TAGS: UV/EB Cure Adhesives Acrylic Adhesives
DELO has developed DELO PHOTOBOND UV acrylates for optoelectronics that enable fast and true-color bonding of holographic films manufactured by Covestro.
The automotive industry and other industries benefit from rapid roll-to-roll manufacturing and better integration of the foils into holographic end-use applications.
Offers Advantages in Automotive Lighting
Head-up displays (HUDs) in car cockpits represent one of the most important future areas of application for holographic films such as Covestro's Bayfol ® HX the street is displayed. With such HUDs, a holographic film is integrated into the windshield, which allows for brighter and larger images while at the same time requiring less installation space.
In addition, film technology also offers advantages in automotive lighting, for example, in rear lights. In addition to more design freedom and reduced space requirements, this enables customizable holograms and an increase in safety, for example if warning messages such as "Stop" can be displayed in the driver's field of vision.
For all their versatility, holographic foils are also thin, light and completely invisible under so-called off-Bragg conditions - i.e. whenever the coupled light does not meet certain requirements such as the right wavelength. The foils usually consist of RGB-sensitive photopolymers on a transparent carrier foil. This is embedded between two protective top layers.
Low-optical Interaction with High-strength
In particular, low optical interaction between the adhesive and the photopolymer is a prerequisite for high component quality. For this purpose, the adhesives are chemically adjusted in such a way that, when combined with the photopolymer, they do not shift the absorption to other wavelength ranges - they must therefore ensure that the color is displayed true to the color under all conditions.
So far, silicones have primarily been used to fix the film layers. Silicones are versatile and powerful materials. This is offset by lower strength, comparatively slow curing and, in some cases, strong outgassing. In doing so, they emit particles into their environment. Because of the potential impact on adjacent manufacturing processes, many automotive suppliers are striving for silicone-free production. The DELO PHOTOBOND UV acrylates tested by DELO and Covestro show significantly improved outgassing behavior compared to silicone and reach their full strength within seconds under UV light.
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Our holographic foils have the potential to push the existing boundaries of what is possible in automotive lighting," said Richard Meisenheimer, Application Development Holographic LightGuiding at Covestro. "
With UV adhesives, DELO gives our customers another manufacturing option and supports them in processing in their application."
Source: DELO