speed, it is important to use a PUR adhesive with a long open time, but at the same time with a high weather resistance.
Special case of monoblock profiles
When it comes to laminating windowsills, so-called monoblock profiles are a special case. In this case, the windowsill is integrated into the frame profile of the window, so the profile must be laminated together with the window sill. This process offers some pitfalls as well as a multitude of possible surface defects that must be avoided. TAKA-WPR have developed a special laminating process for monoblock profiles that offers maximum productivity with absolute process reliability. Contact us to learn more about this special process.