Solid-state lighting (SSL) has been identified as a technology innovation that can significantly impact the future of lighting solutions that will meet new U.S. energy efficiency standards for commercial, residential, and industrial applications. Progressive lighting original equipment manufacturers (OEMs) are focusing R&D on innovations that can stretch the boundaries of conventional lighting engineering and installation, giving architects and designers unparalleled freedom in approaches that achieve the requirements of the Energy Independence and Security Act (EISA) and introduce new aesthetics.
At the same time, new materials are enabling the development of custom lighting solutions tailored to specific usage and installation requirements. For example, it is possible to tailor these high-efficiency technologies for long-life in hard-to-access and high-traffic areas, for applications particularly sensitive to glare or to meet the thermal stability needs of enclosed casework that can be prone to heat buildup.
Lighting designers and engineers more than ever need to consider the environment and needs of the end user upfront in their decision making process to ensure that they can incorporate the right technology into their lighting solution.
Polycarbonate Engineered for LEDs Offers Advantages
Polycarbonate is already considered a good choice for LED lighting because it is a mechanically high-performing material and has properties that are very tunable, making it a strong platform from which to work. Now materials suppliers are optimizing polycarbonate for the lighting market, developing special grades for LEDs. These new polycarbonate materials are helping meet the new energy efficiency standards with custom solutions for specific applications.
New grades of polycarbonate for LED applications are specially engineered to support several key areas within the LED lighting system supply chain, including optics, covers, housings, globes, and lenses. They also are designed to overcome low transmission performance, yellowing, and rapid degradation that standard grades may experience.
Special polycarbonate grades for LED lighting offer superior thermal stability and flame resistance, withstanding temperatures up to 150 degrees C. They are efficient, delivering light transmission of 90 percent and providing glass-like transparency, even with the additions of UV filters and tints which otherwise lower lumens. They have high-impact strength, excellent dimensional stability, and improved luminous flux. Additional grades offer good lighting source hiding power and high reflectance.
LED lighting with specially engineered polycarbonate can be manufactured in a range of sizes and shapes, for optimal design flexibility. The polycarbonate offers exceptional durability for an extraordinarily long life, making the lighting virtually maintenance-free.
There are also light diffusion innovations that can be used to disguise LED hot spots — hiding the point light source yet allowing higher levels of light transmission. Product designers and OEMs can use this versatile technology in just about any lighting application — both indoors and outdoors, from overhead lighting in buildings to parking lot light posts.
The optimized polycarbonate can create the effect of softened LED light with minimal reflection. Until this advancement, light from translucent white colors could be diffused, but never at this light transmission level or with as little reflectance. Using this technology, designers have nearly limitless freedom for their light diffuser packages, with the bonus of a broad palette of colors to customize the application.
Another advancement is the development of grades of polycarbonate and polycarbonate blends for highly reflective surfaces that can exhibit up to 95 percent reflectivity (mostly diffuse). This is beneficial, as molded-in reflectors can streamline luminaire design and production, making it possible to consolidate the assembly and reflector into one component. Furthermore, reflective grades also help manufacturers avoid the time, expense, and environmental side effects associated with secondary processing — such as aluminum or chrome plating or painting — of the reflective surface. Reflectivity can also be adjusted to create a “glowing” effect.
Spotlight on Innovation
Lighting designers are already taking advantage of the design flexibility and optimal physical properties offered by new LED polycarbonate grades.
One such company is Innovations in Optics Inc., a recognized leader in LED lighting that develops solutions for OEMs across many industries. Innovations in Optics’ new product line, LumiBright LE (Light Engine), offers an LED-based system with a long life and low cost. The line was designed specifically around a particular grade of optimized polycarbonate — Makrolon® LED2045 polycarbonate resin from Bayer MaterialScience LLC — because of the unique set of properties it offered.
Innovations in Optics is able to manufacture small volumes of products in its Woburn, MA facility, but also has contract manufacturers that it utilizes for higher volumes. One line of products that is currently being manufactured at a contract manufacturer in China would not have been possible without this particular polycarbonate. According to the company, that particular program would have failed without a material that could survive being close to the LED die — that is, a very high power and high flux area which requires that the material doesn’t yellow — and have the necessary heat resistance.
PolyBrite International Inc.’s Borealis brand of LED lamps is also utilizing polycarbonate designed for LED applications. The company’s solid-state LED lighting systems and products are compliant with Title 24, the new federal energy efficiency requirements, and the European Union’s RoHS (Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations).
Bayer MaterialScience LLC’s Makrolon® FR7067 polycarbonate plastic plays a key role in enabling Borealis® A19, B10, R20, PAR30, and PAR38 LED lamps to achieve maximum brightness and improved energy efficiency — up to 90 percent less energy consumption — than traditional lighting with no radiant heat or ultraviolet (UV) rays.
The flame retardant polycarbonate exhibits outstanding optical properties and meets the Underwriters Laboratory UL94 V-0 flame class rating at 1.5 mm while also offering light transmission of about 89 percent. Using Makrolon FR7067 polycarbonate will also help manufacturers meet the new UL-8750 Standard for Safety for non-class 2 and direct-connected LED lighting, as the new standard requires a V-1 rating for lenses and optics, which V-0 rated materials also meet.