DELO Launches New Adhesive for Automotive Lighting

DELO Introduces New Adhesive for Automotive Lighting DELO has developed a new adhesive for automotive lighting applications. DELO PHOTOBOND OB4189 is resistant to yellowing and, with its high aspect ratio, is particularly suitable for securely bonding microlens arrays found in headlights and projection systems. Today, light is considered one of the most important factors in automotive design and product differentiation. Microlens arrays play a crucial role in enabling these advances; by reflecting LED light positioned behind a very short focal length, they provide sharp images and individual geometries. These systems are increasingly used optically in headlights and projection systems due to the required low assembly depth. To increase efficiency, such microlenses are typically made from optically pure polymers, in other words adhesives. Microlens arrays are then fixed to a housing. DELO PHOTOBOND OB4189, with its high viscosity of 75,000 mPa·s, provides a sufficiently high aspect ratio for the bonding process. Thus, after application, the adhesive retains its shape and does not flow, which is important for bonding microlens arrays. Furthermore, it demonstrates top-level resistance to yellowing, as shown by lifecycle simulations of 500 hours at 140 °C. This property is extremely important for applications requiring high optical precision. Christoph Appel, DELO LED (Automotive) Product Manager, stated: "With DELO PHOTOBOND OB4189, we have added to our portfolio of temperature and moisture-resistant active alignment adhesives a product with high viscosity and exceptional resistance to yellowing, perfectly tailored to the requirements of microlens arrays." It is solvent-free modified acrylate and has been developed for an application temperature range of -40 °C to +120 °C. It has a shear strength of 30 MPa on polycarbonate and 25 MPa on PMMA. It can be cured with UV light (365 nm) and visible light (400 nm). With a layer thickness of 100 μm, typical exposure time at 400 nm is 5 seconds. This enables high-precision active alignment processes for optical components and low cycle times in automated production. Source